/*

Write a function that returns the count of elements in an integer array that are the same value as the average of their neighbors.

​

​

​

e.g. [1,2,3,6] -> 2:

Good Luck!

*/

​

​

using System;

using System.Collections;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    static void Main(string[] args)

        {

            int[] test =  { 3, 6 };

            var result = TestIsValid(test);

            Console.WriteLine("count:");

            Console.Write(result.ToString());

​

        }

​

        public static int TestIsValid(int[] test)

        {

            if (test.Count() <= 1)

            {

                return 0;

            }            

            var output = new List<int>();

​

            for (int i = 0; i < test.Length; i++)

            {

                decimal average = 0;

                int previousNeighbor = 0;

                int nextNeighbor = 0;

                switch (true)

                {

                    case true when i == 0: // first element

                        previousNeighbor = 0;

                        nextNeighbor = test[i + 1];

​

                        average = (previousNeighbor + nextNeighbor) / 2;

                        if (average == test[i])

                        {

                            output.Add(test[i]);

                        }

​

                        break;

                    case true when (i == test.Length -1): //last element

                        previousNeighbor = test[i - 1]; 

                        nextNeighbor = 0;

​

                        average = (previousNeighbor + nextNeighbor) / 2;

                        if (average == test[i])

                        {

                            output.Add(test[i]);

                        }

                        break;

                    default:

                        previousNeighbor = test[i - 1];

                        nextNeighbor = test[i + 1];

                        average = (previousNeighbor + nextNeighbor) / 2;

                        if (average == test[i])

                        {

                            output.Add(test[i]);

                        }

​

                        break;

                }                

            }

​

            Console.WriteLine("Numbers found:");

            output.ForEach(x => Console.WriteLine(x));

            return output.Count;

        }

}