/* nag_blast_dtrsm (f16yjc) Example Program.
 *
 * Copyright 2023 Numerical Algorithms Group.
 *
 * Mark 29.3, 2023.
 */

#include <nag.h>
#include <stdio.h>

int main(void) {

  /* Scalars */
  double alpha;
  Integer exit_status, i, j, m, n, pda, pdb;

  /* Arrays */
  double *a = 0, *b = 0;
  char nag_enum_arg[40];

  /* Nag Types */
  NagError fail;
  Nag_SideType side;
  Nag_DiagType diag;
  Nag_OrderType order;
  Nag_TransType trans;
  Nag_UploType uplo;

#ifdef NAG_COLUMN_MAJOR
#define A(I, J) a[(J - 1) * pda + I - 1]
#define B(I, J) b[(J - 1) * pdb + I - 1]
  order = Nag_ColMajor;
#else
#define A(I, J) a[(I - 1) * pda + J - 1]
#define B(I, J) b[(I - 1) * pdb + J - 1]
  order = Nag_RowMajor;
#endif

  exit_status = 0;
  INIT_FAIL(fail);

  printf("nag_blast_dtrsm (f16yjc) Example Program Results\n\n");

  /* Skip heading in data file */
  scanf("%*[^\n] ");
  /* Read the problem dimensions */
  scanf("%" NAG_IFMT "%" NAG_IFMT "%*[^\n] ", &m, &n);

#ifdef NAG_COLUMN_MAJOR
  pdb = m;
#else
  pdb = n;
#endif

  /* Read side */
  scanf("%39s%*[^\n] ", nag_enum_arg);
  /* nag_enum_name_to_value (x04nac).
   * Converts NAG enum member name to value
   */
  side = (Nag_SideType)nag_enum_name_to_value(nag_enum_arg);
  /* Read uplo */
  scanf("%39s%*[^\n] ", nag_enum_arg);
  /* nag_enum_name_to_value (x04nac), see above. */
  uplo = (Nag_UploType)nag_enum_name_to_value(nag_enum_arg);
  /* Read trans */
  scanf("%39s%*[^\n] ", nag_enum_arg);
  /* nag_enum_name_to_value (x04nac), see above. */
  trans = (Nag_TransType)nag_enum_name_to_value(nag_enum_arg);
  /* Read diag */
  scanf("%39s%*[^\n] ", nag_enum_arg);
  /* nag_enum_name_to_value (x04nac), see above. */
  diag = (Nag_DiagType)nag_enum_name_to_value(nag_enum_arg);
  /* Read scalar parameters */
  scanf("%lf%*[^\n] ", &alpha);

  if (side == Nag_LeftSide) {
    pda = m;
  } else {
    pda = n;
  }

  if (n > 0) {
    /* Allocate memory */
    if (!(a = NAG_ALLOC(pda * pda, double)) ||
        !(b = NAG_ALLOC(n * m, double))) {
      printf("Allocation failure\n");
      exit_status = -1;
      goto END;
    }
  } else {
    printf("Invalid n\n");
    exit_status = 1;
    return exit_status;
  }

  /* Read A from data file */
  if (uplo == Nag_Upper) {
    for (i = 1; i <= pda; ++i) {
      for (j = i; j <= pda; ++j)
        scanf("%lf", &A(i, j));
    }
    scanf("%*[^\n] ");
  } else {
    for (i = 1; i <= pda; ++i) {
      for (j = 1; j <= i; ++j)
        scanf("%lf", &A(i, j));
    }
    scanf("%*[^\n] ");
  }

  /* Input matrix B */
  for (i = 1; i <= m; ++i) {
    for (j = 1; j <= n; ++j)
      scanf("%lf", &B(i, j));
  }

  /* nag_blast_dtrsm (f16yjc).
   * Multiply matrix by inverse of Triangular matrix.
   *
   */
  nag_blast_dtrsm(order, side, uplo, trans, diag, m, n, alpha, a, pda, b, pdb,
                  &fail);
  if (fail.code != NE_NOERROR) {
    printf("Error from nag_blast_dtrsm (f16yjc).\n%s\n", fail.message);
    exit_status = 1;
    goto END;
  }

  /* Print the updated matrix B */
  /* nag_file_print_matrix_real_gen (x04cac).
   * Print real general matrix (easy-to-use)
   */
  fflush(stdout);
  nag_file_print_matrix_real_gen(order, Nag_GeneralMatrix, Nag_NonUnitDiag, m,
                                 n, b, pdb, "Updated matrix B", 0, &fail);
  if (fail.code != NE_NOERROR) {
    printf("Error from nag_file_print_matrix_real_gen (x04cac).\n%s\n",
           fail.message);
    exit_status = 1;
    goto END;
  }

END:
  NAG_FREE(a);
  NAG_FREE(b);

  return exit_status;
}