using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

​

namespace PatternMatch

{

    public class Program

    {

       public static void Main()

        {

            string text = "ushpsghtgapajklhjkhghtjklyghtusus";

            var pattern = GetMatchedPattern(text, 4);

           if(pattern.Any()){

            foreach(var key in pattern.Keys){

                Console.WriteLine(" Pattern " + key + " repeated " + pattern[key] + " no of times");

            }

           }

           else{

               Console.WriteLine("Not able to find any patterns");

           }

        }

​

        static Dictionary<string, int> GetMatchedPattern(string strtext, int len)

        {

            Dictionary<string, int> patterns = new Dictionary<string, int>();

​

            for (int ichIndex = 0; ichIndex < strtext.Length; ichIndex++)

            {

                if (ichIndex + len <= strtext.Length)

                {

                    if (!patterns.ContainsKey(strtext.Substring(ichIndex, len)))

                    {

                        patterns.Add(strtext.Substring(ichIndex, len), 1);

                    }

                    else

                    {

                        patterns[strtext.Substring(ichIndex, len)] = patterns[strtext.Substring(ichIndex, len)] + 1;

                    }

                }

​

            }

​

            return patterns.Where(k => k.Value > 1).ToDictionary(y => y.Key, x => x.Value);

        }

    }

}

​