lemon-project-template-glpk
view deps/glpk/src/glpnet05.c @ 9:33de93886c88
Import GLPK 4.47
| author | Alpar Juttner <alpar@cs.elte.hu> |
|---|---|
| date | Sun, 06 Nov 2011 20:59:10 +0100 |
| parents | |
| children |
line source
1 /* glpnet05.c (Goldfarb's maximum flow problem generator) */
3 /***********************************************************************
4 * This code is part of GLPK (GNU Linear Programming Kit).
5 *
6 * This code is a modified version of the program RMFGEN, a maxflow
7 * problem generator developed by D.Goldfarb and M.Grigoriadis, and
8 * originally implemented by Tamas Badics <badics@rutcor.rutgers.edu>.
9 * The original code is publically available on the DIMACS ftp site at:
10 * <ftp://dimacs.rutgers.edu/pub/netflow/generators/network/genrmf>.
11 *
12 * All changes concern only the program interface, so this modified
13 * version produces exactly the same instances as the original version.
14 *
15 * Changes were made by Andrew Makhorin <mao@gnu.org>.
16 *
17 * GLPK is free software: you can redistribute it and/or modify it
18 * under the terms of the GNU General Public License as published by
19 * the Free Software Foundation, either version 3 of the License, or
20 * (at your option) any later version.
21 *
22 * GLPK is distributed in the hope that it will be useful, but WITHOUT
23 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
24 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
25 * License for more details.
26 *
27 * You should have received a copy of the GNU General Public License
28 * along with GLPK. If not, see <http://www.gnu.org/licenses/>.
29 ***********************************************************************/
31 #include "glpapi.h"
32 #include "glprng.h"
34 /***********************************************************************
35 * NAME
36 *
37 * glp_rmfgen - Goldfarb's maximum flow problem generator
38 *
39 * SYNOPSIS
40 *
41 * int glp_rmfgen(glp_graph *G, int *s, int *t, int a_cap,
42 * const int parm[1+5]);
43 *
44 * DESCRIPTION
45 *
46 * The routine glp_rmfgen is a maximum flow problem generator developed
47 * by D.Goldfarb and M.Grigoriadis.
48 *
49 * The parameter G specifies the graph object, to which the generated
50 * problem data have to be stored. Note that on entry the graph object
51 * is erased with the routine glp_erase_graph.
52 *
53 * The pointer s specifies a location, to which the routine stores the
54 * source node number. If s is NULL, the node number is not stored.
55 *
56 * The pointer t specifies a location, to which the routine stores the
57 * sink node number. If t is NULL, the node number is not stored.
58 *
59 * The parameter a_cap specifies an offset of the field of type double
60 * in the arc data block, to which the routine stores the arc capacity.
61 * If a_cap < 0, the capacity is not stored.
62 *
63 * The array parm contains description of the network to be generated:
64 *
65 * parm[0] not used
66 * parm[1] (seed) random number seed (a positive integer)
67 * parm[2] (a) frame size
68 * parm[3] (b) depth
69 * parm[4] (c1) minimal arc capacity
70 * parm[5] (c2) maximal arc capacity
71 *
72 * RETURNS
73 *
74 * If the instance was successfully generated, the routine glp_netgen
75 * returns zero; otherwise, if specified parameters are inconsistent,
76 * the routine returns a non-zero error code.
77 *
78 * COMMENTS
79 *
80 * The generated network is as follows. It has b pieces of frames of
81 * size a * a. (So alltogether the number of vertices is a * a * b)
82 *
83 * In each frame all the vertices are connected with their neighbours
84 * (forth and back). In addition the vertices of a frame are connected
85 * one to one with the vertices of next frame using a random permutation
86 * of those vertices.
87 *
88 * The source is the lower left vertex of the first frame, the sink is
89 * the upper right vertex of the b'th frame.
90 *
91 * t
92 * +-------+
93 * | .|
94 * | . |
95 * / | / |
96 * +-------+/ -+ b
97 * | | |/.
98 * a | -v- |/
99 * | | |/
100 * +-------+ 1
101 * s a
102 *
103 * The capacities are randomly chosen integers from the range of [c1,c2]
104 * in the case of interconnecting edges, and c2 * a * a for the in-frame
105 * edges.
106 *
107 * REFERENCES
108 *
109 * D.Goldfarb and M.D.Grigoriadis, "A computational comparison of the
110 * Dinic and network simplex methods for maximum flow." Annals of Op.
111 * Res. 13 (1988), pp. 83-123.
