How do you create a merge function for a linked sorted list with the shortest time complexity possible. No duplicates allowed. No memory leaks.

void SortedList::merge(SortedList& list) is the method signiture.

Node *location1 = listData; variable one

Node *location2 = list.listData; variable two

Node* current = NULL;

EDIT: also upon completion the list put inside the parameters should be empty.