Merge Two Sorted Lists You are given the heads of two sorted linked lists list1 and list2. Merge the two lists in a 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. Ex Constraints: 1. The number of nodes in both lists is in the range [0,50], 2. ?100<= Node .val <=100. 3. Both list1 and list2 are sorted in non-decreasing order. Tips : 1. Please consider the extreme case when one of the lists is None or both are None. 2. Please use C++11. flag: static-std=ct+0x compiler if necessary. 3. Please use Listivode Struct below. struct ListNode { int val; ListiNode "next: ListNode(): val(0), next(nullptr) 0 ListNode(int x ) : val( x ), next(nullptr) 0 ListNode(int x, ListNode "next) : val(x), next(next) 0 r Samples: Input:rOutpu