用两个堆实现队列 用两个堆实现

文章来源：https://blog.csdn.net/jsqfengbao/article/details/47089355

`
package com.xeswx.tx.management.dto.bean;

/**

• 用两个栈实现一个队列
  */

import java.util.Stack;

public class E07QueueWithTwoStacks {

/**
* 用两个栈实现一个队列，完成两个函数appendTail和deletedHead,分别是在队列尾部插入节点
* 和在队列头部删除节点的功能
*/
private Stack stack1 = new Stack();
private Stack stack2 = new Stack();

public void appendTail(String s) {
stack1.push(s);
}

public String deletedHead() throws Exception {
if (stack2.isEmpty()) {
while (!stack1.isEmpty()) {
stack2.push(stack1.pop());
}
}
if (stack2.isEmpty()) {
throw new Exception("队列为空，不能删除");
}
return stack2.pop();
}

public static void main(String[] args) throws Exception {
E07QueueWithTwoStacks test = new E07QueueWithTwoStacks();
test.appendTail("1");
test.appendTail("2");
test.deletedHead();
}
}

`
package com.xeswx.tx.management.dto.bean;

/**

• 用两个栈实现一个队列
  */

import java.util.Stack;

public class E07QueueWithTwoStacks {

/**
* 用两个栈实现一个队列，完成两个函数appendTail和deletedHead,分别是在队列尾部插入节点
* 和在队列头部删除节点的功能
*/
private Stack stack1 = new Stack();
private Stack stack2 = new Stack();

public void appendTail(String s) {
stack1.push(s);
}

public String deletedHead() throws Exception {
if (stack2.isEmpty()) {
while (!stack1.isEmpty()) {
stack2.push(stack1.pop());
}
}
if (stack2.isEmpty()) {
throw new Exception("队列为空，不能删除");
}
return stack2.pop();
}

public static void main(String[] args) throws Exception {
E07QueueWithTwoStacks test = new E07QueueWithTwoStacks();
test.appendTail("1");
test.appendTail("2");
test.deletedHead();
}
}

`

`