Задача. Единственный элемент

GetSingleNumber.cs

using System;
					
public class Program
{
	public static int GetSingleNumber(int[] nums) {
		int single = 0;
		int twice = 0;

		foreach (int num in nums)
		{
			single = (single ^ num) & ~twice;
			twice = (twice ^ num) & ~single;
		}

		return single;
	}
	
	public static void Main()
	{
		Console.WriteLine("UniLecs");
		
		// tests
		Console.WriteLine(GetSingleNumber(new int[] { 2, 2, 3, 2 })); // 3
	}
}