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CSharp · Console

/Program.cs

using System;
using System.Collections.Generic;			
using System.Threading.Tasks;
using System.Collections.Concurrent;
public class Program
{

	public static void Main()
	{
		var items = new List<int>();

		var tasks = new List<Task>();
		for (int i = 0; i < 5; i++)
		{
			tasks.Add(Task.Run(() => {
				for (int k = 0; k < 10000; k++)
				{
					items.Add(i);
				}
			}));
		}
	
		Task.WaitAll(tasks.ToArray());
		Console.WriteLine(items.Count);
		
	}
}