Set the Python file maximum line length to 88 characters (#2122)

* flake8 --max-line-length=88

* fixup! Format Python code with psf/black push

Co-authored-by: github-actions <${GITHUB_ACTOR}@users.noreply.github.com>
This commit is contained in:
Christian Clauss 2020-06-16 10:09:19 +02:00 committed by GitHub
parent 9438c6bf0b
commit 9316e7c014
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90 changed files with 473 additions and 320 deletions

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@ -10,7 +10,7 @@ notifications:
on_success: never on_success: never
before_script: before_script:
- black --check . || true - black --check . || true
- flake8 --ignore=E203,W503 --max-complexity=25 --max-line-length=120 --statistics --count . - flake8 --ignore=E203,W503 --max-complexity=25 --max-line-length=88 --statistics --count .
- scripts/validate_filenames.py # no uppercase, no spaces, in a directory - scripts/validate_filenames.py # no uppercase, no spaces, in a directory
- pip install -r requirements.txt # fast fail on black, flake8, validate_filenames - pip install -r requirements.txt # fast fail on black, flake8, validate_filenames
script: script:

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@ -1,9 +1,11 @@
import math import math
def intersection( def intersection(function, x0, x1):
function, x0, x1 """
): # function is the f we want to find its root and x0 and x1 are two random starting points function is the f we want to find its root
x0 and x1 are two random starting points
"""
x_n = x0 x_n = x0
x_n1 = x1 x_n1 = x1
while True: while True:

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@ -16,8 +16,8 @@ def valid_connection(
Checks whether it is possible to add next into path by validating 2 statements Checks whether it is possible to add next into path by validating 2 statements
1. There should be path between current and next vertex 1. There should be path between current and next vertex
2. Next vertex should not be in path 2. Next vertex should not be in path
If both validations succeeds we return true saying that it is possible to connect this vertices If both validations succeeds we return True saying that it is possible to connect
either we return false this vertices either we return False
Case 1:Use exact graph as in main function, with initialized values Case 1:Use exact graph as in main function, with initialized values
>>> graph = [[0, 1, 0, 1, 0], >>> graph = [[0, 1, 0, 1, 0],
@ -52,7 +52,8 @@ def util_hamilton_cycle(graph: List[List[int]], path: List[int], curr_ind: int)
Pseudo-Code Pseudo-Code
Base Case: Base Case:
1. Chceck if we visited all of vertices 1. Chceck if we visited all of vertices
1.1 If last visited vertex has path to starting vertex return True either return False 1.1 If last visited vertex has path to starting vertex return True either
return False
Recursive Step: Recursive Step:
2. Iterate over each vertex 2. Iterate over each vertex
Check if next vertex is valid for transiting from current vertex Check if next vertex is valid for transiting from current vertex
@ -74,7 +75,8 @@ def util_hamilton_cycle(graph: List[List[int]], path: List[int], curr_ind: int)
>>> print(path) >>> print(path)
[0, 1, 2, 4, 3, 0] [0, 1, 2, 4, 3, 0]
Case 2: Use exact graph as in previous case, but in the properties taken from middle of calculation Case 2: Use exact graph as in previous case, but in the properties taken from
middle of calculation
>>> graph = [[0, 1, 0, 1, 0], >>> graph = [[0, 1, 0, 1, 0],
... [1, 0, 1, 1, 1], ... [1, 0, 1, 1, 1],
... [0, 1, 0, 0, 1], ... [0, 1, 0, 0, 1],

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@ -12,8 +12,8 @@ solution = []
def isSafe(board, row, column): def isSafe(board, row, column):
""" """
This function returns a boolean value True if it is safe to place a queen there considering This function returns a boolean value True if it is safe to place a queen there
the current state of the board. considering the current state of the board.
Parameters : Parameters :
board(2D matrix) : board board(2D matrix) : board
@ -56,8 +56,8 @@ def solve(board, row):
return return
for i in range(len(board)): for i in range(len(board)):
""" """
For every row it iterates through each column to check if it is feasible to place a For every row it iterates through each column to check if it is feasible to
queen there. place a queen there.
If all the combinations for that particular branch are successful the board is If all the combinations for that particular branch are successful the board is
reinitialized for the next possible combination. reinitialized for the next possible combination.
""" """

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@ -1,9 +1,10 @@
""" """
The sum-of-subsetsproblem states that a set of non-negative integers, and a value M, The sum-of-subsetsproblem states that a set of non-negative integers, and a
determine all possible subsets of the given set whose summation sum equal to given M. value M, determine all possible subsets of the given set whose summation sum
equal to given M.
Summation of the chosen numbers must be equal to given number M and one number can Summation of the chosen numbers must be equal to given number M and one number
be used only once. can be used only once.
""" """
@ -21,7 +22,8 @@ def create_state_space_tree(nums, max_sum, num_index, path, result, remaining_nu
Creates a state space tree to iterate through each branch using DFS. Creates a state space tree to iterate through each branch using DFS.
It terminates the branching of a node when any of the two conditions It terminates the branching of a node when any of the two conditions
given below satisfy. given below satisfy.
This algorithm follows depth-fist-search and backtracks when the node is not branchable. This algorithm follows depth-fist-search and backtracks when the node is not
branchable.
""" """
if sum(path) > max_sum or (remaining_nums_sum + sum(path)) < max_sum: if sum(path) > max_sum or (remaining_nums_sum + sum(path)) < max_sum:

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@ -1,8 +1,9 @@
# Chinese Remainder Theorem: # Chinese Remainder Theorem:
# GCD ( Greatest Common Divisor ) or HCF ( Highest Common Factor ) # GCD ( Greatest Common Divisor ) or HCF ( Highest Common Factor )
# If GCD(a,b) = 1, then for any remainder ra modulo a and any remainder rb modulo b there exists integer n, # If GCD(a,b) = 1, then for any remainder ra modulo a and any remainder rb modulo b
# such that n = ra (mod a) and n = ra(mod b). If n1 and n2 are two such integers, then n1=n2(mod ab) # there exists integer n, such that n = ra (mod a) and n = ra(mod b). If n1 and n2 are
# two such integers, then n1=n2(mod ab)
# Algorithm : # Algorithm :

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@ -1,5 +1,6 @@
# Diophantine Equation : Given integers a,b,c ( at least one of a and b != 0), the diophantine equation # Diophantine Equation : Given integers a,b,c ( at least one of a and b != 0), the
# a*x + b*y = c has a solution (where x and y are integers) iff gcd(a,b) divides c. # diophantine equation a*x + b*y = c has a solution (where x and y are integers)
# iff gcd(a,b) divides c.
# GCD ( Greatest Common Divisor ) or HCF ( Highest Common Factor ) # GCD ( Greatest Common Divisor ) or HCF ( Highest Common Factor )
@ -29,8 +30,9 @@ def diophantine(a, b, c):
# Finding All solutions of Diophantine Equations: # Finding All solutions of Diophantine Equations:
# Theorem : Let gcd(a,b) = d, a = d*p, b = d*q. If (x0,y0) is a solution of Diophantine Equation a*x + b*y = c. # Theorem : Let gcd(a,b) = d, a = d*p, b = d*q. If (x0,y0) is a solution of Diophantine
# a*x0 + b*y0 = c, then all the solutions have the form a(x0 + t*q) + b(y0 - t*p) = c, where t is an arbitrary integer. # Equation a*x + b*y = c. a*x0 + b*y0 = c, then all the solutions have the form
# a(x0 + t*q) + b(y0 - t*p) = c, where t is an arbitrary integer.
# n is the number of solution you want, n = 2 by default # n is the number of solution you want, n = 2 by default
@ -75,8 +77,9 @@ def greatest_common_divisor(a, b):
>>> greatest_common_divisor(7,5) >>> greatest_common_divisor(7,5)
1 1
Note : In number theory, two integers a and b are said to be relatively prime, mutually prime, or co-prime Note : In number theory, two integers a and b are said to be relatively prime,
if the only positive integer (factor) that divides both of them is 1 i.e., gcd(a,b) = 1. mutually prime, or co-prime if the only positive integer (factor) that
divides both of them is 1 i.e., gcd(a,b) = 1.
>>> greatest_common_divisor(121, 11) >>> greatest_common_divisor(121, 11)
11 11
@ -91,7 +94,8 @@ def greatest_common_divisor(a, b):
return b return b
# Extended Euclid's Algorithm : If d divides a and b and d = a*x + b*y for integers x and y, then d = gcd(a,b) # Extended Euclid's Algorithm : If d divides a and b and d = a*x + b*y for integers
# x and y, then d = gcd(a,b)
def extended_gcd(a, b): def extended_gcd(a, b):

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@ -3,8 +3,8 @@
# GCD ( Greatest Common Divisor ) or HCF ( Highest Common Factor ) # GCD ( Greatest Common Divisor ) or HCF ( Highest Common Factor )
# Given three integers a, b, and n, such that gcd(a,n)=1 and n>1, the algorithm should return an integer x such that # Given three integers a, b, and n, such that gcd(a,n)=1 and n>1, the algorithm should
# 0≤x≤n1, and b/a=x(modn) (that is, b=ax(modn)). # return an integer x such that 0≤x≤n1, and b/a=x(modn) (that is, b=ax(modn)).
# Theorem: # Theorem:
# a has a multiplicative inverse modulo n iff gcd(a,n) = 1 # a has a multiplicative inverse modulo n iff gcd(a,n) = 1
@ -68,7 +68,8 @@ def modular_division2(a, b, n):
return x return x
# Extended Euclid's Algorithm : If d divides a and b and d = a*x + b*y for integers x and y, then d = gcd(a,b) # Extended Euclid's Algorithm : If d divides a and b and d = a*x + b*y for integers x
# and y, then d = gcd(a,b)
def extended_gcd(a, b): def extended_gcd(a, b):
@ -123,8 +124,9 @@ def greatest_common_divisor(a, b):
>>> greatest_common_divisor(7,5) >>> greatest_common_divisor(7,5)
1 1
Note : In number theory, two integers a and b are said to be relatively prime, mutually prime, or co-prime Note : In number theory, two integers a and b are said to be relatively prime,
if the only positive integer (factor) that divides both of them is 1 i.e., gcd(a,b) = 1. mutually prime, or co-prime if the only positive integer (factor) that divides
both of them is 1 i.e., gcd(a,b) = 1.
>>> greatest_common_divisor(121, 11) >>> greatest_common_divisor(121, 11)
11 11

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@ -55,7 +55,8 @@ def check_keys(keyA, keyB, mode):
def encrypt_message(key: int, message: str) -> str: def encrypt_message(key: int, message: str) -> str:
""" """
>>> encrypt_message(4545, 'The affine cipher is a type of monoalphabetic substitution cipher.') >>> encrypt_message(4545, 'The affine cipher is a type of monoalphabetic '
... 'substitution cipher.')
'VL}p MM{I}p~{HL}Gp{vp pFsH}pxMpyxIx JHL O}F{~pvuOvF{FuF{xIp~{HL}Gi' 'VL}p MM{I}p~{HL}Gp{vp pFsH}pxMpyxIx JHL O}F{~pvuOvF{FuF{xIp~{HL}Gi'
""" """
keyA, keyB = divmod(key, len(SYMBOLS)) keyA, keyB = divmod(key, len(SYMBOLS))
@ -72,7 +73,8 @@ def encrypt_message(key: int, message: str) -> str:
def decrypt_message(key: int, message: str) -> str: def decrypt_message(key: int, message: str) -> str:
""" """
>>> decrypt_message(4545, 'VL}p MM{I}p~{HL}Gp{vp pFsH}pxMpyxIx JHL O}F{~pvuOvF{FuF{xIp~{HL}Gi') >>> decrypt_message(4545, 'VL}p MM{I}p~{HL}Gp{vp pFsH}pxMpyxIx JHL O}F{~pvuOvF{FuF'
... '{xIp~{HL}Gi')
'The affine cipher is a type of monoalphabetic substitution cipher.' 'The affine cipher is a type of monoalphabetic substitution cipher.'
""" """
keyA, keyB = divmod(key, len(SYMBOLS)) keyA, keyB = divmod(key, len(SYMBOLS))

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@ -39,7 +39,8 @@ def decode_base64(text):
'WELCOME to base64 encoding 😁' 'WELCOME to base64 encoding 😁'
>>> decode_base64('QcOF4ZCD8JCAj/CfpJM=') >>> decode_base64('QcOF4ZCD8JCAj/CfpJM=')
'AÅᐃ𐀏🤓' 'AÅᐃ𐀏🤓'
>>> decode_base64("QUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFB\r\nQUFB") >>> decode_base64("QUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUF"
... "BQUFBQUFBQUFB\r\nQUFB")
'AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA' 'AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA'
""" """
base64_chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/" base64_chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"

