src/glpnet04.c
author Alpar Juttner <alpar@cs.elte.hu>
Sun, 05 Dec 2010 17:35:23 +0100
changeset 2 4c8956a7bdf4
permissions -rw-r--r--
Set up CMAKE build environment
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/* glpnet04.c (grid-like network problem generator) */
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/***********************************************************************
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*  This code is part of GLPK (GNU Linear Programming Kit).
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*
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*  This code is a modified version of the program GRIDGEN, a grid-like
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*  network problem generator developed by Yusin Lee and Jim Orlin.
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*  The original code is publically available on the DIMACS ftp site at:
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*  <ftp://dimacs.rutgers.edu/pub/netflow/generators/network/gridgen>.
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*
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*  All changes concern only the program interface, so this modified
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*  version produces exactly the same instances as the original version.
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*
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*  Changes were made by Andrew Makhorin <mao@gnu.org>.
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*
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*  GLPK is free software: you can redistribute it and/or modify it
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*  under the terms of the GNU General Public License as published by
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*  the Free Software Foundation, either version 3 of the License, or
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*  (at your option) any later version.
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*
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*  GLPK is distributed in the hope that it will be useful, but WITHOUT
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*  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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*  or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
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*  License for more details.
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*
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*  You should have received a copy of the GNU General Public License
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*  along with GLPK. If not, see <http://www.gnu.org/licenses/>.
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***********************************************************************/
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#include "glpapi.h"
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/***********************************************************************
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*  NAME
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*
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*  glp_gridgen - grid-like network problem generator
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*
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*  SYNOPSIS
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*
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*  int glp_gridgen(glp_graph *G, int v_rhs, int a_cap, int a_cost,
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*     const int parm[1+14]);
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*
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*  DESCRIPTION
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*
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*  The routine glp_gridgen is a grid-like network problem generator
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*  developed by Yusin Lee and Jim Orlin.
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*
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*  The parameter G specifies the graph object, to which the generated
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*  problem data have to be stored. Note that on entry the graph object
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*  is erased with the routine glp_erase_graph.
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*
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*  The parameter v_rhs specifies an offset of the field of type double
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*  in the vertex data block, to which the routine stores the supply or
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*  demand value. If v_rhs < 0, the value is not stored.
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*
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*  The parameter a_cap specifies an offset of the field of type double
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*  in the arc data block, to which the routine stores the arc capacity.
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*  If a_cap < 0, the capacity is not stored.
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*
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*  The parameter a_cost specifies an offset of the field of type double
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*  in the arc data block, to which the routine stores the per-unit cost
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*  if the arc flow. If a_cost < 0, the cost is not stored.
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*
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*  The array parm contains description of the network to be generated:
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*
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*  parm[0]  not used
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*  parm[1]  two-ways arcs indicator:
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*           1 - if links in both direction should be generated
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*           0 - otherwise
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*  parm[2]  random number seed (a positive integer)
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*  parm[3]  number of nodes (the number of nodes generated might be
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*           slightly different to make the network a grid)
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*  parm[4]  grid width
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*  parm[5]  number of sources
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*  parm[6]  number of sinks
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*  parm[7]  average degree
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*  parm[8]  total flow
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*  parm[9]  distribution of arc costs:
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*           1 - uniform
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*           2 - exponential
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*  parm[10] lower bound for arc cost (uniform)
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*           100 * lambda (exponential)
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*  parm[11] upper bound for arc cost (uniform)
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*           not used (exponential)
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*  parm[12] distribution of arc capacities:
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*           1 - uniform
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*           2 - exponential
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*  parm[13] lower bound for arc capacity (uniform)
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*           100 * lambda (exponential)
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*  parm[14] upper bound for arc capacity (uniform)
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*           not used (exponential)
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*
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*  RETURNS
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*
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*  If the instance was successfully generated, the routine glp_gridgen
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*  returns zero; otherwise, if specified parameters are inconsistent,
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*  the routine returns a non-zero error code.
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*
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*  COMMENTS
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*
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*  This network generator generates a grid-like network plus a super
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*  node. In additional to the arcs connecting the nodes in the grid,
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*  there is an arc from each supply node to the super node and from the
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*  super node to each demand node to guarantee feasiblity. These arcs
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*  have very high costs and very big capacities.
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*
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*  The idea of this network generator is as follows: First, a grid of
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*  n1 * n2 is generated. For example, 5 * 3. The nodes are numbered as
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*  1 to 15, and the supernode is numbered as n1*n2+1. Then arcs between
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*  adjacent nodes are generated. For these arcs, the user is allowed to
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*  specify either to generate two-way arcs or one-way arcs. If two-way
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*  arcs are to be generated, two arcs, one in each direction, will be
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*  generated between each adjacent node pairs. Otherwise, only one arc
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*  will be generated. If this is the case, the arcs will be generated
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*  in alterntive directions as shown below.
