[문제 풀이] 백준 10866 덱 (배열로 구현한 덱)

import java.util.Scanner; public class Deck { static int Deck[]; static int rear=-1; static void push_front(int data){ rear++; for(int i=rear;i>0;i--){ Deck[i]=Deck[i-1]; } Deck[0]=data; } static void push_back(int data){ rear++; Deck[rear]=data; } static void pop_front(){ int tmp=Deck[0]; if(rear<0){ System.out.println("-1"); return; } for(int i=0;i<rear;i++){ Deck[i]=Deck[i+1]; } rear--; System.out.println(tmp); return; } static void pop_back(){ if(rear<0){ System.out.println("-1"); return; } //System.out.println("rear:"+rear); int tmp=Deck[rear]; rear--; System.out.println(tmp); return; } static void size(){ if(rear<0){ System.out.println("0"); return; } System.out.println(rear+1); return; } static void empty(){ if(rear<0){ System.out.println("1"); return; } System.out.println("0"); return; } static void front() { if(rear<0){ System.out.println("-1"); return; } System.out.println(Deck[0]); return; } static void back(){ if(rear<0){ System.out.println("-1"); return; } System.out.println(Deck[rear]); return; } public static void main(String args[]){ Scanner sc=new Scanner(System.in); int N=sc.nextInt(); Deck=new int[N]; for(int i=0;i<N;i++){ String s=sc.next(); if(s.equals("push_front")){ int tmp=sc.nextInt(); push_front(tmp); } else if(s.equals("push_back")){ int tmp=sc.nextInt(); push_back(tmp); } else if(s.equals("pop_front")) pop_front(); else if(s.equals("pop_back")) pop_back(); else if(s.equals("size")) size(); else if(s.equals("empty")) empty(); else if(s.equals("front")) front(); else if(s.equals("back")) back(); } return; } }