/* nag_lapacklin_zpbtrs (f07hsc) Example Program.
 *
 * Copyright 2024 Numerical Algorithms Group.
 *
 * Mark 30.2, 2024.
 */

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

int main(void) {
  /* Scalars */
  Integer i, j, k, kd, n, nrhs, pdab, pdb;
  Integer exit_status = 0;
  Nag_UploType uplo;
  NagError fail;
  Nag_OrderType order;
  /* Arrays */
  char nag_enum_arg[40];
  Complex *ab = 0, *b = 0;

#ifdef NAG_COLUMN_MAJOR
#define AB_UPPER(I, J) ab[(J - 1) * pdab + k + I - J - 1]
#define AB_LOWER(I, J) ab[(J - 1) * pdab + I - J]
#define B(I, J) b[(J - 1) * pdb + I - 1]
  order = Nag_ColMajor;
#else
#define AB_UPPER(I, J) ab[(I - 1) * pdab + J - I]
#define AB_LOWER(I, J) ab[(I - 1) * pdab + k + J - I - 1]
#define B(I, J) b[(I - 1) * pdb + J - 1]
  order = Nag_RowMajor;
#endif

  INIT_FAIL(fail);

  printf("nag_lapacklin_zpbtrs (f07hsc) Example Program Results\n\n");

  /* Skip heading in data file */
  scanf("%*[^\n] ");
  scanf("%" NAG_IFMT "%" NAG_IFMT "%" NAG_IFMT "%*[^\n] ", &n, &kd, &nrhs);
  pdab = kd + 1;
#ifdef NAG_COLUMN_MAJOR
  pdb = n;
#else
  pdb = nrhs;
#endif

  /* Allocate memory */
  if (!(ab = NAG_ALLOC((kd + 1) * n, Complex)) ||
      !(b = NAG_ALLOC(n * nrhs, Complex))) {
    printf("Allocation failure\n");
    exit_status = -1;
    goto END;
  }

  /* Read A from data file */
  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);

  k = kd + 1;
  if (uplo == Nag_Upper) {
    for (i = 1; i <= n; ++i) {
      for (j = i; j <= MIN(i + kd, n); ++j)
        scanf(" ( %lf , %lf )", &AB_UPPER(i, j).re, &AB_UPPER(i, j).im);
    }
    scanf("%*[^\n] ");
  } else {
    for (i = 1; i <= n; ++i) {
      for (j = MAX(1, i - kd); j <= i; ++j)
        scanf(" ( %lf , %lf )", &AB_LOWER(i, j).re, &AB_LOWER(i, j).im);
    }
    scanf("%*[^\n] ");
  }
  /* Read B from data file */
  for (i = 1; i <= n; ++i) {
    for (j = 1; j <= nrhs; ++j)
      scanf(" ( %lf , %lf )", &B(i, j).re, &B(i, j).im);
  }
  scanf("%*[^\n] ");

  /* Factorize A */
  /* nag_lapacklin_zpbtrf (f07hrc).
   * Cholesky factorization of complex Hermitian
   * positive-definite band matrix
   */
  nag_lapacklin_zpbtrf(order, uplo, n, kd, ab, pdab, &fail);
  if (fail.code != NE_NOERROR) {
    printf("Error from nag_lapacklin_zpbtrf (f07hrc).\n%s\n", fail.message);
    exit_status = 1;
    goto END;
  }

  /* Compute solution */
  /* nag_lapacklin_zpbtrs (f07hsc).
   * Solution of complex Hermitian positive-definite band
   * system of linear equations, multiple right-hand sides,
   * matrix already factorized by nag_lapacklin_zpbtrf (f07hrc)
   */
  nag_lapacklin_zpbtrs(order, uplo, n, kd, nrhs, ab, pdab, b, pdb, &fail);
  if (fail.code != NE_NOERROR) {
    printf("Error from nag_lapacklin_zpbtrs (f07hsc).\n%s\n", fail.message);
    exit_status = 1;
    goto END;
  }
  /* Print solution */
  /* nag_file_print_matrix_complex_gen_comp (x04dbc).
   * Print complex general matrix (comprehensive)
   */
  fflush(stdout);
  nag_file_print_matrix_complex_gen_comp(
      order, Nag_GeneralMatrix, Nag_NonUnitDiag, n, nrhs, b, pdb,
      Nag_BracketForm, "%7.4f", "Solution(s)", Nag_IntegerLabels, 0,
      Nag_IntegerLabels, 0, 80, 0, 0, &fail);
  if (fail.code != NE_NOERROR) {
    printf("Error from nag_file_print_matrix_complex_gen_comp (x04dbc).\n%s\n",
           fail.message);
    exit_status = 1;
    goto END;
  }
END:
  NAG_FREE(ab);
  NAG_FREE(b);
  return exit_status;
}