using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    static public void Main()

    {

        int[] ints = { 10001, 10002, 10003, 10004, 10005 };

        int[] intsX = ints.Reverse().ToArray();

​

        int hash1;

        int hash2;

        hash1 = GetHashCode(ints);

        Console.WriteLine("hash1={0}", hash1); //954101523

        hash2 = GetHashCode(intsX);

        Console.WriteLine("hash2={0}", hash2); //957855123

        Console.WriteLine("hash1==hash2 : {0}", hash1 == hash2);

    }

​

    static int GetHashCode(IEnumerable<int> integers)

    {

        IEnumerator<int> intEnum = integers.GetEnumerator();

​

        if(intEnum.MoveNext()==false) return 0;

​

        int hash = 0;

        unchecked {

            hash = intEnum.Current.GetHashCode();

            for(;intEnum.MoveNext()==true;)

                hash = 31 * hash + intEnum.Current.GetHashCode();

        }

​

        return hash;

    }

}