mirror of
https://github.com/TheAlgorithms/Python.git
synced 2024-10-06 05:39:30 +00:00
af0810fca1
* Fix mypy errors for armstrong_numbers.py * Fix mypy errors for harmonic_series.py * Fix mypy errors for average_median.py
101 lines
3.0 KiB
Python
101 lines
3.0 KiB
Python
"""
|
|
An Armstrong number is equal to the sum of its own digits each raised to the
|
|
power of the number of digits.
|
|
|
|
For example, 370 is an Armstrong number because 3*3*3 + 7*7*7 + 0*0*0 = 370.
|
|
|
|
Armstrong numbers are also called Narcissistic numbers and Pluperfect numbers.
|
|
|
|
On-Line Encyclopedia of Integer Sequences entry: https://oeis.org/A005188
|
|
"""
|
|
PASSING = (1, 153, 370, 371, 1634, 24678051, 115132219018763992565095597973971522401)
|
|
FAILING: tuple = (-153, -1, 0, 1.2, 200, "A", [], {}, None)
|
|
|
|
|
|
def armstrong_number(n: int) -> bool:
|
|
"""
|
|
Return True if n is an Armstrong number or False if it is not.
|
|
|
|
>>> all(armstrong_number(n) for n in PASSING)
|
|
True
|
|
>>> any(armstrong_number(n) for n in FAILING)
|
|
False
|
|
"""
|
|
if not isinstance(n, int) or n < 1:
|
|
return False
|
|
|
|
# Initialization of sum and number of digits.
|
|
sum = 0
|
|
number_of_digits = 0
|
|
temp = n
|
|
# Calculation of digits of the number
|
|
while temp > 0:
|
|
number_of_digits += 1
|
|
temp //= 10
|
|
# Dividing number into separate digits and find Armstrong number
|
|
temp = n
|
|
while temp > 0:
|
|
rem = temp % 10
|
|
sum += rem ** number_of_digits
|
|
temp //= 10
|
|
return n == sum
|
|
|
|
|
|
def pluperfect_number(n: int) -> bool:
|
|
"""Return True if n is a pluperfect number or False if it is not
|
|
|
|
>>> all(armstrong_number(n) for n in PASSING)
|
|
True
|
|
>>> any(armstrong_number(n) for n in FAILING)
|
|
False
|
|
"""
|
|
if not isinstance(n, int) or n < 1:
|
|
return False
|
|
|
|
# Init a "histogram" of the digits
|
|
digit_histogram = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
|
|
digit_total = 0
|
|
sum = 0
|
|
temp = n
|
|
while temp > 0:
|
|
temp, rem = divmod(temp, 10)
|
|
digit_histogram[rem] += 1
|
|
digit_total += 1
|
|
|
|
for (cnt, i) in zip(digit_histogram, range(len(digit_histogram))):
|
|
sum += cnt * i ** digit_total
|
|
|
|
return n == sum
|
|
|
|
|
|
def narcissistic_number(n: int) -> bool:
|
|
"""Return True if n is a narcissistic number or False if it is not.
|
|
|
|
>>> all(armstrong_number(n) for n in PASSING)
|
|
True
|
|
>>> any(armstrong_number(n) for n in FAILING)
|
|
False
|
|
"""
|
|
if not isinstance(n, int) or n < 1:
|
|
return False
|
|
expo = len(str(n)) # the power that all digits will be raised to
|
|
# check if sum of each digit multiplied expo times is equal to number
|
|
return n == sum(int(i) ** expo for i in str(n))
|
|
|
|
|
|
def main():
|
|
"""
|
|
Request that user input an integer and tell them if it is Armstrong number.
|
|
"""
|
|
num = int(input("Enter an integer to see if it is an Armstrong number: ").strip())
|
|
print(f"{num} is {'' if armstrong_number(num) else 'not '}an Armstrong number.")
|
|
print(f"{num} is {'' if narcissistic_number(num) else 'not '}an Armstrong number.")
|
|
print(f"{num} is {'' if pluperfect_number(num) else 'not '}an Armstrong number.")
|
|
|
|
|
|
if __name__ == "__main__":
|
|
import doctest
|
|
|
|
doctest.testmod()
|
|
main()
|