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*
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*      1 ---> 2 ---> 3 ---> 4 ---> 5
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*      |      ^      |      ^      |
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*      |      |      |      |      |
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*      V      |      V      |      V
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*      6 <--- 7 <--- 8 <--- 9 <--- 10
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*      |      ^      |      ^      |
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*      |      |      |      |      |
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*      V      |      V      |      V
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*     11 --->12 --->13 --->14 ---> 15
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*
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*  Then the arcs between the super node and the source/sink nodes are
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*  added as mentioned before. If the number of arcs still doesn't reach
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*  the requirement, additional arcs will be added by uniformly picking
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*  random node pairs. There is no checking to prevent multiple arcs
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*  between any pair of nodes. However, there will be no self-arcs (arcs
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*  that poins back to its tail node) in the network.
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*
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*  The source and sink nodes are selected uniformly in the network, and
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*  the imbalances of each source/sink node are also assigned by uniform
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*  distribution. */
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struct stat_para
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{     /* structure for statistical distributions */
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      int distribution;
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      /* the distribution: */
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#define UNIFORM      1  /* uniform distribution */
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#define EXPONENTIAL  2  /* exponential distribution */
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      double parameter[5];
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      /* the parameters of the distribution */
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};
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struct arcs
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{     int from;
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      /* the FROM node of that arc */
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      int to;
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      /* the TO node of that arc */
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      int cost;
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      /* original cost of that arc */
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      int u;
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      /* capacity of the arc */
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};
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struct imbalance
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{     int node;
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      /* Node ID */
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      int supply;
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      /* Supply of that node */
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};
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struct csa
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{     /* common storage area */
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      glp_graph *G;
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      int v_rhs, a_cap, a_cost;
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      int seed;
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      /* random number seed */
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      int seed_original;
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      /* the original seed from input */
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      int two_way;
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      /* 0: generate arcs in both direction for the basic grid, except
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         for the arcs to/from the super node.  1: o/w */
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      int n_node;
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      /* total number of nodes in the network, numbered 1 to n_node,
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         including the super node, which is the last one */
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      int n_arc;
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      /* total number of arcs in the network, counting EVERY arc. */
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      int n_grid_arc;
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      /* number of arcs in the basic grid, including the arcs to/from
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         the super node */
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      int n_source, n_sink;
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      /* number of source and sink nodes */
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      int avg_degree;
