diff --git a/problems/0206.翻转链表.md b/problems/0206.翻转链表.md index 45196386..08495259 100644 --- a/problems/0206.翻转链表.md +++ b/problems/0206.翻转链表.md @@ -371,6 +371,45 @@ func reverse(pre: ListNode?, cur: ListNode?) -> ListNode? { } ``` +C: +双指针法: +```c +struct ListNode* reverseList(struct ListNode* head){ + //保存cur的下一个结点 + struct ListNode* temp; + //pre指针指向前一个当前结点的前一个结点 + struct ListNode* pre = NULL; + //用head代替cur,也可以再定义一个cur结点指向head。 + while(head) { + //保存下一个结点的位置 + temp = head->next; + //翻转操作 + head->next = pre; + //更新结点 + pre = head; + head = temp; + } + return pre; +} +``` + +递归法: +```c +struct ListNode* reverse(struct ListNode* pre, struct ListNode* cur) { + if(!cur) + return pre; + struct ListNode* temp = cur->next; + cur->next = pre; + //将cur作为pre传入下一层 + //将temp作为cur传入下一层,改变其指针指向当前cur + return reverse(cur, temp); +} + +struct ListNode* reverseList(struct ListNode* head){ + return reverse(NULL, head); +} +``` + ----------------------- * 作者微信:[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw) * B站视频:[代码随想录](https://space.bilibili.com/525438321)