用题解里面手打了几遍对拍...都过了 但提交还是0分WA了(悲)

#include<bits/stdc++.h>
using namespace std;

map<string,int> storing;
int main()
{
	int n;cin>>n;
	int stuCount=0;
	
	for (int i=1;i<=n;i++)
	{
		int instructID=0;cin>>instructID;
		if (instructID==1)//载入
		{
			string name;cin>>name;
			int score;cin>>score;
			if (storing[name] == 0)
			{
				stuCount++;//只有在这个学生没入过队伍的时候才+1
				storing[name] = score;
			}
			cout<< "OK" <<'\n';
		}
		if (instructID==2)//读取
		{
			string name;cin>>name;
			if (storing[name] ==0) cout<< "Not found" <<'\n';
			else cout<< storing[name] <<'\n';
		}
		if (instructID==3)//删除
		{
			string name;cin>>name;
			if (storing[name] ==0) cout<< "Not found" <<'\n';
			else
			{
				cout<< "Deleted successfully" <<'\n';
				storing[name]=0;
				stuCount--;//当且仅当学生分数不为0(入过map)时候 -1
			}
		}
		if (instructID==4) cout<<stuCount<<'\n';//数量
	}
}