C++ 알고리즘 - 백준 28279 덱 2

https://www.acmicpc.net/problem/28279

 

#include <bits/stdc++.h>
#define endl "\n"

using namespace std;

void CPP_INIT() {
	ios::sync_with_stdio(false);
	cin.tie(NULL);
	cout.tie(NULL);
}

int main(void) {
	CPP_INIT();

	int input1, input2;
	int num;
	deque<int> dq;
	cin >> input1;

	for (int i = 0; i < input1; i++) {
		cin >> input2;

		switch (input2) {
		case 1:
			cin >> num;
			dq.push_front(num);

			break;

		case 2:
			cin >> num;
			dq.push_back(num);

			break;

		case 3:
			if (dq.empty()) {
				cout << -1 << endl;
				break;
			}

			cout << dq.front() << endl;
			dq.pop_front();

			break;

		case 4:
			if (dq.empty()) {
				cout << -1 << endl;
				break;
			}

			cout << dq.back() << endl;
			dq.pop_back();

			break;

		case 5:
			cout << dq.size() << endl;

			break;

		case 6:
			if (dq.empty()) cout << 1 << endl;
			if (!dq.empty()) cout << 0 << endl;

			break;

		case 7:
			if (dq.empty()) {
				cout << -1 << endl;
				break;
			}

			cout << dq.front() << endl;

			break;

		case 8:
			if (dq.empty()) {
				cout << -1 << endl;
				break;
			}

			cout << dq.back() << endl;

			break;
		}
	}
}