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@ -16,7 +16,8 @@ def main():
# I have written my code naively same as definition of primitive root # I have written my code naively same as definition of primitive root
# however every time I run this program, memory exceeded... # however every time I run this program, memory exceeded...
# so I used 4.80 Algorithm in Handbook of Applied Cryptography(CRC Press, ISBN : 0-8493-8523-7, October 1996) # so I used 4.80 Algorithm in
# Handbook of Applied Cryptography(CRC Press, ISBN : 0-8493-8523-7, October 1996)
# and it seems to run nicely! # and it seems to run nicely!
def primitiveRoot(p_val): def primitiveRoot(p_val):
print("Generating primitive root of p") print("Generating primitive root of p")

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@ -106,7 +106,8 @@ class HillCipher:
req_l = len(self.key_string) req_l = len(self.key_string)
if greatest_common_divisor(det, len(self.key_string)) != 1: if greatest_common_divisor(det, len(self.key_string)) != 1:
raise ValueError( raise ValueError(
f"determinant modular {req_l} of encryption key({det}) is not co prime w.r.t {req_l}.\nTry another key." f"determinant modular {req_l} of encryption key({det}) is not co prime "
f"w.r.t {req_l}.\nTry another key."
) )
def process_text(self, text: str) -> str: def process_text(self, text: str) -> str:

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@ -83,19 +83,21 @@ class ShuffledShiftCipher:
Shuffling only 26 letters of the english alphabet can generate 26! Shuffling only 26 letters of the english alphabet can generate 26!
combinations for the shuffled list. In the program we consider, a set of combinations for the shuffled list. In the program we consider, a set of
97 characters (including letters, digits, punctuation and whitespaces), 97 characters (including letters, digits, punctuation and whitespaces),
thereby creating a possibility of 97! combinations (which is a 152 digit number in itself), thereby creating a possibility of 97! combinations (which is a 152 digit number
thus diminishing the possibility of a brute force approach. Moreover, in itself), thus diminishing the possibility of a brute force approach.
shift keys even introduce a multiple of 26 for a brute force approach Moreover, shift keys even introduce a multiple of 26 for a brute force approach
for each of the already 97! combinations. for each of the already 97! combinations.
""" """
# key_list_options contain nearly all printable except few elements from string.whitespace # key_list_options contain nearly all printable except few elements from
# string.whitespace
key_list_options = ( key_list_options = (
string.ascii_letters + string.digits + string.punctuation + " \t\n" string.ascii_letters + string.digits + string.punctuation + " \t\n"
) )
keys_l = [] keys_l = []
# creates points known as breakpoints to break the key_list_options at those points and pivot each substring # creates points known as breakpoints to break the key_list_options at those
# points and pivot each substring
breakpoints = sorted(set(self.__passcode)) breakpoints = sorted(set(self.__passcode))
temp_list = [] temp_list = []
@ -103,7 +105,8 @@ class ShuffledShiftCipher:
for i in key_list_options: for i in key_list_options:
temp_list.extend(i) temp_list.extend(i)
# checking breakpoints at which to pivot temporary sublist and add it into keys_l # checking breakpoints at which to pivot temporary sublist and add it into
# keys_l
if i in breakpoints or i == key_list_options[-1]: if i in breakpoints or i == key_list_options[-1]:
keys_l.extend(temp_list[::-1]) keys_l.extend(temp_list[::-1])
temp_list = [] temp_list = []
@ -131,7 +134,8 @@ class ShuffledShiftCipher:
""" """
decoded_message = "" decoded_message = ""
# decoding shift like Caesar cipher algorithm implementing negative shift or reverse shift or left shift # decoding shift like Caesar cipher algorithm implementing negative shift or
# reverse shift or left shift
for i in encoded_message: for i in encoded_message:
position = self.__key_list.index(i) position = self.__key_list.index(i)
decoded_message += self.__key_list[ decoded_message += self.__key_list[
@ -152,7 +156,8 @@ class ShuffledShiftCipher:
""" """
encoded_message = "" encoded_message = ""
# encoding shift like Caesar cipher algorithm implementing positive shift or forward shift or right shift # encoding shift like Caesar cipher algorithm implementing positive shift or
# forward shift or right shift
for i in plaintext: for i in plaintext:
position = self.__key_list.index(i) position = self.__key_list.index(i)
encoded_message += self.__key_list[ encoded_message += self.__key_list[

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@ -1,6 +1,8 @@
""" """
Peak signal-to-noise ratio - PSNR - https://en.wikipedia.org/wiki/Peak_signal-to-noise_ratio Peak signal-to-noise ratio - PSNR
Source: https://tutorials.techonical.com/how-to-calculate-psnr-value-of-two-images-using-python/ https://en.wikipedia.org/wiki/Peak_signal-to-noise_ratio
Source:
https://tutorials.techonical.com/how-to-calculate-psnr-value-of-two-images-using-python
""" """
import math import math

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@ -66,9 +66,10 @@ def decimal_to_any(num: int, base: int) -> str:
if base > 36: if base > 36:
raise ValueError("base must be <= 36") raise ValueError("base must be <= 36")
# fmt: off # fmt: off
ALPHABET_VALUES = {'10': 'A', '11': 'B', '12': 'C', '13': 'D', '14': 'E', '15': 'F', '16': 'G', '17': 'H', ALPHABET_VALUES = {'10': 'A', '11': 'B', '12': 'C', '13': 'D', '14': 'E', '15': 'F',
'18': 'I', '19': 'J', '20': 'K', '21': 'L', '22': 'M', '23': 'N', '24': 'O', '25': 'P', '16': 'G', '17': 'H', '18': 'I', '19': 'J', '20': 'K', '21': 'L',
'26': 'Q', '27': 'R', '28': 'S', '29': 'T', '30': 'U', '31': 'V', '32': 'W', '33': 'X', '22': 'M', '23': 'N', '24': 'O', '25': 'P', '26': 'Q', '27': 'R',
'28': 'S', '29': 'T', '30': 'U', '31': 'V', '32': 'W', '33': 'X',
'34': 'Y', '35': 'Z'} '34': 'Y', '35': 'Z'}
# fmt: on # fmt: on
new_value = "" new_value = ""

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@ -23,7 +23,8 @@ values = {
def decimal_to_hexadecimal(decimal): def decimal_to_hexadecimal(decimal):
""" """
take integer decimal value, return hexadecimal representation as str beginning with 0x take integer decimal value, return hexadecimal representation as str beginning
with 0x
>>> decimal_to_hexadecimal(5) >>> decimal_to_hexadecimal(5)
'0x5' '0x5'
>>> decimal_to_hexadecimal(15) >>> decimal_to_hexadecimal(15)

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@ -9,7 +9,8 @@ import math
def decimal_to_octal(num: int) -> str: def decimal_to_octal(num: int) -> str:
"""Convert a Decimal Number to an Octal Number. """Convert a Decimal Number to an Octal Number.
>>> all(decimal_to_octal(i) == oct(i) for i in (0, 2, 8, 64, 65, 216, 255, 256, 512)) >>> all(decimal_to_octal(i) == oct(i) for i
... in (0, 2, 8, 64, 65, 216, 255, 256, 512))
True True
""" """
octal = 0 octal = 0

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@ -1,5 +1,7 @@
class Heap: class Heap:
"""A generic Heap class, can be used as min or max by passing the key function accordingly. """
A generic Heap class, can be used as min or max by passing the key function
accordingly.
""" """
def __init__(self, key=None): def __init__(self, key=None):
@ -9,7 +11,8 @@ class Heap:
self.pos_map = {} self.pos_map = {}
# Stores current size of heap. # Stores current size of heap.
self.size = 0 self.size = 0
# Stores function used to evaluate the score of an item on which basis ordering will be done. # Stores function used to evaluate the score of an item on which basis ordering
# will be done.
self.key = key or (lambda x: x) self.key = key or (lambda x: x)
def _parent(self, i): def _parent(self, i):
@ -41,7 +44,10 @@ class Heap:
return self.arr[i][1] < self.arr[j][1] return self.arr[i][1] < self.arr[j][1]
def _get_valid_parent(self, i): def _get_valid_parent(self, i):
"""Returns index of valid parent as per desired ordering among given index and both it's children""" """
Returns index of valid parent as per desired ordering among given index and
both it's children
"""
left = self._left(i) left = self._left(i)
right = self._right(i) right = self._right(i)
valid_parent = i valid_parent = i
@ -87,8 +93,8 @@ class Heap:
self.arr[index] = self.arr[self.size - 1] self.arr[index] = self.arr[self.size - 1]
self.pos_map[self.arr[self.size - 1][0]] = index self.pos_map[self.arr[self.size - 1][0]] = index
self.size -= 1 self.size -= 1
# Make sure heap is right in both up and down direction. # Make sure heap is right in both up and down direction. Ideally only one
# Ideally only one of them will make any change- so no performance loss in calling both. # of them will make any change- so no performance loss in calling both.
if self.size > index: if self.size > index:
self._heapify_up(index) self._heapify_up(index)
self._heapify_down(index) self._heapify_down(index)
@ -109,7 +115,10 @@ class Heap:
return self.arr[0] if self.size else None return self.arr[0] if self.size else None
def extract_top(self): def extract_top(self):
"""Returns top item tuple (Calculated value, item) from heap and removes it as well if present""" """
Return top item tuple (Calculated value, item) from heap and removes it as well
if present
"""
top_item_tuple = self.get_top() top_item_tuple = self.get_top()
if top_item_tuple: if top_item_tuple:
self.delete_item(top_item_tuple[0]) self.delete_item(top_item_tuple[0])

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@ -126,7 +126,8 @@ class SkipList(Generic[KT, VT]):
""" """
:param key: Searched key, :param key: Searched key,
:return: Tuple with searched node (or None if given key is not present) :return: Tuple with searched node (or None if given key is not present)
and list of nodes that refer (if key is present) of should refer to given node. and list of nodes that refer (if key is present) of should refer to
given node.
""" """
# Nodes with refer or should refer to output node # Nodes with refer or should refer to output node
@ -141,7 +142,8 @@ class SkipList(Generic[KT, VT]):
# in skipping searched key. # in skipping searched key.
while i < node.level and node.forward[i].key < key: while i < node.level and node.forward[i].key < key:
node = node.forward[i] node = node.forward[i]
# Each leftmost node (relative to searched node) will potentially have to be updated. # Each leftmost node (relative to searched node) will potentially have to
# be updated.
update_vector.append(node) update_vector.append(node)
update_vector.reverse() # Note that we were inserting values in reverse order. update_vector.reverse() # Note that we were inserting values in reverse order.

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@ -49,10 +49,8 @@ def infix_2_postfix(Infix):
else: else:
if len(Stack) == 0: if len(Stack) == 0:
Stack.append(x) # If stack is empty, push x to stack Stack.append(x) # If stack is empty, push x to stack
else: else: # while priority of x is not > priority of element in the stack
while ( while len(Stack) > 0 and priority[x] <= priority[Stack[-1]]:
len(Stack) > 0 and priority[x] <= priority[Stack[-1]]
): # while priority of x is not greater than priority of element in the stack
Postfix.append(Stack.pop()) # pop stack & add to Postfix Postfix.append(Stack.pop()) # pop stack & add to Postfix
Stack.append(x) # push x to stack Stack.append(x) # push x to stack

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@ -1,8 +1,8 @@
""" """
A Trie/Prefix Tree is a kind of search tree used to provide quick lookup A Trie/Prefix Tree is a kind of search tree used to provide quick lookup
of words/patterns in a set of words. A basic Trie however has O(n^2) space complexity of words/patterns in a set of words. A basic Trie however has O(n^2) space complexity
making it impractical in practice. It however provides O(max(search_string, length of longest word)) making it impractical in practice. It however provides O(max(search_string, length of
lookup time making it an optimal approach when space is not an issue. longest word)) lookup time making it an optimal approach when space is not an issue.
""" """

