How to handle System.OverflowException?

Question

C++ / C#

I started doing tasks on the Codewars platform and ran into a problem that I solved the task, the tests that exist, the program passes, and on the site the program gives the error System.OverflowException : Array dimensions exceeded supported range. Since I don’t know what else they have for tests, I tried to increase the number that goes into the function, but I can’t fix the error, I think for a long time, so I ask you to help.

namespace Test
{

    using System;

    public static class Program
    {
        public static ulong OddCount(ulong n)
        {
            ulong count = 0, odd = 0;
            ulong[] array = new ulong[n];
            for (ulong i = 0; i < n; i++)
            {
                count++;
                array[i] = count;

                if (array[i] % 2 != 0 && array[i] > 0)
                {
                    odd++;
                }
            }
            Console.WriteLine(odd);
            return odd;
        }


        static void Main(string[] args)
        {
            ulong i = 25000;
            OddCount(i);
            Console.ReadKey();
        }
    }
}

//NUnit Test

namespace Solution 
{
  using NUnit.Framework;
  using System;

  [TestFixture]
  public class SampleTest
  {
    [Test]
    public void Test()
    {
      Assert.AreEqual(7, Kata.OddCount(15));
      Assert.AreEqual(7511, Kata.OddCount(15023));
    }
  }
}

Answer 1

Obviously, in the tests, a number is shoved there, such that it is impossible to allocate an array of this size. I will assume that this is something like more than 2 ^ 32.
To solve this problem, an array is not needed at all.