leetcode_c++：链表：Rotate List(061)

Given a list, rotate the list to the right by k places, where k is non-negative.

For example:
Given 1->2->3->4->5->NULL and k = 2,
return 4->5->1->2->3->NULL.

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算法

O（n）

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class Solution {public:    ListNode* rotateRight(ListNode* head, int k) {        if(!head||k<-0)            return head;        //find the length of the list        int len=1;        ListNode* p=head;        while(p->next!=NULL){            p=p->next;            len++;        }        //connect the tail to head        p->next = head;        //find the lefy place(k>len)        k=len-k%len;        //find the place        for(int i=0;i<k;i++)            p=p->next;        //break the list        head = p->next;        p->next=NULL;        return head;    }};