Merge k sorted linked lists and return it as one sorted list. Analyze and describe its complexity.

Example:

Input:
[
  1->4->5,
  1->3->4,
  2->6
]
Output: 1->1->2->3->4->4->5->6

題目大意就是給定多個已經排序的鏈表合並成一個排序的鏈表，我這裏是將多個鏈表的值遍歷添加到一個鏈表中，然後重新組織鏈表。復雜多比較高
代碼如下：

class Solution:
    
 
def mergeKLists(self, lists):
        if lists == []:
            return None
        link = []
        for i in lists:
            while i != None:
                link.append(i.val)
                if i.next == None:
                    break
                i = i.next
        link = sorted(link)
        
 
print(link)
        if len(link) == 0:
            return None
        out = [ListNode(link[0])]
        for i in range(1, len(link)):
            out.append(ListNode(link[i]))
            out[i - 1].next = out[i]

        out.append(ListNode(link[-1]))
        return out[0]

LeetCode算法題python解法：23. Merge k Sorted Lists