using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {

        int[] intList = new int[] { 15, 2, 2, 2, 14, 5, 5, 15, 1, 5, 7, 8, 8 };

        // Does 15 occur next to each other in the list

        var exist = DoesExist(intList);           

        Console.WriteLine(exist);

​

        // How many times does the value in the arrary equeal the next value in the array

        var numRepeat = NumberOfRepeatNumbers(intList);

        Console.WriteLine(numRepeat);

​

        // How many unique numbers exist in the array

        var numUniqueNumbers = NumberOfUniqueNumbers(intList);

        Console.WriteLine(numUniqueNumbers);

    }

    public static bool DoesExist(int[] inList) {

        var returnVal = false;

​

        for(int i = 0; i < inList.Count(); i++)

        {

            if (inList[i] == 15 && inList[i + 1] == 15)

            {

                returnVal = true;

                break;

            }

        }

​

        return returnVal;

    }

​

    public static int NumberOfRepeatNumbers(int[] inList)

    {

        var returnVal = 0;

​

        for (int i = 0; i < inList.Count() -1; i++)

        {                

            if (i == inList.Count())

                break;

            if (inList[i] == inList[i + 1])

            {

                returnVal++;                    

            }

        }

​

        return returnVal;

    }

​

    public static int NumberOfUniqueNumbers(int[] inList)

    {

        var returnVal = 0;

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

​

        for (int i = 0; i < inList.Count(); i++)

        {

            var newValue = inList[i];

​

            // using linq

            if (!tempList.Contains(newValue))

            {

                returnVal++;

                tempList.Add(newValue);

            }

​

            // not using linq

            //var found = false;

            //foreach (var item in tempList)

            //{

            //    if (item == newValue) {

            //        found = true;

            //        break;

            //    }

            //}

            //if (!found) {

            //    returnVal++;

            //    tempList.Add(newValue);

            //}

​

​

       }

        return returnVal;

    }

}