Write in c++

Write a function to merge two sorted linked list into one single sorted linked list and return the head of the merged linked list. For example, for linked list 1:1->5->->NULL, linked list 2: 2->3->8->NULL, the merged linked list should be 1->2->3->5->7->8->NULL. What is time complexity of your algorithm? (30 pts) node* merge_sorted_linkedlist (node *head1, node* head2)