android 堆栈 数组,用数组实现堆栈

public class ArrayStackDemo {

public static void main(String[] args) {

ArrayStack stack = new ArrayStack(5);

String key;

boolean loop = true;

Scanner scanner = new Scanner(System.in);

while (loop) {

System.out.println("===================");

System.out.println("请输入下列指令");

System.out.println("show: 展示栈内容");

System.out.println("pop: 出栈");

System.out.println("peek: 显示栈顶");

System.out.println("push: 入栈");

System.out.println("exit: 退出程序");

System.out.println("===================");

key = scanner.next();

switch (key) {

case "show":

stack.show();

break;

case "push":

System.out.println("输入一个数");

int value = scanner.nextInt();

stack.push(value);

break;

case "peek":

try {

System.out.println("栈顶数值是:" + stack.peek());

} catch (Exception e) {

System.out.println(e.getMessage());

}

break;

case "pop":

try {

int v = stack.pop();

System.out.println("出栈数值: " + v);

} catch (Exception e) {

System.out.println(e.getMessage());

}

break;

case "exit":

scanner.close();

loop = false;

break;

default:

break;

}

}

System.out.println("Exit app successfully!");

}

}

class ArrayStack {

private int size;

private int[] arr;

private int top;

public ArrayStack(int size) {

this.size = size;

arr = new int[size];

top = -1;

}

public boolean isEmpty() {

return top == -1;

}

public boolean isFull() {

return top == size - 1;

}

public void push(int n) {

if (isFull()) {

System.out.println("栈已满，无法继续push!");

return;

}

arr[++top] = n;

}

public int pop() {

if (isEmpty()) {

throw new RuntimeException("栈是空的，pop失败！");

}

return arr[top--];

}

public int peek() {

if (isEmpty()) throw new RuntimeException("栈是空的，peek失败！");

return arr[top];

}

public void show() {

if (isEmpty()) {

System.out.println("栈是空的，show不出来");

return;

}

for (int i = top; i >= 0; i--) {

System.out.println(arr[i]);

}

System.out.println();

}

}