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@ -29,8 +29,9 @@ def canny(image, threshold_low=15, threshold_high=30, weak=128, strong=255):
dst = np.zeros((image_row, image_col)) dst = np.zeros((image_row, image_col))
""" """
Non-maximum suppression. If the edge strength of the current pixel is the largest compared to the other pixels Non-maximum suppression. If the edge strength of the current pixel is the largest
in the mask with the same direction, the value will be preserved. Otherwise, the value will be suppressed. compared to the other pixels in the mask with the same direction, the value will be
preserved. Otherwise, the value will be suppressed.
""" """
for row in range(1, image_row - 1): for row in range(1, image_row - 1):
for col in range(1, image_col - 1): for col in range(1, image_col - 1):
@ -71,10 +72,12 @@ def canny(image, threshold_low=15, threshold_high=30, weak=128, strong=255):
dst[row, col] = sobel_grad[row, col] dst[row, col] = sobel_grad[row, col]
""" """
High-Low threshold detection. If an edge pixels gradient value is higher than the high threshold High-Low threshold detection. If an edge pixels gradient value is higher
value, it is marked as a strong edge pixel. If an edge pixels gradient value is smaller than the high than the high threshold value, it is marked as a strong edge pixel. If an
threshold value and larger than the low threshold value, it is marked as a weak edge pixel. If an edge edge pixels gradient value is smaller than the high threshold value and
pixel's value is smaller than the low threshold value, it will be suppressed. larger than the low threshold value, it is marked as a weak edge pixel. If
an edge pixel's value is smaller than the low threshold value, it will be
suppressed.
""" """
if dst[row, col] >= threshold_high: if dst[row, col] >= threshold_high:
dst[row, col] = strong dst[row, col] = strong
@ -84,9 +87,10 @@ def canny(image, threshold_low=15, threshold_high=30, weak=128, strong=255):
dst[row, col] = weak dst[row, col] = weak
""" """
Edge tracking. Usually a weak edge pixel caused from true edges will be connected to a strong edge pixel while Edge tracking. Usually a weak edge pixel caused from true edges will be connected
noise responses are unconnected. As long as there is one strong edge pixel that is involved in its 8-connected to a strong edge pixel while noise responses are unconnected. As long as there is
neighborhood, that weak edge point can be identified as one that should be preserved. one strong edge pixel that is involved in its 8-connected neighborhood, that weak
edge point can be identified as one that should be preserved.
""" """
for row in range(1, image_row): for row in range(1, image_row):
for col in range(1, image_col): for col in range(1, image_col):

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@ -36,7 +36,8 @@ class NearestNeighbour:
Get parent X coordinate for destination X Get parent X coordinate for destination X
:param x: Destination X coordinate :param x: Destination X coordinate
:return: Parent X coordinate based on `x ratio` :return: Parent X coordinate based on `x ratio`
>>> nn = NearestNeighbour(imread("digital_image_processing/image_data/lena.jpg", 1), 100, 100) >>> nn = NearestNeighbour(imread("digital_image_processing/image_data/lena.jpg",
... 1), 100, 100)
>>> nn.ratio_x = 0.5 >>> nn.ratio_x = 0.5
>>> nn.get_x(4) >>> nn.get_x(4)
2 2
@ -48,7 +49,8 @@ class NearestNeighbour:
Get parent Y coordinate for destination Y Get parent Y coordinate for destination Y
:param y: Destination X coordinate :param y: Destination X coordinate
:return: Parent X coordinate based on `y ratio` :return: Parent X coordinate based on `y ratio`
>>> nn = NearestNeighbour(imread("digital_image_processing/image_data/lena.jpg", 1), 100, 100) >>> nn = NearestNeighbour(imread("digital_image_processing/image_data/lena.jpg",
1), 100, 100)
>>> nn.ratio_y = 0.5 >>> nn.ratio_y = 0.5
>>> nn.get_y(4) >>> nn.get_y(4)
2 2

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@ -6,7 +6,10 @@ from cv2 import imread, imshow, waitKey, destroyAllWindows
def make_sepia(img, factor: int): def make_sepia(img, factor: int):
""" Function create sepia tone. Source: https://en.wikipedia.org/wiki/Sepia_(color) """ """
Function create sepia tone.
Source: https://en.wikipedia.org/wiki/Sepia_(color)
"""
pixel_h, pixel_v = img.shape[0], img.shape[1] pixel_h, pixel_v = img.shape[0], img.shape[1]
def to_grayscale(blue, green, red): def to_grayscale(blue, green, red):

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@ -140,7 +140,8 @@ def _validate_input(points):
Exception Exception
--------- ---------
ValueError: if points is empty or None, or if a wrong data structure like a scalar is passed ValueError: if points is empty or None, or if a wrong data structure like a scalar
is passed
TypeError: if an iterable but non-indexable object (eg. dictionary) is passed. TypeError: if an iterable but non-indexable object (eg. dictionary) is passed.
The exception to this a set which we'll convert to a list before using The exception to this a set which we'll convert to a list before using
@ -229,10 +230,10 @@ def convex_hull_bf(points):
""" """
Constructs the convex hull of a set of 2D points using a brute force algorithm. Constructs the convex hull of a set of 2D points using a brute force algorithm.
The algorithm basically considers all combinations of points (i, j) and uses the The algorithm basically considers all combinations of points (i, j) and uses the
definition of convexity to determine whether (i, j) is part of the convex hull or not. definition of convexity to determine whether (i, j) is part of the convex hull or
(i, j) is part of the convex hull if and only iff there are no points on both sides not. (i, j) is part of the convex hull if and only iff there are no points on both
of the line segment connecting the ij, and there is no point k such that k is on either end sides of the line segment connecting the ij, and there is no point k such that k is
of the ij. on either end of the ij.
Runtime: O(n^3) - definitely horrible Runtime: O(n^3) - definitely horrible
@ -255,9 +256,11 @@ def convex_hull_bf(points):
[(0.0, 0.0), (1.0, 0.0), (10.0, 1.0)] [(0.0, 0.0), (1.0, 0.0), (10.0, 1.0)]
>>> convex_hull_bf([[0, 0], [1, 0], [10, 0]]) >>> convex_hull_bf([[0, 0], [1, 0], [10, 0]])
[(0.0, 0.0), (10.0, 0.0)] [(0.0, 0.0), (10.0, 0.0)]
>>> convex_hull_bf([[-1, 1],[-1, -1], [0, 0], [0.5, 0.5], [1, -1], [1, 1], [-0.75, 1]]) >>> convex_hull_bf([[-1, 1],[-1, -1], [0, 0], [0.5, 0.5], [1, -1], [1, 1],
... [-0.75, 1]])
[(-1.0, -1.0), (-1.0, 1.0), (1.0, -1.0), (1.0, 1.0)] [(-1.0, -1.0), (-1.0, 1.0), (1.0, -1.0), (1.0, 1.0)]
>>> convex_hull_bf([(0, 3), (2, 2), (1, 1), (2, 1), (3, 0), (0, 0), (3, 3), (2, -1), (2, -4), (1, -3)]) >>> convex_hull_bf([(0, 3), (2, 2), (1, 1), (2, 1), (3, 0), (0, 0), (3, 3),
... (2, -1), (2, -4), (1, -3)])
[(0.0, 0.0), (0.0, 3.0), (1.0, -3.0), (2.0, -4.0), (3.0, 0.0), (3.0, 3.0)] [(0.0, 0.0), (0.0, 3.0), (1.0, -3.0), (2.0, -4.0), (3.0, 0.0), (3.0, 3.0)]
""" """
@ -299,9 +302,10 @@ def convex_hull_bf(points):
def convex_hull_recursive(points): def convex_hull_recursive(points):
""" """
Constructs the convex hull of a set of 2D points using a divide-and-conquer strategy Constructs the convex hull of a set of 2D points using a divide-and-conquer strategy
The algorithm exploits the geometric properties of the problem by repeatedly partitioning The algorithm exploits the geometric properties of the problem by repeatedly
the set of points into smaller hulls, and finding the convex hull of these smaller hulls. partitioning the set of points into smaller hulls, and finding the convex hull of
The union of the convex hull from smaller hulls is the solution to the convex hull of the larger problem. these smaller hulls. The union of the convex hull from smaller hulls is the
solution to the convex hull of the larger problem.
Parameter Parameter
--------- ---------
@ -320,9 +324,11 @@ def convex_hull_recursive(points):
[(0.0, 0.0), (1.0, 0.0), (10.0, 1.0)] [(0.0, 0.0), (1.0, 0.0), (10.0, 1.0)]
>>> convex_hull_recursive([[0, 0], [1, 0], [10, 0]]) >>> convex_hull_recursive([[0, 0], [1, 0], [10, 0]])
[(0.0, 0.0), (10.0, 0.0)] [(0.0, 0.0), (10.0, 0.0)]
>>> convex_hull_recursive([[-1, 1],[-1, -1], [0, 0], [0.5, 0.5], [1, -1], [1, 1], [-0.75, 1]]) >>> convex_hull_recursive([[-1, 1],[-1, -1], [0, 0], [0.5, 0.5], [1, -1], [1, 1],
[-0.75, 1]])
[(-1.0, -1.0), (-1.0, 1.0), (1.0, -1.0), (1.0, 1.0)] [(-1.0, -1.0), (-1.0, 1.0), (1.0, -1.0), (1.0, 1.0)]
>>> convex_hull_recursive([(0, 3), (2, 2), (1, 1), (2, 1), (3, 0), (0, 0), (3, 3), (2, -1), (2, -4), (1, -3)]) >>> convex_hull_recursive([(0, 3), (2, 2), (1, 1), (2, 1), (3, 0), (0, 0), (3, 3),
(2, -1), (2, -4), (1, -3)])
[(0.0, 0.0), (0.0, 3.0), (1.0, -3.0), (2.0, -4.0), (3.0, 0.0), (3.0, 3.0)] [(0.0, 0.0), (0.0, 3.0), (1.0, -3.0), (2.0, -4.0), (3.0, 0.0), (3.0, 3.0)]
""" """
@ -335,10 +341,12 @@ def convex_hull_recursive(points):
# use these two anchors to divide all the points into two hulls, # use these two anchors to divide all the points into two hulls,
# an upper hull and a lower hull. # an upper hull and a lower hull.
# all points to the left (above) the line joining the extreme points belong to the upper hull # all points to the left (above) the line joining the extreme points belong to the
# all points to the right (below) the line joining the extreme points below to the lower hull # upper hull
# ignore all points on the line joining the extreme points since they cannot be part of the # all points to the right (below) the line joining the extreme points below to the
# convex hull # lower hull
# ignore all points on the line joining the extreme points since they cannot be
# part of the convex hull
left_most_point = points[0] left_most_point = points[0]
right_most_point = points[n - 1] right_most_point = points[n - 1]
@ -366,10 +374,12 @@ def _construct_hull(points, left, right, convex_set):
Parameters Parameters
--------- ---------
points: list or None, the hull of points from which to choose the next convex-hull point points: list or None, the hull of points from which to choose the next convex-hull
point
left: Point, the point to the left of line segment joining left and right left: Point, the point to the left of line segment joining left and right
right: The point to the right of the line segment joining left and right right: The point to the right of the line segment joining left and right
convex_set: set, the current convex-hull. The state of convex-set gets updated by this function convex_set: set, the current convex-hull. The state of convex-set gets updated by
this function
Note Note
---- ----

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@ -1,5 +1,6 @@
""" """
This is a pure Python implementation of Dynamic Programming solution to the fibonacci sequence problem. This is a pure Python implementation of Dynamic Programming solution to the fibonacci
sequence problem.
""" """

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@ -1,7 +1,8 @@
""" """
The number of partitions of a number n into at least k parts equals the number of partitions into exactly k parts The number of partitions of a number n into at least k parts equals the number of
plus the number of partitions into at least k-1 parts. Subtracting 1 from each part of a partition of n into k parts partitions into exactly k parts plus the number of partitions into at least k-1 parts.
gives a partition of n-k into k parts. These two facts together are used for this algorithm. Subtracting 1 from each part of a partition of n into k parts gives a partition of n-k
into k parts. These two facts together are used for this algorithm.
""" """

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@ -12,7 +12,8 @@ def list_of_submasks(mask: int) -> List[int]:
""" """
Args: Args:
mask : number which shows mask ( always integer > 0, zero does not have any submasks ) mask : number which shows mask ( always integer > 0, zero does not have any
submasks )
Returns: Returns:
all_submasks : the list of submasks of mask (mask s is called submask of mask all_submasks : the list of submasks of mask (mask s is called submask of mask

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@ -9,8 +9,8 @@ Note that only the integer weights 0-1 knapsack problem is solvable
def MF_knapsack(i, wt, val, j): def MF_knapsack(i, wt, val, j):
""" """
This code involves the concept of memory functions. Here we solve the subproblems which are needed This code involves the concept of memory functions. Here we solve the subproblems
unlike the below example which are needed unlike the below example
F is a 2D array with -1s filled up F is a 2D array with -1s filled up
""" """
global F # a global dp table for knapsack global F # a global dp table for knapsack

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@ -1,6 +1,7 @@
""" """
LCS Problem Statement: Given two sequences, find the length of longest subsequence present in both of them. LCS Problem Statement: Given two sequences, find the length of longest subsequence
A subsequence is a sequence that appears in the same relative order, but not necessarily continuous. present in both of them. A subsequence is a sequence that appears in the same relative
order, but not necessarily continuous.
Example:"abc", "abg" are subsequences of "abcdefgh". Example:"abc", "abg" are subsequences of "abcdefgh".
""" """

