/*	matrix3.cpp

        Multiplication of matrixes.
        Dynamic arrays, optimized.

	(C) R.N.Shakirov, IMach of RAS(UB), 1998 - 2000
	All Rights Reserved.
*/
#include <fstream.h>
#include "exarray.h"

int	scalar	(const int* p1, const int *p2, int dim)
{
  int sum = 0;
  for (int k = 0; k < dim; k++)
    sum += p1 [k] * p2 [k];
  return sum;
}

int	main	(int argc, char **argv)
{
  if (argc < 3) return 1;
  typedef exarray<int> vector;
  exarray <vector> m1,m2,m3;
  int i,j,k,dim = 0;

  // Input

  ifstream fin (argv [1]);
  if (!fin) return 1;
  fin >> dim;

  for (i = 0; i < dim; i++)
    for (j = 0; j < dim; j++)
      fin >> m1 [i] [j];

  for (i = 0; i < dim; i++)
    for (j = 0; j < dim; j++)
      fin >> m2 [j] [i];   // m2 is transposed!

  // Multiplication

  for (i = 0; i < dim; i++)
    for (j = 0; j < dim; j++)
      m3 [i] [j] = scalar (m1 [i], m2 [j], dim);

  // Output   

  ofstream fout (argv [2]);
  if (!fout) return 1;
  for (i = 0; i < dim; i++)
  {
    for (j = 0; j < dim; j++)
      { fout.width (6); fout << m3 [i] [j]; }
    fout << '\n';
  }

  return 0;
}