java栈的模拟实现

不念不忘少年蓝@ 2024-03-17 11:24 33阅读 0赞

## 栈的模拟实现 ##

![在这里插入图片描述][7dbcf983a5a641d08edb76ad7f6268b4.png]  
从上图中可以看到，Stack继承了Vector，Vector和ArrayList类似，都是动态的顺序表，不同的是Vector是线程安 全的。  
所以栈的底层就是一个输入输出限制的动态顺序表

模拟实现主要定义三个类  
![在这里插入图片描述][a10bc08e6b034f3fa72facfd06b96a2e.png]  
MyStack 用于栈相关的成员变量和方法的定义，Test类提供主程序入口和测试，EmptyException类用于栈空时错误的定义

**EmptyException**

public class EmptyException extends RuntimeException{
        
        public EmptyException(String message) {
        
            super(message);
        }
    
        public EmptyException() {
        
    
        }
    }

**MyStack**

import java.util.ArrayList;
    import java.util.Arrays;
    public class MyStack {
        
        public int[] elem;
        public  int usesize;
    
        public MyStack() {
        
            this.elem = new int[10];
        }
    
        //压栈
        public void push(int data){
        
            if(this.isFull()){
        
                elem = Arrays.copyOf(elem,2*elem.length);
            }
            elem[usesize] = data;
            usesize++;
        }
        //判满
    
        public boolean isFull(){
        
            return this.usesize == elem.length;
        }
    
        //出栈
        public int pop(){
        
            if(isEmpty()){
        
                throw new EmptyException("栈为空，不能出栈");
            }
            this.usesize--;
            return elem[usesize];
        }
        //判空
        public boolean isEmpty(){
        
            if(this.usesize == 0){
        
                return true;
            }
            return false;
    
        }
        //获取栈顶元素值
        public int peek(){
        
            if(isEmpty()){
        
                throw new EmptyException("栈为空");
            }
            int ret = usesize-1;
            return elem[ret];
        }
    
        public void display(){
        
            for (int i = 0; i < usesize ;i++) {
        
                System.out.print(this.elem[i] + " ");
            }
            System.out.println();
        }
    }

**Test**

import java.util.Stack;
    
    public class Test {
        
        public static void main(String[] args) {
        
            MyStack myStack = new MyStack();
            myStack.push(1);//压栈
            myStack.push(2);
            myStack.push(3);
            myStack.display();
            Integer a = myStack.pop();//出栈
            myStack.display();
            Integer  b = myStack.peek();//获取栈顶元素
            System.out.println(b);
            myStack.display();
        }
    }

至此栈的模拟实现就简单介绍到这

[7dbcf983a5a641d08edb76ad7f6268b4.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/17/5b5fb606409347cdb2afb6c933c00ec3.png
[a10bc08e6b034f3fa72facfd06b96a2e.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/17/8871d3b0c33c455eafc18fe0c48e1596.png