static Osobnik generateChild(Osobnik first, Osobnik second)
        {
            double x, y;

            if (Abs(first.X) - Abs(second.X) >= 0)
            {
                x = (first.X - second.X) / 2;
            }
            else
            {
                x = (second.X - first.X) / 2;
            }

            if (Abs(first.Y) - Abs(second.Y) >= 0)
            {
                y = (first.Y - second.Y) / 2;
            }
            else
            {
                y = (second.Y - first.Y) / 2;
            }

            return(new Osobnik {
                X = x, Y = y, Dopasowanie = f(x, y)
            });
        }
        static Osobnik[] generatePopulation()
        {
            Osobnik[] population = new Osobnik[PopSize];

            for (int i = 0; i < PopSize; i++)
            {
                double x = -XD + 2 * XD * rnd.NextDouble();
                double y = -YD + 2 * YD * rnd.NextDouble();

                population[i] = new Osobnik {
                    X = x, Y = y, Dopasowanie = f(x, y)
                };
            }

            return(population);
        }
        static Osobnik[] crossPopulation(Osobnik[] population)
        {
            Osobnik[] newPopulation = new Osobnik[population.Length];

            for (int i = 0; i < newPopulation.Length; i++)
            {
                int firstIndex = rnd.Next(population.Length);
                int secondIndex;
                do
                {
                    secondIndex = rnd.Next(population.Length);
                } while (firstIndex == secondIndex);
                Console.WriteLine($"First: {firstIndex} --- Second: {secondIndex}");
                newPopulation[i] = generateChild(population[firstIndex], population[secondIndex]);
            }

            return(newPopulation);
        }
        static Osobnik[] selectNewPopulation(Osobnik[] population)
        {
            Osobnik[] newPopulation = new Osobnik[population.Length];

            for (int i = 0; i < population.Length; i++)
            {
                int?enemyIndex = null;
                do
                {
                    enemyIndex = rnd.Next(population.Length);
                } while (enemyIndex == i);

                if (population[i].Dopasowanie <= population[enemyIndex.Value].Dopasowanie)
                {
                    newPopulation[i] = population[enemyIndex.Value];
                }
                else
                {
                    newPopulation[i] = population[i];
                }
            }

            return(newPopulation);
        }