Given two sorted linked lists, merge them so that the resulting linked list is also sorted.
Solution
Python 3
class Solution:
def mergeTwoLists(self, list1: Optional[ListNode], list2: Optional[ListNode]) -> Optional[ListNode]:
cur = dummy = ListNode()
while list1 and list2:
if list1.val < list2.val:
cur.next = list1
list1, cur = list1.next, list1
else:
cur.next = list2
list2, cur = list2.next, list2
if list1 or list2:
cur.next = list1 if list1 else list2
return dummy.next