diff --git a/高频面试系列/k个一组反转链表.md b/高频面试系列/k个一组反转链表.md index a338879..a637312 100644 --- a/高频面试系列/k个一组反转链表.md +++ b/高频面试系列/k个一组反转链表.md @@ -175,8 +175,51 @@ private: ![labuladong](../pictures/labuladong.jpg) + +[KAGAWA317](https://github.com/KAGAWA317) 提供Python3解法代码: + +```python +# 反转区间 [a, b) 的元素 +def reverse(a, b): + pre = None + cur = a + while cur != b: + cur.next, pre, cur = pre, cur, cur.next + return pre +``` + +[KAGAWA317](https://github.com/KAGAWA317) 提供Python3解法代码: + +```python +class Solution: + def reverseKGroup(self, head: ListNode, k: int) -> ListNode: + if not head: + return + # 区间 [a, b) 包含 k 个待反转元素 + a = b = head + for _ in range(k): + # 不足 k 个,不需要反转,base case + if not b: + return head + b = b.next + + # 反转区间 [a, b) 的元素 + def reverse(a, b): + pre = None + cur = a + while cur != b: + cur.next, pre, cur = pre, cur, cur.next + return pre + + # 反转前 k 个元素 + newHead = reverse(a, b) + # 递归反转后续链表并连接起来 + a.next = self.reverseKGroup(b, k) + return newHead +``` + [上一篇:如何寻找最长回文子串](../高频面试系列/最长回文子串.md) [下一篇:如何判定括号合法性](../高频面试系列/合法括号判定.md) -[目录](../README.md#目录) +[目录](../README.md#目录) \ No newline at end of file