Write an Algorithm (psuedo code) that determines if a list of four numbers contains two numbers that are negatives of each other.

Depending on your viewpoint, the input for this algorithm can be divided into classes based on the structure of your algorithm or the structure of the problem. Describe how one of these two class divisions would be set up. Using your classes, what is the best case for your algorithm? What is the worst case? What is the average case? (If the best and worst cases are the same, rewrite your algorithm with simple conditionals and without temporary variables so the best case is better than the worst case.)