Leetcode题解

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.

链接

先遍历一次链表找到链表长度，根据要翻转的K个位置来确定此时表头，即len-k+1
从表尾开始查找，找到表头即可。

class Solution {public:    ListNode* rotateRight(ListNode* head, int k) {        if(!head) return head;        int len=1;        ListNode *newH, *tail;        newH=tail=head;        while(tail->next)        {            tail = tail->next;            len++;        }        tail->next = head;        if(k %= len)         {            for(auto i=0; i<len-k; i++) tail = tail->next;        }        newH = tail->next;         tail->next = NULL;        return newH;    }};