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@ -1,10 +1,12 @@
""" """
Author : Yvonne Author : Yvonne
This is a pure Python implementation of Dynamic Programming solution to the longest_sub_array problem. This is a pure Python implementation of Dynamic Programming solution to the
longest_sub_array problem.
The problem is : The problem is :
Given an array, to find the longest and continuous sub array and get the max sum of the sub array in the given array. Given an array, to find the longest and continuous sub array and get the max sum of the
sub array in the given array.
""" """

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@ -13,8 +13,9 @@ pieces separately or not cutting it at all if the price of it is the maximum obt
def naive_cut_rod_recursive(n: int, prices: list): def naive_cut_rod_recursive(n: int, prices: list):
""" """
Solves the rod-cutting problem via naively without using the benefit of dynamic programming. Solves the rod-cutting problem via naively without using the benefit of dynamic
The results is the same sub-problems are solved several times leading to an exponential runtime programming. The results is the same sub-problems are solved several times
leading to an exponential runtime
Runtime: O(2^n) Runtime: O(2^n)
@ -26,7 +27,8 @@ def naive_cut_rod_recursive(n: int, prices: list):
Returns Returns
------- -------
The maximum revenue obtainable for a rod of length n given the list of prices for each piece. The maximum revenue obtainable for a rod of length n given the list of prices
for each piece.
Examples Examples
-------- --------
@ -50,8 +52,9 @@ def naive_cut_rod_recursive(n: int, prices: list):
def top_down_cut_rod(n: int, prices: list): def top_down_cut_rod(n: int, prices: list):
""" """
Constructs a top-down dynamic programming solution for the rod-cutting problem Constructs a top-down dynamic programming solution for the rod-cutting
via memoization. This function serves as a wrapper for _top_down_cut_rod_recursive problem via memoization. This function serves as a wrapper for
_top_down_cut_rod_recursive
Runtime: O(n^2) Runtime: O(n^2)
@ -63,12 +66,13 @@ def top_down_cut_rod(n: int, prices: list):
Note Note
---- ----
For convenience and because Python's lists using 0-indexing, length(max_rev) = n + 1, For convenience and because Python's lists using 0-indexing, length(max_rev) =
to accommodate for the revenue obtainable from a rod of length 0. n + 1, to accommodate for the revenue obtainable from a rod of length 0.
Returns Returns
------- -------
The maximum revenue obtainable for a rod of length n given the list of prices for each piece. The maximum revenue obtainable for a rod of length n given the list of prices
for each piece.
Examples Examples
------- -------
@ -99,7 +103,8 @@ def _top_down_cut_rod_recursive(n: int, prices: list, max_rev: list):
Returns Returns
------- -------
The maximum revenue obtainable for a rod of length n given the list of prices for each piece. The maximum revenue obtainable for a rod of length n given the list of prices
for each piece.
""" """
if max_rev[n] >= 0: if max_rev[n] >= 0:
return max_rev[n] return max_rev[n]
@ -144,7 +149,8 @@ def bottom_up_cut_rod(n: int, prices: list):
""" """
_enforce_args(n, prices) _enforce_args(n, prices)
# length(max_rev) = n + 1, to accommodate for the revenue obtainable from a rod of length 0. # length(max_rev) = n + 1, to accommodate for the revenue obtainable from a rod of
# length 0.
max_rev = [float("-inf") for _ in range(n + 1)] max_rev = [float("-inf") for _ in range(n + 1)]
max_rev[0] = 0 max_rev[0] = 0
@ -167,7 +173,8 @@ def _enforce_args(n: int, prices: list):
Throws ValueError: Throws ValueError:
if n is negative or there are fewer items in the price list than the length of the rod if n is negative or there are fewer items in the price list than the length of
the rod
""" """
if n < 0: if n < 0:
raise ValueError(f"n must be greater than or equal to 0. Got n = {n}") raise ValueError(f"n must be greater than or equal to 0. Got n = {n}")

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@ -1,4 +1,4 @@
# Python program to print all subset combinations of n element in given set of r element. # Print all subset combinations of n element in given set of r element.
def combination_util(arr, n, r, index, data, i): def combination_util(arr, n, r, index, data, i):

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@ -9,7 +9,8 @@ def isSumSubset(arr, arrLen, requiredSum):
# initially no subsets can be formed hence False/0 # initially no subsets can be formed hence False/0
subset = [[False for i in range(requiredSum + 1)] for i in range(arrLen + 1)] subset = [[False for i in range(requiredSum + 1)] for i in range(arrLen + 1)]
# for each arr value, a sum of zero(0) can be formed by not taking any element hence True/1 # for each arr value, a sum of zero(0) can be formed by not taking any element
# hence True/1
for i in range(arrLen + 1): for i in range(arrLen + 1):
subset[i][0] = True subset[i][0] = True

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@ -14,7 +14,8 @@ if __name__ == "__main__":
# Create universe of discourse in Python using linspace () # Create universe of discourse in Python using linspace ()
X = np.linspace(start=0, stop=75, num=75, endpoint=True, retstep=False) X = np.linspace(start=0, stop=75, num=75, endpoint=True, retstep=False)
# Create two fuzzy sets by defining any membership function (trapmf(), gbellmf(),gaussmf(), etc). # Create two fuzzy sets by defining any membership function
# (trapmf(), gbellmf(), gaussmf(), etc).
abc1 = [0, 25, 50] abc1 = [0, 25, 50]
abc2 = [25, 50, 75] abc2 = [25, 50, 75]
young = fuzz.membership.trimf(X, abc1) young = fuzz.membership.trimf(X, abc1)

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@ -11,15 +11,16 @@ def lamberts_ellipsoidal_distance(
two points on the surface of earth given longitudes and latitudes two points on the surface of earth given longitudes and latitudes
https://en.wikipedia.org/wiki/Geographical_distance#Lambert's_formula_for_long_lines https://en.wikipedia.org/wiki/Geographical_distance#Lambert's_formula_for_long_lines
NOTE: This algorithm uses geodesy/haversine_distance.py to compute central angle, sigma NOTE: This algorithm uses geodesy/haversine_distance.py to compute central angle,
sigma
Representing the earth as an ellipsoid allows us to approximate distances between points Representing the earth as an ellipsoid allows us to approximate distances between
on the surface much better than a sphere. Ellipsoidal formulas treat the Earth as an points on the surface much better than a sphere. Ellipsoidal formulas treat the
oblate ellipsoid which means accounting for the flattening that happens at the North Earth as an oblate ellipsoid which means accounting for the flattening that happens
and South poles. Lambert's formulae provide accuracy on the order of 10 meteres over at the North and South poles. Lambert's formulae provide accuracy on the order of
thousands of kilometeres. Other methods can provide millimeter-level accuracy but this 10 meteres over thousands of kilometeres. Other methods can provide
is a simpler method to calculate long range distances without increasing computational millimeter-level accuracy but this is a simpler method to calculate long range
intensity. distances without increasing computational intensity.
Args: Args:
lat1, lon1: latitude and longitude of coordinate 1 lat1, lon1: latitude and longitude of coordinate 1
@ -50,7 +51,8 @@ def lamberts_ellipsoidal_distance(
# Equation Parameters # Equation Parameters
# https://en.wikipedia.org/wiki/Geographical_distance#Lambert's_formula_for_long_lines # https://en.wikipedia.org/wiki/Geographical_distance#Lambert's_formula_for_long_lines
flattening = (AXIS_A - AXIS_B) / AXIS_A flattening = (AXIS_A - AXIS_B) / AXIS_A
# Parametric latitudes https://en.wikipedia.org/wiki/Latitude#Parametric_(or_reduced)_latitude # Parametric latitudes
# https://en.wikipedia.org/wiki/Latitude#Parametric_(or_reduced)_latitude
b_lat1 = atan((1 - flattening) * tan(radians(lat1))) b_lat1 = atan((1 - flattening) * tan(radians(lat1)))
b_lat2 = atan((1 - flattening) * tan(radians(lat2))) b_lat2 = atan((1 - flattening) * tan(radians(lat2)))

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@ -53,8 +53,8 @@ def search(grid, init, goal, cost, heuristic):
while not found and not resign: while not found and not resign:
if len(cell) == 0: if len(cell) == 0:
return "FAIL" return "FAIL"
else: else: # to choose the least costliest action so as to move closer to the goal
cell.sort() # to choose the least costliest action so as to move closer to the goal cell.sort()
cell.reverse() cell.reverse()
next = cell.pop() next = cell.pop()
x = next[2] x = next[2]

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@ -1,7 +1,7 @@
# floyd_warshall.py # floyd_warshall.py
""" """
The problem is to find the shortest distance between all pairs of vertices in a weighted directed graph that can The problem is to find the shortest distance between all pairs of vertices in a
have negative edge weights. weighted directed graph that can have negative edge weights.
""" """
@ -26,10 +26,11 @@ def floyd_warshall(graph, v):
distance[u][v] will contain the shortest distance from vertex u to v. distance[u][v] will contain the shortest distance from vertex u to v.
1. For all edges from v to n, distance[i][j] = weight(edge(i, j)). 1. For all edges from v to n, distance[i][j] = weight(edge(i, j)).
3. The algorithm then performs distance[i][j] = min(distance[i][j], distance[i][k] + distance[k][j]) for each 3. The algorithm then performs distance[i][j] = min(distance[i][j], distance[i][k] +
possible pair i, j of vertices. distance[k][j]) for each possible pair i, j of vertices.
4. The above is repeated for each vertex k in the graph. 4. The above is repeated for each vertex k in the graph.
5. Whenever distance[i][j] is given a new minimum value, next vertex[i][j] is updated to the next vertex[i][k]. 5. Whenever distance[i][j] is given a new minimum value, next vertex[i][j] is
updated to the next vertex[i][k].
""" """
dist = [[float("inf") for _ in range(v)] for _ in range(v)] dist = [[float("inf") for _ in range(v)] for _ in range(v)]

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@ -72,7 +72,8 @@ def PrimsAlgorithm(l): # noqa: E741
visited = [0 for i in range(len(l))] visited = [0 for i in range(len(l))]
Nbr_TV = [-1 for i in range(len(l))] # Neighboring Tree Vertex of selected vertex Nbr_TV = [-1 for i in range(len(l))] # Neighboring Tree Vertex of selected vertex
# Minimum Distance of explored vertex with neighboring vertex of partial tree formed in graph # Minimum Distance of explored vertex with neighboring vertex of partial tree
# formed in graph
Distance_TV = [] # Heap of Distance of vertices from their neighboring vertex Distance_TV = [] # Heap of Distance of vertices from their neighboring vertex
Positions = [] Positions = []

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@ -5,19 +5,20 @@ def tarjan(g):
""" """
Tarjan's algo for finding strongly connected components in a directed graph Tarjan's algo for finding strongly connected components in a directed graph
Uses two main attributes of each node to track reachability, the index of that node within a component(index), Uses two main attributes of each node to track reachability, the index of that node
and the lowest index reachable from that node(lowlink). within a component(index), and the lowest index reachable from that node(lowlink).
We then perform a dfs of the each component making sure to update these parameters for each node and saving the We then perform a dfs of the each component making sure to update these parameters
nodes we visit on the way. for each node and saving the nodes we visit on the way.
If ever we find that the lowest reachable node from a current node is equal to the index of the current node then it If ever we find that the lowest reachable node from a current node is equal to the
must be the root of a strongly connected component and so we save it and it's equireachable vertices as a strongly index of the current node then it must be the root of a strongly connected
component and so we save it and it's equireachable vertices as a strongly
connected component. connected component.
Complexity: strong_connect() is called at most once for each node and has a complexity of O(|E|) as it is DFS. Complexity: strong_connect() is called at most once for each node and has a
complexity of O(|E|) as it is DFS.
Therefore this has complexity O(|V| + |E|) for a graph G = (V, E) Therefore this has complexity O(|V| + |E|) for a graph G = (V, E)
""" """
n = len(g) n = len(g)

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@ -1,7 +1,9 @@
""" """
Adler-32 is a checksum algorithm which was invented by Mark Adler in 1995. Adler-32 is a checksum algorithm which was invented by Mark Adler in 1995.
Compared to a cyclic redundancy check of the same length, it trades reliability for speed (preferring the latter). Compared to a cyclic redundancy check of the same length, it trades reliability for
Adler-32 is more reliable than Fletcher-16, and slightly less reliable than Fletcher-32.[2] speed (preferring the latter).
Adler-32 is more reliable than Fletcher-16, and slightly less reliable than
Fletcher-32.[2]
source: https://en.wikipedia.org/wiki/Adler-32 source: https://en.wikipedia.org/wiki/Adler-32
""" """

