std_adjacent like behavior in C# (of course, using linq :) )

std_adjacent_like.cs

using System;
using System.Linq;

namespace EnumurateAdjacent
{
    class Program
    {
        static void Main(string[] args)
        {
            var input = new[] {1, 1, 2, 3, 4, 5, 5, 6, 7, 8, 9, 9, 9, 10};

            foreach (var i in 
                input.Zip(input.Skip(1), Tuple.Create)
                .Where(tuple => tuple.Item1 == tuple.Item2))
            {
                Console.WriteLine("[{0},{1}]", i.Item1, i.Item2);
            }

            Console.ReadKey();
        }
    }
}