Project Euler : Problem 020

[Franck]

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!

Code: Select all

: sumDigits(n) { 0 while(n) [ n 10 /mod ->n + ] }

: fact(n) { | i | 1 n loop: i [ i * ] }

100 fact sumDigits