Python Implementation of Problem 20
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Includes
Problem Solution
Project Euler Problem 20
If I need to do bigger numbers than this, or multiple times, a recursive approach will almost certainly be better. This works for now, though.
Problem:
n! means n × (n − 1) × ... × 3 × 2 × 1
For example, 10! = 10 × 9 × ... × 3 × 2 × 1 = 3628800, and the sum of the digits in the number 10! is 3 + 6 + 2 + 8 + 8 + 0 + 0 = 27.
Find the sum of the digits in the number 100!
1"""
2Project Euler Problem 20
3
4If I need to do bigger numbers than this, or multiple times, a recursive
5approach will almost certainly be better. This works for now, though.
6
7Problem:
8
9n! means n × (n − 1) × ... × 3 × 2 × 1
10
11For example, 10! = 10 × 9 × ... × 3 × 2 × 1 = 3628800,
12and the sum of the digits in the number 10! is 3 + 6 + 2 + 8 + 8 + 0 + 0 = 27.
13
14Find the sum of the digits in the number 100!
15"""
16from math import factorial
17
18
19def main() -> int:
20 return sum(int(x) for x in repr(factorial(100)))