[실4] 10866 - 덱

#include <iostream>
#include <functional>
#include <algorithm>
#include <string>
#include <vector>
#include <map>
#include <list>
#include <stack>
#include <queue>
using namespace std;

deque<int> my_deque;
vector<int> my_vec;

void Push_front(int _value)
{
    my_deque.push_front(_value);
}

void Push_back(int _value)
{
    my_deque.push_back(_value);
}

void Pop_front()
{
    if (my_deque.empty())
    {
        my_vec.push_back(-1);
        return;
    }
    my_vec.push_back(my_deque.front());
    my_deque.pop_front();
}

void Pop_back()
{
    if (my_deque.empty())
    {
        my_vec.push_back(-1);
        return;
    }
    my_vec.push_back(my_deque.back());
    my_deque.pop_back();
}

void Size()
{
    my_vec.push_back(my_deque.size());
}

void Empty()
{
    if (my_deque.empty())
        my_vec.push_back(1);

    else
        my_vec.push_back(0);
}

void Front()
{
    if (my_deque.empty())
        my_vec.push_back(-1);

    else
        my_vec.push_back(my_deque.front());
}

void Back()
{
    if (my_deque.empty())
        my_vec.push_back(-1);

    else
        my_vec.push_back(my_deque.back());
}

int main()
{
    string menu = "";
    int num = 0;
    cin >> num;

    while(num--)
    {
        cin >> menu;

        if (menu == "pop_front")
            Pop_front();

        else if (menu == "pop_back")
            Pop_back();

        else if (menu == "front")
            Front();

        else if (menu == "back")
            Back();

        else if (menu == "push_front")
        {
            int value = 0;
            cin >> value;
            Push_front(value);
        }
        else if (menu == "push_back")
        {
            int value = 0;
            cin >> value;
            Push_back(value);
        }
        else if (menu == "empty")
            Empty();

        else if (menu == "size")
            Size();
    }
    for (const auto& item : my_vec)
        cout << item << endl;

    return 0;
}