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@ -1,13 +1,17 @@
""" """
This algorithm was created for sdbm (a public-domain reimplementation of ndbm) database library. This algorithm was created for sdbm (a public-domain reimplementation of ndbm)
It was found to do well in scrambling bits, causing better distribution of the keys and fewer splits. database library.
It was found to do well in scrambling bits, causing better distribution of the keys
and fewer splits.
It also happens to be a good general hashing function with good distribution. It also happens to be a good general hashing function with good distribution.
The actual function (pseudo code) is: The actual function (pseudo code) is:
for i in i..len(str): for i in i..len(str):
hash(i) = hash(i - 1) * 65599 + str[i]; hash(i) = hash(i - 1) * 65599 + str[i];
What is included below is the faster version used in gawk. [there is even a faster, duff-device version] What is included below is the faster version used in gawk. [there is even a faster,
The magic constant 65599 was picked out of thin air while experimenting with different constants. duff-device version]
The magic constant 65599 was picked out of thin air while experimenting with
different constants.
It turns out to be a prime. It turns out to be a prime.
This is one of the algorithms used in berkeley db (see sleepycat) and elsewhere. This is one of the algorithms used in berkeley db (see sleepycat) and elsewhere.
@ -18,7 +22,8 @@
def sdbm(plain_text: str) -> str: def sdbm(plain_text: str) -> str:
""" """
Function implements sdbm hash, easy to use, great for bits scrambling. Function implements sdbm hash, easy to use, great for bits scrambling.
iterates over each character in the given string and applies function to each of them. iterates over each character in the given string and applies function to each of
them.
>>> sdbm('Algorithms') >>> sdbm('Algorithms')
1462174910723540325254304520539387479031000036 1462174910723540325254304520539387479031000036

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@ -3,7 +3,8 @@ Demonstrates implementation of SHA1 Hash function in a Python class and gives ut
to find hash of string or hash of text from a file. to find hash of string or hash of text from a file.
Usage: python sha1.py --string "Hello World!!" Usage: python sha1.py --string "Hello World!!"
python sha1.py --file "hello_world.txt" python sha1.py --file "hello_world.txt"
When run without any arguments, it prints the hash of the string "Hello World!! Welcome to Cryptography" When run without any arguments, it prints the hash of the string "Hello World!!
Welcome to Cryptography"
Also contains a Test class to verify that the generated Hash is same as that Also contains a Test class to verify that the generated Hash is same as that
returned by the hashlib library returned by the hashlib library
@ -39,7 +40,8 @@ class SHA1Hash:
def __init__(self, data): def __init__(self, data):
""" """
Inititates the variables data and h. h is a list of 5 8-digit Hexadecimal Inititates the variables data and h. h is a list of 5 8-digit Hexadecimal
numbers corresponding to (1732584193, 4023233417, 2562383102, 271733878, 3285377520) numbers corresponding to
(1732584193, 4023233417, 2562383102, 271733878, 3285377520)
respectively. We will start with this as a message digest. 0x is how you write respectively. We will start with this as a message digest. 0x is how you write
Hexadecimal numbers in Python Hexadecimal numbers in Python
""" """
@ -74,8 +76,8 @@ class SHA1Hash:
# @staticmethod # @staticmethod
def expand_block(self, block): def expand_block(self, block):
""" """
Takes a bytestring-block of length 64, unpacks it to a list of integers and returns a Takes a bytestring-block of length 64, unpacks it to a list of integers and
list of 80 integers after some bit operations returns a list of 80 integers after some bit operations
""" """
w = list(struct.unpack(">16L", block)) + [0] * 64 w = list(struct.unpack(">16L", block)) + [0] * 64
for i in range(16, 80): for i in range(16, 80):
@ -84,12 +86,13 @@ class SHA1Hash:
def final_hash(self): def final_hash(self):
""" """
Calls all the other methods to process the input. Pads the data, then splits into Calls all the other methods to process the input. Pads the data, then splits
blocks and then does a series of operations for each block (including expansion). into blocks and then does a series of operations for each block (including
expansion).
For each block, the variable h that was initialized is copied to a,b,c,d,e For each block, the variable h that was initialized is copied to a,b,c,d,e
and these 5 variables a,b,c,d,e undergo several changes. After all the blocks are and these 5 variables a,b,c,d,e undergo several changes. After all the blocks
processed, these 5 variables are pairwise added to h ie a to h[0], b to h[1] and so on. are processed, these 5 variables are pairwise added to h ie a to h[0], b to h[1]
This h becomes our final hash which is returned. and so on. This h becomes our final hash which is returned.
""" """
self.padded_data = self.padding() self.padded_data = self.padding()
self.blocks = self.split_blocks() self.blocks = self.split_blocks()
@ -138,8 +141,8 @@ class SHA1HashTest(unittest.TestCase):
def main(): def main():
""" """
Provides option 'string' or 'file' to take input and prints the calculated SHA1 hash. Provides option 'string' or 'file' to take input and prints the calculated SHA1
unittest.main() has been commented because we probably don't want to run hash. unittest.main() has been commented because we probably don't want to run
the test each time. the test each time.
""" """
# unittest.main() # unittest.main()

View File

@ -1,5 +1,6 @@
""" """
Implementation of gradient descent algorithm for minimizing cost of a linear hypothesis function. Implementation of gradient descent algorithm for minimizing cost of a linear hypothesis
function.
""" """
import numpy import numpy
@ -75,7 +76,8 @@ def summation_of_cost_derivative(index, end=m):
:param index: index wrt derivative is being calculated :param index: index wrt derivative is being calculated
:param end: value where summation ends, default is m, number of examples :param end: value where summation ends, default is m, number of examples
:return: Returns the summation of cost derivative :return: Returns the summation of cost derivative
Note: If index is -1, this means we are calculating summation wrt to biased parameter. Note: If index is -1, this means we are calculating summation wrt to biased
parameter.
""" """
summation_value = 0 summation_value = 0
for i in range(end): for i in range(end):
@ -90,7 +92,8 @@ def get_cost_derivative(index):
""" """
:param index: index of the parameter vector wrt to derivative is to be calculated :param index: index of the parameter vector wrt to derivative is to be calculated
:return: derivative wrt to that index :return: derivative wrt to that index
Note: If index is -1, this means we are calculating summation wrt to biased parameter. Note: If index is -1, this means we are calculating summation wrt to biased
parameter.
""" """
cost_derivative_value = summation_of_cost_derivative(index, m) / m cost_derivative_value = summation_of_cost_derivative(index, m) / m
return cost_derivative_value return cost_derivative_value

View File

@ -10,7 +10,8 @@ from sklearn.preprocessing import PolynomialFeatures
# Importing the dataset # Importing the dataset
dataset = pd.read_csv( dataset = pd.read_csv(
"https://s3.us-west-2.amazonaws.com/public.gamelab.fun/dataset/position_salaries.csv" "https://s3.us-west-2.amazonaws.com/public.gamelab.fun/dataset/"
"position_salaries.csv"
) )
X = dataset.iloc[:, 1:2].values X = dataset.iloc[:, 1:2].values
y = dataset.iloc[:, 2].values y = dataset.iloc[:, 2].values

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@ -42,7 +42,10 @@ import pandas as pd
from sklearn.datasets import make_blobs, make_circles from sklearn.datasets import make_blobs, make_circles
from sklearn.preprocessing import StandardScaler from sklearn.preprocessing import StandardScaler
CANCER_DATASET_URL = "http://archive.ics.uci.edu/ml/machine-learning-databases/breast-cancer-wisconsin/wdbc.data" CANCER_DATASET_URL = (
"http://archive.ics.uci.edu/ml/machine-learning-databases/"
"breast-cancer-wisconsin/wdbc.data"
)
class SmoSVM: class SmoSVM:
@ -124,7 +127,8 @@ class SmoSVM:
b_old = self._b b_old = self._b
self._b = b self._b = b
# 4: update error value,here we only calculate those non-bound samples' error # 4: update error value,here we only calculate those non-bound samples'
# error
self._unbound = [i for i in self._all_samples if self._is_unbound(i)] self._unbound = [i for i in self._all_samples if self._is_unbound(i)]
for s in self.unbound: for s in self.unbound:
if s == i1 or s == i2: if s == i1 or s == i2:
@ -231,8 +235,10 @@ class SmoSVM:
""" """
Choose first alpha ;steps: Choose first alpha ;steps:
1:First loop over all sample 1:First loop over all sample
2:Second loop over all non-bound samples till all non-bound samples does not voilate kkt condition. 2:Second loop over all non-bound samples till all non-bound samples does not
3:Repeat this two process endlessly,till all samples does not voilate kkt condition samples after first loop. voilate kkt condition.
3:Repeat this two process endlessly,till all samples does not voilate kkt
condition samples after first loop.
""" """
while True: while True:
all_not_obey = True all_not_obey = True
@ -352,8 +358,8 @@ class SmoSVM:
) )
""" """
# way 2 # way 2
Use objective function check which alpha2 new could get the minimal objectives Use objective function check which alpha2 new could get the minimal
objectives
""" """
if ol < (oh - self._eps): if ol < (oh - self._eps):
a2_new = L a2_new = L
@ -572,11 +578,11 @@ def plot_partition_boundary(
model, train_data, ax, resolution=100, colors=("b", "k", "r") model, train_data, ax, resolution=100, colors=("b", "k", "r")
): ):
""" """
We can not get the optimum w of our kernel svm model which is different from linear svm. We can not get the optimum w of our kernel svm model which is different from linear
For this reason, we generate randomly distributed points with high desity and prediced values of these points are svm. For this reason, we generate randomly distributed points with high desity and
calculated by using our tained model. Then we could use this prediced values to draw contour map. prediced values of these points are calculated by using our tained model. Then we
could use this prediced values to draw contour map.
And this contour map can represent svm's partition boundary. And this contour map can represent svm's partition boundary.
""" """
train_data_x = train_data[:, 1] train_data_x = train_data[:, 1]
train_data_y = train_data[:, 2] train_data_y = train_data[:, 2]

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@ -4,7 +4,8 @@ def bailey_borwein_plouffe(digit_position: int, precision: int = 1000) -> str:
Bailey-Borwein-Plouffe (BBP) formula to calculate the nth hex digit of pi. Bailey-Borwein-Plouffe (BBP) formula to calculate the nth hex digit of pi.
Wikipedia page: Wikipedia page:
https://en.wikipedia.org/wiki/Bailey%E2%80%93Borwein%E2%80%93Plouffe_formula https://en.wikipedia.org/wiki/Bailey%E2%80%93Borwein%E2%80%93Plouffe_formula
@param digit_position: a positive integer representing the position of the digit to extract. @param digit_position: a positive integer representing the position of the digit to
extract.
The digit immediately after the decimal point is located at position 1. The digit immediately after the decimal point is located at position 1.
@param precision: number of terms in the second summation to calculate. @param precision: number of terms in the second summation to calculate.
A higher number reduces the chance of an error but increases the runtime. A higher number reduces the chance of an error but increases the runtime.
@ -41,7 +42,8 @@ def bailey_borwein_plouffe(digit_position: int, precision: int = 1000) -> str:
elif (not isinstance(precision, int)) or (precision < 0): elif (not isinstance(precision, int)) or (precision < 0):
raise ValueError("Precision must be a nonnegative integer") raise ValueError("Precision must be a nonnegative integer")
# compute an approximation of (16 ** (n - 1)) * pi whose fractional part is mostly accurate # compute an approximation of (16 ** (n - 1)) * pi whose fractional part is mostly
# accurate
sum_result = ( sum_result = (
4 * _subsum(digit_position, 1, precision) 4 * _subsum(digit_position, 1, precision)
- 2 * _subsum(digit_position, 4, precision) - 2 * _subsum(digit_position, 4, precision)
@ -70,8 +72,9 @@ def _subsum(
denominator = 8 * sum_index + denominator_addend denominator = 8 * sum_index + denominator_addend
exponential_term = 0.0 exponential_term = 0.0
if sum_index < digit_pos_to_extract: if sum_index < digit_pos_to_extract:
# if the exponential term is an integer and we mod it by the denominator before # if the exponential term is an integer and we mod it by the denominator
# dividing, only the integer part of the sum will change; the fractional part will not # before dividing, only the integer part of the sum will change;
# the fractional part will not
exponential_term = pow( exponential_term = pow(
16, digit_pos_to_extract - 1 - sum_index, denominator 16, digit_pos_to_extract - 1 - sum_index, denominator
) )

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@ -6,7 +6,8 @@ def ceil(x) -> int:
:return: the smallest integer >= x. :return: the smallest integer >= x.
>>> import math >>> import math
>>> all(ceil(n) == math.ceil(n) for n in (1, -1, 0, -0, 1.1, -1.1, 1.0, -1.0, 1_000_000_000)) >>> all(ceil(n) == math.ceil(n) for n
... in (1, -1, 0, -0, 1.1, -1.1, 1.0, -1.0, 1_000_000_000))
True True
""" """
return ( return (

