172. Factorial Trailing Zeroes

172. Factorial Trailing Zeroes

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

Note: Your solution should be in logarithmic time complexity.

Analysis:
参考：http://bookshadow.com/weblog/2014/12/30/leetcode-factorial-trailing-zeroes/ 和 http://www.cnblogs.com/ganganloveu/p/4193373.html
两个其实说的是一个意思，一种方法。
Source Code（C++）:

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

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


int main() {
    Solution sol;
    cout << sol.trailingZeroes(50);
    return 0;
}