[编程实现单链表逆转][java代码]

代码如下，核心的代码在于：

	public static  Node reverse(Node head) {
		if(head==null) {
			return null;
		}
		Node p = head;
		Node q = head.next;
		p.next=null; //这个必须的~~~，否则链表就成有环的了。
		while(q!=null) {
			Node temp = q.next;
			q.next = p;
			p = q;
			q = temp;
		}
		
		return p;
		
	}
	

 

 

 

 

整个程序如下所示：

 

package com.jy.list;

public class ReverseList {
	public static void main(String[] args) {
		Node head = add(null, "a");
		add(head, "b");
		add(head, "c");
		add(head, "d");
		add(head, "e");
		print(head);
		head = reverse(head);
		print(head);
	}
	
	public static  Node reverse(Node head) {
		if(head==null) {
			return null;
		}
		Node p = head;
		Node q = head.next;
		p.next=null; //这个必须的~~~，否则链表就成有环的了。
		while(q!=null) {
			Node temp = q.next;
			q.next = p;
			p = q;
			q = temp;
		}
		
		return p;
		
	}
	
	public static  Node add(Node head,String data) {
		if(head==null) {
			return new Node(data);
		} else {
			Node p = head;
			while(p.next!=null) {
				p = p.next;
			}
			p.next = new Node(data);
			return head;
		}
	}
	
	public static void print(Node head) {
		if(head==null) {
			System.out.println("null");
		}else {
			Node p = head;
			while(p!=null) {
				System.out.print(p.data+"\t");
				p = p.next;
			}
			System.out.print("\n");
		}
	}
}


class Node {
	public Node(String data2) {
		this.data = data2;
	}
	public String toString() {
		return data;
	};
	String data;
	Node next;
	
}