逆FizzBuzz問題解きなおし #C#

問題は http://d.hatena.ne.jp/matarillo/20120515/p1

周期7のテーブルなんか作らなくても、1..15の範囲の中で解探索して最短のものを選べばよかったんですね。
問題文にもあるとおり、IsFizzBuzzとToFizzBuzzで数字をFizzBuzzに変換して、入力と一致しているかを確かめていっています。

Program.cs

using System;
using System.Linq;

class Program
{
    static void Main()
    {
        WriteInverseFizzBuzz(new[] { "fizz" });
        WriteInverseFizzBuzz(new[] { "buzz" });
        WriteInverseFizzBuzz(new[] { "fizz", "buzz" });
        WriteInverseFizzBuzz(new[] { "buzz", "fizz" });
        WriteInverseFizzBuzz(new[] { "fizz", "buzz", "fizz" });
        WriteInverseFizzBuzz(new[] { "fizz", "fizz" });
        WriteInverseFizzBuzz(new[] { "fizz", "fizz", "buzz" });
        WriteInverseFizzBuzz(new[] { "buzz", "fizz", "buzz" });
    }

    static void WriteInverseFizzBuzz(string[] input)
    {
        string input2 = string.Join(",", input);
        string output2 = string.Join(",", InverseFizzBuzz(input));
        Console.WriteLine("{0} -> {1}", input2, output2);
    }

    static bool IsFizzBuzz(int number)
    {
        return (number % 3 == 0 || number % 5 == 0);
    }

    static string ToFizzBuzz(int number)
    {
        bool m3 = (number % 3 == 0);
        bool m5 = (number % 5 == 0);
        return
            (m3 && m5) ? "fizzbuzz" :
            (m5) ? "buzz" :
            (m3) ? "fizz" :
            null;
    }

    static Tuple<int, int> Inverse(string[] input, int start)
    {
        int n = start;
        foreach (string element in input)
        {
            while (!IsFizzBuzz(n)) n++;
            if (element != ToFizzBuzz(n)) return null;
            n++;
        }
        return Tuple.Create(start, n);
    }

    static int[] InverseFizzBuzz(string[] input)
    {
        var list = Enumerable.Range(1, 15)
            .Select(x => Inverse(input, x))
            .Where(x => x != null);

        if (list.Count() == 0) return new int[0];

        var range = list
            .OrderBy(x => x.Item2 - x.Item1)
            .First();

        return Enumerable.Range(range.Item1, range.Item2 - range.Item1)
            .ToArray();
    }
}

結果

fizz -> 3
buzz -> 5
fizz,buzz -> 9,10
buzz,fizz -> 5,6
fizz,buzz,fizz -> 3,4,5,6
fizz,fizz -> 6,7,8,9
fizz,fizz,buzz -> 6,7,8,9,10
buzz,fizz,buzz ->

逆FizzBuzz問題 解きなおし

逆FizzBuzz問題解きなおし