LeetCode——Factorial Trailing Zeroes

题目：

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

Note: Your solution should be in logarithmic time complexity.

解答：

class Solution {
public:
    int trailingZeroes(int n) {
        int i = 0;
        while (n >= 5) {
            i += n / 5;
            n /= 5;
        }
        return i;
    }
};