LeetCode 92.反转链表II

题目：

给你单链表的头指针?head?和两个整数?left?和?right?，其中?left <= right?。请你反转从位置?left?到位置?right?的链表节点，返回?反转后的链表?。

方法：灵神 反转链表

代码：

class Solution {
    public ListNode reverseBetween(ListNode head, int left, int right) {
        ListNode dummy = new ListNode(0, head), p0 = dummy;
        int n = left - 1;
        while (n-- > 0) {
            p0 = p0.next; // p0 保存开始翻转的前一个节点，后面操作需要用到
        }
        ListNode pre = null, cur = p0.next;
        for (int i = 0; i < (right - left + 1); i++) {
            ListNode next = cur.next;
            cur.next = pre;
            pre = cur;
            cur = next;
        }
        p0.next.next = cur;
        p0.next = pre;
        return dummy.next;
    }
}