[BOJ]10866번: 덱(c++)

https://www.acmicpc.net/problem/10866

10866번: 덱

 

//https://www.acmicpc.net/problem/10866
#include <iostream>
#include <deque>
 
using namespace std;
 
int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(NULL);
    cout.tie(NULL);
 
    int cnt;
    cin >> cnt;
    cin.ignore();
 
    deque<int> dq;
 
    while (cnt--)
    {
        string cmd;
        cin >> cmd;
 
        if (cmd == "push_front")
        {
            int n;
            cin >> n;
            dq.push_front(n);
        }
        else if (cmd == "push_back")
        {
            int n;
            cin >> n;
            dq.push_back(n);
        }
        else if (cmd == "pop_front")
        {
            if (dq.empty())
            {
                cout << -1 << '\n';
                continue;
            }
            cout << dq.front() << '\n';
            dq.pop_front();
        }
        else if (cmd == "pop_back")
        {
            if (dq.empty())
            {
                cout << -1 << '\n';
                continue;
            }
            cout << dq.back() << '\n';
            dq.pop_back();
        }
        else if (cmd == "size")
        {
            cout << dq.size() << '\n';
        }
        else if (cmd == "empty")
        {
            cout << (dq.empty() ? 1 : 0) << '\n';
        }
        else if (cmd == "front")
        {
            cout << ((dq.empty()) ? -1 : dq.front()) << '\n';
        }
        else if (cmd == "back")
        {
            cout << (dq.empty() ? -1 : dq.back()) << '\n';
        }
    }
 
    return 0;
}