2个易错点

1.数据类型要开unsigned long long，用int会爆掉(0<=x<2⁶⁴)

2.多组测试数据，每个数据输完要对栈清零

#include<iostream>
#include<string>
#include<stack>

using namespace std;

stack<unsigned long long> s; //一定要开unsigned long long！！！！！
int t,n;
unsigned long long x;
string op;


int main()
{
	cin>>t;
	while(t--)
	{
		cin>>n;
		while(n--)
		{
			cin>>op;
			if(op=="push")
			{
				cin>>x;
				s.push(x);
			}
			else if(op=="pop")
				if(s.empty())cout<<"Empty"<<endl;
				else s.pop();
			else if(op=="query")
				if(s.empty())cout<<"Anguei!"<<endl;
				else cout<<s.top()<<endl;
			else if(op=="size")
				cout<<s.size()<<endl;
		}
		while(!s.empty())s.pop();//每个数据输完要清零！！！
	}
}

1.用string可以不用考虑数据大小 2.一组完后对栈清零

#include<bits/stdc++.h>
#include<iostream>
#include<stack>
using namespace std;
stack<string> de;
unsigned int T,n,ptr,ptr2;
string a,num;
int main(){
    cin>>T;
    for(unsigned int i=1;i<=T;i++){
        cin>>n;
        ptr2=ptr;
        if(ptr>0){
            for(unsigned int i=ptr;i>0;i--){
                ptr2--;
                de.pop();}
        }ptr=ptr2;
        for(unsigned int j=1;j<=n;j++){
            cin>>a;
            if(a=="push"){
                cin>>num;
                de.push(num);
                ptr++;}
            if(a=="pop"){
                if(ptr!=0){
                    de.pop();
                    ptr--;}
                else cout<<"Empty"<<endl;
            }
            if(a=="query"){
                if(ptr==0) cout<<"Anguei!"<<endl;
                else cout<<de.top()<<endl;}
            if(a=="size"){
                cout<<ptr<<endl;
            }
        }
    }
    return 0;
}

#include<bits/stdc++.h>
using namespace std;
#define ull unsigned long long
stack<ull> st, st1;
ull T, n, x;
string s;
int main()
{
	ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
	cin >> T;
	while (T--)
	{
		cin >> n;
		while (n--)
		{
			cin >> s;
			if (s == "push")
			{
				cin >> x;
				st.push(x);
			}
			if (s == "pop")
			{
				if (st.empty()) cout << "Empty" << "\n";
				else st.pop();
			}
			if (s == "query")
			{
				if (st.empty()) cout << "Anguei!" << "\n";
				else cout << st.top() << "\n";
			}	
			if (s == "size") cout << st.size() << "\n";
		}
		st = st1;
	}
	return 0;
}

#include<bits/stdc++.h>
using namespace std;
stack<unsigned long long> line;
stack<unsigned long long> line1;//给后面清空 
unsigned long long t, n;
unsigned long long x;
string str;
int main()
{
	cin >> t;
	for(int i = 1; i <= t; i++)
	{
		cin >> n;
		for(int j = 1; j <= n; j++)
		{
			cin >> str;
			if(str=="push")
			{
				cin >> x;
				line.push(x);
			}
			else 
			if(str=="pop")
			{
				if(line.empty())
				{
					cout<<"Empty"<<endl;
				}
				else 
				{
					line.pop();
				}
			}
			else 
			if(str=="query")
			{
				if(line.empty())
				{
					cout<<"Anguei!"<<endl;
				}
				else 
				{
					cout<<line.top()<<endl;
				}
			}	
			else 
			if(str=="size")
			{
				cout<<line.size()<<endl;				
			}
		}
		line = line1;
	}
	return 0;
}

回来发个题解[乐]

#include <bits/stdc++.h>
using namespace std;
typedef unsigned long long ull; 
int main(int argc, char **argv){
	int t;
	cin >> t;
	while (t--){
		stack<ull> a; 
		int n;
		cin >> n;
		while (n--){
			string op;
			cin >> op;
			if (op == "push"){
				ull x;
				scanf("%llu",&x);
				a.push(x); 
			} else if (op == "pop") {
				if (a.empty())	printf("Empty\n");
				else	a.pop();
			}else if (op == "query"){
				if (a.empty())	printf("Anguei!\n");
				else	printf("%llu\n",a.top());
			}else{
				printf("%ld\n",a.size());
			}
		}
	} 
}