解题思路:
    1、向后遍历节点,找到符合要求的left节点,开始翻转
    2、用right节点,计算翻转的数据
    3、遍历翻转区间的数据,使得数据转移

    1. var reverseBetween = function(head, left, right) {
    2. let preNode = new ListNode(null)
    3. preNode.next = head
    4. //找到left和pre结点
    5. for (let i = 0; i < left - 1; i++) {
    6. preNode = preNode.next
    7. }
    8. let leftNode = preNode.next
    9. for (let i = 0; i < right - left; i++) {
    10. let dummy = preNode.next
    11. let lnext = leftNode.next
    12. preNode.next = leftNode.next
    13. leftNode.next = lnext.next
    14. lnext.next = dummy
    15. }
    16. return left===1?preNode.next:head
    17. };