アルゴリズム第4版1.3リュックサック、キューとスタック:練習問題1.3.48

import edu.princeton.cs.algs4.StdOut;

public class E1_3_48 {
    public static void main(String[]args){
        E1_3_48 twoStackWithDeque=new E1_3_48<>();
        for (int i=0;i<5;i++)// 0-4    
            twoStackWithDeque.pushLeftStack(i);
        for (int i=5;i<10;i++)// 5-9    
            twoStackWithDeque.pushRightStack(i);
        for (int i:twoStackWithDeque.deque)//     ，     4,3,2,1,0,5,6,7,8,9
            StdOut.print(i+" ");
        StdOut.println();
        int count=twoStackWithDeque.LeftStackSize();
        for (int i=0;i deque=new Deque<>();
    private int LeftCount;
    private int RightCount;
    private class Node{
        Item item;
        Node next;
    }
    public boolean LeftStackIsEmpty(){return LeftCount==0;}
    public boolean RightStackIsEmpty(){return RightCount==0;}
    public int LeftStackSize(){return LeftCount;}
    public int RightStackSize(){return RightCount;}
    public void pushLeftStack(Item item){
        deque.pushLeft(item);
        LeftCount++;
    }
    public void pushRightStack(Item item){
        deque.pushRight(item);
        RightCount++;
    }
    public Item popLeftStack(){
        if (LeftStackIsEmpty())return null;
        LeftCount--;
        return  deque.popLeft();
    }
    public Item popRightStack(){
        if (RightStackIsEmpty())return null;
        RightCount--;
        return  deque.popRight();
    }
}