数组模拟栈的思路

数组模拟栈的思路

代码示例：

import java.util.Scanner;
import java.util.Stack;

/**
 * @author xiaoka
 * @create 2020--07--19 14:35
 */
public class ArrayStackDemo {
    public static void main(String[] args) {
        ArrayStack arrayStack = 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（入栈）");
            System.out.println("pop:表示从栈取数据（出栈）");
            System.out.println("请输入你的选择");
            key = scanner.next();
            switch (key) {
                case "show":
                    arrayStack.list();
                    break;
                case "push":
                    System.out.println("请输入一个数：");
                    int value = scanner.nextInt();
                    arrayStack.push(value);
                    break;
                case "pop":
                    try {
                        int pop = arrayStack.pop();
                        System.out.printf("出栈的数据是%d\n", pop);
                    } catch (Exception e) {
                        System.out.println(e.getMessage());
                    }
                    break;
                case "exit":
                    scanner.close();
                    loop = false;
                    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，初始化为-1

    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) {
        //先判断栈是否满
        if (isFull()) {
            System.out.println("栈满");
            return;
        }
//        top++;
        stack[++top] = value;
    }

    //出栈-pop,将栈顶的数据返回，pop--
    public int pop() {
        //先判断是否空
        if (isEmpty()) {
            //抛出异常
            throw new RuntimeException("栈空");
        }
        int value = stack[top--];
//        top--;
        return value;
    }

    //遍历栈的情况,遍历时需要从栈顶开始显示
    public void list() {
        if (isEmpty()) {
            System.out.println("栈空");
            return;
        }
        for (int i = top; i >= 0; i--) {
            System.out.printf("stack[%d]=%d\n", i, stack[i]);

        }
    }
}


```java
在这里插入代码片