/* nag_lapacklin_zgerfs (f07avc) Example Program.
 *
 * Copyright 2024 Numerical Algorithms Group.
 *
 * Mark 30.3, 2024.
 */

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

int main(void) {
  /* Scalars */
  Integer berr_len, i, ferr_len, ipiv_len, j, n, nrhs;
  Integer pda, pdaf, pdb, pdx;
  Integer exit_status = 0;
  NagError fail;
  Nag_OrderType order;
  /* Arrays */
  Complex *a = 0, *af = 0, *b = 0, *x = 0;
  double *berr = 0, *ferr = 0;
  Integer *ipiv = 0;

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

  INIT_FAIL(fail);

  printf("nag_lapacklin_zgerfs (f07avc) Example Program Results\n\n");

  /* Skip heading in data file */
  scanf("%*[^\n] ");
  scanf("%" NAG_IFMT "%" NAG_IFMT "%*[^\n] ", &n, &nrhs);
#ifdef NAG_COLUMN_MAJOR
  pda = n;
  pdaf = n;
  pdb = n;
  pdx = n;
#else
  pda = n;
  pdaf = n;
  pdb = nrhs;
  pdx = nrhs;
#endif
  ipiv_len = n;
  ferr_len = n;
  berr_len = nrhs;

  /* Allocate memory */
  if (!(a = NAG_ALLOC(n * n, Complex)) || !(af = NAG_ALLOC(n * n, Complex)) ||
      !(b = NAG_ALLOC(n * nrhs, Complex)) || !(x = NAG_ALLOC(n * n, Complex)) ||
      !(berr = NAG_ALLOC(berr_len, double)) ||
      !(ferr = NAG_ALLOC(ferr_len, double)) ||
      !(ipiv = NAG_ALLOC(ipiv_len, Integer))) {
    printf("Allocation failure\n");
    exit_status = -1;
    goto END;
  }

  /* Read A and B from data file, and copy A to AF and B to X */
  for (i = 1; i <= n; ++i) {
    for (j = 1; j <= n; ++j)
      scanf(" ( %lf , %lf )", &A(i, j).re, &A(i, j).im);
  }
  scanf("%*[^\n] ");
  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] ");

  for (i = 1; i <= n; ++i) {
    for (j = 1; j <= n; ++j) {
      AF(i, j).re = A(i, j).re;
      AF(i, j).im = A(i, j).im;
    }
  }
  for (i = 1; i <= n; ++i) {
    for (j = 1; j <= nrhs; ++j) {
      X(i, j).re = B(i, j).re;
      X(i, j).im = B(i, j).im;
    }
  }
  /* Factorize A in the array AF */
  /* nag_lapacklin_zgetrf (f07arc).
   * LU factorization of complex m by n matrix
   */
  nag_lapacklin_zgetrf(order, n, n, af, pdaf, ipiv, &fail);
  if (fail.code != NE_NOERROR) {
    printf("Error from nag_lapacklin_zgetrf (f07arc).\n%s\n", fail.message);
    exit_status = 1;
    goto END;
  }
  /* Compute solution in the array X */
  /* nag_lapacklin_zgetrs (f07asc).
   * Solution of complex system of linear equations, multiple
   * right-hand sides, matrix already factorized by nag_lapacklin_zgetrf
   * (f07arc)
   */
  nag_lapacklin_zgetrs(order, Nag_NoTrans, n, nrhs, af, pdaf, ipiv, x, pdx,
                       &fail);
  if (fail.code != NE_NOERROR) {
    printf("Error from nag_lapacklin_zgetrs (f07asc).\n%s\n", fail.message);
    exit_status = 1;
    goto END;
  }
  /* Improve solution, and compute backward errors and */
  /* estimated bounds on the forward errors */
  /* nag_lapacklin_zgerfs (f07avc).
   * Refined solution with error bounds of complex system of
   * linear equations, multiple right-hand sides
   */
  nag_lapacklin_zgerfs(order, Nag_NoTrans, n, nrhs, a, pda, af, pdaf, ipiv, b,
                       pdb, x, pdx, ferr, berr, &fail);
  if (fail.code != NE_NOERROR) {
    printf("Error from nag_lapacklin_zgerfs (f07avc).\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, x, pdx,
      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;
  }

  printf("\nBackward errors (machine-dependent)\n");

  for (j = 1; j <= nrhs; ++j)
    printf("%11.1e%s", berr[j - 1], j % 4 == 0 ? "\n" : " ");
  printf("\nEstimated forward error bounds (machine-dependent)\n");
  for (j = 1; j <= nrhs; ++j)
    printf("%11.1e%s", ferr[j - 1], j % 4 == 0 || j == nrhs ? "\n" : " ");
END:
  NAG_FREE(a);
  NAG_FREE(af);
  NAG_FREE(b);
  NAG_FREE(x);
  NAG_FREE(berr);
  NAG_FREE(ferr);
  NAG_FREE(ipiv);
  return exit_status;
}