package com.yuteng.stack;

import java.util.Scanner;

/**

  • @version 1.0
  • @author： 余腾
  • @date： 2021-07-26 10:34
    */
    public class ArrayStackDemo {
    public static void main(String[] args) {
    ArrayStack stack = new ArrayStack(4);
    String key = "";
    boolean loop = true;//控制是否退出菜单
    Scanner scanner = new Scanner(System.in);
    while (loop) {
    System.out.println("show:表示显示栈");
    System.out.println("exit:表示退出程序");
    System.out.println("push:表示添加数据到栈");
    System.out.println("pop:表示从栈中取出数据");
    System.out.println("请输入你要进行的操作");
    key = scanner.next();
    switch (key) {
    case "show":
    stack.list();
    break;
    case "exit":
    scanner.close();
    loop = false;
    break;
    case "push":
    System.out.println("请输入你要输入的数据");
    int data = scanner.nextInt();
    stack.push(data);
    break;
    case "pop":
    try {
    int pop = stack.pop();
    System.out.println("出栈的数据是"+pop);
    }catch (Exception e){
    System.out.println(e.getMessage());
    }
    break; default: break; } } System.out.println("程序退出");
    }
    }

//定义一个ArrayStack表示栈

class ArrayStack {

private int maxSize;//栈的大小

private int[] stack;//数组，数组模拟栈，数据就放在该数组中

private int top = -1;//top表示栈顶

public ArrayStack(int maxSize) {
    this.maxSize = maxSize;
    stack = new int[this.maxSize];

}

//判断栈满
public boolean isFull() {
    return top == maxSize - 1;
}

//判断栈空
public boolean isEmpty() {
    return top == -1;
}

//入栈
public void push(int value) {
    //先判断是否满
    if (isFull()) {
        System.out.println("栈满");
        return;
    }
    top++;
    stack[top] = value;
}

public int pop() {
    //先判断是否栈空
    if (isEmpty()) {
        throw new RuntimeException("栈空不能返回数据");
    }
    return stack[top--];
}

//显示栈的情况[遍历栈]，遍历时，需要从栈顶开始显示数据
public void list() {
    if (isEmpty()) {
        System.out.println("栈空不能输出");
        return;
    }
    for (int i=top;i>=0;i--){
        System.out.println("stack["+i+"]="+stack[i]);
    }
}


}