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;
}
}
?
原文:http://hcx2013.iteye.com/blog/2221312