判断存储，是栈？还是队列？

　　判断一段 输入-输出 模式，是利用了栈还是队列的一个方法

import java.util.*;

public class Stack_Queue {
        static Scanner sc = new Scanner(System.in);
        
        public static boolean isQueue(int a[], int n){
            Queue<Integer> p = new LinkedList<Integer>();
            int t = 1;
            for(int i = 0; i < n; i++){
                while(t <= n || (!p.isEmpty() && p.peek() <= n)){
//                  System.out.println("p.peek="+p.peek()+",t="+t+",a="+a[i]);
                    if(!p.isEmpty() && p.peek() == a[i]){
//                      System.out.println("p="+p.peek()+"->out");
                        p.poll();
                        break;
                    }
                    else if(t == a[i]){
//                      System.out.println(t+"->out");
                        t++;
                        break;
                    }
//                  System.out.println("noout,"+t+"->p");
                    p.add(t++);
                    if(t > n+1)
                        break;
                }
            }
            return p.isEmpty();
        }
        public static boolean isStack(int a[], int n){
            Stack<Integer> s = new Stack<Integer>();
            int k = 1;
            for(int i = 0; i < n; i++){
                while((s.isEmpty() || s.peek() != a[i]) && k <= n){
                    s.push(k++);
//                    System.out.print("s.peek="+s.peek()+",");
                }
                if(!s.isEmpty() && s.peek() == a[i])
                    s.pop();
            }
            return s.isEmpty();
        }
        
        public static void Stack_Or_Queue(String[] args) {
            int id = 1;
            while(sc.hasNext()){
                while(sc.hasNext()){
                    int n = sc.nextInt();
                    if(n == 0)    break;
                    Queue<Integer> p = new LinkedList<Integer>();
                    Stack<Integer> s = new Stack<Integer>();
                    int[] a = new int[n];
                    for(int i = 0; i < n; i++)
                        a[i] = sc.nextInt();
                    
                    for(int i = 0; i < n; i++){
                        if(i != n-1)
                            System.out.print(a[i] + " ");
                        else
                            System.out.print(a[i] + "：");
                    }
                    if(isStack(a, n) && isQueue(a, n))
                        System.out.println("both");
                    else if(isStack(a, n))
                        System.out.println("stack");
                    else if(isQueue(a, n))
                        System.out.println("queue");
                    else
                        System.out.println("neither");
                }
                
            }
            
            System.gc();sc.close();
        }
}