Merge k sorted linked lists and return it as one sorted list. Analyze and describe its complexity.
与21. Merge Two Sorted Lists的拓展，这道题要合并k个有序链表，还是可以两两合并。
类似题目：
Merge k sorted linked lists and return it as one sorted list. Analyze and describe its complexity.
与21. Merge Two Sorted Lists的拓展，这道题要合并k个有序链表，还是可以两两合并。
类似题目：
[LeetCode] 23. Merge k Sorted Lists 合并k个有序链表
原文：https://www.cnblogs.com/lightwindy/p/8512912.html