Java 头结点型和头指针型单链表

小咪咪 2022-11-21 09:29 127阅读 0赞

带头结点的单链表List

import java.util.Scanner;
    class List{
        
    	int data;
    	List next;
    	List(int x){
         data = x;}
    	void append() {
        
    		List tail,p;
    		Scanner sc = new Scanner(System.in);
    		System.out.println("请输入一组数，以-1结尾：");
    		int x = sc.nextInt();
    		tail = this; //tail = head; this代表对象自己，就是头结点
    		while(x != -1) {
        
    			p = new List(x);
    			tail.next = p;
    			tail = p;
    			x = sc.nextInt();
    		}
    	}
    	void print() {
        
    		for(List p=this.next; p!=null; p=p.next)
    			System.out.print(p.data+" ");
    	}
    }
    class App{
        
    	public static void main(String [] args) {
        
    		List h = new List(0);
    		h.append();
    		h.print();
    	}
    }

头指针型的单链表List1

import java.util.Scanner;
    class List1{
        
    	int data;
    	List1 next;
    	List1(int x){
         data = x;}
    	List1 append() {
         //区别带头结点型
    		List1 tail,p;
    		Scanner sc = new Scanner(System.in);
    		System.out.println("请输入一组数，以-1结尾：");
    		int x = sc.nextInt();     //区别带头结点型
    		if(x == -1) return null;  //
    		this.data = x;            //
    		
    		x = sc.nextInt();
    		tail = this;
    		while(x != -1) {
        
    			p = new List1(x);
    			tail.next = p;
    			tail = p;
    			x = sc.nextInt();
    		}
    		return this;
    	}
    	void print() {
        
    		for(List1 p=this; p!=null; p=p.next) //区别
    			System.out.print(p.data+" ");
    	}
    }
    class App{
        
    	public static void main(String [] args) {
        
    		List1 h = new List1(0);
    		h = h.append(); //
    		if(h == null)   //先判断，若直接h.print()，h为空时会报错
    			System.out.print("为空！");
    		else
    			h.print();
    	}
    }

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L20wXzQ2NTI3NTAz_size_16_color_FFFFFF_t_70_pic_center]  
//本例掌握：

1.  this不得不用的场合，tail=this;即单链表中，表达【表头】自己
2.  构造函数的作用：不是构造，而是初始化（构造，即分配空间，由new实现，空间大小由构造函数名决定）。

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