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@ -1,5 +1,6 @@
# Python program to show the usage of Fermat's little theorem in a division # Python program to show the usage of Fermat's little theorem in a division
# According to Fermat's little theorem, (a / b) mod p always equals a * (b ^ (p - 2)) mod p # According to Fermat's little theorem, (a / b) mod p always equals
# a * (b ^ (p - 2)) mod p
# Here we assume that p is a prime number, b divides a, and p doesn't divide b # Here we assume that p is a prime number, b divides a, and p doesn't divide b
# Wikipedia reference: https://en.wikipedia.org/wiki/Fermat%27s_little_theorem # Wikipedia reference: https://en.wikipedia.org/wiki/Fermat%27s_little_theorem

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@ -4,7 +4,8 @@
2. Calculates the fibonacci sequence with a formula 2. Calculates the fibonacci sequence with a formula
an = [ Phin - (phi)n ]/Sqrt[5] an = [ Phin - (phi)n ]/Sqrt[5]
reference-->Su, Francis E., et al. "Fibonacci Number Formula." Math Fun Facts. <http://www.math.hmc.edu/funfacts> reference-->Su, Francis E., et al. "Fibonacci Number Formula." Math Fun Facts.
<http://www.math.hmc.edu/funfacts>
""" """
import math import math
import functools import functools
@ -71,11 +72,13 @@ def _check_number_input(n, min_thresh, max_thresh=None):
print("Incorrect Input: number must not be less than 0") print("Incorrect Input: number must not be less than 0")
except ValueTooSmallError: except ValueTooSmallError:
print( print(
f"Incorrect Input: input number must be > {min_thresh} for the recursive calculation" f"Incorrect Input: input number must be > {min_thresh} for the recursive "
"calculation"
) )
except ValueTooLargeError: except ValueTooLargeError:
print( print(
f"Incorrect Input: input number must be < {max_thresh} for the recursive calculation" f"Incorrect Input: input number must be < {max_thresh} for the recursive "
"calculation"
) )
return False return False

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@ -6,7 +6,8 @@ def floor(x) -> int:
:return: the largest integer <= x. :return: the largest integer <= x.
>>> import math >>> import math
>>> all(floor(n) == math.floor(n) for n in (1, -1, 0, -0, 1.1, -1.1, 1.0, -1.0, 1_000_000_000)) >>> all(floor(n) == math.floor(n) for n
... in (1, -1, 0, -0, 1.1, -1.1, 1.0, -1.0, 1_000_000_000))
True True
""" """
return ( return (

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@ -8,7 +8,8 @@ def gamma(num: float) -> float:
https://en.wikipedia.org/wiki/Gamma_function https://en.wikipedia.org/wiki/Gamma_function
In mathematics, the gamma function is one commonly In mathematics, the gamma function is one commonly
used extension of the factorial function to complex numbers. used extension of the factorial function to complex numbers.
The gamma function is defined for all complex numbers except the non-positive integers The gamma function is defined for all complex numbers except the non-positive
integers
>>> gamma(-1) >>> gamma(-1)

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@ -25,9 +25,9 @@ def greatest_common_divisor(a, b):
""" """
Below method is more memory efficient because it does not use the stack (chunk of memory). Below method is more memory efficient because it does not use the stack (chunk of
While above method is good, uses more memory for huge numbers because of the recursive calls memory). While above method is good, uses more memory for huge numbers because of the
required to calculate the greatest common divisor. recursive calls required to calculate the greatest common divisor.
""" """
@ -50,7 +50,8 @@ def main():
num_1 = int(nums[0]) num_1 = int(nums[0])
num_2 = int(nums[1]) num_2 = int(nums[1])
print( print(
f"greatest_common_divisor({num_1}, {num_2}) = {greatest_common_divisor(num_1, num_2)}" f"greatest_common_divisor({num_1}, {num_2}) = "
f"{greatest_common_divisor(num_1, num_2)}"
) )
print(f"By iterative gcd({num_1}, {num_2}) = {gcd_by_iterative(num_1, num_2)}") print(f"By iterative gcd({num_1}, {num_2}) = {gcd_by_iterative(num_1, num_2)}")
except (IndexError, UnboundLocalError, ValueError): except (IndexError, UnboundLocalError, ValueError):

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@ -1,6 +1,6 @@
""" """
In mathematics, the LucasLehmer test (LLT) is a primality test for Mersenne numbers. In mathematics, the LucasLehmer test (LLT) is a primality test for Mersenne
https://en.wikipedia.org/wiki/Lucas%E2%80%93Lehmer_primality_test numbers. https://en.wikipedia.org/wiki/Lucas%E2%80%93Lehmer_primality_test
A Mersenne number is a number that is one less than a power of two. A Mersenne number is a number that is one less than a power of two.
That is M_p = 2^p - 1 That is M_p = 2^p - 1

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@ -15,7 +15,7 @@ class Matrix:
if isinstance(arg, list): # Initializes a matrix identical to the one provided. if isinstance(arg, list): # Initializes a matrix identical to the one provided.
self.t = arg self.t = arg
self.n = len(arg) self.n = len(arg)
else: # Initializes a square matrix of the given size and set the values to zero. else: # Initializes a square matrix of the given size and set values to zero.
self.n = arg self.n = arg
self.t = [[0 for _ in range(self.n)] for _ in range(self.n)] self.t = [[0 for _ in range(self.n)] for _ in range(self.n)]

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@ -1,7 +1,8 @@
""" """
Modular Exponential. Modular Exponential.
Modular exponentiation is a type of exponentiation performed over a modulus. Modular exponentiation is a type of exponentiation performed over a modulus.
For more explanation, please check https://en.wikipedia.org/wiki/Modular_exponentiation For more explanation, please check
https://en.wikipedia.org/wiki/Modular_exponentiation
""" """
"""Calculate Modular Exponential.""" """Calculate Modular Exponential."""

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@ -44,7 +44,8 @@ if __name__ == "__main__":
Example: Example:
>>> poly = (0.0, 0.0, 5.0, 9.3, 7.0) # f(x) = 7.0x^4 + 9.3x^3 + 5.0x^2 >>> poly = (0.0, 0.0, 5.0, 9.3, 7.0) # f(x) = 7.0x^4 + 9.3x^3 + 5.0x^2
>>> x = -13.0 >>> x = -13.0
>>> print(evaluate_poly(poly, x)) # f(-13) = 7.0(-13)^4 + 9.3(-13)^3 + 5.0(-13)^2 = 180339.9 >>> # f(-13) = 7.0(-13)^4 + 9.3(-13)^3 + 5.0(-13)^2 = 180339.9
>>> print(evaluate_poly(poly, x))
180339.9 180339.9
""" """
poly = (0.0, 0.0, 5.0, 9.3, 7.0) poly = (0.0, 0.0, 5.0, 9.3, 7.0)

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@ -1,7 +1,8 @@
""" """
This script demonstrates the implementation of the ReLU function. This script demonstrates the implementation of the ReLU function.
It's a kind of activation function defined as the positive part of its argument in the context of neural network. It's a kind of activation function defined as the positive part of its argument in the
context of neural network.
The function takes a vector of K real numbers as input and then argmax(x, 0). The function takes a vector of K real numbers as input and then argmax(x, 0).
After through ReLU, the element of the vector always 0 or real number. After through ReLU, the element of the vector always 0 or real number.

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@ -1,8 +1,10 @@
""" """
Sieve of Eratosthones Sieve of Eratosthones
The sieve of Eratosthenes is an algorithm used to find prime numbers, less than or equal to a given value. The sieve of Eratosthenes is an algorithm used to find prime numbers, less than or
Illustration: https://upload.wikimedia.org/wikipedia/commons/b/b9/Sieve_of_Eratosthenes_animation.gif equal to a given value.
Illustration:
https://upload.wikimedia.org/wikipedia/commons/b/b9/Sieve_of_Eratosthenes_animation.gif
Reference: https://en.wikipedia.org/wiki/Sieve_of_Eratosthenes Reference: https://en.wikipedia.org/wiki/Sieve_of_Eratosthenes
doctest provider: Bruno Simas Hadlich (https://github.com/brunohadlich) doctest provider: Bruno Simas Hadlich (https://github.com/brunohadlich)

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@ -25,7 +25,8 @@ def square_root_iterative(
Square root is aproximated using Newtons method. Square root is aproximated using Newtons method.
https://en.wikipedia.org/wiki/Newton%27s_method https://en.wikipedia.org/wiki/Newton%27s_method
>>> all(abs(square_root_iterative(i)-math.sqrt(i)) <= .00000000000001 for i in range(0, 500)) >>> all(abs(square_root_iterative(i)-math.sqrt(i)) <= .00000000000001
... for i in range(500))
True True
>>> square_root_iterative(-1) >>> square_root_iterative(-1)

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@ -1,6 +1,7 @@
""" """
Implementation of finding nth fibonacci number using matrix exponentiation. Implementation of finding nth fibonacci number using matrix exponentiation.
Time Complexity is about O(log(n)*8), where 8 is the complexity of matrix multiplication of size 2 by 2. Time Complexity is about O(log(n)*8), where 8 is the complexity of matrix
multiplication of size 2 by 2.
And on the other hand complexity of bruteforce solution is O(n). And on the other hand complexity of bruteforce solution is O(n).
As we know As we know
f[n] = f[n-1] + f[n-1] f[n] = f[n-1] + f[n-1]
@ -70,7 +71,10 @@ def nth_fibonacci_bruteforce(n):
def main(): def main():
fmt = "{} fibonacci number using matrix exponentiation is {} and using bruteforce is {}\n" fmt = (
"{} fibonacci number using matrix exponentiation is {} and using bruteforce "
"is {}\n"
)
for ordinal in "0th 1st 2nd 3rd 10th 100th 1000th".split(): for ordinal in "0th 1st 2nd 3rd 10th 100th 1000th".split():
n = int("".join(c for c in ordinal if c in "0123456789")) # 1000th --> 1000 n = int("".join(c for c in ordinal if c in "0123456789")) # 1000th --> 1000
print(fmt.format(ordinal, nth_fibonacci_matrix(n), nth_fibonacci_bruteforce(n))) print(fmt.format(ordinal, nth_fibonacci_matrix(n), nth_fibonacci_bruteforce(n)))

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@ -1,5 +1,6 @@
""" """
In this problem, we want to rotate the matrix elements by 90, 180, 270 (counterclockwise) In this problem, we want to rotate the matrix elements by 90, 180, 270
(counterclockwise)
Discussion in stackoverflow: Discussion in stackoverflow:
https://stackoverflow.com/questions/42519/how-do-you-rotate-a-two-dimensional-array https://stackoverflow.com/questions/42519/how-do-you-rotate-a-two-dimensional-array
""" """

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@ -207,8 +207,10 @@ class Matrix:
""" """
<method Matrix.ShermanMorrison> <method Matrix.ShermanMorrison>
Apply Sherman-Morrison formula in O(n^2). Apply Sherman-Morrison formula in O(n^2).
To learn this formula, please look this: https://en.wikipedia.org/wiki/Sherman%E2%80%93Morrison_formula To learn this formula, please look this:
This method returns (A + uv^T)^(-1) where A^(-1) is self. Returns None if it's impossible to calculate. https://en.wikipedia.org/wiki/Sherman%E2%80%93Morrison_formula
This method returns (A + uv^T)^(-1) where A^(-1) is self. Returns None if it's
impossible to calculate.
Warning: This method doesn't check if self is invertible. Warning: This method doesn't check if self is invertible.
Make sure self is invertible before execute this method. Make sure self is invertible before execute this method.