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      /* average degree, arcs to and from the super node are counted */
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      int t_supply;
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      /* total supply in the network */
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      int n1, n2;
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      /* the two edges of the network grid.  n1 >= n2 */
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      struct imbalance *source_list, *sink_list;
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      /* head of the array of source/sink nodes */
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      struct stat_para arc_costs;
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      /* the distribution of arc costs */
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      struct stat_para capacities;
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      /* distribution of the capacities of the arcs */
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      struct arcs *arc_list;
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      /* head of the arc list array.  Arcs in this array are in the
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         order of grid_arcs, arcs to/from super node, and other arcs */
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};
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#define G (csa->G)
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#define v_rhs (csa->v_rhs)
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#define a_cap (csa->a_cap)
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#define a_cost (csa->a_cost)
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#define seed (csa->seed)
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#define seed_original (csa->seed_original)
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#define two_way (csa->two_way)
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#define n_node (csa->n_node)
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#define n_arc (csa->n_arc)
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#define n_grid_arc (csa->n_grid_arc)
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#define n_source (csa->n_source)
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#define n_sink (csa->n_sink)
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#define avg_degree (csa->avg_degree)
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#define t_supply (csa->t_supply)
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#define n1 (csa->n1)
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#define n2 (csa->n2)
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#define source_list (csa->source_list)
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#define sink_list (csa->sink_list)
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#define arc_costs (csa->arc_costs)
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#define capacities (csa->capacities)
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#define arc_list (csa->arc_list)
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static void assign_capacities(struct csa *csa);
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static void assign_costs(struct csa *csa);
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static void assign_imbalance(struct csa *csa);
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static int exponential(struct csa *csa, double lambda[1]);
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static struct arcs *gen_additional_arcs(struct csa *csa, struct arcs
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      *arc_ptr);
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static struct arcs *gen_basic_grid(struct csa *csa, struct arcs
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      *arc_ptr);
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static void gen_more_arcs(struct csa *csa, struct arcs *arc_ptr);
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static void generate(struct csa *csa);
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static void output(struct csa *csa);
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static double randy(struct csa *csa);
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static void select_source_sinks(struct csa *csa);
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static int uniform(struct csa *csa, double a[2]);
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int glp_gridgen(glp_graph *G_, int _v_rhs, int _a_cap, int _a_cost,
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      const int parm[1+14])
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{     struct csa _csa, *csa = &_csa;
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      int n, ret;
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      G = G_;
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      v_rhs = _v_rhs;
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      a_cap = _a_cap;
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      a_cost = _a_cost;
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      if (G != NULL)
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      {  if (v_rhs >= 0 && v_rhs > G->v_size - (int)sizeof(double))
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            xerror("glp_gridgen: v_rhs = %d; invalid offset\n", v_rhs);
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         if (a_cap >= 0 && a_cap > G->a_size - (int)sizeof(double))
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            xerror("glp_gridgen: a_cap = %d; invalid offset\n", a_cap);
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         if (a_cost >= 0 && a_cost > G->a_size - (int)sizeof(double))
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            xerror("glp_gridgen: a_cost = %d; invalid offset\n", a_cost)
