動機

直接用23的解就ok了

Problem

Merge two sorted linked lists and return it as a sorted list. The list should be made by splicing together the nodes of the first two lists.

 

Example 1:

Input: l1 = [1,2,4], l2 = [1,3,4]Output: [1,1,2,3,4,4]

Example 2:

Input: l1 = [], l2 = []Output: []

Example 3:

Input: l1 = [], l2 = [0]Output: [0]

 

Constraints:

  • The number of nodes in both lists is in the range [0, 50].
  • -100 <= Node.val <= 100
  • Both l1 and l2 are sorted in non-decreasing order.

Sol

class Solution:
    def mergeKLists(self, lists: List[ListNode]) -> ListNode:
        lists = [x for x in lists if x]
        ret = cur = ListNode()
        while lists:
            tmp = min(enumerate(lists), key=lambda x: x[1].val)
            cur.next = tmp[1]
            cur = cur.next
            
            if lists[tmp[0]].next is None:
                del lists[tmp[0]]
            else:
                lists[tmp[0]] = lists[tmp[0]].next
        return ret.next
    def mergeTwoLists(self, l1: ListNode, l2: ListNode) -> ListNode:
        return self.mergeKLists([l1,l2])