package ch03;

public class MyStack {
    // 底層實現是一個數組
    private long[] arr;
    private int top;

    /**
     * 默認的構造方法
     */
    public MyStack() {
        arr = new long[10];
        top = -1;
    }

    /**
     * 帶參數構造方法，參數為數組初始化大小
     */
    public MyStack(int maxsize) {
        arr = new long[maxsize];
        top 
 
= -1;
    }

    /**
     * 添加數據
     */
    public void push(int value) {
        arr[++top] = value;
    }

    /**
     * 移除數據
     */
    public long pop() {
        return arr[top--];
    }

    /**
     * 查看數據
     */
    public long peek() {
        return arr[top];
    }

    /**
     * 判斷是否為空
     
 
*/
    public boolean isEmpty() {
        return top == -1;
    }

    /**
     * 判斷是否滿了
     */
    public boolean isFull() {
        return top == arr.length - 1;
    }
}

package ch03;

public class TestMyStack {
    public static void main(String[] args) {
        MyStack ms = new MyStack(4);
        ms.push(
 
23);
        ms.push(12);
        ms.push(1);
        ms.push(90);
        System.out.println(ms.isEmpty());
        System.out.println(ms.isFull());
        
        System.out.println(ms.peek());
        System.out.println(ms.peek());
        
        while(!ms.isEmpty()) {
            System.out.print(ms.pop() + ",");
        }
        
        System.out.println(ms.isEmpty());
        System.out.println(ms.isFull());
    }
}

棧（Java實現）