基本思路:
1、链表向右循环k个位置,若k大于链表长度,则相当于向右循环k%len个位置。
2、循环的操作相当于不断将最尾节点摘到链表前。
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||k == 0)
return head;
ListNode *L = new ListNode(0);
L->next = head;
ListNode *p = head, *q = L;
int len = 1;
while (p->next != NULL){
len++;
p = p->next;
q = q->next;
}
k = k%len;
while (k--){
p->next = L->next;
L->next = p;
q->next = NULL;
while (p->next != q){
p = p->next;
}
ListNode *tmp = p;
p = q;
q = tmp;
}
return L->next;
}
};