Rotate a List Right by a Large Count

### Problem Rotate a singly linked list to the right by `k` positions and return its resulting head. One right rotation moves the last node to the front. Preserve the list order induced by those rotations. The source uses `ListNode`, with `int val` and `ListNode* next` fields: ```cpp ListNode* rotateRight(ListNode* head, int k); ``` Square brackets in the examples display node values along the chain; they do not replace the pointer interface. ### Examples ```text Input: head = [9,2,7,4], k = 6 Output list: [7,4,9,2] ``` Six right rotations have the same effect as two for this four-node list. ```text Input: head = [5,8], k = 0 Output list: [5,8] ``` ### Constraints - The list contains between 0 and 500 nodes. - Node values are between -100 and 100, inclusive. - `0 <= k <= 2000000000`. - Return a list head, not a flattened value array.