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;
}