# include <stdio.h>
# include <stdlib.h>

# include "ppc_array.h"
# include "ppc_random_pbm.h"

/******************************************************************************/

char **make_random_matrix ( int m, int n, double f )

/******************************************************************************/
/*
  Purpose:

    make_random_matrix() creates an MxN matrix and fills it with random values.

  Licensing:

    This code is distributed under the MIT license. 

  Modified:

    08 September 2023

  Author:

    John Burkardt

  Reference:

    Rouben Rostamian,
    Programming Projects in C 
    for Students of Engineering, Science, and Mathematics,
    SIAM, 2014,
    ISBN: 978-1-611973-49-5

  Input:

    int m, n: the number of rows and columns of the matrix.

    double f: the percentage of nonzero elements to be created.

  Output:

    char M[m][n]: the random matrix.
*/
{
  int i;
  int j;
  int k;
  char **M;

  make_matrix ( M, m, n );

  for ( i = 0; i < m; i++ )
  {
    for ( j = 0; j < n; j++ )
    {
      M[i][j] = 0;
    }
  }

  k = 0;
  while ( k < f * m * n )
  {
    i = random_index ( m );
    j = random_index ( n );
    if ( M[i][j] == 0 )
    {
      M[i][j] = 1;
      k = k + 1;
    }
  }

  return M;
}
/******************************************************************************/

int random_index ( int n )

/******************************************************************************/
/*
  Purpose:

    random_index() returns a random index in a given range.

  Discussion:

    We have 0 <= random_index() < n

  Licensing:

    This code is distributed under the MIT license. 

  Modified:

    08 September 2023

  Author:

    John Burkardt

  Reference:

    Rouben Rostamian,
    Programming Projects in C 
    for Students of Engineering, Science, and Mathematics,
    SIAM, 2014,
    ISBN: 978-1-611973-49-5

  Input:

    int n: the upper limit for the index.

  Output:

    int random_index: a randomly chosen index value.
*/
{
  int value;

  value = rand ( ) / ( RAND_MAX / n + 1 );

  return value;
}
/******************************************************************************/

int write_pbm ( char **M, int m, int n, char *filename )

/******************************************************************************/
/*
  Purpose:

    write_pbm() writes an MxN matrix of 0's and 1's as a PBM graphics file.

  Licensing:

    This code is distributed under the MIT license. 

  Modified:

    08 September 2023

  Author:

    John Burkardt

  Reference:

    Rouben Rostamian,
    Programming Projects in C 
    for Students of Engineering, Science, and Mathematics,
    SIAM, 2014,
    ISBN: 978-1-611973-49-5

  Input:

    char M[m][n]: the matrix of 0's and 1's.

    int m, n: the number of rows and columns of the matrix.

    char *filename: the name of the output file.

  Output:

    int write_pbm: 1 on success, 0 on failure.
*/
{
  int i;
  int j;
  FILE *output;
/*
  Open the file.
*/
  output = fopen ( filename, "wt" );

  if ( ! output )
  {
    fprintf ( stderr, "\n" );
    fprintf ( stderr, "write_pbm(): Fatal error!\n" );
    fprintf ( stderr, "  Cannot open the output file '%s'.\n", filename );
    return 0;
  }
/*
  Write header.
*/
  fprintf ( output, "%s\n", "P1" );
  fprintf ( output, "# %s\n", filename );
  fprintf ( output, "%d  %d\n", n, m );
/*
  Write data.
*/
  for ( i = 0; i < m; i++ )
  {
    for ( j = 0; j < n; j++ )
    {
      fprintf ( output, " %d", M[i][j] );
    }
    fprintf ( output, "\n" );
  }
/*
  Close the file.
*/
  fclose ( output );

  return 1;
}