using System;

public class Program

{

    public static void Main()

    {

        /*

        You are given a string of numbers between 0-9. 

        Find the average of these numbers and return it as a floored whole number (ie: no decimal places) written out as a string.

        Eg: 

        Input -> "four nine five two"

        Output -> "five"

        The calculation will be : (4+9+5+2) divided by how many number in string, in this case is 4 number in string, so divided by 4

        And the result will be (4+9+5+2)/4 = 5, convert into string is five, so the output will be 5

        And please be noted that if the string is empty or includes a number greater than 9, return "n/a"

        Example 1

        Input -> "five four"

        Output -> "four"

        Example 2

        Input -> "zero zero zero zero zero zero zero zero"

        Output -> "zero"

​

        Example 3

        Input -> "twenty"

        Output -> "n/a"

        Example 4

        Input -> "one one eight one"

        Output -> "two"

        Example 5

        Input -> ""

        Output -> "n/a" 

        Example 6

        Input -> "zero nine five two six"

        Output -> "four"

        */ 

        //Codes

            string[] numset = { "five four", "zero zero zero zero zero zero zero zero", "twenty", "one one eight one", "", "zero nine five two six" };

​

            for(int s = 0; s<=5; s++)

            {

                Console.Write("Input    -> " + numset[s]);

                geteverage(numset[s]);

            }

            Console.ReadKey();

​

            void geteverage(string inn)

            {

                //Console.Write("Input    -> ");//input

                //string input = Console.ReadLine();

                string input;

                input = inn;

                input += " ";

                string instnum = "";// temporary variable to store number form stirng

                int num = 0;// termporary variable to store total value

                int numCount = 0;

​

                int everage;

​

                string output = "n/a";// string for output

​

                string[] stnum = { "zero", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine", "n/a" };//string numbers

                if (input.Equals(" "))

                {

                    Console.WriteLine("\nOutput   -> n/a\n-----------");//output

                    //Console.ReadKey();

                }

                else

                {

                    for (int i = 0; i <= input.Length - 1; i++)

                    {

                        if (input[i].Equals(' '))

                        {

                            if (instnum.Equals(stnum[0]))

                            {

                                num += 0;

                                numCount++;

                                instnum = "";

                            }

                            else if (instnum.Equals(stnum[1]))

                            {

                                num += 1;

                                numCount++;

                                instnum = "";

                            }

                            else if (instnum.Equals(stnum[2]))

                            {

                                num += 2;

                                numCount++;

                                instnum = "";

                            }

                            else if (instnum.Equals(stnum[3]))

                            {

                                num += 3;

                                numCount++;

                                instnum = "";

                            }

                            else if (instnum.Equals(stnum[4]))

                            {

                                num += 4;

                                numCount++;

                                instnum = "";

                            }

                            else if (instnum.Equals(stnum[5]))

                            {

                                num += 5;

                                numCount++;

                                instnum = "";

                            }

                            else if (instnum.Equals(stnum[6]))

                            {

                                num += 6;

                                numCount++;

                                instnum = "";

                            }

                            else if (instnum.Equals(stnum[7]))

                            {

                                num += 7;

                                numCount++;

                                instnum = "";

                            }

                            else if (instnum.Equals(stnum[8]))

                            {

                                num += 8;

                                numCount++;

                                instnum = "";

                            }

                            else if (instnum.Equals(stnum[9]))

                            {

                                num += 9;

                                numCount++;

                                instnum = "";

                            }

                            else

                            {

                                num = 20;

                                numCount = 2;

                                break;

                            }//if (instnum.Equals(stnum[0]))

                        }

                        else

                        {

                            instnum += "" + input[i];

                        }//if(input[i].Equals(' '))

                    }//for (int i = 0; i <= input.Length - 1; i++)

                    everage = num / numCount;

                    output = stnum[everage];

                    Console.WriteLine("\nOutput   -> " + output +"\n-----------");//output

                    //Console.ReadKey();

                }//if (input.Equals(""))

            }//void geteverage(string inn)

    }

}