README.md

172. Factorial Trailing Zeroes

Given an integer n, return the number of trailing zeroes in n!.

Example 1:

Input: 3
Output: 0
Explanation: 3! = 6, no trailing zero.

Example 2:

Input: 5
Output: 1
Explanation: 5! = 120, one trailing zero.

Note: Your solution should be in logarithmic time complexity.

Solutions (Rust)

1. Count 5

impl Solution {
    pub fn trailing_zeroes(n: i32) -> i32 {
        let mut n = n;
        let mut zeroes = 0;
        while n >= 5 {
            n /= 5;
            zeroes += n;
        }
        zeroes
    }
}