21. Merge Two Sorted Lists Hardness: \(\color{green}\textsf{Easy}\) Ralated Topics: Linked List、Recursion 一、題目 You are given the heads of two sorted linked lists list1 and list2. Merge the two lists in a one sorted list. The list should be made by splicing together the nodes of the first two lists. Return the head of the merged linked list. Example 1: Input: list1 = [1,2,4], list2 = [1,3,4] Output: [1,1,2,3,4,4] Example 2:...