二维数组中的查找某个target—二分法查找

23. 合并K个排序链表

合并 k 个排序链表，返回合并后的排序链表。请分析和描述算法的复杂度。

示例:

输入:
[
1->4->5,
1->3->4,
2->6
]
输出: 1->1->2->3->4->4->5->6
原题链接

# 23. 合并K个排序链表
class ListNode:
    def __init__(self, x):
        self.val = x
        self.next = None
class Solution:
    def mergeKLists(self, lists: List[ListNode]) -> ListNode:
        import heapq
        que , curs = [] , [] # curs存K个链表滑动的头指针
        for index, node in enumerate(lists):
                if node!=None:
                    heapq.heappush(que ,(node.val, index))
                curs.append(node)

        dummy_node = ListNode(-1)
        cur = dummy_node
        while que:
            val, index =  heapq.heappop(que)
            cur.next = lists[index]
            cur = cur.next
            lists[index] = lists[index].next
            if lists[index] != None:
                heapq.heappush(que, (lists[index].val, index))
        return dummy_node.next