MonteCarlo/montekarlo/MonteKarlo.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace montekarlo
{
    internal class MonteKarlo
    {
        public static void MonteKarloP()
        {
            int n = 1000;
            int k = 0;
            double S;
            Random rand = new Random();

            for (int i = 1; i < n; i++) 
            {
                double x = rand.NextDouble();
                double y = rand.NextDouble();

                if (x * x + y * y <= 1)
                {
                    k++;
                }
            }

            S = 4.0 * k / n;

            Console.WriteLine("Результат Pi = " +  S);
            Console.WriteLine("Точно Pi = " + Math.PI);
        }
    }
}