如何使用LinkedList实现栈和队列结构

一时失言乱红尘 2024-02-05 11:41 25阅读 0赞

#### 如何使用LinkedList实现栈和队列结构 ####

*  利用现有LinkedList中现有方法实现
 *  形成类的形式

## 利用现有LinkedList中现有方法实现 ##

使用LinkedList的addFirt作为栈的push操作，removeFirst作为栈的pop操作，具体代码如下：

import java.util.LinkedList;
    
    public class Main {
        
        public static void main(String[] args) {
        
            LinkedList<String> stack = new LinkedList<>();
            stack.addFirst("第1个");
            stack.addFirst("第2个");
            stack.addFirst("第3个");
            System.out.println(stack.removeFirst());
            System.out.println(stack.removeFirst());
            System.out.println(stack.removeFirst());
        }
    }

## 形成类的形式 ##

import java.util.LinkedList;
    
    public class Main {
        
        public static void main(String[] args) {
        
            LinkedStack stack = new LinkedStack();
    
            stack.push(1);
            stack.push(2);
            stack.push(3);
    
            System.out.println("Pop: " + stack.pop());
            System.out.println("Pop: " + stack.pop());
            System.out.println("Pop: " + stack.pop());
        }
    }
    
    class Node{
        
        int data;
        Node next;
        public Node(int data){
        
            this.data = data;
            this.next = null;
        }
    }
    
    class LinkedStack{
        
        private LinkedList<Node> linkedList;
    
        public LinkedStack(){
        
            linkedList = new LinkedList<>();
        }
    
        // 入栈操作
        public void push(int data){
        
            Node newNode = new Node(data);
            linkedList.addFirst(newNode);
        }
    
        // 出栈操作
        public int pop(){
        
            if(linkedList.isEmpty()){
        
                throw new IllegalStateException("Stack is empty");
            }
            Node poppedNode = linkedList.removeFirst();
            return poppedNode.data;
        }
    
        // 查看栈顶元素但不出栈
        public int peek() {
        
            if (linkedList.isEmpty()) {
        
                throw new IllegalStateException("Stack is empty");
            }
            return linkedList.getFirst().data;
        }
    }