import java.util.Scanner;

public class Gauss2
{
   public static void main(String[] args)
   {
      Scanner in = new Scanner(System.in);

      double[][] A;
      double[]   b, x;
      double     pivot, factor;
      int        n;   // Number of variables

      int i, j, k;

      System.out.print("Number of unknows: ");
      n = in.nextInt();         // Read in problem size

      A = new double[n][n];     // Reserve space for coefficient matrix
      b = new double[n];        // Reserve space for RHS vector

      // Read in the rows, one row at a time
      for (i = 0; i < n; i++)
      {
         // Read in row i's coefficients
         for (j = 0; j < n; j++)
         {
             System.out.print("A["+i+"]["+j+"] = ");
             A[i][j] = in.nextDouble();
         }

         // Read in row i's RHS
         System.out.print("b["+i+"] = ");
         b[i] = in.nextDouble();
      }

      System.out.println("\nSimultaneous equations:");
      Print(A, b);

      x = MathTools.GaussianElim(A, b);

      System.out.println("Solution:");
      for (i = 0; i < n; i++)
         System.out.println("x[" + (i+1) + "] = " + x[i]);

   }


   public static void Print(double[][] A, double b[])
   {
      int i, j;

      // Print the equations
      for (i = 0; i < b.length; i++)
      {  
         // Print row i
         for (j = 0; j < b.length; j++)
         {
            if ( j != 0 )
               System.out.print(" + ");

            System.out.print(A[i][j] + " x" + (j+1));    
         }

         System.out.println(" = " + b[i]);
      }

      System.out.println();
   }
}