/* glpapi03.c (row and column searching routines) */

/***********************************************************************

*  This code is part of GLPK (GNU Linear Programming Kit).

*

*  Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008,

*  2009, 2010 Andrew Makhorin, Department for Applied Informatics,

*  Moscow Aviation Institute, Moscow, Russia. All rights reserved.

*  E-mail: <mao@gnu.org>.

*

*  GLPK is free software: you can redistribute it and/or modify it

*  under the terms of the GNU General Public License as published by

*  the Free Software Foundation, either version 3 of the License, or

*  (at your option) any later version.

*

*  GLPK is distributed in the hope that it will be useful, but WITHOUT

*  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY

*  or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public

*  License for more details.

*

*  You should have received a copy of the GNU General Public License

*  along with GLPK. If not, see <http://www.gnu.org/licenses/>.

***********************************************************************/

#include "glpapi.h"

/***********************************************************************

*  NAME

*

*  glp_create_index - create the name index

*

*  SYNOPSIS

*

*  void glp_create_index(glp_prob *lp);

*

*  DESCRIPTION

*

*  The routine glp_create_index creates the name index for the

*  specified problem object. The name index is an auxiliary data

*  structure, which is intended to quickly (i.e. for logarithmic time)

*  find rows and columns by their names.

*

*  This routine can be called at any time. If the name index already

*  exists, the routine does nothing. */

void glp_create_index(glp_prob *lp)

{     GLPROW *row;

      GLPCOL *col;

      int i, j;

      /* create row name index */

      if (lp->r_tree == NULL)

      {  lp->r_tree = avl_create_tree(avl_strcmp, NULL);

         for (i = 1; i <= lp->m; i++)

         {  row = lp->row[i];

            xassert(row->node == NULL);

            if (row->name != NULL)

            {  row->node = avl_insert_node(lp->r_tree, row->name);

               avl_set_node_link(row->node, row);

            }

         }

      }

      /* create column name index */

      if (lp->c_tree == NULL)

      {  lp->c_tree = avl_create_tree(avl_strcmp, NULL);

         for (j = 1; j <= lp->n; j++)

         {  col = lp->col[j];

            xassert(col->node == NULL);

            if (col->name != NULL)

            {  col->node = avl_insert_node(lp->c_tree, col->name);

               avl_set_node_link(col->node, col);

            }

         }

      }

      return;

}

/***********************************************************************

*  NAME

*

*  glp_find_row - find row by its name

*

*  SYNOPSIS

*

*  int glp_find_row(glp_prob *lp, const char *name);

*

*  RETURNS

*

*  The routine glp_find_row returns the ordinal number of a row,

*  which is assigned (by the routine glp_set_row_name) the specified

*  symbolic name. If no such row exists, the routine returns 0. */

int glp_find_row(glp_prob *lp, const char *name)

{     AVLNODE *node;

      int i = 0;

      if (lp->r_tree == NULL)

         xerror("glp_find_row: row name index does not exist\n");

      if (!(name == NULL || name[0] == '\0' || strlen(name) > 255))

      {  node = avl_find_node(lp->r_tree, name);

         if (node != NULL)

            i = ((GLPROW *)avl_get_node_link(node))->i;

      }

      return i;

}

/***********************************************************************

*  NAME

*

*  glp_find_col - find column by its name

*

*  SYNOPSIS

*

*  int glp_find_col(glp_prob *lp, const char *name);

*

*  RETURNS

*

*  The routine glp_find_col returns the ordinal number of a column,

*  which is assigned (by the routine glp_set_col_name) the specified

*  symbolic name. If no such column exists, the routine returns 0. */

int glp_find_col(glp_prob *lp, const char *name)

{     AVLNODE *node;

      int j = 0;

      if (lp->c_tree == NULL)

         xerror("glp_find_col: column name index does not exist\n");

      if (!(name == NULL || name[0] == '\0' || strlen(name) > 255))

      {  node = avl_find_node(lp->c_tree, name);

         if (node != NULL)

            j = ((GLPCOL *)avl_get_node_link(node))->j;

      }

      return j;

}

/***********************************************************************

*  NAME

*

*  glp_delete_index - delete the name index

*

*  SYNOPSIS

*

*  void glp_delete_index(glp_prob *lp);

*

*  DESCRIPTION

*

*  The routine glp_delete_index deletes the name index previously

*  created by the routine glp_create_index and frees the memory

*  allocated to this auxiliary data structure.

*

*  This routine can be called at any time. If the name index does not

*  exist, the routine does nothing. */

void glp_delete_index(glp_prob *lp)

{     int i, j;

      /* delete row name index */

      if (lp->r_tree != NULL)

      {  for (i = 1; i <= lp->m; i++) lp->row[i]->node = NULL;

         avl_delete_tree(lp->r_tree), lp->r_tree = NULL;

      }

      /* delete column name index */

      if (lp->c_tree != NULL)

      {  for (j = 1; j <= lp->n; j++) lp->col[j]->node = NULL;

         avl_delete_tree(lp->c_tree), lp->c_tree = NULL;

      }

      return;

}

/* eof */