using System;

using Newtonsoft.Json.Linq;

using System.Collections;

using System.Collections.Generic;

using System.Linq;

using NUnit.Framework; 

​

public class CShartTest{

    //Requirement 4

    public int[] mostCommonElements(int[] elements){

        //convert Array to list 

        List<int> lstElements = elements.OfType<int>().ToList(); 

        //group input vals

        var grpElements = lstElements

                .GroupBy(item => item)

                .OrderByDescending (item => item.Count())

                .Select(g => new { selectedval = g.Key, Count = g.Count() });

        //get max cnt val for filter purpose

        int selectedCnt=grpElements.ToArray()[0].Count;

        List<int>  retElements = grpElements

                .Where(item => item.Count == selectedCnt)

                .Select(item => item.selectedval )

                .ToList();

        return retElements.ToArray();

    }

    //Requirement 2

    public int[] positiveDivisors(int num){

        List<int> list = new List<int>();

        for(int i=1;i<=num;i++){

            if(num % i ==0){

                list.Add(i);

            }

        }

        return list.ToArray();

    }

    //Requirement 3

    public double triangleArea(int x,int y,int z){

        try   

        {

            //UNit will reject Negative Int.

            Convert.ToUInt32(x);

            Convert.ToUInt32(y);

            Convert.ToUInt32(z); 

            if(Math.Pow(x, 2) + Math.Pow(y, 2)== Math.Pow(z, 2) || Math.Pow(z, 2) + Math.Pow(x, 2)== Math.Pow(y, 2) || Math.Pow(y, 2)+ Math.Pow(z, 2)== Math.Pow(x, 2) )

            {

                double s=(x+y+z)/2;

                double area = Math.Sqrt(s*(s-x)*(s-y)*(s-z));

                return area;

                //console.log(area);

            }

            else{

                throw new InvalidTriangleException("Not Valid Inputs for Triangle");

            }

        }

        catch(OverflowException  ex){

            //Console.WriteLine(ex.Message);

            throw new InvalidTriangleException(ex.Message);

        }

    }

}

//Unit Testing.

[TestFixture]

class CSharpTestUnits

{ 

    private int[] inn1 ={5, 4, 3, 2, 4, 5, 1, 6, 1, 2, 5, 4};

    private int[] inn2 ={1, 2, 3, 4, 5, 1, 6, 7};

    private int[] inn3 ={1, 2, 3, 4, 5,  6, 7};

​

    [TestCaseSource("inn1")]

    [TestCaseSource("inn2")]

    [TestCaseSource("inn3")]

    public void Requirement4Test(int[] inn, int[] res)

    {

        CShartTest cs=new CShartTest();

        Assert.AreEqual( res,cs.mostCommonElements(inn));

    }

    private int[] res2 ={1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30, 60};

​

    [TestCase(60)]

    public void Requirement2Test1(int inn)

    {

        CShartTest cs=new CShartTest();

        Assert.AreEqual( res2,cs.positiveDivisors(inn) );

    }

    private int[] res3 ={1, 2, 3, 6, 7, 14, 21, 42};

    [TestCase(42)]

    public void Requirement2Test2(int inn)

    {

        CShartTest cs=new CShartTest();

        Assert.AreEqual( res3,cs.positiveDivisors(inn) );

    }

    [TestCase(3,4,5, Result=6)]

    public void Requirement3Test(int inn1, int inn2,int inn3,int res)

    {

        CShartTest cs=new CShartTest();

        Assert.AreEqual( res,cs.triangleArea(inn1,inn2,inn3) );

    }

}

​

public class Program

{

    public static void Main()

    {

        CShartTest cs=new CShartTest();

        Console.WriteLine("Requirement 4 starts Test 1");

        int[] m ={5, 4, 3, 2, 4, 5, 1, 6, 1, 2, 5, 4};

        int[] mc=  cs.mostCommonElements(m);

        Console.WriteLine("Requirement 4  Test 2");

        int[] m2 ={1, 2, 3, 4, 5, 1, 6, 7};

        int[] mc2=  cs.mostCommonElements(m2);

        Console.WriteLine("Requirement 4  Test 3");

        int[] m3 ={1, 2, 3, 4, 5,  6, 7};

        int[] mc3=  cs.mostCommonElements(m3);

​

        //mostCommonElements

        //Console.WriteLine(mc.Length);

        int[] res11=cs.positiveDivisors(60);

        Console.WriteLine("Requirement 2  Test 1");

        List<int> lst1 = new List<int>(res11);

        foreach (int num in lst1) // Loop through List with foreach.

            {

                Console.WriteLine(num);

            }

​

        Console.WriteLine("End R2T1");

        int[] res22=cs.positiveDivisors(42);

        Console.WriteLine("Requirement 2  Test 2");

        lst1 = new List<int>(res22);

        foreach (int num in lst1) // Loop through List with foreach.

            {

                Console.WriteLine(num);

            }

        Console.WriteLine("End R2T2");

        Console.WriteLine("Requirement 4  Test 1");

        Console.WriteLine(cs.triangleArea(3,4,5));

        Console.WriteLine("Requirement 4  Test 2");

        Console.WriteLine(cs.triangleArea(-3,4,5));

        Console.WriteLine("Requirement 4  Test 3");

        Console.WriteLine(cs.triangleArea(11,4,5));

    }

}

​

​

//Custom Exception Class

public class InvalidTriangleException: Exception

{

    public InvalidTriangleException()

    {

    }

​

    public InvalidTriangleException(string message)

        : base(message)

    {

    }

​

}

​