Arithmetic Encoding

Encoding.cs

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


namespace Encoding {
    class Program {
        static double sum;
        static Dictionary<char, double> Val, Low, High;
        static string Input;
        static void Main(string[] args) {
            if(false) {
                Val = new Dictionary<char, double>() { { 't', 3 }, { 'e', 3 }, { 's', 2 }, { 'i', 1 }, { 'n', 1 } };
                Low = new Dictionary<char, double>() { { 't', 0 }, { 'e', 3 }, { 's', 6 }, { 'i', 8 }, { 'n', 9 } };
                High = new Dictionary<char, double>() { { 't', 3 }, { 'e', 6 }, { 's', 8 }, { 'i', 9 }, { 'n', 10 } };
                Input = "teststeine";
            } else {
                Val = new Dictionary<char, double>() { { 'd', 7 }, { 'u', 5 }, { 's', 4 }, { 'a', 3 }, { 'r', 2 }, { 'e', 1 } };
                Low = new Dictionary<char, double>() { { 'd', 0 }, { 'u', 7 }, { 's', 12 }, { 'a', 16 }, { 'r', 19 }, { 'e', 21 } };
                High = new Dictionary<char, double>() { { 'd', 7 }, { 'u', 12 }, { 's', 16 }, { 'a', 19 }, { 'r', 21 }, { 'e', 22 } };
                Input = "dudadsusdrausredausdud";
            }



            sum = Val.Values.Aggregate(0.0, (a, b) => a + b);
            var x = new Intervall(0, 1);
            Console.WriteLine("Start: " + x);
            foreach(char c in Input) {
                x = newIntervall(x, c);
                Console.WriteLine(string.Format("{0}: {1}", c, x));
            }
            Console.ReadKey(false);
        }

        static Intervall newIntervall(Intervall i, char c) {
            var r = new Intervall(0, 0);
            r.Lower = i.Lower + i.Length * (Low[c] / sum);
            r.Higher = i.Lower + i.Length * (High[c] / sum);
            return r;
        }

        private class Intervall {
            public double Lower, Higher;
            public double Length { get { return Higher - Lower; } }
            public Intervall(double l, double h) {
                Lower = l;
                Higher = h;
            }
            public override string ToString() {
                return "(" + Lower + "," + Higher + ")";
            }
        }

    }
}