题解 | #合并有序链表#

'''
解题思路：
1、读入两个链表合成一个list再由大小到排序
2、对输出链表向尾向头赋值，引入一个临时变量next，尾部时next=None, 后续next=cur
'''
# class ListNode:
#     def __init__(self, x):
#         self.val = x
#         self.next = None

#
# 
# @param l1 ListNode类 
# @param l2 ListNode类 
# @return ListNode类
#
class Solution:
    def mergeTwoLists(self , l1 , l2 ):
        # write code here
        if l1==None and l2==None:
            return None

        tmp = []
        while l1:
            tmp.append(l1.val)
            l1 = l1.next
        while l2:
            tmp.append(l2.val)
            l2 = l2.next

        tmp = sorted(tmp,reverse=1)
        n = len(tmp)
        next = None
        for i in range(n):
            cur = ListNode(tmp[i])
            cur.next = next
            next = cur

        return cur