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               ;
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      }
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      /* Check the parameters for consistency. */
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      if (!(parm[1] == 0 || parm[1] == 1))
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      {  ret = 1;
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         goto done;
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      }
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      if (parm[2] < 1)
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      {  ret = 2;
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         goto done;
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      }
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      if (!(10 <= parm[3] && parm[3] <= 40000))
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      {  ret = 3;
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         goto done;
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      }
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      if (!(1 <= parm[4] && parm[4] <= 40000))
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      {  ret = 4;
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         goto done;
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      }
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      if (!(parm[5] >= 0 && parm[6] >= 0 && parm[5] + parm[6] <=
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         parm[3]))
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      {  ret = 5;
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         goto done;
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      }
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      if (!(1 <= parm[7] && parm[7] <= parm[3]))
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      {  ret = 6;
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         goto done;
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      }
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      if (parm[8] < 0)
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      {  ret = 7;
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         goto done;
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      }
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      if (!(parm[9] == 1 || parm[9] == 2))
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      {  ret = 8;
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         goto done;
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      }
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      if (parm[9] == 1 && parm[10] > parm[11] ||
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          parm[9] == 2 && parm[10] < 1)
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      {  ret = 9;
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         goto done;
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      }
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      if (!(parm[12] == 1 || parm[12] == 2))
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      {  ret = 10;
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         goto done;
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      }
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      if (parm[12] == 1 && !(0 <= parm[13] && parm[13] <= parm[14]) ||
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          parm[12] == 2 && parm[13] < 1)
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      {  ret = 11;
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         goto done;
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      }
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      /* Initialize the graph object. */
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      if (G != NULL)
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      {  glp_erase_graph(G, G->v_size, G->a_size);
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         glp_set_graph_name(G, "GRIDGEN");
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      }
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      /* Copy the generator parameters. */
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      two_way = parm[1];
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      seed_original = seed = parm[2];
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      n_node = parm[3];
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      n = parm[4];
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      n_source = parm[5];
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      n_sink = parm[6];
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      avg_degree = parm[7];
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      t_supply = parm[8];
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      arc_costs.distribution = parm[9];
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      if (parm[9] == 1)
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      {  arc_costs.parameter[0] = parm[10];
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         arc_costs.parameter[1] = parm[11];
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      }
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      else
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      {  arc_costs.parameter[0] = (double)parm[10] / 100.0;
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         arc_costs.parameter[1] = 0.0;
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      }
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      capacities.distribution = parm[12];
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      if (parm[12] == 1)
