백준 10866번: 덱

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

문제 접근

10828 스택, 10845 큐 문제 푸는 방식을 덱에 사용하면 된다.

#include <iostream>
#include <deque>
using namespace std;

int main()
{
    int num;
    cin >> num;
    deque<int> deq;
    for(int i = 0; i < num; i++)
    {
        string str;
        cin >> str;
        int temp;
        if(str == "push_front"){
            cin >> temp;
            deq.push_front(temp);
        }
        else if(str == "push_back")
        {
            cin >> temp;
            deq.push_back(temp);
        }
        else if(str == "pop_front")
        {
            if(deq.empty())
                cout << -1 << endl;
            else{
                cout << deq.front() << endl;
                deq.pop_front();
            }
        }
        else if(str == "pop_back")
        {
            if(deq.empty())
                cout << -1 << endl;
            else{
                cout << deq.back() << endl;
                deq.pop_back();
            }
        }
        else if(str == "size")
        {
            cout << deq.size() << endl;
        }
        else if(str == "empty")
        {
            cout << deq.empty() << endl;
        }
        else if(str == "front")
        {
            if(deq.empty())
                cout << -1 << endl;
            else{
                cout << deq.front() << endl;
            }
        }
        else if(str == "back")
        {
            if(deq.empty())
                cout << -1 << endl;
            else{
                cout << deq.back() << endl;
            }
        }
    }
}