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@ -1,7 +1,8 @@
""" """
Testing here assumes that numpy and linalg is ALWAYS correct!!!! Testing here assumes that numpy and linalg is ALWAYS correct!!!!
If running from PyCharm you can place the following line in "Additional Arguments" for the pytest run configuration If running from PyCharm you can place the following line in "Additional Arguments" for
the pytest run configuration
-vv -m mat_ops -p no:cacheprovider -vv -m mat_ops -p no:cacheprovider
""" """

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@ -88,9 +88,11 @@ class BankersAlgorithm:
This function builds an index control dictionary to track original ids/indices This function builds an index control dictionary to track original ids/indices
of processes when altered during execution of method "main" of processes when altered during execution of method "main"
Return: {0: [a: int, b: int], 1: [c: int, d: int]} Return: {0: [a: int, b: int], 1: [c: int, d: int]}
>>> BankersAlgorithm(test_claim_vector, test_allocated_res_table, >>> (BankersAlgorithm(test_claim_vector, test_allocated_res_table,
... test_maximum_claim_table)._BankersAlgorithm__need_index_manager() ... test_maximum_claim_table)._BankersAlgorithm__need_index_manager()
{0: [1, 2, 0, 3], 1: [0, 1, 3, 1], 2: [1, 1, 0, 2], 3: [1, 3, 2, 0], 4: [2, 0, 0, 3]} ... ) # doctest: +NORMALIZE_WHITESPACE
{0: [1, 2, 0, 3], 1: [0, 1, 3, 1], 2: [1, 1, 0, 2], 3: [1, 3, 2, 0],
4: [2, 0, 0, 3]}
""" """
return {self.__need().index(i): i for i in self.__need()} return {self.__need().index(i): i for i in self.__need()}

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@ -1,6 +1,7 @@
#!/usr/bin/python #!/usr/bin/python
""" """
The FisherYates shuffle is an algorithm for generating a random permutation of a finite sequence. The FisherYates shuffle is an algorithm for generating a random permutation of a
finite sequence.
For more details visit For more details visit
wikipedia/Fischer-Yates-Shuffle. wikipedia/Fischer-Yates-Shuffle.
""" """

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@ -52,7 +52,8 @@ def seed(canvas):
def run(canvas): def run(canvas):
""" This function runs the rules of game through all points, and changes their status accordingly.(in the same canvas) """ This function runs the rules of game through all points, and changes their
status accordingly.(in the same canvas)
@Args: @Args:
-- --
canvas : canvas of population to run the rules on. canvas : canvas of population to run the rules on.

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@ -4,7 +4,8 @@ Github : faizan2700
Purpose : You have one function f(x) which takes float integer and returns Purpose : You have one function f(x) which takes float integer and returns
float you have to integrate the function in limits a to b. float you have to integrate the function in limits a to b.
The approximation proposed by Thomas Simpsons in 1743 is one way to calculate integration. The approximation proposed by Thomas Simpsons in 1743 is one way to calculate
integration.
( read article : https://cp-algorithms.com/num_methods/simpson-integration.html ) ( read article : https://cp-algorithms.com/num_methods/simpson-integration.html )
@ -25,7 +26,8 @@ def f(x: float) -> float:
Summary of Simpson Approximation : Summary of Simpson Approximation :
By simpsons integration : By simpsons integration :
1.integration of fxdx with limit a to b is = f(x0) + 4 * f(x1) + 2 * f(x2) + 4 * f(x3) + 2 * f(x4)..... + f(xn) 1. integration of fxdx with limit a to b is =
f(x0) + 4 * f(x1) + 2 * f(x2) + 4 * f(x3) + 2 * f(x4)..... + f(xn)
where x0 = a where x0 = a
xi = a + i * h xi = a + i * h
xn = b xn = b
@ -71,7 +73,7 @@ def simpson_integration(function, a: float, b: float, precision: int = 4) -> flo
>>> simpson_integration('wrong_input',2,3,4) >>> simpson_integration('wrong_input',2,3,4)
Traceback (most recent call last): Traceback (most recent call last):
... ...
AssertionError: the function(object) passed should be callable your input : wrong_input AssertionError: the function(object) passed should be callable your input : ...
>>> simpson_integration(lambda x : x*x,3.45,3.2,1) >>> simpson_integration(lambda x : x*x,3.45,3.2,1)
-2.8 -2.8
@ -93,9 +95,10 @@ def simpson_integration(function, a: float, b: float, precision: int = 4) -> flo
assert isinstance(a, float) or isinstance( assert isinstance(a, float) or isinstance(
a, int a, int
), f"a should be float or integer your input : {a}" ), f"a should be float or integer your input : {a}"
assert isinstance(function(a), float) or isinstance( assert isinstance(function(a), float) or isinstance(function(a), int), (
function(a), int "the function should return integer or float return type of your function, "
), f"the function should return integer or float return type of your function, {type(a)}" f"{type(a)}"
)
assert isinstance(b, float) or isinstance( assert isinstance(b, float) or isinstance(
b, int b, int
), f"b should be float or integer your input : {b}" ), f"b should be float or integer your input : {b}"

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@ -23,7 +23,8 @@ class LinearCongruentialGenerator:
def next_number(self): def next_number(self):
""" """
The smallest number that can be generated is zero. The smallest number that can be generated is zero.
The largest number that can be generated is modulo-1. modulo is set in the constructor. The largest number that can be generated is modulo-1. modulo is set in the
constructor.
""" """
self.seed = (self.multiplier * self.seed + self.increment) % self.modulo self.seed = (self.multiplier * self.seed + self.increment) % self.modulo
return self.seed return self.seed

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@ -9,9 +9,8 @@ if any of the following conditions are true:
For example, the string "()()[()]" is properly nested but "[(()]" is not. For example, the string "()()[()]" is properly nested but "[(()]" is not.
The function called is_balanced takes as input a string S which is a sequence of brackets and The function called is_balanced takes as input a string S which is a sequence of
returns true if S is nested and false otherwise. brackets and returns true if S is nested and false otherwise.
""" """
@ -37,14 +36,11 @@ def is_balanced(S):
def main(): def main():
s = input("Enter sequence of brackets: ")
S = input("Enter sequence of brackets: ") if is_balanced(s):
print(s, "is balanced")
if is_balanced(S):
print((S, "is balanced"))
else: else:
print((S, "is not balanced")) print(s, "is not balanced")
if __name__ == "__main__": if __name__ == "__main__":

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@ -1,7 +1,9 @@
""" """
Given an array of integers, return indices of the two numbers such that they add up to a specific target. Given an array of integers, return indices of the two numbers such that they add up to
a specific target.
You may assume that each input would have exactly one solution, and you may not use the same element twice. You may assume that each input would have exactly one solution, and you may not use the
same element twice.
Example: Example:
Given nums = [2, 7, 11, 15], target = 9, Given nums = [2, 7, 11, 15], target = 9,

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@ -1,6 +1,7 @@
""" Problem Statement (Digit Fifth Power ): https://projecteuler.net/problem=30 """ Problem Statement (Digit Fifth Power ): https://projecteuler.net/problem=30
Surprisingly there are only three numbers that can be written as the sum of fourth powers of their digits: Surprisingly there are only three numbers that can be written as the sum of fourth
powers of their digits:
1634 = 1^4 + 6^4 + 3^4 + 4^4 1634 = 1^4 + 6^4 + 3^4 + 4^4
8208 = 8^4 + 2^4 + 0^4 + 8^4 8208 = 8^4 + 2^4 + 0^4 + 8^4
@ -9,7 +10,8 @@ As 1 = 1^4 is not a sum it is not included.
The sum of these numbers is 1634 + 8208 + 9474 = 19316. The sum of these numbers is 1634 + 8208 + 9474 = 19316.
Find the sum of all the numbers that can be written as the sum of fifth powers of their digits. Find the sum of all the numbers that can be written as the sum of fifth powers of their
digits.
(9^5)=59,049 (9^5)=59,049
59049*7=4,13,343 (which is only 6 digit number ) 59049*7=4,13,343 (which is only 6 digit number )

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@ -15,7 +15,8 @@ def maximum_digital_sum(a: int, b: int) -> int:
1872 1872
""" """
# RETURN the MAXIMUM from the list of SUMs of the list of INT converted from STR of BASE raised to the POWER # RETURN the MAXIMUM from the list of SUMs of the list of INT converted from STR of
# BASE raised to the POWER
return max( return max(
[ [
sum([int(x) for x in str(base ** power)]) sum([int(x) for x in str(base ** power)])

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@ -101,7 +101,8 @@ if __name__ == "__main__":
print("Process ID\tDuration Time\tWaiting Time\tTurnaround Time") print("Process ID\tDuration Time\tWaiting Time\tTurnaround Time")
for i, process in enumerate(processes): for i, process in enumerate(processes):
print( print(
f"{process}\t\t{duration_times[i]}\t\t{waiting_times[i]}\t\t{turnaround_times[i]}" f"{process}\t\t{duration_times[i]}\t\t{waiting_times[i]}\t\t"
f"{turnaround_times[i]}"
) )
print(f"Average waiting time = {average_waiting_time}") print(f"Average waiting time = {average_waiting_time}")
print(f"Average turn around time = {average_turnaround_time}") print(f"Average turn around time = {average_turnaround_time}")

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@ -14,7 +14,8 @@ python linear_search.py
def linear_search(sequence, target): def linear_search(sequence, target):
"""Pure implementation of linear search algorithm in Python """Pure implementation of linear search algorithm in Python
:param sequence: a collection with comparable items (as sorted items not required in Linear Search) :param sequence: a collection with comparable items (as sorted items not required
in Linear Search)
:param target: item value to search :param target: item value to search
:return: index of found item or None if item is not found :return: index of found item or None if item is not found

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@ -18,11 +18,13 @@ def simulated_annealing(
threshold_temp: float = 1, threshold_temp: float = 1,
) -> SearchProblem: ) -> SearchProblem:
""" """
implementation of the simulated annealing algorithm. We start with a given state, find Implementation of the simulated annealing algorithm. We start with a given state,
all its neighbors. Pick a random neighbor, if that neighbor improves the solution, we move find all its neighbors. Pick a random neighbor, if that neighbor improves the
in that direction, if that neighbor does not improve the solution, we generate a random solution, we move in that direction, if that neighbor does not improve the solution,
real number between 0 and 1, if the number is within a certain range (calculated using we generate a random real number between 0 and 1, if the number is within a certain
temperature) we move in that direction, else we pick another neighbor randomly and repeat the process. range (calculated using temperature) we move in that direction, else we pick
another neighbor randomly and repeat the process.
Args: Args:
search_prob: The search state at the start. search_prob: The search state at the start.
find_max: If True, the algorithm should find the minimum else the minimum. find_max: If True, the algorithm should find the minimum else the minimum.

