|
| 1 | + |
| 2 | + |
| 3 | + |
| 4 | +import java.io.BufferedReader; |
| 5 | +import java.io.BufferedWriter; |
| 6 | +import java.io.IOException; |
| 7 | +import java.io.InputStreamReader; |
| 8 | +import java.io.OutputStreamWriter; |
| 9 | +import java.nio.charset.Charset; |
| 10 | +import java.util.Collection; |
| 11 | +import java.util.Deque; |
| 12 | +import java.util.Iterator; |
| 13 | +import java.util.LinkedList; |
| 14 | +import java.util.Queue; |
| 15 | +import java.util.Stack; |
| 16 | +import java.util.StringJoiner; |
| 17 | +import java.util.StringTokenizer; |
| 18 | + |
| 19 | +public class Main { |
| 20 | + public static void main(String[] args)throws IOException { |
| 21 | + BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); |
| 22 | + BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out)); |
| 23 | + int cnt = Integer.parseInt(br.readLine()); |
| 24 | + Deque <Integer> deque = new LinkedList<>(); |
| 25 | + StringTokenizer st; |
| 26 | + for (int i = 0; i <cnt ; i++) { |
| 27 | + st = new StringTokenizer(br.readLine()); |
| 28 | + int key = Integer.parseInt(st.nextToken()); |
| 29 | + switch (key){ |
| 30 | + case 1: |
| 31 | + deque.addFirst(Integer.parseInt(st.nextToken())); |
| 32 | + break; |
| 33 | + case 2: |
| 34 | + deque.addLast(Integer.parseInt(st.nextToken())); |
| 35 | + break; |
| 36 | + case 3: |
| 37 | + if (deque.size()!=0){ |
| 38 | + bw.write(deque.pollFirst()+"\n"); |
| 39 | + }else { |
| 40 | + bw.write(-1+"\n"); |
| 41 | + } |
| 42 | + break; |
| 43 | + case 4: |
| 44 | + if (deque.size()!=0){ |
| 45 | + bw.write(deque.pollLast()+"\n"); |
| 46 | + }else { |
| 47 | + bw.write(-1+"\n"); |
| 48 | + } |
| 49 | + break; |
| 50 | + case 5: |
| 51 | + bw.write(deque.size()+"\n"); |
| 52 | + break; |
| 53 | + case 6: |
| 54 | + if (deque.isEmpty()){ |
| 55 | + bw.write(1+"\n"); |
| 56 | + }else { |
| 57 | + bw.write(0+"\n"); |
| 58 | + } |
| 59 | + break; |
| 60 | + case 7: |
| 61 | + if (!deque.isEmpty()){ |
| 62 | + bw.write(deque.peekFirst()+"\n"); |
| 63 | + }else { |
| 64 | + bw.write(-1+"\n"); |
| 65 | + } |
| 66 | + break; |
| 67 | + case 8: |
| 68 | + if (!deque.isEmpty()){ |
| 69 | + bw.write(deque.peekLast()+"\n"); |
| 70 | + }else { |
| 71 | + bw.write(-1+"\n"); |
| 72 | + } |
| 73 | + break; |
| 74 | + } |
| 75 | + |
| 76 | + } |
| 77 | + bw.flush(); |
| 78 | + } |
| 79 | +} |
0 commit comments