题解 | #链表内指定区间反转#
链表内指定区间反转
https://www.nowcoder.com/practice/b58434e200a648c589ca2063f1faf58c
using System; using System.Collections.Generic; /* public class ListNode { public int val; public ListNode next; public ListNode (int x) { val = x; } } */ class Solution { /** * 代码中的类名、方法名、参数名已经指定,请勿修改,直接返回方法规定的值即可 * * * @param head ListNode类 * @param m int整型 * @param n int整型 * @return ListNode类 */ public ListNode reverseBetween (ListNode head, int m, int n) { // write code here if (head == null) return null; if (m > n) return head; int nCount = 0; ListNode lnRtnL, lnRtn, lnRtnR; lnRtnR = lnRtnL = lnRtn = new ListNode(0); while (head != null) { nCount++; if (nCount >= m && nCount <= n) { ListNode ln = lnRtnL.next; lnRtnL.next = head; head = head.next; lnRtnL.next.next = ln; if (lnRtnR.next != null) lnRtnR = lnRtnR.next; } else { ListNode ln = lnRtnR.next; lnRtnR.next = head; head = head.next; lnRtnR = lnRtnR.next; lnRtnR.next = null; lnRtnL = lnRtnR; } } return lnRtn.next; } }