题解 | #阶乘末尾0的数量#

import java.util.*;

//暴力解法:时间复杂度大，超时

 public class Solution {

/**
 * the number of 0
 * @param n long长整型 the number
 * @return long长整型
 */
public long thenumberof0 (long n) {
    // write code here
    //特殊值处理
    if(n == 0){
        return 0;
    }
    
    long m = 1;
    //求阶乘
    for(long i=1;i<=n;i++){
        m = m*i;
    }
    
    //求个数
    int count = 0;
    long remainder = m%10;
    long temp = m/10;
    while(remainder==0){
        count++;
        remainder = temp%10;
        temp = temp/10;
    }
    
    return count;
}

}