题目信息

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问题解答

https://leetcode-cn.com/submissions/detail/118746750/
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  1. function swapPairs(head: ListNode | null): ListNode | null {
  2.     const dummyHead = new ListNode()
  3.     dummyHead.next = head
  4.     let pre = dummyHead
  6.     while(head && head.next) {
  7.         let next = head.next
  9.         //完成一次交换
  10.         head.next = next.next
  11.         next.next = head
  12.         pre.next = next
  14.         pre = head
  15.         head = head.next
  16.     }
  17.     return dummyHead.next
  18. };