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CSharp · Console

/Program.cs

using System;
using System.Collections.Immutable;
using System.Linq;
					
public class Program
{
	public static void Main()
	{
		const int Repeats = 10000; 
		const int Group = 200;
		
		var x = Enumerable.Repeat(1.0, Group).ToArray();
        var r = new Random();
		for (int i=0; i<Repeats; i++)
		{
		   for (int n=0; n<Group; n++)
		   {
              if (r.NextDouble() > 0.5)
			      x[n] += 0.5 * x[n] * 0.5;
		      else
			      x[n] -= 0.5 * x[n] * 0.4;
		   }
		}

		for (int n=0; n<Group; n++)  
		   Console.WriteLine($"{x[n]:F2}");
	}
}