triangle

Implementation of triangle challenge

The problem

Write a program that will determine the type of a triangle. It should take the lengths of the triangle's three sides as input, and return whether the triangle is equilateral, isosceles or scalene.

How to run

This is a maven project. Use the following command to run tests:

mvn test

to run the TriangleDemo app use the following command:

 java -cp target/classes com.vizog.triangle.TriangleDemo

Brief discussion

I have used TDD in design of this application. Detection of triangle type and instantiation is done by a factory class called TriangleFactory. This class uses various validator types (one for each type of triangle) to check if the given side values match the specific type. The matching check is done with order of being more specific (Equilateral > Isosceles > Scalene) Sanity checking the inputs and asserting the Triangle Inequality Theorem is performed by the base class TriangleValidator. This checking cannot be overruled because the only way to instantiate the triangles outside the library package is by TriangleFactory static methods which ensure the validation.