leetcode61

解题思路

很简单的思路，把链表合成环，然后遍历就好了

代码

/**
 * Definition for singly-linked list.
 * 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; }
 * }
 */
class Solution {
    public ListNode rotateRight(ListNode head, int k) {
        ListNode tmp=head;
        ListNode ans =head;
        int count = 0;
        if(head==null||head.next==null)
            return head;
        while(head.next!=null){
            ++count;
            head=head.next;
        }
        head.next=ans;
        ++count;
        while(k%count!=count-1){
            ++k;
            ans=ans.next;
        }
        tmp=ans.next;
        ans.next=null;
        ans=tmp;
        return ans;
    }
}