namespace CountOfOccurences
{
    using System;
    using System.Linq;

    public static class CountOfOccurences
    {
        private const int MaxNumber = 1000;

        public static void Main()
        {
            var nums = new[] { 3, 4, 4, 2, 3, 3, 4, 3, 2 };
            var occurences = Enumerable.Repeat(0, MaxNumber + 1).ToList();

            foreach (var num in nums)
            {
                occurences[num]++;
            }

            for (int i = 0; i <= MaxNumber; i++)
            {
                if (occurences[i] != 0)
                {
                    var number = occurences.IndexOf(occurences[i]);
                    var times = occurences[i];

                    Console.WriteLine($"{number} -> {times} times");
                }
            }
        }
    }
}