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      {  capacities.parameter[0] = parm[13];
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         capacities.parameter[1] = parm[14];
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      }
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      else
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      {  capacities.parameter[0] = (double)parm[13] / 100.0;
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         capacities.parameter[1] = 0.0;
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      }
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      /* Calculate the edge lengths of the grid according to the
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         input. */
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      if (n * n >= n_node)
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      {  n1 = n;
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         n2 = (int)((double)n_node / (double)n + 0.5);
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      }
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      else
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      {  n2 = n;
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         n1 = (int)((double)n_node / (double)n + 0.5);
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      }
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      /* Recalculate the total number of nodes and plus 1 for the super
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         node. */
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      n_node = n1 * n2 + 1;
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      n_arc = n_node * avg_degree;
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      n_grid_arc = (two_way + 1) * ((n1 - 1) * n2 + (n2 - 1) * n1) +
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         n_source + n_sink;
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      if (n_grid_arc > n_arc) n_arc = n_grid_arc;
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      arc_list = xcalloc(n_arc, sizeof(struct arcs));
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      source_list = xcalloc(n_source, sizeof(struct imbalance));
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      sink_list = xcalloc(n_sink, sizeof(struct imbalance));
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      /* Generate a random network. */
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      generate(csa);
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      /* Output the network. */
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      output(csa);
alpar@1
   361
      /* Free all allocated memory. */
alpar@1
   362
      xfree(arc_list);
alpar@1
   363
      xfree(source_list);
alpar@1
   364
      xfree(sink_list);
alpar@1
   365
      /* The instance has been successfully generated. */
alpar@1
   366
      ret = 0;
alpar@1
   367
done: return ret;
alpar@1
   368
}
alpar@1
   369
alpar@1
   370
#undef random
alpar@1
   371
alpar@1
   372
static void assign_capacities(struct csa *csa)
alpar@1
   373
{     /* Assign a capacity to each arc. */
alpar@1
   374
      struct arcs *arc_ptr = arc_list;
alpar@1
   375
      int (*random)(struct csa *csa, double *);
alpar@1
   376
      int i;
alpar@1
   377
      /* Determine the random number generator to use. */
alpar@1
   378
      switch (arc_costs.distribution)
alpar@1
   379
      {  case UNIFORM:
alpar@1
   380
            random = uniform;
alpar@1
   381
            break;
alpar@1
   382
         case EXPONENTIAL:
alpar@1
   383
            random = exponential;
alpar@1
   384
            break;
alpar@1
   385
         default:
alpar@1
   386
            xassert(csa != csa);
alpar@1
   387
      }
alpar@1
   388
      /* Assign capacities to grid arcs. */
alpar@1
   389
      for (i = n_source + n_sink; i < n_grid_arc; i++, arc_ptr++)
alpar@1
   390
         arc_ptr->u = random(csa, capacities.parameter);
alpar@1
   391
      i = i - n_source - n_sink;
alpar@1
   392
      /* Assign capacities to arcs to/from supernode. */
alpar@1
   393
      for (; i < n_grid_arc; i++, arc_ptr++)
alpar@1
   394
         arc_ptr->u = t_supply;
alpar@1
   395
      /* Assign capacities to all other arcs. */
alpar@1
   396
      for (; i < n_arc; i++, arc_ptr++)
alpar@1
   397
         arc_ptr->u = random(csa, capacities.parameter);
alpar@1
   398
      return;
alpar@1
   399
}
alpar@1
   400
alpar@1
   401
static void assign_costs(struct csa *csa)
alpar@1
   402
{     /* Assign a cost to each arc. */
alpar@1
   403
      struct arcs *arc_ptr = arc_list;
alpar@1
   404
      int (*random)(struct csa *csa, double *);
alpar@1
   405
      int i;
alpar@1
   406
      /* A high cost assigned to arcs to/from the supernode. */
alpar@1
   407
      int high_cost;
alpar@1
   408
      /* The maximum cost assigned to arcs in the base grid. */
alpar@1
   409
      int max_cost = 0;
alpar@1
   410
      /* Determine the random number generator to use. */
alpar@1
   411
      switch (arc_costs.distribution)
alpar@1
   412
      {  case UNIFORM:
alpar@1
   413
            random = uniform;
alpar@1
   414
            break;
alpar@1
   415
         case EXPONENTIAL:
alpar@1
   416
            random = exponential;
alpar@1
   417
            break;
alpar@1
   418
         default:
alpar@1
   419
            xassert(csa != csa);
alpar@1
   420
      }
alpar@1
   421
      /* Assign costs to arcs in the base grid. */
alpar@1
   422
      for (i = n_source + n_sink; i < n_grid_arc; i++, arc_ptr++)
alpar@1
   423
      {  arc_ptr->cost = random(csa, arc_costs.parameter);
alpar@1
   424
         if (max_cost < arc_ptr->cost) max_cost = arc_ptr->cost;
alpar@1
   425
      }
alpar@1
   426
      i = i - n_source - n_sink;
alpar@1
   427
      /* Assign costs to arcs to/from the super node. */
