package LeetCode;

public class LC_61 {
    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;
        }
    }

    public ListNode rotateRight(ListNode head, int k) {
        if (head == null) return null;
        if (head.next == null) return head;
        int len = 1;
        ListNode tmp = head;
        while (tmp.next != null) {
            tmp = tmp.next;
            len++;
        }
        int move = k % len;
        if (move == 0 || move == len) return head;
        ListNode slow = head;
        ListNode fast = head;
        for (int i = 0; i < move; i++) {
            fast = fast.next;
        }
        while (fast.next != null) {
            slow = slow.next;
            fast = fast.next;
        }
        ListNode newHead = slow.next;
        slow.next = null;
        fast.next = head;
        return newHead;
    }
}