/* nag_blast_dsyr2k (f16yrc) Example Program.
 *
 * Copyright 2024 Numerical Algorithms Group.
 *
 * Mark 30.2, 2024.
 */

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

int main(void) {

  /* Scalars */
  double alpha, beta;
  Integer adim1, adim2, exit_status, i, j, k, n, pda, pdb, pdc;

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

  /* Nag Types */
  NagError fail;
  Nag_OrderType order;
  Nag_UploType uplo;
  Nag_TransType trans;
  Nag_MatrixType matrix;

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

  exit_status = 0;
  INIT_FAIL(fail);

  printf("nag_blast_dsyr2k (f16yrc) Example Program Results\n\n");

  /* Skip heading in data file */
  scanf("%*[^\n] ");

  /* Read the problem dimensions */
  scanf("%" NAG_IFMT "%" NAG_IFMT "%*[^\n] ", &n, &k);

  /* Read the uplo parameter */
  scanf("%39s%*[^\n] ", nag_enum_arg);
  /* nag_enum_name_to_value (x04nac).
   * Converts NAG enum member name to value
   */
  uplo = (Nag_UploType)nag_enum_name_to_value(nag_enum_arg);
  /* Read the transpose parameter */
  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 scalar parameters */
  scanf("%lf%lf%*[^\n] ", &alpha, &beta);

  if (trans == Nag_NoTrans) {
    adim1 = n;
    adim2 = k;
  } else {
    adim1 = k;
    adim2 = n;
  }

#ifdef NAG_COLUMN_MAJOR
  pda = adim1;
#else
  pda = adim2;
#endif
  pdb = pda;
  pdc = n;
  if (k > 0 && n > 0) {
    /* Allocate memory */
    if (!(a = NAG_ALLOC(k * n, double)) || !(b = NAG_ALLOC(k * n, double)) ||
        !(c = NAG_ALLOC(n * n, double))) {
      printf("Allocation failure\n");
      exit_status = -1;
      goto END;
    }
  } else {
    printf("Invalid k or n\n");
    exit_status = 1;
    goto END;
  }

  /* Input matrix A. */
  for (i = 1; i <= adim1; ++i) {
    for (j = 1; j <= adim2; ++j)
      scanf("%lf", &A(i, j));
    scanf("%*[^\n] ");
  }
  /* Input matrix B. */
  for (i = 1; i <= adim1; ++i) {
    for (j = 1; j <= adim2; ++j)
      scanf("%lf", &B(i, j));
    scanf("%*[^\n] ");
  }
  /* Input matrix C. */
  if (uplo == Nag_Upper) {
    for (i = 1; i <= n; ++i) {
      for (j = i; j <= n; ++j)
        scanf("%lf", &C(i, j));
    }
    scanf("%*[^\n] ");
  } else {
    for (i = 1; i <= n; ++i) {
      for (j = 1; j <= i; ++j)
        scanf("%lf", &C(i, j));
    }
    scanf("%*[^\n] ");
  }

  /* nag_blast_dsyr2k (f16yrc).
   * Rank 2k update of symmetric matrix.
   *
   */
  nag_blast_dsyr2k(order, uplo, trans, n, k, alpha, a, pda, b, pdb, beta, c,
                   pdc, &fail);
  if (fail.code != NE_NOERROR) {
    printf("Error from nag_blast_dsyr2k.\n%s\n", fail.message);
    exit_status = 1;
    goto END;
  }
  if (uplo == Nag_Upper) {
    matrix = Nag_UpperMatrix;
  } else {
    matrix = Nag_LowerMatrix;
  }
  /* Print updated matrix C */
  /* nag_file_print_matrix_real_gen (x04cac).
   * Print real general matrix (easy-to-use)
   */
  fflush(stdout);
  nag_file_print_matrix_real_gen(order, matrix, Nag_NonUnitDiag, n, n, c, pdc,
                                 "Updated Matrix C", 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);
  NAG_FREE(c);

  return exit_status;
}