class Solution:
    def mergeKLists(self, lists: List[ListNode]) -> ListNode:
        heap = []
        for each in lists: #遍历所有值加入堆中
            while each:
                heapq.heappush(heap, each.val)
                each = each.next
        head = ne = ListNode()
        while heap: #遍历堆中值加入到listnode里
            t = ListNode(heapq.heappop(heap))
            ne.next = t
            ne = ne.next

        return head.next