[백준/BOJ] 백준 10866번 : 덱

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

10866번: 덱

deque를 사용해 문제를 해결했다.

 

코드

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

int n;

int main()
{
	cin.tie(NULL);
	ios_base::sync_with_stdio(false);

	deque<int> dq; //deque를 사용한다
	string command;
	int input;

	cin >> n;

	for (int i = 0; i < n; i++)
	{
		cin >> command;

		if (command == "push_front")
		{
			cin >> input;
			dq.push_front(input);
		}

		else if (command == "push_back")
		{
			cin >> input;
			dq.push_back(input);
		}

		else if (command == "pop_front")
		{
			if (dq.empty())
				cout << -1 << "\n";
			else
			{
				cout << dq.front() << "\n";
				dq.pop_front();
			}
		}

		else if (command == "pop_back")
		{
			if (dq.empty())
				cout << -1 << "\n";
			else
			{
				cout << dq.back() << "\n";
				dq.pop_back();
			}
		}

		else if (command == "size")
		{
			cout << dq.size() << "\n";
		}

		else if (command == "empty")
		{
			if (dq.empty())
				cout << 1 << "\n";
			else
				cout << 0 << "\n";
		}

		else if (command == "front")
		{
			if (dq.empty())
				cout << -1 << "\n";
			else
				cout << dq.front() << "\n";
		}

		else if (command == "back")
		{
			if (dq.empty())
				cout << -1 << "\n";
			else
				cout << dq.back() << "\n";
		}
	}

	return 0;
}