112 *
113 * U.Derigs and W.Meier, "Implementing Goldberg's max-flow algorithm:
114 * A computational investigation." Zeitschrift fuer Operations Research
115 * 33 (1989), pp. 383-403. */
117 typedef struct VERTEX
118 { struct EDGE **edgelist;
119 /* Pointer to the list of pointers to the adjacent edges.
120 (No matter that to or from edges) */
121 struct EDGE **current;
122 /* Pointer to the current edge */
123 int degree;
124 /* Number of adjacent edges (both direction) */
125 int index;
126 } vertex;
128 typedef struct EDGE
129 { int from;
130 int to;
131 int cap;
132 /* Capacity */
133 } edge;
135 typedef struct NETWORK
136 { struct NETWORK *next, *prev;
137 int vertnum;
138 int edgenum;
139 vertex *verts;
140 /* Vertex array[1..vertnum] */
141 edge *edges;
142 /* Edge array[1..edgenum] */
143 int source;
144 /* Pointer to the source */
145 int sink;
146 /* Pointer to the sink */
147 } network;
149 struct csa
150 { /* common storage area */
151 glp_graph *G;
152 int *s, *t, a_cap;
153 RNG *rand;
154 network *N;
155 int *Parr;
156 int A, AA, C2AA, Ec;
157 };
159 #define G (csa->G)
160 #define s (csa->s)
161 #define t (csa->t)
162 #define a_cap (csa->a_cap)
163 #define N (csa->N)
164 #define Parr (csa->Parr)
165 #define A (csa->A)
166 #define AA (csa->AA)
167 #define C2AA (csa->C2AA)
168 #define Ec (csa->Ec)
170 #undef random
171 #define random(A) (int)(rng_unif_01(csa->rand) * (double)(A))
172 #define RANDOM(A, B) (int)(random((B) - (A) + 1) + (A))
173 #define sgn(A) (((A) > 0) ? 1 : ((A) == 0) ? 0 : -1)
175 static void make_edge(struct csa *csa, int from, int to, int c1, int c2)
176 { Ec++;
177 N->edges[Ec].from = from;
178 N->edges[Ec].to = to;
179 N->edges[Ec].cap = RANDOM(c1, c2);
180 return;
181 }
183 static void permute(struct csa *csa)
184 { int i, j, tmp;
185 for (i = 1; i < AA; i++)
186 { j = RANDOM(i, AA);
187 tmp = Parr[i];
188 Parr[i] = Parr[j];
189 Parr[j] = tmp;
190 }
191 return;
192 }
194 static void connect(struct csa *csa, int offset, int cv, int x1, int y1)
195 { int cv1;
196 cv1 = offset + (x1 - 1) * A + y1;
197 Ec++;
198 N->edges[Ec].from = cv;
199 N->edges[Ec].to = cv1;
200 N->edges[Ec].cap = C2AA;
201 return;
202 }
204 static network *gen_rmf(struct csa *csa, int a, int b, int c1, int c2)
205 { /* generates a network with a*a*b nodes and 6a*a*b-4ab-2a*a edges
206 random_frame network:
207 Derigs & Meier, Methods & Models of OR (1989), 33:383-403 */
208 int x, y, z, offset, cv;
209 A = a;
210 AA = a * a;
211 C2AA = c2 * AA;
212 Ec = 0;
213 N = (network *)xmalloc(sizeof(network));
214 N->vertnum = AA * b;
215 N->edgenum = 5 * AA * b - 4 * A * b - AA;
216 N->edges = (edge *)xcalloc(N->edgenum + 1, sizeof(edge));
217 N->source = 1;
218 N->sink = N->vertnum;
219 Parr = (int *)xcalloc(AA + 1, sizeof(int));
220 for (x = 1; x <= AA; x++)
221 Parr[x] = x;
222 for (z = 1; z <= b; z++)
223 { offset = AA * (z - 1);
224 if (z != b)
225 permute(csa);
226 for (x = 1; x <= A; x++)
227 { for (y = 1; y <= A; y++)
228 { cv = offset + (x - 1) * A + y;
229 if (z != b)
230 make_edge(csa, cv, offset + AA + Parr[cv - offset],
231 c1, c2); /* the intermediate edges */
232 if (y < A)
233 connect(csa, offset, cv, x, y + 1);
234 if (y > 1)
235 connect(csa, offset, cv, x, y - 1);
236 if (x < A)
237 connect(csa, offset, cv, x + 1, y);
238 if (x > 1)
