백준 10866 덱 [C++]

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

소스코드

#include <iostream>

#include <deque>

#include <string>

using namespace std;

int main() {

    int N;

    deque<int> dq;

    cin >> N;

    cin.ignore();

    for (int i = 0; i < N; ++i) {

        string text;

        getline(cin, text);

        if (text == "front") {

            if (dq.empty()) cout << -1 << "\n";

            else cout << dq.front() << "\n";

        }

        else if (text == "back") {

            if (dq.empty()) cout << -1 << "\n";

            else cout << dq.back() << "\n";

        }

        else if (text[1] == 'u') { // push

            string backup = text;

            if (text[5] == 'f') { //push_front

                int x = stoi(backup.erase(0, 10));

                dq.push_front(x);

            }

            else { // push_back

                int x = stoi(backup.erase(0, 9));

                dq.push_back(x);

            }

        }

        else if (text[1] == 'o') {

            if (text[4] == 'f') {

                if (dq.empty()) cout << -1 << "\n";

                else {

                    cout << dq.front() << "\n";

                    dq.pop_front();

                }

            }

            else {

                if (dq.empty()) cout << -1 << "\n";

                else {

                    cout << dq.back() << "\n";

                    dq.pop_back();

                }

            }

        }

        else if (text == "size")

            cout << dq.size() << "\n";

        else if (text == "empty") {

            if (dq.empty()) cout << 1 << "\n";

            else cout << 0 << "\n";

        }

    }

}

스택은 후입선출 큐는 선입선출이라면,

덱은 앞뒤로 푸쉬와 팝을 자유롭게 할 수 있는 자료구조입니다.

C++ STL 덱 사용법 : http://woodforest.tistory.com/80