diff -r d59bea55db9b -r c445c931472f src/glpapi03.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/glpapi03.c	Mon Dec 06 13:09:21 2010 +0100
@@ -0,0 +1,166 @@
+/* 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 */