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

namespace igorgay
{
    class Program
    {
        static double a11, a12, a13, a22, a23, a33,
                      a14, a24, a34;

        static List<double> FSHTR(List<double> X)
            => new List<double>()
            {
                a14+a11*X[0] + a12*X[1] + a13*X[2],
                a24+a22*X[1] + a12*X[0] + a23*X[2],
                a34+a33*X[2] + a13*X[0] + a23*X[1]
            };

        static List<double> H(List<double> X)
            => new List<double>()
            {
                a11*X[0]+a12*X[1]+a13*X[2],
                a12*X[0]+a22*X[1]+a23*X[2],
                a13*X[0]+a23*X[1]+a33*X[2]
            };

        static List<double> Add(List<double> x, List<double> y)
            => new List<double>()
            {
                x[0]+y[0],
                x[1]+y[1],
                x[2]+y[2]
            };

        static List<double> Subs(List<double> x, List<double> y)
            => new List<double>()
            {
                x[0]-y[0],
                x[1]-y[1],
                x[2]-y[2]
            };

        static List<double> DecMult(double x, List<double> y)
            => new List<double>()
            {
                x*y[0],
                x*y[1],
                x*y[2]
            };

        static double ScalMult(List<double> x, List<double> y)
            => x[0]*y[0] +
                x[1]*y[1] +
                x[2]*y[2];

        static double NORM(List<double> x)
            => Math.Sqrt(ScalMult(x, x));

        static void Main(string[] args)
        {
            a11 = 1.2775; a12 = 0.9314; a13 = 0.5983; a22 = 0.9925; a23 = 0.1963; a33 = 0.7299;
            a14 = -1.5337; a24 = -1.1257; a34 = -0.8848;
            var e = 0.000001;

            var x_k = new List<double>() { 0, 0, 0 };
            var x_k_1 = new List<double>() { 0, 0, 0 };
            var h_k = new List<double>() { 0, 0, 0 };
            var lambda = 0.0;
            do
            {
                x_k_1 = x_k;

                h_k = DecMult(-1, FSHTR(x_k_1));

                lambda = ScalMult(FSHTR(x_k_1), h_k) / ScalMult(h_k, H(h_k));

                x_k = Add(x_k, DecMult(lambda, h_k));


            } while (NORM(Subs(x_k, x_k_1)) > e);
            Console.WriteLine(string.Join(", ", x_k_1));
        }
    }
}