alpar@1
   428
      high_cost = max_cost * 2;
alpar@1
   429
      for (; i < n_grid_arc; i++, arc_ptr++)
alpar@1
   430
         arc_ptr->cost = high_cost;
alpar@1
   431
      /* Assign costs to all other arcs. */
alpar@1
   432
      for (; i < n_arc; i++, arc_ptr++)
alpar@1
   433
         arc_ptr->cost = random(csa, arc_costs.parameter);
alpar@1
   434
      return;
alpar@1
   435
}
alpar@1
   436
alpar@1
   437
static void assign_imbalance(struct csa *csa)
alpar@1
   438
{     /* Assign an imbalance to each node. */
alpar@1
   439
      int total, i;
alpar@1
   440
      double avg;
alpar@1
   441
      struct imbalance *ptr;
alpar@1
   442
      /* assign the supply nodes */
alpar@1
   443
      avg = 2.0 * t_supply / n_source;
alpar@1
   444
      do
alpar@1
   445
      {  for (i = 1, total = t_supply, ptr = source_list + 1;
alpar@1
   446
            i < n_source; i++, ptr++)
alpar@1
   447
         {  ptr->supply = (int)(randy(csa) * avg + 0.5);
alpar@1
   448
            total -= ptr->supply;
alpar@1
   449
         }
alpar@1
   450
         source_list->supply = total;
alpar@1
   451
      }
alpar@1
   452
      /* redo all if the assignment "overshooted" */
alpar@1
   453
      while (total <= 0);
alpar@1
   454
      /* assign the demand nodes */
alpar@1
   455
      avg = -2.0 * t_supply / n_sink;
alpar@1
   456
      do
alpar@1
   457
      {  for (i = 1, total = t_supply, ptr = sink_list + 1;
alpar@1
   458
            i < n_sink; i++, ptr++)
alpar@1
   459
         {  ptr->supply = (int)(randy(csa) * avg - 0.5);
alpar@1
   460
            total += ptr->supply;
alpar@1
   461
         }
alpar@1
   462
         sink_list->supply = - total;
alpar@1
   463
      }
alpar@1
   464
      while (total <= 0);
alpar@1
   465
      return;
alpar@1
   466
}
alpar@1
   467
alpar@1
   468
static int exponential(struct csa *csa, double lambda[1])
alpar@1
   469
{     /* Returns an "exponentially distributed" integer with parameter
alpar@1
   470
         lambda. */
alpar@1
   471
      return ((int)(- lambda[0] * log((double)randy(csa)) + 0.5));
alpar@1
   472
}
alpar@1
   473
alpar@1
   474
static struct arcs *gen_additional_arcs(struct csa *csa, struct arcs
alpar@1
   475
      *arc_ptr)
alpar@1
   476
{     /* Generate an arc from each source to the supernode and from
alpar@1
   477
         supernode to each sink. */
alpar@1
   478
      int i;
alpar@1
   479
      for (i = 0; i < n_source; i++, arc_ptr++)
alpar@1
   480
      {  arc_ptr->from = source_list[i].node;
alpar@1
   481
         arc_ptr->to = n_node;
alpar@1
   482
      }
alpar@1
   483
      for (i = 0; i < n_sink; i++, arc_ptr++)
alpar@1
   484
      {  arc_ptr->to = sink_list[i].node;
alpar@1
   485
         arc_ptr->from = n_node;
alpar@1
   486
      }
alpar@1
   487
      return arc_ptr;
alpar@1
   488
}
alpar@1
   489
alpar@1
   490
static struct arcs *gen_basic_grid(struct csa *csa, struct arcs
alpar@1
   491
      *arc_ptr)
alpar@1
   492
{     /* Generate the basic grid. */
alpar@1
   493
      int direction = 1, i, j, k;
alpar@1
   494
      if (two_way)
alpar@1
   495
      {  /* Generate an arc in each direction. */
alpar@1
   496
         for (i = 1; i < n_node; i += n1)
alpar@1
   497
         {  for (j = i, k = j + n1 - 1; j < k; j++)
alpar@1
   498
            {  arc_ptr->from = j;
alpar@1
   499
               arc_ptr->to = j + 1;
alpar@1
   500
               arc_ptr++;
alpar@1
   501
               arc_ptr->from = j + 1;
alpar@1
   502
               arc_ptr->to = j;
alpar@1
   503
               arc_ptr++;
alpar@1
   504
            }
alpar@1
   505
         }
alpar@1
   506
         for (i = 1; i <= n1; i++)
alpar@1
   507
         {  for (j = i + n1; j < n_node; j += n1)
alpar@1
   508
            {  arc_ptr->from = j;
alpar@1
   509
               arc_ptr->to = j - n1;
alpar@1
   510
               arc_ptr++;
alpar@1
   511
               arc_ptr->from = j - n1;
alpar@1
   512
               arc_ptr->to = j;
alpar@1
   513
               arc_ptr++;
alpar@1
   514
            }
alpar@1
   515
         }
alpar@1
   516
      }
alpar@1
   517
      else
alpar@1
   518
      {  /* Generate one arc in each direction. */
alpar@1
   519
         for (i = 1; i < n_node; i += n1)
alpar@1
   520
         {  if (direction == 1)
alpar@1
   521
               j = i;
alpar@1
   522
            else
alpar@1
   523
               j = i + 1;
alpar@1
   524
            for (k = j + n1 - 1; j < k; j++)
alpar@1
   525
            {  arc_ptr->from = j;
alpar@1
   526
               arc_ptr->to = j + direction;
alpar@1
   527
               arc_ptr++;
alpar@1
   528
            }
alpar@1
   529
            direction = - direction;
alpar@1
   530
         }
alpar@1
   531
         for (i = 1; i <= n1; i++)
alpar@1
   532
         {  j = i + n1;
alpar@1
   533
            if (direction == 1)
alpar@1
   534
            {  for (; j < n_node; j += n1)
alpar@1
   535
               {  arc_ptr->from = j - n1;
alpar@1
   536
                  arc_ptr->to = j;
alpar@1
   537
                  arc_ptr++;
alpar@1
   538
               }
alpar@1
   539
            }
alpar@1
   540
            else
alpar@1
   541
            {  for (; j < n_node; j += n1)
alpar@1
   542
               {  arc_ptr->from = j - n1;
alpar@1
   543
                  arc_ptr->to = j;
alpar@1
   544
                  arc_ptr++;
alpar@1
   545
               }
alpar@1
   546
            }
alpar@1
   547
            direction = - direction;
alpar@1
   548
         }
alpar@1
   549
      }
alpar@1
   550
      return arc_ptr;
alpar@1
   551
}
alpar@1
   552
alpar@1
   553
static void gen_more_arcs(struct csa *csa, struct arcs *arc_ptr)
alpar@1
   554
{     /* Generate random arcs to meet the specified density. */
alpar@1
   555
      int i;
alpar@1
   556
      double ab[2];
alpar@1
   557
      ab[0] = 0.9;
alpar@1
   558
      ab[1] = n_node - 0.99;  /* upper limit is n_node-1 because the
alpar@1
   559
