题解 | #重排链表#

个人感觉不存在 时间复杂度 n 和空间复杂度l 同时存在，以下1.5n也是超出了n

public void reorderList(ListNode head) {
        if (head == null){
            return;
        }
        ListNode h = head;
        ListNode mid =head;
        while (h.next != null && h.next.next != null){
            h = h.next.next;
            mid = mid.next;
        }
        ListNode midH = mid;
        while (midH.next != null){
            ListNode midN = midH.next;
            midH.next = midN.next;
            midN.next = mid;
            mid = midN;
        }
        h = head;
        while (h != null && mid.next != null){
            ListNode temp = mid.next;
            mid.next = h.next;
            h.next = mid;
            h = mid.next;
            mid = temp;
        }
    }