/* 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 */