                                 supernode cannot be selected */
alpar@1
   560
      for (i = n_grid_arc; i < n_arc; i++, arc_ptr++)
alpar@1
   561
      {  arc_ptr->from = uniform(csa, ab);
alpar@1
   562
         arc_ptr->to = uniform(csa, ab);
alpar@1
   563
         if (arc_ptr->from == arc_ptr->to)
alpar@1
   564
         {  arc_ptr--;
alpar@1
   565
            i--;
alpar@1
   566
         }
alpar@1
   567
      }
alpar@1
   568
      return;
alpar@1
   569
}
alpar@1
   570
alpar@1
   571
static void generate(struct csa *csa)
alpar@1
   572
{     /* Generate a random network. */
alpar@1
   573
      struct arcs *arc_ptr = arc_list;
alpar@1
   574
      arc_ptr = gen_basic_grid(csa, arc_ptr);
alpar@1
   575
      select_source_sinks(csa);
alpar@1
   576
      arc_ptr = gen_additional_arcs(csa, arc_ptr);
alpar@1
   577
      gen_more_arcs(csa, arc_ptr);
alpar@1
   578
      assign_costs(csa);
alpar@1
   579
      assign_capacities(csa);
alpar@1
   580
      assign_imbalance(csa);
alpar@1
   581
      return;
alpar@1
   582
}
alpar@1
   583
alpar@1
   584
static void output(struct csa *csa)
alpar@1
   585
{     /* Output the network in DIMACS format. */
alpar@1
   586
      struct arcs *arc_ptr;
alpar@1
   587
      struct imbalance *imb_ptr;
alpar@1
   588
      int i;
alpar@1
   589
      if (G != NULL) goto skip;
alpar@1
   590
      /* Output "c", "p" records. */
alpar@1
   591
      xprintf("c generated by GRIDGEN\n");
alpar@1
   592
      xprintf("c seed %d\n", seed_original);
alpar@1
   593
      xprintf("c nodes %d\n", n_node);
alpar@1
   594
      xprintf("c grid size %d X %d\n", n1, n2);
alpar@1
   595
      xprintf("c sources %d sinks %d\n", n_source, n_sink);
alpar@1
   596
      xprintf("c avg. degree %d\n", avg_degree);
alpar@1
   597
      xprintf("c supply %d\n", t_supply);
alpar@1
   598
      switch (arc_costs.distribution)
alpar@1
   599
      {  case UNIFORM:
alpar@1
   600
            xprintf("c arc costs: UNIFORM distr. min %d max %d\n",
alpar@1
   601
               (int)arc_costs.parameter[0],
alpar@1
   602
               (int)arc_costs.parameter[1]);
alpar@1
   603
            break;
alpar@1
   604
         case EXPONENTIAL:
alpar@1
   605
            xprintf("c arc costs: EXPONENTIAL distr. lambda %d\n",
alpar@1
   606
               (int)arc_costs.parameter[0]);
alpar@1
   607
            break;
alpar@1
   608
         default:
alpar@1
   609
            xassert(csa != csa);
alpar@1
   610
      }
alpar@1
   611
      switch (capacities.distribution)
alpar@1
   612
      {  case UNIFORM:
alpar@1
   613
            xprintf("c arc caps :  UNIFORM distr. min %d max %d\n",
alpar@1
   614
               (int)capacities.parameter[0],
alpar@1
   615
               (int)capacities.parameter[1]);
alpar@1
   616
            break;
alpar@1
   617
         case EXPONENTIAL:
alpar@1
   618
            xprintf("c arc caps :  EXPONENTIAL distr. %d lambda %d\n",
alpar@1
   619
               (int)capacities.parameter[0]);
alpar@1
   620
            break;
alpar@1
   621
         default:
alpar@1
   622
            xassert(csa != csa);
alpar@1
   623
      }
alpar@1
   624
skip: if (G == NULL)
alpar@1
   625
         xprintf("p min %d %d\n", n_node, n_arc);
alpar@1
   626
      else
alpar@1
   627
      {  glp_add_vertices(G, n_node);
alpar@1
   628
         if (v_rhs >= 0)
alpar@1
   629
         {  double zero = 0.0;
alpar@1
   630
            for (i = 1; i <= n_node; i++)
alpar@1
   631
            {  glp_vertex *v = G->v[i];
alpar@1
   632
               memcpy((char *)v->data + v_rhs, &zero, sizeof(double));
alpar@1
   633
            }
alpar@1
   634
         }
alpar@1
   635
      }
alpar@1
   636
      /* Output "n node supply". */
alpar@1
   637
      for (i = 0, imb_ptr = source_list; i < n_source; i++, imb_ptr++)
alpar@1
   638
      {  if (G == NULL)
alpar@1
   639
            xprintf("n %d %d\n", imb_ptr->node, imb_ptr->supply);
alpar@1
   640
         else
alpar@1
   641
         {  if (v_rhs >= 0)
alpar@1
   642
            {  double temp = (double)imb_ptr->supply;
alpar@1
   643
               glp_vertex *v = G->v[imb_ptr->node];
alpar@1
   644
               memcpy((char *)v->data + v_rhs, &temp, sizeof(double));
alpar@1
   645
            }
alpar@1
   646
         }
alpar@1
   647
      }
alpar@1
   648
      for (i = 0, imb_ptr = sink_list; i < n_sink; i++, imb_ptr++)
alpar@1
   649
      {  if (G == NULL)
alpar@1
   650
            xprintf("n %d %d\n", imb_ptr->node, imb_ptr->supply);
alpar@1
   651
         else
alpar@1
   652
         {  if (v_rhs >= 0)
alpar@1
   653
            {  double temp = (double)imb_ptr->supply;
alpar@1
   654
               glp_vertex *v = G->v[imb_ptr->node];
alpar@1
   655
               memcpy((char *)v->data + v_rhs, &temp, sizeof(double));
alpar@1
   656
            }
alpar@1
   657
         }
alpar@1
   658
      }
alpar@1
   659
      /* Output "a from to lowcap=0 hicap cost". */
alpar@1
   660
      for (i = 0, arc_ptr = arc_list; i < n_arc; i++, arc_ptr++)
alpar@1
   661
      {  if (G == NULL)
alpar@1
   662
            xprintf("a %d %d 0 %d %d\n", arc_ptr->from, arc_ptr->to,
alpar@1
   663
               arc_ptr->u, arc_ptr->cost);
alpar@1
   664
         else
alpar@1
   665
         {  glp_arc *a = glp_add_arc(G, arc_ptr->from, arc_ptr->to);
alpar@1
   666
            if (a_cap >= 0)
alpar@1
   667
            {  double temp = (double)arc_ptr->u;
alpar@1
   668
               memcpy((char *)a->data + a_cap, &temp, sizeof(double));
alpar@1
   669
            }
alpar@1
   670
            if (a_cost >= 0)
alpar@1
   671
            {  double temp = (double)arc_ptr->cost;
alpar@1
   672
               memcpy((char *)a->data + a_cost, &temp, sizeof(double));
alpar@1
   673
            }
alpar@1
   674
         }
alpar@1
   675
      }
alpar@1
   676
      return;
alpar@1
   677
}
alpar@1
   678
alpar@1
   679
static double randy(struct csa *csa)
alpar@1
   680
{     /* Returns a random number between 0.0 and 1.0.
