using System;

using System.Collections.Generic;

using System.Linq;

​

namespace stairNways

{

    public class Program

    {

        public static void Main(string[] args)

        {

            int noOfPossibilities = 2;

            int noOfSteps = 5;

            List<int> combinationsList = new List<int>(){1,2};

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

            bool reached = false;

            //Console.Write("Enter the number of steps: ");

            Console.WriteLine("Number of steps: {0}", noOfSteps);

            //noOfSteps = Convert.ToInt32(Console.ReadLine());

            //Console.Write("Enter the number of possible step overs that you want to make: ");

            Console.WriteLine("Number of possible stepovers: {0}", noOfPossibilities);

            //noOfPossibilities = Convert.ToInt32(Console.ReadLine());

            if (noOfPossibilities > 0)

            {

                //Console.WriteLine("Enter the step over values: ");

                //for (int i = 0; i < noOfPossibilities; i++)

                //{

                    //Console.Write("> ");

                    //combinationsList.Add(Convert.ToInt32(Console.ReadLine()));

                //}             

                combinationsList.ForEach(x => {Console.WriteLine("> {0}", x);});

                Console.WriteLine("You can reach your destination in following possible ways");

                do

                {

                    noOfWaysList = GetArray(noOfWaysList, combinationsList, noOfSteps);

                    reached = checkReached(noOfWaysList, noOfSteps);

                } while (!reached);

                Console.WriteLine(">>>>>>>>>>>>>>>>{0}<<<<<<<<<<<<<<<", noOfWaysList.Count());

            }

            else

            {

                Console.WriteLine("you entered an invalid nuber");

            }

        }

​

        private static bool checkReached(List<int> noOfWaysList, int noOfSteps)

        {

            bool reached = true;

            foreach (var nwl in noOfWaysList)

            {

                if (nwl != noOfSteps)

                    reached = false;

            }

            return reached;

        }

​

        private static List<int> GetArray(List<int> possibleWaysList, List<int> stepOvers, int noOfSteps)

        {

            if (possibleWaysList == null || possibleWaysList.Count() == 0)

            {

                foreach (var stepOver in stepOvers)

                {

                    possibleWaysList.Add(stepOver);

                }

            }

            else

            {

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

                foreach (var pwl in possibleWaysList)

                {

                    if (pwl == noOfSteps)

                    {

                        dummyList.Add(pwl);

                        continue;

                    }

​

                    foreach (var so in stepOvers)

                    {

                        if ((pwl + so) <= noOfSteps)

                        {

                            dummyList.Add(pwl + so);

                        }

                    }

                }

                return dummyList;

            }

            return possibleWaysList;

        }

    }

}