# The gyroball code challenge

Thycotic presented a code challenge where you could win a gyroball here. Since I live in Sweden, I'm not eligible to win this challenge but I thought it would be fun to solve the problem.

```
// We have designed a new magical number system called "alpha-end". This number system is
// similar to hexadecimal but has the following characters: 0 1 2 3 4 5 6 7 8 9 x y z
// (basically the decimal number system plus the 3 characters x, y and z)
// Therefore converting from decimal to alpha-end gives the following:
// 5 => 5
// 10 => x
// 13 => 10
// 20 => 17
// Your task is to implement the Converter.Convert method for this new number system to get all the
// unit tests passing. Feel free to add more unit tests as you work if it helps you test drive to the goal.
// You will be judged based on the accuracy and design of your code.
//
// Extra challenge:
// Try extending from your Converter to support other number systems such as binary, octal and hexadecimal.
// Is there an easy way to refactor your code/algorithm to support this?</pre>
```

Simply, write a method that will convert from decimal to any number system. Lucky for us all their examples contains only positive discrete numbers.

type Converter(alphabet:list<string>) = let alphabet = alphabet`new () = Converter(["0"; "1"; "2"; "3"; "4"; "5"; "6"; "7"; "8"; "9"; "x"; "y"; "z"]) member this.Convert (n:int) = let division = (n |> float) / (alphabet.Length |> float) |> System.Math.Truncate |> int match division with | 0 -> alphabet.Item(n) | _ -> this.Convert division + alphabet.Item(n % alphabet.Length)`

type BinaryConverter() = inherit Converter(["0"; "1"])

type OctalConverter() = inherit Converter(["0"; "1"; "2"; "3"; "4"; "5"; "6"; "7"])

type HexConverter() = inherit Converter(["0"; "1"; "2"; "3"; "4"; "5"; "6"; "7"; "8"; "9"; "a"; "b"; "c"; "d"; "e"; "f"])

Here's the same thing in C#.

public class Converter2 { private readonly string[] alphabet; private static string[] AlphaEnd = new[] { "0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "x", "y", "z" };`public Converter2() : this(AlphaEnd) { } public Converter2(string[] alphabet) { this.alphabet = alphabet; } public string Convert(int number) { int division = (int) Math.Truncate(((double)number) / alphabet.Length); if (division == 0) { return alphabet[number]; } return Convert(division) + alphabet[number % alphabet.Length]; }`

}

Personally I think F# looks much better.

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