alpar@1
   681
         See Ward Cheney & David Kincaid, "Numerical Mathematics and
alpar@1
   682
         Computing," 2Ed, pp. 335. */
alpar@1
   683
      seed = 16807 * seed % 2147483647;
alpar@1
   684
      if (seed < 0) seed = - seed;
alpar@1
   685
      return seed * 4.6566128752459e-10;
alpar@1
   686
}
alpar@1
   687
alpar@1
   688
static void select_source_sinks(struct csa *csa)
alpar@1
   689
{     /* Randomly select the source nodes and sink nodes. */
alpar@1
   690
      int i, *int_ptr;
alpar@1
   691
      int *temp_list;   /* a temporary list of nodes */
alpar@1
   692
      struct imbalance *ptr;
alpar@1
   693
      double ab[2];     /* parameter for random number generator */
alpar@1
   694
      ab[0] = 0.9;
alpar@1
   695
      ab[1] = n_node - 0.99;  /* upper limit is n_node-1 because the
alpar@1
   696
                                 supernode cannot be selected */
alpar@1
   697
      temp_list = xcalloc(n_node, sizeof(int));
alpar@1
   698
      for (i = 0, int_ptr = temp_list; i < n_node; i++, int_ptr++)
alpar@1
   699
         *int_ptr = 0;
alpar@1
   700
      /* Select the source nodes. */
alpar@1
   701
      for (i = 0, ptr = source_list; i < n_source; i++, ptr++)
alpar@1
   702
      {  ptr->node = uniform(csa, ab);
alpar@1
   703
         if (temp_list[ptr->node] == 1) /* check for duplicates */
alpar@1
   704
         {  ptr--;
alpar@1
   705
            i--;
alpar@1
   706
         }
alpar@1
   707
         else
alpar@1
   708
            temp_list[ptr->node] = 1;
alpar@1
   709
      }
alpar@1
   710
      /* Select the sink nodes. */
alpar@1
   711
      for (i = 0, ptr = sink_list; i < n_sink; i++, ptr++)
alpar@1
   712
      {  ptr->node = uniform(csa, ab);
alpar@1
   713
         if (temp_list[ptr->node] == 1)
alpar@1
   714
         {  ptr--;
alpar@1
   715
            i--;
alpar@1
   716
         }
alpar@1
   717
         else
alpar@1
   718
            temp_list[ptr->node] = 1;
alpar@1
   719
      }
alpar@1
   720
      xfree(temp_list);
alpar@1
   721
      return;
alpar@1
   722
}
alpar@1
   723
alpar@1
   724
int uniform(struct csa *csa, double a[2])
alpar@1
   725
{     /* Generates an integer uniformly selected from [a[0],a[1]]. */
alpar@1
   726
      return (int)((a[1] - a[0]) * randy(csa) + a[0] + 0.5);
alpar@1
   727
}
alpar@1
   728
alpar@1
   729
/**********************************************************************/
alpar@1
   730
alpar@1
   731
#if 0
alpar@1
   732
int main(void)
alpar@1
   733
{     int parm[1+14];
alpar@1
   734
      double temp;
alpar@1
   735
      scanf("%d", &parm[1]);
alpar@1
   736
      scanf("%d", &parm[2]);
alpar@1
   737
      scanf("%d", &parm[3]);
alpar@1
   738
      scanf("%d", &parm[4]);
alpar@1
   739
      scanf("%d", &parm[5]);
alpar@1
   740
      scanf("%d", &parm[6]);
alpar@1
   741
      scanf("%d", &parm[7]);
alpar@1
   742
      scanf("%d", &parm[8]);
alpar@1
   743
      scanf("%d", &parm[9]);
alpar@1
   744
      if (parm[9] == 1)
alpar@1
   745
      {  scanf("%d", &parm[10]);
alpar@1
   746
         scanf("%d", &parm[11]);
alpar@1
   747
      }
alpar@1
   748
      else
alpar@1
   749
      {  scanf("%le", &temp);
alpar@1
   750
         parm[10] = (int)(100.0 * temp + .5);
alpar@1
   751
         parm[11] = 0;
alpar@1
   752
      }
alpar@1
   753
      scanf("%d", &parm[12]);
alpar@1
   754
      if (parm[12] == 1)
alpar@1
   755
      {  scanf("%d", &parm[13]);
alpar@1
   756
         scanf("%d", &parm[14]);
alpar@1
   757
      }
alpar@1
   758
      else
alpar@1
   759
      {  scanf("%le", &temp);
alpar@1
   760
         parm[13] = (int)(100.0 * temp + .5);
alpar@1
   761
         parm[14] = 0;
alpar@1
   762
      }
alpar@1
   763
      glp_gridgen(NULL, 0, 0, 0, parm);
alpar@1
   764
      return 0;
alpar@1
   765
}
alpar@1
   766
#endif
alpar@1
   767
alpar@1
   768
/* eof */