src/glpapi03.c
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     1 /* glpapi03.c (row and column searching routines) */
       
     2 
       
     3 /***********************************************************************
       
     4 *  This code is part of GLPK (GNU Linear Programming Kit).
       
     5 *
       
     6 *  Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008,
       
     7 *  2009, 2010 Andrew Makhorin, Department for Applied Informatics,
       
     8 *  Moscow Aviation Institute, Moscow, Russia. All rights reserved.
       
     9 *  E-mail: <mao@gnu.org>.
       
    10 *
       
    11 *  GLPK is free software: you can redistribute it and/or modify it
       
    12 *  under the terms of the GNU General Public License as published by
       
    13 *  the Free Software Foundation, either version 3 of the License, or
       
    14 *  (at your option) any later version.
       
    15 *
       
    16 *  GLPK is distributed in the hope that it will be useful, but WITHOUT
       
    17 *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
       
    18 *  or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
       
    19 *  License for more details.
       
    20 *
       
    21 *  You should have received a copy of the GNU General Public License
       
    22 *  along with GLPK. If not, see <http://www.gnu.org/licenses/>.
       
    23 ***********************************************************************/
       
    24 
       
    25 #include "glpapi.h"
       
    26 
       
    27 /***********************************************************************
       
    28 *  NAME
       
    29 *
       
    30 *  glp_create_index - create the name index
       
    31 *
       
    32 *  SYNOPSIS
       
    33 *
       
    34 *  void glp_create_index(glp_prob *lp);
       
    35 *
       
    36 *  DESCRIPTION
       
    37 *
       
    38 *  The routine glp_create_index creates the name index for the
       
    39 *  specified problem object. The name index is an auxiliary data
       
    40 *  structure, which is intended to quickly (i.e. for logarithmic time)
       
    41 *  find rows and columns by their names.
       
    42 *
       
    43 *  This routine can be called at any time. If the name index already
       
    44 *  exists, the routine does nothing. */
       
    45 
       
    46 void glp_create_index(glp_prob *lp)
       
    47 {     GLPROW *row;
       
    48       GLPCOL *col;
       
    49       int i, j;
       
    50       /* create row name index */
       
    51       if (lp->r_tree == NULL)
       
    52       {  lp->r_tree = avl_create_tree(avl_strcmp, NULL);
       
    53          for (i = 1; i <= lp->m; i++)
       
    54          {  row = lp->row[i];
       
    55             xassert(row->node == NULL);
       
    56             if (row->name != NULL)
       
    57             {  row->node = avl_insert_node(lp->r_tree, row->name);
       
    58                avl_set_node_link(row->node, row);
       
    59             }
       
    60          }
       
    61       }
       
    62       /* create column name index */
       
    63       if (lp->c_tree == NULL)
       
    64       {  lp->c_tree = avl_create_tree(avl_strcmp, NULL);
       
    65          for (j = 1; j <= lp->n; j++)
       
    66          {  col = lp->col[j];
       
    67             xassert(col->node == NULL);
       
    68             if (col->name != NULL)
       
    69             {  col->node = avl_insert_node(lp->c_tree, col->name);
       
    70                avl_set_node_link(col->node, col);
       
    71             }
       
    72          }
       
    73       }
       
    74       return;
       
    75 }
       
    76 
       
    77 /***********************************************************************
       
    78 *  NAME
       
    79 *
       
    80 *  glp_find_row - find row by its name
       
    81 *
       
    82 *  SYNOPSIS
       
    83 *
       
    84 *  int glp_find_row(glp_prob *lp, const char *name);
       
    85 *
       
    86 *  RETURNS
       
    87 *
       
    88 *  The routine glp_find_row returns the ordinal number of a row,
       
    89 *  which is assigned (by the routine glp_set_row_name) the specified
       
    90 *  symbolic name. If no such row exists, the routine returns 0. */
       
    91 
       
    92 int glp_find_row(glp_prob *lp, const char *name)
       
    93 {     AVLNODE *node;
       
    94       int i = 0;
       
    95       if (lp->r_tree == NULL)
       
    96          xerror("glp_find_row: row name index does not exist\n");
       
    97       if (!(name == NULL || name[0] == '\0' || strlen(name) > 255))
       
    98       {  node = avl_find_node(lp->r_tree, name);
       
    99          if (node != NULL)
       
   100             i = ((GLPROW *)avl_get_node_link(node))->i;
       
   101       }
       
   102       return i;
       
   103 }
       
   104 
       
   105 /***********************************************************************
       
   106 *  NAME
       
   107 *
       
   108 *  glp_find_col - find column by its name
       
   109 *
       
   110 *  SYNOPSIS
       
   111 *
       
   112 *  int glp_find_col(glp_prob *lp, const char *name);
       
   113 *
       
   114 *  RETURNS
       
   115 *
       
   116 *  The routine glp_find_col returns the ordinal number of a column,
       
   117 *  which is assigned (by the routine glp_set_col_name) the specified
       
   118 *  symbolic name. If no such column exists, the routine returns 0. */
       
   119 
       
   120 int glp_find_col(glp_prob *lp, const char *name)
       
   121 {     AVLNODE *node;
       
   122       int j = 0;
       
   123       if (lp->c_tree == NULL)
       
   124          xerror("glp_find_col: column name index does not exist\n");
       
   125       if (!(name == NULL || name[0] == '\0' || strlen(name) > 255))
       
   126       {  node = avl_find_node(lp->c_tree, name);
       
   127          if (node != NULL)
       
   128             j = ((GLPCOL *)avl_get_node_link(node))->j;
       
   129       }
       
   130       return j;
       
   131 }
       
   132 
       
   133 /***********************************************************************
       
   134 *  NAME
       
   135 *
       
   136 *  glp_delete_index - delete the name index
       
   137 *
       
   138 *  SYNOPSIS
       
   139 *
       
   140 *  void glp_delete_index(glp_prob *lp);
       
   141 *
       
   142 *  DESCRIPTION
       
   143 *
       
   144 *  The routine glp_delete_index deletes the name index previously
       
   145 *  created by the routine glp_create_index and frees the memory
       
   146 *  allocated to this auxiliary data structure.
       
   147 *
       
   148 *  This routine can be called at any time. If the name index does not
       
   149 *  exist, the routine does nothing. */
       
   150 
       
   151 void glp_delete_index(glp_prob *lp)
       
   152 {     int i, j;
       
   153       /* delete row name index */
       
   154       if (lp->r_tree != NULL)
       
   155       {  for (i = 1; i <= lp->m; i++) lp->row[i]->node = NULL;
       
   156          avl_delete_tree(lp->r_tree), lp->r_tree = NULL;
       
   157       }
       
   158       /* delete column name index */
       
   159       if (lp->c_tree != NULL)
       
   160       {  for (j = 1; j <= lp->n; j++) lp->col[j]->node = NULL;
       
   161          avl_delete_tree(lp->c_tree), lp->c_tree = NULL;
       
   162       }
       
   163       return;
       
   164 }
       
   165 
       
   166 /* eof */