Merge Two Sorted Lists LeetCode solution in Python

1
# Runtime: 43 ms (Top 67.2%) | Memory: 16.18 MB (Top 97.5%)
2

3

4
class Solution:
5
    def mergeTwoLists(
6
        self, list1: Optional[ListNode], list2: Optional[ListNode]
7
    ) -> Optional[ListNode]:
8
        cur = dummy = ListNode()
9
        while list1 and list2:
10
            if list1.val < list2.val:
11
                cur.next = list1
12
                list1, cur = list1.next, list1
13
            else:
14
                cur.next = list2
15
                list2, cur = list2.next, list2
16

17
        if list1 or list2:
18
            cur.next = list1 if list1 else list2
19

20
        return dummy.next