java实现栈

Posted 2022-11-23 大数据最好

/**
 * Created by murphy on 2016/7/4.
 */
public class Stack 
    private int DEFAULT_SIZE=12;
    private int[] arr;
    private int count=0;

    public Stack(int size)
        arr=new int[size];
    
    public Stack()
        arr=new int[DEFAULT_SIZE];
    

    public void push(int val)
        arr[count++]=val;
    
    public int pop()
        int temp=arr[count-1];
        count--;
        return temp;
    
    public int peek()
        return arr[count-1];
    
    public int size()
        return count;
    

    public boolean isEmpty()
        return count == 0;
    
    public static void main(String[] args)
        Stack stack = new Stack();
        stack.push(10);

        stack.push(20);

        stack.push(30);

        System.out.println(stack.peek());
        System.out.println(stack.pop());
        System.out.println(stack.pop());
        System.out.println(stack.size());
        System.out.println(stack.isEmpty());
        System.out.println(stack.pop());
        System.out.println(stack.isEmpty());