24 https://leetcode.com/problems/swap-nodes-in-pairs/ 가져와서 구현해준다. https://leetcode.com/problems/swap-nodes-in-pairs/discuss/œ/Python-or-Dummynode에 좋은 풀이가 있다. 내 답은 드러워서 안적음 class Solution: def swapPairs(self, head: Optional[ListNode]) -> Optional[ListNode]: dummy = p = ListNode(0) dummy.next = head while head and head.next: tmp = head.next head.next = tmp.next tmp.next = head p.next = tmp head = ..