[LeetCode] Rotate List 单项链表旋转

 1 #include <iostream>
 2 using namespace std;
 3 
 4 /**
 5  * Definition for singly-linked list.
 6  */
 7 struct ListNode {
 8     int val;
 9     ListNode *next;
10     ListNode(int x) : val(x), next(NULL) {}
11 };
12 
13 class Solution {
14 public:
15     ListNode *rotateRight(ListNode *head, int k) {
16         if(head==NULL||k==0)  return head;
17         int cnt =0;
18         ListNode * first=head,*slow=head;
19         while(cnt<k){
20             if(first==NULL) first = head;
21             first=first->next;
22             cnt++;
23         }
24         if(first==NULL) return head;
25         while(first->next!=NULL){
26             first=first->next;
27             slow=slow->next;
28         }
29         first->next=head;
30         head = slow->next;
31         slow->next = NULL;
32         return head;
33     }
34 };
35 
36 int main()
37 {
38 
39     return 0;
40 }