这是我的代码：

#include <iostream>
#include <stack>
#include <string>
using namespace std;
int t, n;
unsigned long long x;
stack<unsigned long long> s;
string str;
int main() {
	cin >> t;
	while (t--) {
		cin >> n;
		for (int i = 0; i < n; i++) {
			cin >> str;
			if (str == "push") {
				cin >> x;
				s.push(x);
			}
			else if (str == "pop")
				if (s.empty())
					cout << "Empty\n";
				else
					s.pop();
			else if (str == "query")
				if (s.empty())
					cout << "Anguei!\n";
				else
					cout << s.top() << endl;
			else if (str == "size")
				cout << s.size() << endl; 
		}
	}
	return 0;
}

感觉与作者的题解没有多大区别，为什么测试点三错了呢？