/* nag_sparse_real_symm_sort (f11zbc) Example Program.
 *
 * Copyright 2024 Numerical Algorithms Group.
 *
 * Mark 30.2, 2024.
 */

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

int main(void) {
  double *a = 0;
  Integer *icol = 0;
  Integer *irow = 0, *istr = 0;
  Integer exit_status = 0, i, n, nnz;
  Nag_SparseSym_Zeros zero;
  Nag_SparseSym_Dups dup;
  NagError fail;

  INIT_FAIL(fail);

  printf("nag_sparse_real_symm_sort (f11zbc) Example Program Results\n");

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

  /* Read order of matrix and number of nonzero entries */
  scanf("%" NAG_IFMT "%*[^\n]", &n);
  scanf("%" NAG_IFMT "%*[^\n]", &nnz);

  /* Allocate memory */
  istr = NAG_ALLOC(n + 1, Integer);
  a = NAG_ALLOC(nnz, double);
  irow = NAG_ALLOC(nnz, Integer);
  icol = NAG_ALLOC(nnz, Integer);

  if (!istr || !irow || !icol || !a) {
    printf("Allocation failure\n");
    exit_status = -1;
    goto END;
  }

  /* Read and output the original nonzero elements */
  for (i = 1; i <= nnz; ++i)
    scanf("%lf%" NAG_IFMT "%" NAG_IFMT "%*[^\n]", &a[i - 1], &irow[i - 1],
          &icol[i - 1]);
  printf(" Original elements \n");
  printf(" nnz =  %6" NAG_IFMT "\n", nnz);
  for (i = 1; i <= nnz; ++i)
    printf(" %8" NAG_IFMT "%16.4e%8" NAG_IFMT "%8" NAG_IFMT "\n", i, a[i - 1],
           irow[i - 1], icol[i - 1]);

  /* Reorder, sum duplicates and remove zeros */
  dup = Nag_SparseSym_SumDups;
  zero = Nag_SparseSym_RemoveZeros;

  /* nag_sparse_real_symm_sort (f11zbc).
   * Sparse sort (symmetric)
   */
  nag_sparse_real_symm_sort(n, &nnz, a, irow, icol, dup, zero, istr, &fail);
  if (fail.code != NE_NOERROR) {
    printf("Error from nag_sparse_real_symm_sort (f11zbc).\n%s\n",
           fail.message);
    exit_status = 1;
    goto END;
  }

  /* Output results */
  printf(" Reordered elements \n");
  printf(" nnz = %4" NAG_IFMT "\n", nnz);

  for (i = 1; i <= nnz; ++i)
    printf(" %8" NAG_IFMT "%16.4e%8" NAG_IFMT "%8" NAG_IFMT "\n", i, a[i - 1],
           irow[i - 1], icol[i - 1]);

END:
  NAG_FREE(istr);
  NAG_FREE(irow);
  NAG_FREE(icol);
  NAG_FREE(a);
  return exit_status;
}