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; }
 * }
 */
public class Solution {
    public ListNode rotateRight(ListNode head, int k) {
    	if (head == null) {
    		return null;
    	}
        Stack<ListNode> stack = new Stack<ListNode>();
        ListNode node = head;
        while (node != null) {
        	stack.push(node);
        	node = node.next;
        }
        k = k%stack.size();
        if (k == 0) {
        	return head;
        }
        ListNode tail = stack.peek();
        for (int i = k; i > 0; i--) {
        	node = stack.pop();
        }
        stack.peek().next = null;
        tail.next = head;
        return node;
    }
}