# 61. Rotate List (Medium)

https://leetcode.com/problems/rotate-list/

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

Example 1:

```Input: 1->2->3->4->5->NULL, k = 2
Output: 4->5->1->2->3->NULL
Explanation:
rotate 1 steps to the right: 5->1->2->3->4->NULL
rotate 2 steps to the right: 4->5->1->2->3->NULL
```

Example 2:

```Input: 0->1->2->NULL, k = 4
Output: `2->0->1->NULL`
Explanation:
rotate 1 steps to the right: 2->0->1->NULL
rotate 2 steps to the right: 1->2->0->NULL
rotate 3 steps to the right: `0->1->2->NULL`
rotate 4 steps to the right: `2->0->1->NULL````

## Solutions

``````class Solution {
public ListNode rotateRight(ListNode head, int k) {
}

// For convenience, create a dummy node that doesn't belong to the give ListNode.
ListNode dummy = new ListNode(-1);

ListNode endP = dummy;
ListNode kthP = dummy;

int len;

// Get the total length of the list
for (len = 0; endP.next != null; len++) {
endP = endP.next;
}

// Get the (len - k%len)th node
for (int j = len - (k % len); j > 0; j--) {
kthP = kthP.next;
}

// Rotate the list
endP.next = dummy.next;
dummy.next = kthP.next;
kthP.next = null;

return dummy.next;
}
}
``````