leetcode-21-merge-two-lists

将两个有序链表合并为一个新的有序链表并返回。新链表是通过拼接给定的两个链表的所有节点组成的。 

示例：

输入：1->2->4, 1->3->4
输出：1->1->2->3->4->4

Solution

# Definition for singly-linked list.
# class ListNode(object):
#     def __init__(self, x):
#         self.val = x
#         self.next = None

class Solution(object):
    def mergeTwoLists(self, l1, l2):
        """
        :type l1: ListNode
        :type l2: ListNode
        :rtype: ListNode
        """
        res = ListNode(0)
        tmp = res
        while l1 and l2:
            if l1.val < l2.val:
                tmp.next, l1 = l1, l1.next
            else:
                tmp.next, l2 = l2, l2.next
            tmp = tmp.next

        if l1: tmp.next = l1
        else: tmp.next = l2

        return res.next