Comma quibbling is a task originally set by Eric Lippert in his blog.



Task

Write a function to generate a string output which is the concatenation of input words from a list/sequence where:

 An input of no words produces the output string of just the two brace characters "{}".
 An input of just one word, e.g. ["ABC"], produces the output string of the word inside the two braces, e.g. "{ABC}".
 An input of two words, e.g. ["ABC", "DEF"], produces the output string of the two words inside the two braces with the words separated by the string " and ", e.g. "{ABC and DEF}".
 An input of three or more words, e.g. ["ABC", "DEF", "G", "H"], produces the output string of all but the last word separated by ", " with the last word separated by " and " and all within braces; e.g. "{ABC, DEF, G and H}".


Test your function with the following series of inputs showing your output here on this page:

 [] # (No input words).
 ["ABC"]
 ["ABC", "DEF"]
 ["ABC", "DEF", "G", "H"]


Note: Assume words are non-empty strings of uppercase characters for this task.




using System;
using System.Linq;
 
namespace CommaQuibbling
{
    internal static class Program
    {
        #region Static Members
	private static string Quibble(string[] input)
	{
            return
                String.Format("{{{0}}}",
                    String.Join("",
                        input.Reverse().Zip(
                            new [] { "", " and " }.Concat(Enumerable.Repeat(", ", int.MaxValue)),
                            (x, y) => x + y).Reverse()));
	}
 
 
        private static void Main()
        {
            Console.WriteLine( Quibble( new string[] {} ) );
            Console.WriteLine( Quibble( new[] {"ABC"} ) );
            Console.WriteLine( Quibble( new[] {"ABC", "DEF"} ) );
            Console.WriteLine( Quibble( new[] {"ABC", "DEF", "G", "H"} ) );
 
            Console.WriteLine( "< Press Any Key >" );
            Console.ReadKey();
        }
 
        #endregion
    }
}