21. Merge Two Sorted Lists# Definition for singly-linked list.# class ListNode:# def __init__(self, val=0, next=None):# self.val = val# self.next = nextclass Solution: def mergeTwoLists(self, list1: Optional[ListNode], list2: Optional[ListNode]) -> Optional[ListNode]: dummy = ListNode() cur = dummy # for l1, l2 in range(min(len(list1), len(list2))): ❌ ..