using System;

using System.Collections.Generic;

using System.Text;

using System.Linq;

public class Program

{

    public static void Main()

    {

        var d1 = new Dictionary<int, string>();

        var d2 = new Dictionary<int, string>();

        var d3 = new Dictionary<int, string>();

        var d4 = new Dictionary<int, string>();

        d1.Add(57, "FiftySeven");

        d2.Add(57, "FiftySeven");

        d3.Add(57, "Fifty       Seven");

        d4.Add(5757, "FiftySeven");

        Console.WriteLine("1: " + d1.GetValueBasedHashCode(17, 31) + " << Baseline");

        Console.WriteLine("2: " + d2.GetValueBasedHashCode(17, 31) + " << Coincidently matches #1 because the key is the same");

        Console.WriteLine("3: " + d3.GetValueBasedHashCode(17, 31) + " << Should be different than # 1, but isn't because the key is the same.");

        Console.WriteLine("4: " + d4.GetValueBasedHashCode(17, 31) + " << Is (correctly) different than #1, because of a different key.  Not b/c of the value");

        Console.WriteLine("");

        Console.WriteLine(d1.GetHashCode());

        Console.WriteLine(d2.GetHashCode());

    }

}

​

public static class EnumerableExtensions

{

    public static TResult[,] ToRectangularArray<TSource, TResult>(this IEnumerable<TSource> source,

                                                                  Func<TSource, (int, int, TResult)> selector)

    {

        // check if source is null

        if (source == null)

            throw new ArgumentNullException("source");

​

        // load all items from source and pass it through selector delegate

        var items = source.Select(x => selector(x));

​

        // allocate array

        var result = new TResult[items.Select(x => x.Item1).Max(), items.Select(x => x.Item2).Max()];

​

        // loop over enumerables and store in array

        foreach (var item in items)

        {

            result[item.Item1 - 1, item.Item2 - 1] = item.Item3;

        }

​

        return result;

    }

​

    internal static int GetValueBasedHashCode<T>(this IEnumerable<T> lst, int seed, int factor)

    {

        int hash = seed;

​

        foreach (var item in lst.AsEnumerable().OrderBy(x => x.GetHashCode()))

        {

            hash = (hash * factor) + item.GetHashCode();

        }

​

        return hash;

    }

}