[C++/스택] BOJ 10828 스택

https://www.acmicpc.net/problem/10828

10828번: 스택

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

using namespace std;

int main()
{
    int n, input;
    stack<int> nums;
    cin >> n;
    string comm;

    while(n--){
        cin >> comm;

        if(comm == "push"){
            cin >> input;
            nums.push(input);
        }else if(comm == "pop"){
            if(nums.size() != 0){
                cout << nums.top() << '\n';
                nums.pop();
            }else{
                cout << "-1" << '\n';
            }
        }else if(comm == "size"){
            cout << nums.size() << '\n';
        }else if(comm == "empty"){
            if(nums.size() == 0) cout <<'1'<<'\n';
            else cout << '0'<< '\n';
        }else if(comm == "top"){
            if(nums.size() != 0){
                cout << nums.top() << '\n';
            }else cout << "-1" << '\n';
        }
    }
}