#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
int main()
{
	freopen("1.in","r",stdin);
	freopen("1.out","w",stdout);
	ios::sync_with_stdio(false);
	cin.tie(0);cout.tie(0);
  	//......
	return 0;
}

rt.

如果做题前先敲上上述代码是否有问题