LeetCode Solutions : Rotate List

Given a list, rotate the list to the right by k places, where k is non-negative.

For example:

Given

1->2->3->4->5->NULL

and k =

2

,

return

4->5->1->2->3->NULL

.

/**
* Definition for singly-linked list.
* public class ListNode {
*     int val;
*     ListNode next;
*     ListNode(int x) {
*         val = x;
*         next = null;
*     }
* }
*/
public class Solution {
public ListNode rotateRight(ListNode head, int n) {
if(head==null||head.next==null)
return head;
ListNode rear=head;
int len=1;
while(rear.next!=null){
rear=rear.next;
len++;
}
rear.next=head;
int breakPoint=len-n%len;
rear=head;
int count=1;
while(count<breakPoint){
rear=rear.next;
count++;
}
head=rear.next;
rear.next=null;
return head;
}
}