LeetCode 61. Rotate List
c++
/**
* Definition for singly-linked list.
* struct ListNode {
* int val;
* ListNode *next;
* ListNode(int x) : val(x), next(NULL) {}
* };
*/
class Solution {
public:
ListNode* rotateRight(ListNode* head, int k) {
if(head==NULL)
return head;
if(k==0)
return head;
ListNode* end ;
ListNode* start = head;
ListNode* pre;
ListNode* term =head;
int len=1;
while(head->next!=NULL)
{
head = head->next;
len++;
}
if(len==1)
return head;
end = head;
int n = k%len;
if(n==0)
return start;
int m = len-n;
head = start;
int i=0;
while(head!=NULL)
{
if(i==m)
{
start = head;
break;
}
if(i==m-1)
{
pre=head;
}
i++;
head=head->next;
}
pre->next=NULL;
end->next=term;
return start;
}
};