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@ -1,8 +1,9 @@
""" """
This is pure Python implementation of Tabu search algorithm for a Travelling Salesman Problem, that the distances This is pure Python implementation of Tabu search algorithm for a Travelling Salesman
between the cities are symmetric (the distance between city 'a' and city 'b' is the same between city 'b' and city 'a'). Problem, that the distances between the cities are symmetric (the distance between city
The TSP can be represented into a graph. The cities are represented by nodes and the distance between them is 'a' and city 'b' is the same between city 'b' and city 'a').
represented by the weight of the ark between the nodes. The TSP can be represented into a graph. The cities are represented by nodes and the
distance between them is represented by the weight of the ark between the nodes.
The .txt file with the graph has the form: The .txt file with the graph has the form:
@ -10,8 +11,8 @@ node1 node2 distance_between_node1_and_node2
node1 node3 distance_between_node1_and_node3 node1 node3 distance_between_node1_and_node3
... ...
Be careful node1, node2 and the distance between them, must exist only once. This means in the .txt file Be careful node1, node2 and the distance between them, must exist only once. This means
should not exist: in the .txt file should not exist:
node1 node2 distance_between_node1_and_node2 node1 node2 distance_between_node1_and_node2
node2 node1 distance_between_node2_and_node1 node2 node1 distance_between_node2_and_node1
@ -19,7 +20,8 @@ For pytests run following command:
pytest pytest
For manual testing run: For manual testing run:
python tabu_search.py -f your_file_name.txt -number_of_iterations_of_tabu_search -s size_of_tabu_search python tabu_search.py -f your_file_name.txt -number_of_iterations_of_tabu_search \
-s size_of_tabu_search
e.g. python tabu_search.py -f tabudata2.txt -i 4 -s 3 e.g. python tabu_search.py -f tabudata2.txt -i 4 -s 3
""" """
@ -33,16 +35,16 @@ def generate_neighbours(path):
neighbor, given a path file that includes a graph. neighbor, given a path file that includes a graph.
:param path: The path to the .txt file that includes the graph (e.g.tabudata2.txt) :param path: The path to the .txt file that includes the graph (e.g.tabudata2.txt)
:return dict_of_neighbours: Dictionary with key each node and value a list of lists with the neighbors of the node :return dict_of_neighbours: Dictionary with key each node and value a list of lists
and the cost (distance) for each neighbor. with the neighbors of the node and the cost (distance) for each neighbor.
Example of dict_of_neighbours: Example of dict_of_neighbours:
>>) dict_of_neighbours[a] >>) dict_of_neighbours[a]
[[b,20],[c,18],[d,22],[e,26]] [[b,20],[c,18],[d,22],[e,26]]
This indicates the neighbors of node (city) 'a', which has neighbor the node 'b' with distance 20, This indicates the neighbors of node (city) 'a', which has neighbor the node 'b'
the node 'c' with distance 18, the node 'd' with distance 22 and the node 'e' with distance 26. with distance 20, the node 'c' with distance 18, the node 'd' with distance 22 and
the node 'e' with distance 26.
""" """
dict_of_neighbours = {} dict_of_neighbours = {}
@ -71,19 +73,19 @@ def generate_neighbours(path):
def generate_first_solution(path, dict_of_neighbours): def generate_first_solution(path, dict_of_neighbours):
""" """
Pure implementation of generating the first solution for the Tabu search to start, with the redundant resolution Pure implementation of generating the first solution for the Tabu search to start,
strategy. That means that we start from the starting node (e.g. node 'a'), then we go to the city nearest (lowest with the redundant resolution strategy. That means that we start from the starting
distance) to this node (let's assume is node 'c'), then we go to the nearest city of the node 'c', etc node (e.g. node 'a'), then we go to the city nearest (lowest distance) to this node
(let's assume is node 'c'), then we go to the nearest city of the node 'c', etc.
till we have visited all cities and return to the starting node. till we have visited all cities and return to the starting node.
:param path: The path to the .txt file that includes the graph (e.g.tabudata2.txt) :param path: The path to the .txt file that includes the graph (e.g.tabudata2.txt)
:param dict_of_neighbours: Dictionary with key each node and value a list of lists with the neighbors of the node :param dict_of_neighbours: Dictionary with key each node and value a list of lists
and the cost (distance) for each neighbor. with the neighbors of the node and the cost (distance) for each neighbor.
:return first_solution: The solution for the first iteration of Tabu search using the redundant resolution strategy :return first_solution: The solution for the first iteration of Tabu search using
in a list. the redundant resolution strategy in a list.
:return distance_of_first_solution: The total distance that Travelling Salesman will travel, if he follows the path :return distance_of_first_solution: The total distance that Travelling Salesman
in first_solution. will travel, if he follows the path in first_solution.
""" """
with open(path) as f: with open(path) as f:
@ -124,22 +126,23 @@ def generate_first_solution(path, dict_of_neighbours):
def find_neighborhood(solution, dict_of_neighbours): def find_neighborhood(solution, dict_of_neighbours):
""" """
Pure implementation of generating the neighborhood (sorted by total distance of each solution from Pure implementation of generating the neighborhood (sorted by total distance of
lowest to highest) of a solution with 1-1 exchange method, that means we exchange each node in a solution with each each solution from lowest to highest) of a solution with 1-1 exchange method, that
other node and generating a number of solution named neighborhood. means we exchange each node in a solution with each other node and generating a
number of solution named neighborhood.
:param solution: The solution in which we want to find the neighborhood. :param solution: The solution in which we want to find the neighborhood.
:param dict_of_neighbours: Dictionary with key each node and value a list of lists with the neighbors of the node :param dict_of_neighbours: Dictionary with key each node and value a list of lists
and the cost (distance) for each neighbor. with the neighbors of the node and the cost (distance) for each neighbor.
:return neighborhood_of_solution: A list that includes the solutions and the total distance of each solution :return neighborhood_of_solution: A list that includes the solutions and the total
(in form of list) that are produced with 1-1 exchange from the solution that the method took as an input distance of each solution (in form of list) that are produced with 1-1 exchange
from the solution that the method took as an input
Example: Example:
>>) find_neighborhood(['a','c','b','d','e','a']) >>> find_neighborhood(['a','c','b','d','e','a']) # doctest: +NORMALIZE_WHITESPACE
[['a','e','b','d','c','a',90], [['a','c','d','b','e','a',90],['a','d','b','c','e','a',93], [['a','e','b','d','c','a',90], [['a','c','d','b','e','a',90],
['a','c','b','e','d','a',102], ['a','c','e','d','b','a',113], ['a','b','c','d','e','a',93]] ['a','d','b','c','e','a',93], ['a','c','b','e','d','a',102],
['a','c','e','d','b','a',113], ['a','b','c','d','e','a',93]]
""" """
neighborhood_of_solution = [] neighborhood_of_solution = []
@ -177,20 +180,21 @@ def tabu_search(
first_solution, distance_of_first_solution, dict_of_neighbours, iters, size first_solution, distance_of_first_solution, dict_of_neighbours, iters, size
): ):
""" """
Pure implementation of Tabu search algorithm for a Travelling Salesman Problem in Python. Pure implementation of Tabu search algorithm for a Travelling Salesman Problem in
Python.
:param first_solution: The solution for the first iteration of Tabu search using the redundant resolution strategy :param first_solution: The solution for the first iteration of Tabu search using
in a list. the redundant resolution strategy in a list.
:param distance_of_first_solution: The total distance that Travelling Salesman will travel, if he follows the path :param distance_of_first_solution: The total distance that Travelling Salesman will
in first_solution. travel, if he follows the path in first_solution.
:param dict_of_neighbours: Dictionary with key each node and value a list of lists with the neighbors of the node :param dict_of_neighbours: Dictionary with key each node and value a list of lists
and the cost (distance) for each neighbor. with the neighbors of the node and the cost (distance) for each neighbor.
:param iters: The number of iterations that Tabu search will execute. :param iters: The number of iterations that Tabu search will execute.
:param size: The size of Tabu List. :param size: The size of Tabu List.
:return best_solution_ever: The solution with the lowest distance that occurred during the execution of Tabu search. :return best_solution_ever: The solution with the lowest distance that occurred
:return best_cost: The total distance that Travelling Salesman will travel, if he follows the path in best_solution during the execution of Tabu search.
ever. :return best_cost: The total distance that Travelling Salesman will travel, if he
follows the path in best_solution ever.
""" """
count = 1 count = 1
solution = first_solution solution = first_solution

View File

@ -17,8 +17,9 @@
# number of buckets. # number of buckets.
# Time Complexity of Solution: # Time Complexity of Solution:
# Worst case scenario occurs when all the elements are placed in a single bucket. The overall performance # Worst case scenario occurs when all the elements are placed in a single bucket. The
# would then be dominated by the algorithm used to sort each bucket. In this case, O(n log n), because of TimSort # overall performance would then be dominated by the algorithm used to sort each bucket.
# In this case, O(n log n), because of TimSort
# #
# Average Case O(n + (n^2)/k + k), where k is the number of buckets # Average Case O(n + (n^2)/k + k), where k is the number of buckets
# #

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@ -1,9 +1,11 @@
""" """
This is pure Python implementation of comb sort algorithm. This is pure Python implementation of comb sort algorithm.
Comb sort is a relatively simple sorting algorithm originally designed by Wlodzimierz Dobosiewicz in 1980. Comb sort is a relatively simple sorting algorithm originally designed by Wlodzimierz
It was rediscovered by Stephen Lacey and Richard Box in 1991. Comb sort improves on bubble sort algorithm. Dobosiewicz in 1980. It was rediscovered by Stephen Lacey and Richard Box in 1991.
Comb sort improves on bubble sort algorithm.
In bubble sort, distance (or gap) between two compared elements is always one. In bubble sort, distance (or gap) between two compared elements is always one.
Comb sort improvement is that gap can be much more than 1, in order to prevent slowing down by small values Comb sort improvement is that gap can be much more than 1, in order to prevent slowing
down by small values
at the end of a list. at the end of a list.
More info on: https://en.wikipedia.org/wiki/Comb_sort More info on: https://en.wikipedia.org/wiki/Comb_sort

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@ -57,6 +57,7 @@ r = len(M) - 1
z = _inPlaceQuickSort(M, 0, r) z = _inPlaceQuickSort(M, 0, r)
print( print(
"No of Comparisons for 100 elements selected from a standard normal distribution is :" "No of Comparisons for 100 elements selected from a standard normal distribution"
"is :"
) )
print(z) print(z)

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@ -1,7 +1,8 @@
""" """
Python implementation of a sort algorithm. Python implementation of a sort algorithm.
Best Case Scenario : O(n) Best Case Scenario : O(n)
Worst Case Scenario : O(n^2) because native Python functions:min, max and remove are already O(n) Worst Case Scenario : O(n^2) because native Python functions:min, max and remove are
already O(n)
""" """

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@ -41,7 +41,9 @@ class BoyerMooreSearch:
return -1 return -1
def mismatch_in_text(self, currentPos): def mismatch_in_text(self, currentPos):
""" finds the index of mis-matched character in text when compared with pattern from last """
find the index of mis-matched character in text when compared with pattern
from last
Parameters : Parameters :
currentPos (int): current index position of text currentPos (int): current index position of text

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@ -14,8 +14,8 @@ def is_palindrome(s: str) -> bool:
>>> is_palindrome("Mr. Owl ate my metal worm?") >>> is_palindrome("Mr. Owl ate my metal worm?")
True True
""" """
# Since Punctuation, capitalization, and spaces are usually ignored while checking Palindrome, # Since Punctuation, capitalization, and spaces are usually ignored while checking
# we first remove them from our string. # Palindrome, we first remove them from our string.
s = "".join([character for character in s.lower() if character.isalnum()]) s = "".join([character for character in s.lower() if character.isalnum()])
return s == s[::-1] return s == s[::-1]

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@ -3,7 +3,8 @@
def jaro_winkler(str1: str, str2: str) -> float: def jaro_winkler(str1: str, str2: str) -> float:
""" """
JaroWinkler distance is a string metric measuring an edit distance between two sequences. JaroWinkler distance is a string metric measuring an edit distance between two
sequences.
Output value is between 0.0 and 1.0. Output value is between 0.0 and 1.0.
>>> jaro_winkler("martha", "marhta") >>> jaro_winkler("martha", "marhta")

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@ -5,11 +5,11 @@ def kmp(pattern, text):
1) Preprocess pattern to identify any suffixes that are identical to prefixes 1) Preprocess pattern to identify any suffixes that are identical to prefixes
This tells us where to continue from if we get a mismatch between a character in our pattern This tells us where to continue from if we get a mismatch between a character
and the text. in our pattern and the text.
2) Step through the text one character at a time and compare it to a character in the pattern 2) Step through the text one character at a time and compare it to a character in
updating our location within the pattern if necessary the pattern updating our location within the pattern if necessary
""" """

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@ -16,8 +16,9 @@ def lower(word: str) -> str:
'what' 'what'
""" """
# converting to ascii value int value and checking to see if char is a capital letter # converting to ascii value int value and checking to see if char is a capital
# if it is a capital letter it is getting shift by 32 which makes it a lower case letter # letter if it is a capital letter it is getting shift by 32 which makes it a lower
# case letter
return "".join( return "".join(
chr(ord(char) + 32) if 65 <= ord(char) <= 90 else char for char in word chr(ord(char) + 32) if 65 <= ord(char) <= 90 else char for char in word
) )

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@ -1,5 +1,6 @@
""" """
Algorithm for calculating the most cost-efficient sequence for converting one string into another. Algorithm for calculating the most cost-efficient sequence for converting one string
into another.
The only allowed operations are The only allowed operations are
---Copy character with cost cC ---Copy character with cost cC
---Replace character with cost cR ---Replace character with cost cR

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@ -8,15 +8,18 @@ def rabin_karp(pattern, text):
""" """
The Rabin-Karp Algorithm for finding a pattern within a piece of text The Rabin-Karp Algorithm for finding a pattern within a piece of text
with complexity O(nm), most efficient when it is used with multiple patterns with complexity O(nm), most efficient when it is used with multiple patterns
as it is able to check if any of a set of patterns match a section of text in o(1) given the precomputed hashes. as it is able to check if any of a set of patterns match a section of text in o(1)
given the precomputed hashes.
This will be the simple version which only assumes one pattern is being searched for but it's not hard to modify This will be the simple version which only assumes one pattern is being searched
for but it's not hard to modify
1) Calculate pattern hash 1) Calculate pattern hash
2) Step through the text one character at a time passing a window with the same length as the pattern 2) Step through the text one character at a time passing a window with the same
calculating the hash of the text within the window compare it with the hash of the pattern. Only testing length as the pattern
equality if the hashes match calculating the hash of the text within the window compare it with the hash
of the pattern. Only testing equality if the hashes match
""" """
p_len = len(pattern) p_len = len(pattern)
t_len = len(text) t_len = len(text)

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@ -1,6 +1,7 @@
def split(string: str, separator: str = " ") -> list: def split(string: str, separator: str = " ") -> list:
""" """
Will split the string up into all the values separated by the separator (defaults to spaces) Will split the string up into all the values separated by the separator
(defaults to spaces)
>>> split("apple#banana#cherry#orange",separator='#') >>> split("apple#banana#cherry#orange",separator='#')
['apple', 'banana', 'cherry', 'orange'] ['apple', 'banana', 'cherry', 'orange']

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@ -14,7 +14,8 @@ def upper(word: str) -> str:
""" """
# converting to ascii value int value and checking to see if char is a lower letter # converting to ascii value int value and checking to see if char is a lower letter
# if it is a capital letter it is getting shift by 32 which makes it a capital case letter # if it is a capital letter it is getting shift by 32 which makes it a capital case
# letter
return "".join( return "".join(
chr(ord(char) - 32) if 97 <= ord(char) <= 122 else char for char in word chr(ord(char) - 32) if 97 <= ord(char) <= 122 else char for char in word
) )