trailingZero

class Solution {
public:
    /*
     * @param n: A long integer
     * @return: An integer, denote the number of trailing zeros in n!
     */

long long trailingZeros(long long n) {
    long long counter=0;
    while (n!=0) {
        n /= 5;
        counter +=  n;
    }
    return counter;
}

};