using System;
namespace ConsoleApp6
{
    class Program
    {
        static double foo(double x)
        {
            return x * x - 2 * x - 2 * Math.Cos(x);
        }
        static void Main(string[] args)
        {
            double masheps = 1;
            while (1 + masheps > 1)
                masheps = masheps / 2;
            masheps = Math.Sqrt(masheps);

            double a = -0.5;
            double b = 1;
            double L = b - a;
            // Шаг 2
            double x0 = (foo(a) - foo(b) + L * (a + b)) / (2 * L);
            double y0 = (foo(a) + foo(b) + L * (a - b)) / 2;
            double phiMin = y0;
            // Шаг 3
            var i = 0;
            double x1L = 0;
            double x1R = 0;
            double phi = 0;
            double delta = (foo(x0) - phiMin) / (2 * L);
            do
            { // Шаг 4
                if ((2 * L * delta) < masheps)
                {
                    Console.WriteLine(x0);
                    Console.WriteLine(foo(x0));
                    Console.WriteLine($"{i} - i");
                }
                else
                {
                    //шаг 5
                    x1L = x0 - delta;
                    x1R = x0 + delta;
                    phi = (foo(x0) + phiMin) / 2;
                    //шаг 6
                    if (foo(x1L) < foo(x1R))
                    {
                        x0 = x1L;
                    }
                    else
                    {
                        x0 = x1R;
                    }
                    phiMin = phi;
                    i++;
                }
            } while (i<28);
            Console.WriteLine($"{i} - i");
            Console.WriteLine(x0);
            Console.WriteLine(foo(x0));
            Console.ReadKey();

        }
    }
}