10866) 덱 c++

문제 ) www.acmicpc.net/problem/10866

2164번: 카드2

 

풀이 ) 

 

 

코드 )

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

int N;
string cmd;
deque<int> dq;

int main(void)
{
	ios::sync_with_stdio(0);
	cin.tie(0); cout.tie(0);

	cin >> N ;
	
	while( N-- ) {
		cin >> cmd;

		int num = 0;
		if(cmd == "push_front"){
			cin >> num;
			dq.push_front(num);
		}
		else if(cmd == "push_back") {
			cin >> num;
			dq.push_back(num);
		}
		else if(cmd == "pop_front") {
			if( !dq.empty() ) {
				cout << dq.front() << "\n";
				dq.pop_front();
			}
			else cout << "-1\n";
		}
		else if(cmd == "pop_back") {
			if( !dq.empty() ) {
				cout << dq.back() << "\n";
				dq.pop_back();
			}
			else cout << "-1\n";
		}
		else if(cmd == "size") cout << dq.size() << "\n";
		else if(cmd == "empty") {
			if ( !dq.empty() ) cout << "0\n";
			else cout << "1\n";
		}
		else if(cmd == "front"){
			if( !dq.empty() ) cout << dq.front() << "\n";
			else cout << "-1\n";
		}
		else if(cmd == "back"){
			if( !dq.empty() ) cout << dq.back() << "\n";
			else cout << "-1\n";
		}
	}
}