/*
 * Aresh Saharkhiz
 * saharkiz@gmail.com
 * Associate Professor / Mapua Institute of Technology / Philippines
 */

using System;
using System.IO;

// Introduction to Software Testing
// Authors: Paul Ammann & Jeff Offutt
// Chapter 3, section 3.3, page 121

// Jeff Offutt--Java version Feb 2003
// Classify triangles

internal class trityp
{
    private static string[] triTypes = new string[] { "", "scalene", "isosceles", "equilateral", "not a valid triangle" }; // Ignore 0.
    private static string instructions = "This is the ancient TriTyp program.\nEnter three integers that represent the lengths of the sides of a triangle.\nThe triangle will be categorized as either scalene, isosceles, equilateral\nor invalid.\n";

    public static void Main(string[] argv)
    { // Driver program for trityp
        int A, B, C;
        int T;

        Console.WriteLine(instructions);
        Console.WriteLine("Enter side 1: ");
        A = N;
        Console.WriteLine("Enter side 2: ");
        B = N;
        Console.WriteLine("Enter side 3: ");
        C = N;
        T = Triang(A, B, C);

        Console.WriteLine("Result is: " + triTypes[T]);
    }

    // ====================================
    // The main triangle classification method
    private static int Triang(int Side1, int Side2, int Side3)
    {
        int triOut;

        // triOut is output from the routine:
        //    Triang = 1 if triangle is scalene
        //    Triang = 2 if triangle is isosceles
        //    Triang = 3 if triangle is equilateral
        //    Triang = 4 if not a triangle

        // After a quick confirmation that it's a valid
        // triangle, detect any sides of equal length
        if (Side1 <= 0 || Side2 <= 0 || Side3 <= 0)
        {
            triOut = 4;
            return (triOut);
        }

        triOut = 0;
        if (Side1 == Side2)
        {
            triOut = triOut + 1;
        }
        if (Side1 == Side3)
        {
            triOut = triOut + 2;
        }
        if (Side2 == Side3)
        {
            triOut = triOut + 3;
        }
        if (triOut == 0)
        { // Confirm it's a valid triangle before declaring
            // it to be scalene

            if (Side1 + Side2 <= Side3 || Side2 + Side3 <= Side1 || Side1 + Side3 <= Side2)
            {
                triOut = 4;
            }
            else
            {
                triOut = 1;
            }
            return (triOut);
        }

        // Confirm it's a valid triangle before declaring
        // it to be isosceles or equilateral

        if (triOut > 3)
        {
            triOut = 3;
        }
        else if (triOut == 1 && Side1 + Side2 > Side3)
        {
            triOut = 2;
        }
        else if (triOut == 2 && Side1 + Side3 > Side2)
        {
            triOut = 2;
        }
        else if (triOut == 3 && Side2 + Side3 > Side1)
        {
            triOut = 2;
        }
        else
        {
            triOut = 4;
        }
        return (triOut);
    } // end Triang

    // ====================================
    // Read (or choose) an integer
    private static int N
    {
        get
	{
	   int inputInt = 1;
	   string inStr;
    
	   try
	   {
		  inStr = Console.ReadLine();
		  inputInt = Convert.ToInt32(inStr);
	   }
	   catch (IOException)
	   {
		  Console.WriteLine("Could not read input, choosing 1.");
	   }
	   catch (FormatException)
	   {
		  Console.WriteLine("Entry must be a number, choosing 1.");
	   }
    
	   return (inputInt);
	}
    } // end getN

} // end trityp class