mirror of
https://github.com/TheAlgorithms/Python.git
synced 2024-11-24 05:21:09 +00:00
37 lines
941 B
Python
37 lines
941 B
Python
"""
|
|
Problem 34: https://projecteuler.net/problem=34
|
|
|
|
145 is a curious number, as 1! + 4! + 5! = 1 + 24 + 120 = 145.
|
|
Find the sum of all numbers which are equal to the sum of the factorial of their digits.
|
|
Note: As 1! = 1 and 2! = 2 are not sums they are not included.
|
|
"""
|
|
|
|
from math import factorial
|
|
|
|
|
|
def sum_of_digit_factorial(n: int) -> int:
|
|
"""
|
|
Returns the sum of the factorial of digits in n
|
|
>>> sum_of_digit_factorial(15)
|
|
121
|
|
>>> sum_of_digit_factorial(0)
|
|
1
|
|
"""
|
|
return sum(factorial(int(char)) for char in str(n))
|
|
|
|
|
|
def solution() -> int:
|
|
"""
|
|
Returns the sum of all numbers whose
|
|
sum of the factorials of all digits
|
|
add up to the number itself.
|
|
>>> solution()
|
|
40730
|
|
"""
|
|
limit = 7 * factorial(9) + 1
|
|
return sum(i for i in range(3, limit) if sum_of_digit_factorial(i) == i)
|
|
|
|
|
|
if __name__ == "__main__":
|
|
print(f"{solution() = }")
|