using System;

using System.Collections.Generic;

​

namespace Fiddle_FrozenMountain

{

    public class MainClass

    {

        public static void Main(string[] args)

        {

            string input = String.Empty;

            int patLen;

            Console.WriteLine("Parker's Solution to Interview Question of Frozen Mountain - Fizzle");

            while (input.Length <= 1)

            {

                Console.Write("Please enter a string as input: ");

                input = Console.ReadLine();

                if (input.Length <= 1)

                {

                    Console.WriteLine("Error! String must have more than one character!");

                }

            }

​

            Console.Write("Please enter the length of the pattern (integer, must be smaller than the size of the string): ");

            patLen = input.Length + 1;

            while (patLen >= input.Length || patLen <= 0)

            {

                while (!int.TryParse(Console.ReadLine(), out patLen))

                {

                    Console.WriteLine("Error! Input must be an integer!");

                    Console.Write("Please enter the length of the pattern: ");

                }

                if (patLen >= input.Length || patLen <= 0)

                {

                    Console.WriteLine("Error! Input must be a positive integer smaller than the length of string!");

                    Console.Write("Please enter the length of the pattern (integer, must be larger than the size of the string): ");

                }

            }

​

            Dictionary<string, int> patterns = countPatterns(input, patLen);

​

            foreach (var pattern in patterns)

            {

                if (pattern.Value > 1)

                {

                    Console.WriteLine("Pattern {0} appeared {1} times!", pattern.Key, pattern.Value);

                }

            }

        }

​

        private static Dictionary<string, int> countPatterns(string str, int len)

        {

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

            for (int i = 0; i < str.Length - len + 1; i++)

            {

                string substr = str.Substring(i, len);

                int value;

                if (patterns.TryGetValue(substr, out value))

                {

                    patterns[substr] = value + 1;

                }

                else

                {

                    patterns.Add(substr, 1);

                }

            }

            return patterns;

        }

    }

}