题目:原题链接(简单)
标签:链表
| 解法 | 时间复杂度 | 空间复杂度 | 执行用时 | 
| Ans 1 (Python) | O ( N 1 + N 2 ) | O ( 1 ) | 48ms (99.67%) | 
| Ans 2 (Python) | |||
| Ans 3 (Python) | 
解法一:

class Solution:
    def mergeTwoLists(self, l1: ListNode, l2: ListNode) -> ListNode:
        ans = node = ListNode(0)
        while l1 and l2:
            if l1.val <= l2.val:
                node.next = l1
                node = node.next
                l1 = l1.next
            else:
                node.next = l2
                node = node.next
                l2 = l2.next
        if l1 or l2:
            node.next = l1 or l2
        return ans.next









