zcq

    1. package com.atguigu.stack;
    3. import java.util.Scanner;
    5. public class ArrayStackDemo {
    7.     public static void main(String[] args) {
    8.         //测试一下ArrayStack 是否正确
    9.         //先创建一个ArrayStack对象->表示栈
    10.         ArrayStack stack = new ArrayStack(4);
    11.         String key = "";
    12.         boolean loop = true; //控制是否退出菜单
    13.         Scanner scanner = new Scanner(System.in);
    15.         while(loop) {
    16.             System.out.println("show: 表示显示栈");
    17.             System.out.println("exit: 退出程序");
    18.             System.out.println("push: 表示添加数据到栈(入栈)");
    19.             System.out.println("pop: 表示从栈取出数据(出栈)");
    20.             System.out.println("请输入你的选择");
    21.             key = scanner.next();
    22.             switch (key) {
    23.             case "show":
    24.                 stack.list();
    25.                 break;
    26.             case "push":
    27.                 System.out.println("请输入一个数");
    28.                 int value = scanner.nextInt();
    29.                 stack.push(value);
    30.                 break;
    31.             case "pop":
    32.                 try {
    33.                     int res = stack.pop();
    34.                     System.out.printf("出栈的数据是 %d\n", res);
    35.                 } catch (Exception e) {
    36.                     // TODO: handle exception
    37.                     System.out.println(e.getMessage());
    38.                 }
    39.                 break;
    40.             case "exit":
    41.                 scanner.close();
    42.                 loop = false;
    43.                 break;
    44.             default:
    45.                 break;
    46.             }
    47.         }
    49.         System.out.println("程序退出~~~");
    50.     }
    52. }
    54. //定义一个 ArrayStack 表示栈
    55. class ArrayStack {
    56.     private int maxSize; // 栈的大小
    57.     private int[] stack; // 数组，数组模拟栈，数据就放在该数组
    58.     private int top = -1;// top表示栈顶，初始化为-1
    60.     //构造器
    61.     public ArrayStack(int maxSize) {
    62.         this.maxSize = maxSize;
    63.         stack = new int[this.maxSize];
    64.     }
    66.     //栈满
    67.     public boolean isFull() {
    68.         return top == maxSize - 1;
    69.     }
    70.     //栈空
    71.     public boolean isEmpty() {
    72.         return top == -1;
    73.     }
    74.     //入栈-push
    75.     public void push(int value) {
    76.         //先判断栈是否满
    77.         if(isFull()) {
    78.             System.out.println("栈满");
    79.             return;
    80.         }
    81.         top++;
    82.         stack[top] = value;
    83.     }
    84.     //出栈-pop, 将栈顶的数据返回
    85.     public int pop() {
    86.         //先判断栈是否空
    87.         if(isEmpty()) {
    88.             //抛出异常
    89.             throw new RuntimeException("栈空，没有数据~");
    90.         }
    91.         int value = stack[top];
    92.         top--;
    93.         return value;
    94.     }
    95.     //显示栈的情况[遍历栈]， 遍历时，需要从栈顶开始显示数据
    96.     public void list() {
    97.         if(isEmpty()) {
    98.             System.out.println("栈空，没有数据~~");
    99.             return;
    100.         }
    101.         //需要从栈顶开始显示数据
    102.         for(int i = top; i >= 0 ; i--) {
    103.             System.out.printf("stack[%d]=%d\n", i, stack[i]);
    104.         }
    105.     }
    107. }