阶乘末尾0的数量（分解问题）

#include<iostream>#include<algorithm>#include<string>#include<map>//int dx[4]={0,0,-1,1};int dy[4]={-1,1,0,0};#include<set>//int gcd(int a,int b){return b?gcd(b,a%b):a;}#include<vector>#include<cmath>#include<queue>#include<string.h>#include<stdlib.h>#include<cstdio>#define mod 1e9+7#define ll long longusing namespace std;int main(){int n;cin>>n;ll p=5,s=0;for(int i=p;;++i){s+=n/p;p*=5;if(p>n)break;}cout<<s<<endl;return 0;}