LeetCode 25 K个一组翻转链表

Posted 2021-12-14 Starzkg

https://leetcode-cn.com/problems/reverse-nodes-in-k-group/

解决方案

class Solution 
    public ListNode reverseKGroup(ListNode head, int k) 
        return reverseKGroup(head, head, k, 1);
    

    public ListNode reverseKGroup(ListNode head, ListNode tail, int k, int k0) 
        if (tail == null) 
            return head;
        
        if (k0 % k == 0) 
            ListNode nex = reverseKGroup(tail.next, tail.next, k, k0 + 1);
            ListNode prev = head;
            ListNode now = head.next;
            while (prev != tail) 
                ListNode next = now.next;
                now.next = prev;
                prev = now;
                now = next;
            
            head.next = nex;
            return tail;
        
        return reverseKGroup(head, tail.next, k, k0 + 1);