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

namespace Jakobi
{
    class Method
    {
        public double [,] _Amatrix = new double[,]
            {
                { 2, 2, 10 },
                { 10, 1, 1 },
                { 2, 10, 1 }
            };

        public double [] _Bmatrix = new double[] { 14, 12, 13 };

        public double[] _B;

        public double[] _C;

        public double[] _A;

        public double E = 0.01;


        public void prepare()
        {
            for (int i = _Amatrix.GetLength(0) - 1; i >= 0; i--)
            {
                for (int j = _Amatrix.GetLength(1) - 1; j >= 0; j--)
                {
                    double sum = 0;

                    if (_Amatrix[i, i] != _Amatrix[i, j])
                    {
                        sum += _Amatrix[i, j];
                    }

                    if (_Amatrix[i, i] < sum)
                    {
                        for (int k = _Amatrix.GetLength(1) - 1; k >= 0; k--)
                        {
                            if (_Amatrix[i, i] < _Amatrix[k, i])
                            {
                                double[] res = new double[_Amatrix.GetLength(0)];

                                for (int s = 0; s < _Amatrix.GetLength(0); s++)
                                {
                                    res[s] = _Amatrix[k, s];
                                    _Amatrix[k, s] = _Amatrix[i, s];
                                    _Amatrix[i, s] = res[s];

                                    res[s] = _Bmatrix[k];
                                    _Bmatrix[k] = _Bmatrix[i];
                                    _Bmatrix[i] = res[s];
                                }
                            }
                        }
                    }
                }
            }
        }

        public void getB()
        {
            _B = new double[_Amatrix.GetLength(0)];

            for (int i = 0; i < _Bmatrix.Length; i++)
            {
                _B[i] = _Bmatrix[i];
            }
        }

        public void zeroing()
        {
            for (int i = 0; i < _Amatrix.GetLength(0); i++)
            {
                double data = _Amatrix[i, i];

                for (int j = 0; j < _Amatrix.GetLength(1); j++)
                {
                    if (_Amatrix[i, j] == _Amatrix[i, i])
                    {
                        _Amatrix[i, j] = 0;
                    }
                    else
                    {
                        _Amatrix[i, j] /= -data;
                    }
                }

                _Bmatrix[i] /= data;
            }
        }

        public void Iteration()
        {
            _C = new double[_Amatrix.GetLength(0)];
            _A = new double[_Amatrix.GetLength(0)];

            for (int i = 0; i < _Bmatrix.Length; i++)
            {
                _A[i] = _Bmatrix[i];
            }

            for (int i = 0; i < _Amatrix.GetLength(0); i++)
            {
                double sum = 0;

                for (int j = 0; j < _Amatrix.GetLength(1); j++)
                {
                    sum += _Amatrix[i, j] * _Bmatrix[j];
                }

                _C[i] = sum + _B[i];
            }

            for(int i = 0; i < _Bmatrix.Length; i++)
            {
                _Bmatrix[i] = _C[i];
            }
        }

        public void showAmatrix()
        {
            Console.WriteLine();

            for(int i = 0; i < _Amatrix.GetLength(0); i++)
            {
                for(int j =0 ; j < _Amatrix.GetLength(1); j++)
                {
                    Console.Write("{0}\t", _Amatrix[i, j]);
                }
                Console.WriteLine("|\t{0}", _Bmatrix[i]);
            }

            Console.WriteLine();
        }

        public double convergence()
        {
            return Math.Abs(_A[_Bmatrix.Length - 1] - _C[_Bmatrix.Length - 1]);
        }

        public void showC()
        {
            Console.WriteLine("C:");

            for (int i = 0; i < _C.Length; i++)
            {
                Console.Write("{0}\t", _C[i]);
            }

            Console.WriteLine();
        }

        public void showB()
        {
            Console.WriteLine("B:");

            for (int i = 0; i < _B.Length; i++)
            {
                Console.Write("{0}\t", _B[i]);
            }

            Console.WriteLine();
        }

        public void showA()
        {
            Console.WriteLine("A:");

            for (int i = 0; i < _A.Length; i++)
            {
                Console.Write("{0}\t", _A[i]);
            }

            Console.WriteLine();
        }

    }

    class Program
    {
        static void Main(string[] args)
        {
            Method method = new Method();

            method.showAmatrix();

            method.prepare();

            method.showAmatrix();

            method.zeroing();

            method.showAmatrix();

            method.getB();

            int k = 1;

            Console.WriteLine("{0} итерация", k);

            method.Iteration();

            method.showAmatrix();

            k++;

            Console.WriteLine("----------------------------------------");

            while (method.convergence() > method.E)
            {
                Console.WriteLine("{0} итерация", k);

                method.Iteration();

                method.showAmatrix();

                Console.WriteLine("{0:f5}", method.convergence());

                Console.WriteLine("----------------------------------------");
                k++;
            }

            Console.ReadKey();
        }
    }
}