/* nag_mesh_dim2_renumber (d06ccc) Example Program.
 *
 * Copyright 2019 Numerical Algorithms Group.
 *
 * Mark 27.0, 2019.
 */

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

#define EDGE(I, J) edge[3*((J) -1)+(I) -1]
#define CONN(I, J) conn[3*((J) -1)+(I) -1]
#define COOR(I, J) coor[2*((J) -1)+(I) -1]

int main(void)
{
  Integer exit_status, i, itrace, nedge, nelt, nnz, nnzmax, nv, reftk;
  NagError fail;
  char pmesh[2];
  double *coor = 0;
  Integer *conn = 0, *edge = 0, *icol = 0, *irow = 0;

  INIT_FAIL(fail);

  exit_status = 0;

  printf(" nag_mesh_dim2_renumber (d06ccc) Example Program Results\n\n");
  fflush(stdout);

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

  /* Reading of the geometry */
  scanf("%" NAG_IFMT "", &nv);
  scanf("%" NAG_IFMT "", &nelt);
  scanf("%" NAG_IFMT "", &nedge);
  scanf("%*[^\n] ");

  nnzmax = 10 * nv;

  /* Allocate memory */

  if (!(coor = NAG_ALLOC(2 * nv, double)) ||
      !(conn = NAG_ALLOC(3 * nelt, Integer)) ||
      !(edge = NAG_ALLOC(3 * nedge, Integer)) ||
      !(irow = NAG_ALLOC(nnzmax, Integer)) ||
      !(icol = NAG_ALLOC(nnzmax, Integer)))
  {
    printf("Allocation failure\n");
    exit_status = -1;
    goto END;
  }

  for (i = 1; i <= nv; ++i) {
    scanf("%lf", &COOR(1, i));
    scanf("%lf", &COOR(2, i));
    scanf("%*[^\n] ");
  }

  for (i = 1; i <= nelt; ++i) {
    scanf("%" NAG_IFMT "", &CONN(1, i));
    scanf("%" NAG_IFMT "", &CONN(2, i));
    scanf("%" NAG_IFMT "", &CONN(3, i));
    scanf("%" NAG_IFMT "", &reftk);
    scanf("%*[^\n] ");
  }

  for (i = 1; i <= nedge; ++i) {
    scanf("%" NAG_IFMT "", &reftk);
    scanf("%" NAG_IFMT "", &EDGE(1, i));
    scanf("%" NAG_IFMT "", &EDGE(2, i));
    scanf("%" NAG_IFMT "", &EDGE(3, i));
    scanf("%*[^\n] ");
  }
  scanf(" ' %1s '", pmesh);
  scanf("%*[^\n] ");

  /* Compute the sparsity of the FE matrix */
  /* from the input geometry */

  /* nag_mesh_dim2_sparsity (d06cbc).
   * Generates a sparsity pattern of a Finite Element matrix
   * associated with a given mesh
   */
  nag_mesh_dim2_sparsity(nv, nelt, nnzmax, conn, &nnz, irow, icol, &fail);

  if (fail.code == NE_NOERROR) {
    if (pmesh[0] == 'N') {
      printf(" The Matrix Sparsity characteristics\n");
      printf(" before the renumbering\n");
      printf(" nv  =%6" NAG_IFMT "\n", nv);
      printf(" nnz =%6" NAG_IFMT "\n", nnz);
    }
    else if (pmesh[0] == 'Y') {
      /* Output the sparsity of the mesh to view */
      /* it using the NAG Graphics Library */

      printf(" %10" NAG_IFMT "%10" NAG_IFMT "\n", nv, nnz);

      for (i = 0; i < nnz; ++i)
        printf(" %10" NAG_IFMT "%10" NAG_IFMT "\n", irow[i], icol[i]);
    }
    else {
      printf("Problem with the printing option Y or N\n");
      exit_status = -1;
      goto END;
    }
  }
  else {
    printf("Error from nag_mesh_dim2_sparsity (d06cbc).\n%s\n", fail.message);
    exit_status = 1;
    goto END;
  }

  /* Call the renumbering routine and get the new sparsity */

  itrace = 1;

  /* nag_mesh_dim2_renumber (d06ccc).
   * Renumbers a given mesh using Gibbs method
   */
  fflush(stdout);
  nag_mesh_dim2_renumber(nv, nelt, nedge, nnzmax, &nnz, coor, edge, conn, irow,
                   icol, itrace, 0, &fail);
  if (fail.code == NE_NOERROR) {
    if (pmesh[0] == 'N') {
      printf("\n The Matrix Sparsity characteristics\n");
      printf(" after the renumbering\n");
      printf(" nv   =%6" NAG_IFMT "\n", nv);
      printf(" nnz  =%6" NAG_IFMT "\n", nnz);
      printf(" nelt =%6" NAG_IFMT "\n", nelt);
    }
    else if (pmesh[0] == 'Y') {
      /* Output the sparsity of the renumbered mesh */
      /* to view it using the NAG Graphics Library */

      printf("%10" NAG_IFMT "%10" NAG_IFMT "\n", nv, nnz);

      for (i = 0; i < nnz; ++i)
        printf(" %10" NAG_IFMT "%10" NAG_IFMT "\n", irow[i], icol[i]);

      /* Output the renumbered mesh to view */
      /* it using the NAG Graphics Library */

      printf(" %10" NAG_IFMT "%10" NAG_IFMT "\n", nv, nelt);

      for (i = 1; i <= nv; ++i)
        printf("  %15.6e  %15.6e  \n", COOR(1, i), COOR(2, i));

      reftk = 0;
      for (i = 1; i <= nelt; ++i)
        printf(" %10" NAG_IFMT "%10" NAG_IFMT "%10" NAG_IFMT "%10" NAG_IFMT
               "\n", CONN(1, i), CONN(2, i), CONN(3, i), reftk);
    }
  }
  else {
    printf("Error from nag_mesh_dim2_renumber (d06ccc).\n%s\n", fail.message);
    exit_status = 1;
    goto END;
  }

END:
  NAG_FREE(coor);
  NAG_FREE(conn);
  NAG_FREE(edge);
  NAG_FREE(irow);
  NAG_FREE(icol);

  return exit_status;
}