Search for repeated character combinations algorithm

khalid Johnson

Hi everybody,

I have an tool that reads an file. That file has for example the follow content:

wvtnfhxyz1hdxyz1fdxyz1ejxyz1dhxyz1dxyz1eeaa1oeys

I would like to search for repeated character combinations like the bold characters. The character combination xyz1 repeated 6 times.

I would like to return some top 5 with the most repeated character combinations. Something like this:

xyz1 : 6 times
aa5 : 5 times
ab4 : 3 times
ab : 2 times
66 : 2 times

This is the code that reads the file:


string path = @openFileDialog1.FileName;
                try
                {
                    // Open the stream and read it back.
                    using (FileStream fs = File.OpenRead(path))
                    {
                        byte[] b = new byte[1024];
                        //UTF8Encoding temp = new UTF8Encoding(true);
                        UTF7Encoding temp = new UTF7Encoding(true);

                        while (fs.Read(b, 0, b.Length) > 0)
                        {
                            textBox1.Text += temp.GetString(b);

                        }
                    }
                }

Thanks!

2 Replies

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khalid Johnson17y ago
Hi,

Thanks for your support! I have test it, but why is the output inconsistent? In the example below you can see that the character combination ab 34 times occurs instead of 4 times. And is it possible to add an parameter combinationWidth to search only at character combinations with the combinationWidth value.

example

Thank you.

Roei Bar17y ago

here is the code for your problem :

 using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            string _givenString = "wvtnfhxyz1hdxyz1fdxyz1ejxyz1dhxyz1dxyz1eeaa1oeys";
            Dictionary _codes = new Dictionary();
            int _startingPoint = 0;
            while (_startingPoint < _givenString.Length)
            {
                for (int j = 2; j < _givenString.Length; j++)
                {
                    for (int i = _startingPoint; i < _givenString.Length && i + j < _givenString.Length; i++)
                    {
                        if (!_codes.ContainsKey(_givenString.Substring(i, j)))
                        {
                            _codes.Add(_givenString.Substring(i, j), 1);
                        }
                        else
                        {
                            _codes[_givenString.Substring(i, j)] += 1;
                        }
                    }
                }
                
                _startingPoint++;
            }

            List> _sortedCodes = SortDictionary(_codes);
            for (int i = 0; i < 5; i++)
            {
                Console.WriteLine(_sortedCodes[i].Key + " : " + _sortedCodes[i].Value + " times");
            }
            Console.ReadKey();
        }

        public static List> SortDictionary(Dictionary data)
        {
            List> result =
                  new List>(data);
            result.Sort(
              delegate(
                KeyValuePair first,
                KeyValuePair second)
              {
                  return second.Value.CompareTo(first.Value);
              }
              );
            return result;
        }
    }
}

it would be easier in Linq but hope this helps