using System;

using System.Linq;

using System.Collections.Generic;

​

/*  The only Difference between Version 1 and version 2 is MakePatterns and SearchAndCount functions

    MakePatterns is returning the list of all the different patterns

    SearchAndCount is searching the similar patterns in the list using foreach loop and storing into dictionary with its count

*/

​

public class SearchPattern

{

    public static void Main()

    {

​

        // user inputs

        var data = GetStringInput();

        var patternLength = GetPatternLengthInput(data);

        // return the list with the different patterns

        var results = MakePatterns(data, patternLength);

        // return a dictionary with all the different patterns and its count    

        var dict = SearchAndCount(results);

        //show results

        DisplayOutput(dict);

​

        Console.WriteLine("Press any key to exit");

        Console.ReadLine();

    }

    // string input from user 

    public static string GetStringInput()

    {

        Console.WriteLine("Enter string input:");

        var data = Console.ReadLine();

​

        while (string.IsNullOrEmpty(data))

        {

            Console.WriteLine("please enter valid string:");

            data = Console.ReadLine();

        }

​

        return data;

     }

​

    // pattern length input from user

    public static int GetPatternLengthInput(string data)

    {

        Console.WriteLine("Enter pattern length:");

        var patternLengthAsString = Console.ReadLine(); 

​

        int patternLength;

        while(!int.TryParse(patternLengthAsString, out patternLength) || patternLength > data.Length || patternLength <= 0)

        {  

          Console.WriteLine("please enter a valid length integer");

          patternLengthAsString = Console.ReadLine();

        } 

​

        return patternLength;  

    }

​

    // return the list with the different patterns 

    public static List<string> MakePatterns(string data, int length)

    {

        List<string> patterns = new List<string>();

        for(int i = 0; i + length <= data.Length; i++)

        {

            patterns.Add(data.Substring(i, length));

        }

        return patterns;

    }

​

    public static IDictionary<string, int> SearchAndCount(List<string> patterns)

    {

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

        foreach(string pattern in patterns)

        {

            if (!searchResults.ContainsKey(pattern))

            {

                searchResults.Add(pattern, 1);

            }

            else

            {

                int count = 0;

                searchResults.TryGetValue(pattern, out count);

                searchResults.Remove(pattern);

                searchResults.Add(pattern, count+1);

            }

        }

​

        DictCleanup(searchResults);

        return searchResults;

    }

​

    // removing all the patterns with count == 1

    public static IDictionary<string,int> DictCleanup(IDictionary<string,int> dict)

    {

        foreach(var item in dict.Where(key => key.Value <= 1).ToList())

        {

          dict.Remove(item.Key);

        }

        return dict;

    }

    // show results to the user

    public static void DisplayOutput(IDictionary<string,int> dict)

    {

        if(dict.Count == 0)

        {

            Console.WriteLine("No pattern found in the provided string");

        }

​

        for (int i = 0; i < dict.Count; i++)

        {

            Console.WriteLine("String Pattern: {0}, Count: {1}", 

                              dict.Keys.ElementAt(i), 

                              dict[ dict.Keys.ElementAt(i)]);

        }

    }

}