两个堆栈实现队列及排序

package com.ranger.demo;

import java.util.Stack;

/**

* Created by on 2019/2/11.

*/

public class TestStack {

Stackstack1 =new Stack();

    Stackstack2 =new Stack();

    /**

* 初始化，插入

    * @param num

    */

    private void push(int num) {

stack1.push(num);

    }

/**

* 实现队列

    * @return

    */

    private int pop() {

Integerp =null;

        if (!stack2.isEmpty()) {

p =stack2.pop();

        }else {

while (!stack1.isEmpty()) {

p =stack1.pop();

                stack2.push(p);

            }

if (!stack2.empty()) {

p =stack2.pop();

            }

}

return p;

    }

/**

* 实现排序

    * @param stack

    * @return

    */

    private Stacksort(Stack stack) {

Stack tempStack =new Stack<>();

        while (!stack.isEmpty()) {

int cur = stack.pop();

            while (!tempStack.isEmpty() && tempStack.peek() < cur) {

stack.push(tempStack.pop());

            }

tempStack.push(cur);

        }

return tempStack;

    }

public static void main(String args[]) {

TestStack testStack =new TestStack();

        int a[] = {2, 5, 6, 1, 10};

        System.out.println("----入栈----");

        for (int b : a) {

testStack.push(b);

            System.out.print(b +"\t");

        }

System.out.println("\n----队列先进先出----");

        int s = a.length;

        for (int i =0; i < s; i++) {

System.out.print(testStack.pop() +"\t");

        }

for (int b : a) {

testStack.push(b);

        }

System.out.println("\n----排序----");

        Stack sort = testStack.sort(testStack.stack1);

        while (!sort.isEmpty()) {

System.out.print(sort.pop() +"\t");

        }

}

}