using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {

        string input = "hello world";

        Console.WriteLine("Provided text : " + input);

        Dictionary<char, int> charCount = GetOccuranceOfEachChar(input);

        foreach(var item in charCount)

        {

            Console.WriteLine(item.Key + " - " + item.Value);

        }

        Console.WriteLine("---------Second Way ---------------");

        charCount = GetOccuranceOfEachCharByLINQ(input);

        foreach(var item in charCount)

        {

            Console.WriteLine(item.Key + " - " + item.Value);

        }

    }

    private static Dictionary<char, int> GetOccuranceOfEachChar(string input)

    {

        Dictionary<char, int> result = new Dictionary<char, int>();

        char[] arrInput = input.ToCharArray();

        int length = input.Length;

        int count = 1;

        for(int i = 0 ; i < length; i++)

        {

            count = 1;

            if(arrInput[i] == ' ')

            {

                continue;

            }

            else if( i == length - 1 && arrInput[i] != ' ')

            {

                result.Add(arrInput[i],count);

                break;

            }

            for(int j=i+1; j< length; j++)

            {

                if(arrInput[i] == arrInput[j])

                {

                    count++;                

                    arrInput[j] = ' ';

                }

            }

            result.Add(arrInput[i],count);

        }

        return result;

    }

    private static Dictionary<char, int> GetOccuranceOfEachCharByLINQ(string input)

    {

        Dictionary<char, int> res = new Dictionary<char, int>();

        char[] arrDistinctChar = input.Distinct().ToArray();

        int occurance;

        foreach(char item in arrDistinctChar)

        {

            if(item != ' ')

            {

                occurance = input.Where(c => c.Equals(item)).Count();

                res.Add(item, occurance);

            }

        }

        return res;

    }

}