using System;

using System.Collections.Generic;

using System.Collections;                   

​

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

        Console.WriteLine("{0}",FindLogestSubstring("araaci",1));

    }

    //Given a string, find the length of the longest substring in it with no more than K distinct characters.

    public static int FindLogestSubstring(string inputStr, int numDistinctChar) {

        char[] chrArr = inputStr.ToCharArray();

        Hashtable ht = new Hashtable();

        int windowSTART =0;

        int maxSubStringLength = 0;

        for ( int windowEND = 0; windowEND < chrArr.GetLength(0); windowEND++) {

            if (!ht.ContainsKey(chrArr[windowEND])) 

                ht.Add(chrArr[windowEND],1);

            else 

                ht[chrArr[windowEND]] = Convert.ToInt32(ht[chrArr[windowEND]]) + 1;

            while ( ht.Count > numDistinctChar) {

                if (Convert.ToInt32(ht[chrArr[windowSTART]]) == 1) 

                    ht.Remove(chrArr[windowSTART]);

                else

                    ht[chrArr[windowSTART]] = Convert.ToInt32(ht[chrArr[windowSTART]]) - 1;

                windowSTART++;

            }

            maxSubStringLength = Math.Max(maxSubStringLength, windowEND- windowSTART +1);

        }

        return maxSubStringLength;

    }

}