八个wonderful answer

#include <iostream>
#include <stack>
using namespace std;
stack<int> stk,mstk;
int main(){
    int n;
    int min_num = 0x3f3f3f3f;
    cin >> n;
    while (n--){
        string x;
        cin >> x;
        if(x == "top"){
            if(stk.empty()){
                cout << "error" << "\n";
            }else{
                cout << stk.top() << "\n";
            }
        }else if(x == "push"){
            int x2;
            cin >> x2;
            stk.push(x2);
            if (x2 < min_num){
                min_num = x2;
                mstk.push(x2);
            }else{
                mstk.push(mstk.top());
            }
        }else if(x == "pop"){
            if(stk.empty()){
                cout << "error" << "\n";
            }else{
                stk.pop();
                mstk.pop();
            }
        }else{
            if(stk.empty()||mstk.empty()){
                cout << "error" << "\n";
            }else{
                cout << min_num << "\n";
                }
        }
    }
    return 0;
}