算法中心思想：

始终向非空队列进行入队操作

初始化时两个队列都为空，我们对q1进行入队操作

 

入栈：

只需执行其中一个队列入队操作即可，

具体操作哪一个队列，用一个标记变量标记 

出栈流程图

 

代码实现

1 package hello; 2 import java.util.*; 3  4 public class TwoQueueOneStack
     
       { 5     private Queue
      
        q1 = new LinkedList<>(); 6     private Queue
       
         q2 = new LinkedList<>(); 7     private String pushFlag = "q1"; 8  9     public void push(E item){10         if(pushFlag == "q1"){11             q1.add(item);12         }13         if(pushFlag == "q2"){14             q2.add(item);15         }16     }17 18     public E pop(){19         E top;20         if(!empty()){21             if(!q1.isEmpty()) {22                 top = move(q1, q2);23                 this.pushFlag = "q2";24             } else {25                 top = move(q2, q1);26                 this.pushFlag = "q1";27             }28         }else{29             throw new ArrayIndexOutOfBoundsException();30         }31         return top;32     }33 34     private E move(Queue
        
          qSource, Queue
         
           qTarget){35         Iterator
          
            it = qSource.iterator();36 while(it.hasNext()){37 E item = it.next();38 if(it.hasNext()){39 qTarget.add(item);40 }else{41 qSource.clear();42 return item;43 }44 }45 46 throw new ArrayIndexOutOfBoundsException();47 }48 49 public boolean empty(){50 if (q1.isEmpty() && q2.isEmpty())51 return true;52 else53 return false;54 }55 56 public static void main(String[] args){57 TwoQueueOneStack
           
             tqos = new TwoQueueOneStack<>();58 for (int i = 0; i < 20; i++) {59 tqos.push(i);60 }61 for (int i = 0; i < 10; i++){62 System.out.println(tqos.pop());63 }64 for (int i = 20; i < 40; i++){65 tqos.push(i);66 }67 for (int i = 0; i < 30; i++){68 System.out.println(tqos.pop());69 }70 }71 72 }