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"""

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()

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