LeetCode 206-Reverse Linked List

/**
 * Definition for singly-linked list.
 * public class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode(int x) { val = x; }
 * }
 */
public class Solution {
    public ListNode reverseList(ListNode head) {
        if(head==null){
            return null;
        }
        ListNode left ,middle,right;
        left=head;
        middle=left.next;
        if(middle==null){
        	return left;
        }
        right=middle.next;
        left.next=null;
        while(right!=null){
    	  
    	   middle.next=left;
    	   left=middle;
    	   middle=right;
    	   right=middle.next;
    	   
       }
        middle.next=left;
        
		return middle;
        
        
    }
}