Given the head of a linked list, rotate the list to the right by k places.
Example 1:
Input: head = [1,2,3,4,5], k = 2
Output: [4,5,1,2,3]
Example 2:
Input: head = [0,1,2], k = 4
Output: [2,0,1]
Constraints:
The number of nodes in the list is in the range [0, 500].
-100 <= Node.val <= 100
0 <= k <= 2 * 109
Solution:1
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28/**
* Definition for singly-linked list.
* public class ListNode {
* int val;
* ListNode next;
* ListNode() {}
* ListNode(int val) { this.val = val; }
* ListNode(int val, ListNode next) { this.val = val; this.next = next; }
* }
*/
class Solution {
public ListNode rotateRight(ListNode head, int k) {
if (head == null) return null;
int len = 1;
ListNode newHead = head;
while (newHead.next != null) {
newHead = newHead.next;
len++;
}
newHead.next = head;
for (int i = len-k % len; i > 1; i--) {
head = head.next;
}
newHead = head.next;
head.next = null;
return newHead;
}
}