From e74adc4a6d00df8711243fe94f9192662b323b48 Mon Sep 17 00:00:00 2001
From: Vladimir Evgrafov <evgrafov.vladimir@gmail.com>
Date: Tue, 6 Oct 2020 15:18:07 +0300
Subject: [PATCH] Project Euler Problem 10: style improvements (#2924)
Rename the main solution functions to solution.
Rename prime chec functions to is_prime.
Add default args, typehints, expand variable names.
---
project_euler/problem_10/sol1.py | 40 +++++++++++++++----------
project_euler/problem_10/sol2.py | 21 ++++++++++---
project_euler/problem_10/sol3.py | 51 ++++++++++++++++----------------
3 files changed, 66 insertions(+), 46 deletions(-)
diff --git a/project_euler/problem_10/sol1.py b/project_euler/problem_10/sol1.py
index c81085951..4f3b3a4a4 100644
--- a/project_euler/problem_10/sol1.py
+++ b/project_euler/problem_10/sol1.py
@@ -1,4 +1,6 @@
"""
+https://projecteuler.net/problem=10
+
Problem Statement:
The sum of the primes below 10 is 2 + 3 + 5 + 7 = 17.
@@ -7,7 +9,17 @@ Find the sum of all the primes below two million.
from math import sqrt
-def is_prime(n):
+def is_prime(n: int) -> bool:
+ """Returns boolean representing primality of given number num.
+ >>> is_prime(2)
+ True
+ >>> is_prime(3)
+ True
+ >>> is_prime(27)
+ False
+ >>> is_prime(2999)
+ True
+ """
for i in range(2, int(sqrt(n)) + 1):
if n % i == 0:
return False
@@ -15,20 +27,7 @@ def is_prime(n):
return True
-def sum_of_primes(n):
- if n > 2:
- sumOfPrimes = 2
- else:
- return 0
-
- for i in range(3, n, 2):
- if is_prime(i):
- sumOfPrimes += i
-
- return sumOfPrimes
-
-
-def solution(n):
+def solution(n: int = 2000000) -> int:
"""Returns the sum of all the primes below n.
# The code below has been commented due to slow execution affecting Travis.
@@ -43,7 +42,16 @@ def solution(n):
>>> solution(7)
10
"""
- return sum_of_primes(n)
+ if n > 2:
+ sum_of_primes = 2
+ else:
+ return 0
+
+ for i in range(3, n, 2):
+ if is_prime(i):
+ sum_of_primes += i
+
+ return sum_of_primes
if __name__ == "__main__":
diff --git a/project_euler/problem_10/sol2.py b/project_euler/problem_10/sol2.py
index b2e2b6e1a..39f5f5604 100644
--- a/project_euler/problem_10/sol2.py
+++ b/project_euler/problem_10/sol2.py
@@ -1,4 +1,6 @@
"""
+https://projecteuler.net/problem=10
+
Problem Statement:
The sum of the primes below 10 is 2 + 3 + 5 + 7 = 17.
@@ -6,23 +8,34 @@ Find the sum of all the primes below two million.
"""
import math
from itertools import takewhile
+from typing import Iterator
-def primeCheck(number):
+def is_prime(number: int) -> bool:
+ """Returns boolean representing primality of given number num.
+ >>> is_prime(2)
+ True
+ >>> is_prime(3)
+ True
+ >>> is_prime(27)
+ False
+ >>> is_prime(2999)
+ True
+ """
if number % 2 == 0 and number > 2:
return False
return all(number % i for i in range(3, int(math.sqrt(number)) + 1, 2))
-def prime_generator():
+def prime_generator() -> Iterator[int]:
num = 2
while True:
- if primeCheck(num):
+ if is_prime(num):
yield num
num += 1
-def solution(n):
+def solution(n: int = 2000000) -> int:
"""Returns the sum of all the primes below n.
# The code below has been commented due to slow execution affecting Travis.
diff --git a/project_euler/problem_10/sol3.py b/project_euler/problem_10/sol3.py
index 739aaa9f1..ef895f546 100644
--- a/project_euler/problem_10/sol3.py
+++ b/project_euler/problem_10/sol3.py
@@ -4,55 +4,54 @@ https://projecteuler.net/problem=10
Problem Statement:
The sum of the primes below 10 is 2 + 3 + 5 + 7 = 17.
-Find the sum of all the primes below two million using Sieve_of_Eratosthenes:
-
-The sieve of Eratosthenes is one of the most efficient ways to find all primes
-smaller than n when n is smaller than 10 million. Only for positive numbers.
+Find the sum of all the primes below two million.
"""
-def prime_sum(n: int) -> int:
- """Returns the sum of all the primes below n.
+def solution(n: int = 2000000) -> int:
+ """Returns the sum of all the primes below n using Sieve of Eratosthenes:
- >>> prime_sum(2_000_000)
+ https://en.wikipedia.org/wiki/Sieve_of_Eratosthenes
+ The sieve of Eratosthenes is one of the most efficient ways to find all primes
+ smaller than n when n is smaller than 10 million. Only for positive numbers.
+
+ >>> solution(2_000_000)
142913828922
- >>> prime_sum(1_000)
+ >>> solution(1_000)
76127
- >>> prime_sum(5_000)
+ >>> solution(5_000)
1548136
- >>> prime_sum(10_000)
+ >>> solution(10_000)
5736396
- >>> prime_sum(7)
+ >>> solution(7)
10
- >>> prime_sum(7.1) # doctest: +ELLIPSIS
+ >>> solution(7.1) # doctest: +ELLIPSIS
Traceback (most recent call last):
...
TypeError: 'float' object cannot be interpreted as an integer
- >>> prime_sum(-7) # doctest: +ELLIPSIS
+ >>> solution(-7) # doctest: +ELLIPSIS
Traceback (most recent call last):
...
IndexError: list assignment index out of range
- >>> prime_sum("seven") # doctest: +ELLIPSIS
+ >>> solution("seven") # doctest: +ELLIPSIS
Traceback (most recent call last):
...
TypeError: can only concatenate str (not "int") to str
"""
- list_ = [0 for i in range(n + 1)]
- list_[0] = 1
- list_[1] = 1
+ primality_list = [0 for i in range(n + 1)]
+ primality_list[0] = 1
+ primality_list[1] = 1
for i in range(2, int(n ** 0.5) + 1):
- if list_[i] == 0:
+ if primality_list[i] == 0:
for j in range(i * i, n + 1, i):
- list_[j] = 1
- s = 0
+ primality_list[j] = 1
+ sum_of_primes = 0
for i in range(n):
- if list_[i] == 0:
- s += i
- return s
+ if primality_list[i] == 0:
+ sum_of_primes += i
+ return sum_of_primes
if __name__ == "__main__":
- # import doctest
- # doctest.testmod()
- print(prime_sum(int(input().strip())))
+ print(solution(int(input().strip())))