HR25

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

namespace hf25
{
    class Program
    {
        static void Main(string[] args)
        {
            FileStream f = new FileStream("datahf25.txt", FileMode.Open, FileAccess.Read);
            StreamReader s = new StreamReader(f);

            string line = s.ReadLine();
            Console.WriteLine(line);
            int w = line.Length;
            int k = w - 1;
            for (; k >= 0; k--)
            {
                if (line[k] == ' ') break;
            }
            string r = line.Substring(k + 1, w - 1 - k);
            int n = int.Parse(r);

            double[,] a = new double[n, n];
            string[] sn;
            char[] sep = new char[] { ' ' };

            for (int i = 0; i < n; i++)
            {
                line=s.ReadLine();
                sn=line.Split(sep);
                int j = 0;
                for (int z = 0; z < sn.Length; z++)
                {
                    if (sn[z].Length == 0) continue;
                    double d = double.Parse(sn[z]);
                    a[i, j] = d;
                    Console.Write("{0,8:f2}", d);

                    if (++j > n) break;
                }
                Console.WriteLine();
            }
            s.Close();

            double[,] o = new double[n,n];
            Fadeev(o, a, n);

            PrintM("matrix a", a, n);
            PrintM("obratnaya", o, n);

            double[,] e = new double[n, n];
            for (int i = 0; i < n; i++)
                for (int j = 0; j < n; j++)
                {
                    double sum = 0.0;
                    for (int m = 0; m < n; m++)
                        sum += a[i, m] * o[m, j];
                    e[i, j] = sum;
                }
            PrintM("matrix e=a*o", e, n);

            Console.ReadKey();

        }
        static void PrintM(string text, double[,] a, int n)
        {
            Console.WriteLine(text);
            for (int i = 0; i < n; i++)
            {
                for (int j = 0; j < n; j++)
                    Console.Write("{0,8:F2}", a[i, j]);
                Console.WriteLine();
            }
        }
        //-------------------------------------------
        static bool Fadeev(double[,] r, double[,] a, int n)
        {
            double[,] b = new double[n, n];
            for (int i = 0; i < n; i++)
            {
                for (int j = 0; j < n; j++)
                    b[i, j] = 0;
                b[i, i] = 1;
            }
         //   PrintM(" обратная матрица B", b, n);

            double[,] u = new double[n, n];
            double p = 0.0, s = 0.0;

            for (int k = 1; k <= n; k++)
            {

               // Console.WriteLine("{0}", k);
                for (int i = 0; i < n; i++)

                    for (int j = 0; j < n; j++)
                    {
                        s = 0.0;

                        for (int m = 0; m < n; m++)
                        {
                            s += a[i, m] * b[m, j];
                        }
                        u[i, j] = s;
                    }
           //     PrintM(" матрица U", u, n);

                s = 0.0;
                for (int i = 0; i < n; i++)
                    s += u[i, i];
             //   Console.WriteLine("{0}", s);

                p = s / k;
             //   Console.WriteLine("{0}", p);

                if (k == n) break;

                for (int i = 0; i < n; i++)
                {
                    for (int j = 0; j < n; j++)
                        b[i, j] = u[i, j];
                    b[i, i] -= p;
                }
            //    PrintM(" матрица B", b, n);
            }

            bool z = true;
            if (p == 0.0) z = false;
            else for (int i = 0; i < n; i++)
                    for (int j = 0; j < n; j++)
                        r[i, j] = b[i, j] / p;

            return z;
        }
        /*
        Fadeev(r, a, n);
            PrintM(" матрица R", r, n);

        //вектор свободных членов
        double[] B = new double[n]
            {22,19,-10,49};

        double[,] e = new double[n, n];
            for (int i = 0; i<n; i++)
             for (int j = 0; j<n;j++)
                {  double s = 0.0;
                     for( int m = 0; m<n; m++)
                     s+=a[i, m]*r[m, j];
                     e[i, j] = s;
                }
            PrintM("матрица E", e, n);
            */
    }
}