Design and implement an efficient algorithm (VB)

Design and implement an efficient algorithm that gives a set of S of an intergers and another x, determines whether or not there exist two elements in S whose sum is exactly x

Using Vitual Basic or Java.

Provide an analysis for the running time of this approach.

1 Solve this problem by checking all possible pairs of elements

2 solve this problem by using a more efficient algorithm that does not require checking all possible pairs of elements