栈（数组实现）

package com.dai.stack;

import java.util.Scanner;

public class ArrayStackDemo {

    public static void main(String[] args) {
        //先创建一个ArrayStack对象
        ArrayStack stack = new ArrayStack(4);
        String key = "";
        boolean loop = true;
        Scanner scanner = new Scanner(System.in);
        
        while(loop) {
            System.out.println("show:显示栈");
            System.out.println("exit:退出程序");
            System.out.println("push:添加数据");
            System.out.println("pop:取出数据");
            
            System.out.println("请输入选项：");
            key = scanner.next();
            
            switch (key) {
            case "show":
                stack.list();
                break;
            case "push":
                System.out.println("请输入一个数：");
                int value = scanner.nextInt();
                stack.push(value);
                break;
            case "pop":
                try {
                    int res = stack.pop();
                    System.out.printf("出栈的数据是:%d
", res);
                } catch (Exception e) {
                    // TODO: handle exception
                    System.out.println(e.getMessage());
                }
                break;
            case "exit":
                scanner.close();
                loop  = false;
                break;
            default:
                break;
            }
        }
        System.out.println("程序退出");
    }
}

class ArrayStack{
    private int maxSzie;
    private int[] stack; //数组模拟栈，数据放在这
    private int top = -1; //表示栈顶，初始化为-1
    
    public ArrayStack(int maxSize) {
        this.maxSzie = maxSize;
        stack = new int[this.maxSzie];
    }
    //栈满
    public boolean isFull() {
        return top==maxSzie-1;
    }
    //栈空
    public boolean isEmpty() {
        return top == -1;
    }
    //入栈 - push
    public void push(int value) {
        if(isFull()) {
            System.out.println("栈满了");
            return;
        }
        top++;
        stack[top] = value;
    }
    //出栈
    public int pop() {
        if(isEmpty()) {
            throw new RuntimeException("栈空，无数据");
        }
        int value = stack[top];
        top--;
        return value;
    }
    //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，没有数据");
            return;  
        }
        for(int i=top; i>=0; i--) {
            System.out.printf("stack[%d] = %d
", i, stack[i]);
        }
    }
}