239 connect(csa, offset, cv, x - 1, y);
240 }
241 }
242 }
243 xfree(Parr);
244 return N;
245 }
247 static void print_max_format(struct csa *csa, network *n, char *comm[],
248 int dim)
249 { /* prints a network heading with dim lines of comments (no \n
250 needs at the ends) */
251 int i, vnum, e_num;
252 edge *e;
253 vnum = n->vertnum;
254 e_num = n->edgenum;
255 if (G == NULL)
256 { for (i = 0; i < dim; i++)
257 xprintf("c %s\n", comm[i]);
258 xprintf("p max %7d %10d\n", vnum, e_num);
259 xprintf("n %7d s\n", n->source);
260 xprintf("n %7d t\n", n->sink);
261 }
262 else
263 { glp_add_vertices(G, vnum);
264 if (s != NULL) *s = n->source;
265 if (t != NULL) *t = n->sink;
266 }
267 for (i = 1; i <= e_num; i++)
268 { e = &n->edges[i];
269 if (G == NULL)
270 xprintf("a %7d %7d %10d\n", e->from, e->to, (int)e->cap);
271 else
272 { glp_arc *a = glp_add_arc(G, e->from, e->to);
273 if (a_cap >= 0)
274 { double temp = (double)e->cap;
275 memcpy((char *)a->data + a_cap, &temp, sizeof(double));
276 }
277 }
278 }
279 return;
280 }
282 static void gen_free_net(network *n)
283 { xfree(n->edges);
284 xfree(n);
285 return;
286 }
288 int glp_rmfgen(glp_graph *G_, int *_s, int *_t, int _a_cap,
289 const int parm[1+5])
290 { struct csa _csa, *csa = &_csa;
291 network *n;
292 char comm[10][80], *com1[10];
293 int seed, a, b, c1, c2, ret;
294 G = G_;
295 s = _s;
296 t = _t;
297 a_cap = _a_cap;
298 if (G != NULL)
299 { if (a_cap >= 0 && a_cap > G->a_size - (int)sizeof(double))
300 xerror("glp_rmfgen: a_cap = %d; invalid offset\n", a_cap);
301 }
302 seed = parm[1];
303 a = parm[2];
304 b = parm[3];
305 c1 = parm[4];
306 c2 = parm[5];
307 if (!(seed > 0 && 1 <= a && a <= 1000 && 1 <= b && b <= 1000 &&
308 0 <= c1 && c1 <= c2 && c2 <= 1000))
309 { ret = 1;
310 goto done;
311 }
312 if (G != NULL)
313 { glp_erase_graph(G, G->v_size, G->a_size);
314 glp_set_graph_name(G, "RMFGEN");
315 }
316 csa->rand = rng_create_rand();
317 rng_init_rand(csa->rand, seed);
318 n = gen_rmf(csa, a, b, c1, c2);
319 sprintf(comm[0], "This file was generated by genrmf.");
320 sprintf(comm[1], "The parameters are: a: %d b: %d c1: %d c2: %d",
321 a, b, c1, c2);
322 com1[0] = comm[0];
323 com1[1] = comm[1];
324 print_max_format(csa, n, com1, 2);
325 gen_free_net(n);
326 rng_delete_rand(csa->rand);
327 ret = 0;
328 done: return ret;
329 }
331 /**********************************************************************/
333 #if 0
334 int main(int argc, char *argv[])
335 { int seed, a, b, c1, c2, i, parm[1+5];
336 seed = 123;
337 a = b = c1 = c2 = -1;
338 for (i = 1; i < argc; i++)
339 { if (strcmp(argv[i], "-seed") == 0)
340 seed = atoi(argv[++i]);
341 else if (strcmp(argv[i], "-a") == 0)
342 a = atoi(argv[++i]);
343 else if (strcmp(argv[i], "-b") == 0)
344 b = atoi(argv[++i]);
345 else if (strcmp(argv[i], "-c1") == 0)
346 c1 = atoi(argv[++i]);
347 else if (strcmp(argv[i], "-c2") == 0)
348 c2 = atoi(argv[++i]);
349 }
350 if (a < 0 || b < 0 || c1 < 0 || c2 < 0)
351 { xprintf("Usage:\n");
352 xprintf("genrmf [-seed seed] -a frame_size -b depth\n");
353 xprintf(" -c1 cap_range1 -c2 cap_range2\n");
354 }
355 else
356 { parm[1] = seed;
357 parm[2] = a;
358 parm[3] = b;
359 parm[4] = c1;
360 parm[5] = c2;
361 glp_rmfgen(NULL, NULL, NULL, 0, parm);
362 }
363 return 0;
364 }
365 #endif
367 /* eof */