LintCode-2.尾部的零

class Solution {
    /*
     * param n: An desciption
     * return: An integer, denote the number of trailing zeros in n!
     */
    public long trailingZeros(long n) {
        // write your code here
        long num = 0;
        while(n>0){
            num+=(n/5);
            n/=5;
        }
        return num;
    }
};