using System;

using System.Collections.Generic;

using System.Linq;

​

public class MainClass 

{

  public static void Main () 

  {

    var emptyRole = Tuple.Create(0, String.Empty);

​

    var rules = new List<Func<Int32, Tuple<Int32, String>>>

    {

        s => s % 3 == 0 && s % 5 == 0 ? Tuple.Create(1, @"FizzBuzz") : emptyRole,

        s => s % 3 == 0 ? Tuple.Create(2, @"Fizz") : emptyRole,

        s => s % 5 == 0 ? Tuple.Create(3, @"Buzz") : emptyRole

    };

​

    Enumerable

        .Range(1, 20)

        .Select(s => rules

          .Select(sr => Tuple.Create(s, sr.Invoke(s)))

          .Where(p => p.Item2.Item1 >= 1)

          .ToList())

        .Where(p => p.Count >= 1)

        .Select(s => s.Aggregate((seed, rs) => seed.Item2.Item1 < rs.Item2.Item1 ? seed : rs))

        .Select(s => $"{s.Item1.ToString().PadLeft(2, '0')} - {s.Item2.Item2}")

        .ToList()

        .ForEach(Console.WriteLine);

  }

}

​

// C# 7

​

//var emptyRole = (0, String.Empty);

​

//var rules = new List<Func<Int32, (Int32 Priority, String Value)>>

//{

//    s => s % 3 == 0 && s % 5 == 0 ? (1, @"FizzBuzz") : emptyRole,

//    s => s % 3 == 0 ? (2, @"Fizz") : emptyRole,

//    s => s % 5 == 0 ? (3, @"Buzz") : emptyRole

//};

​

//Enumerable

//    .Range(1, 20)

//    .Select(s => rules

//        .Select(sr => (No: s, Data: sr.Invoke(s)))

//        .Where(p => p.Data.Priority >= 1)

//        .ToList())

//    .Where(p => p.Count >= 1)

//    .Select(s => s.Aggregate((seed, rs) => seed.Data.Priority < rs.Data.Priority ? seed : rs))

//    .Select(s => $"{s.No.ToString().PadLeft(2, '0')} - {s.Data.Value}")

//    .ToList()

//    .ForEach(Console.WriteLine);