#### Armstrong Number

and 11 more contributors
"""
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.
total = 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
total += rem**number_of_digits
temp //= 10
return n == total

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
total = 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))):
total += cnt * i**digit_total

return n == total

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()  