diff -r d59bea55db9b -r c445c931472f src/glpnet05.c --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/glpnet05.c Mon Dec 06 13:09:21 2010 +0100 @@ -0,0 +1,367 @@ +/* glpnet05.c (Goldfarb's maximum flow problem generator) */ + +/*********************************************************************** +* This code is part of GLPK (GNU Linear Programming Kit). +* +* This code is a modified version of the program RMFGEN, a maxflow +* problem generator developed by D.Goldfarb and M.Grigoriadis, and +* originally implemented by Tamas Badics . +* The original code is publically available on the DIMACS ftp site at: +* . +* +* All changes concern only the program interface, so this modified +* version produces exactly the same instances as the original version. +* +* Changes were made by Andrew Makhorin . +* +* 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 . +***********************************************************************/ + +#include "glpapi.h" +#include "glprng.h" + +/*********************************************************************** +* NAME +* +* glp_rmfgen - Goldfarb's maximum flow problem generator +* +* SYNOPSIS +* +* int glp_rmfgen(glp_graph *G, int *s, int *t, int a_cap, +* const int parm[1+5]); +* +* DESCRIPTION +* +* The routine glp_rmfgen is a maximum flow problem generator developed +* by D.Goldfarb and M.Grigoriadis. +* +* The parameter G specifies the graph object, to which the generated +* problem data have to be stored. Note that on entry the graph object +* is erased with the routine glp_erase_graph. +* +* The pointer s specifies a location, to which the routine stores the +* source node number. If s is NULL, the node number is not stored. +* +* The pointer t specifies a location, to which the routine stores the +* sink node number. If t is NULL, the node number is not stored. +* +* The parameter a_cap specifies an offset of the field of type double +* in the arc data block, to which the routine stores the arc capacity. +* If a_cap < 0, the capacity is not stored. +* +* The array parm contains description of the network to be generated: +* +* parm[0] not used +* parm[1] (seed) random number seed (a positive integer) +* parm[2] (a) frame size +* parm[3] (b) depth +* parm[4] (c1) minimal arc capacity +* parm[5] (c2) maximal arc capacity +* +* RETURNS +* +* If the instance was successfully generated, the routine glp_netgen +* returns zero; otherwise, if specified parameters are inconsistent, +* the routine returns a non-zero error code. +* +* COMMENTS +* +* The generated network is as follows. It has b pieces of frames of +* size a * a. (So alltogether the number of vertices is a * a * b) +* +* In each frame all the vertices are connected with their neighbours +* (forth and back). In addition the vertices of a frame are connected +* one to one with the vertices of next frame using a random permutation +* of those vertices. +* +* The source is the lower left vertex of the first frame, the sink is +* the upper right vertex of the b'th frame. +* +* t +* +-------+ +* | .| +* | . | +* / | / | +* +-------+/ -+ b +* | | |/. +* a | -v- |/ +* | | |/ +* +-------+ 1 +* s a +* +* The capacities are randomly chosen integers from the range of [c1,c2] +* in the case of interconnecting edges, and c2 * a * a for the in-frame +* edges. +* +* REFERENCES +* +* D.Goldfarb and M.D.Grigoriadis, "A computational comparison of the +* Dinic and network simplex methods for maximum flow." Annals of Op. +* Res. 13 (1988), pp. 83-123. +* +* U.Derigs and W.Meier, "Implementing Goldberg's max-flow algorithm: +* A computational investigation." Zeitschrift fuer Operations Research +* 33 (1989), pp. 383-403. */ + +typedef struct VERTEX +{ struct EDGE **edgelist; + /* Pointer to the list of pointers to the adjacent edges. + (No matter that to or from edges) */ + struct EDGE **current; + /* Pointer to the current edge */ + int degree; + /* Number of adjacent edges (both direction) */ + int index; +} vertex; + +typedef struct EDGE +{ int from; + int to; + int cap; + /* Capacity */ +} edge; + +typedef struct NETWORK +{ struct NETWORK *next, *prev; + int vertnum; + int edgenum; + vertex *verts; + /* Vertex array[1..vertnum] */ + edge *edges; + /* Edge array[1..edgenum] */ + int source; + /* Pointer to the source */ + int sink; + /* Pointer to the sink */ +} network; + +struct csa +{ /* common storage area */ + glp_graph *G; + int *s, *t, a_cap; + RNG *rand; + network *N; + int *Parr; + int A, AA, C2AA, Ec; +}; + +#define G (csa->G) +#define s (csa->s) +#define t (csa->t) +#define a_cap (csa->a_cap) +#define N (csa->N) +#define Parr (csa->Parr) +#define A (csa->A) +#define AA (csa->AA) +#define C2AA (csa->C2AA) +#define Ec (csa->Ec) + +#undef random +#define random(A) (int)(rng_unif_01(csa->rand) * (double)(A)) +#define RANDOM(A, B) (int)(random((B) - (A) + 1) + (A)) +#define sgn(A) (((A) > 0) ? 1 : ((A) == 0) ? 0 : -1) + +static void make_edge(struct csa *csa, int from, int to, int c1, int c2) +{ Ec++; + N->edges[Ec].from = from; + N->edges[Ec].to = to; + N->edges[Ec].cap = RANDOM(c1, c2); + return; +} + +static void permute(struct csa *csa) +{ int i, j, tmp; + for (i = 1; i < AA; i++) + { j = RANDOM(i, AA); + tmp = Parr[i]; + Parr[i] = Parr[j]; + Parr[j] = tmp; + } + return; +} + +static void connect(struct csa *csa, int offset, int cv, int x1, int y1) +{ int cv1; + cv1 = offset + (x1 - 1) * A + y1; + Ec++; + N->edges[Ec].from = cv; + N->edges[Ec].to = cv1; + N->edges[Ec].cap = C2AA; + return; +} + +static network *gen_rmf(struct csa *csa, int a, int b, int c1, int c2) +{ /* generates a network with a*a*b nodes and 6a*a*b-4ab-2a*a edges + random_frame network: + Derigs & Meier, Methods & Models of OR (1989), 33:383-403 */ + int x, y, z, offset, cv; + A = a; + AA = a * a; + C2AA = c2 * AA; + Ec = 0; + N = (network *)xmalloc(sizeof(network)); + N->vertnum = AA * b; + N->edgenum = 5 * AA * b - 4 * A * b - AA; + N->edges = (edge *)xcalloc(N->edgenum + 1, sizeof(edge)); + N->source = 1; + N->sink = N->vertnum; + Parr = (int *)xcalloc(AA + 1, sizeof(int)); + for (x = 1; x <= AA; x++) + Parr[x] = x; + for (z = 1; z <= b; z++) + { offset = AA * (z - 1); + if (z != b) + permute(csa); + for (x = 1; x <= A; x++) + { for (y = 1; y <= A; y++) + { cv = offset + (x - 1) * A + y; + if (z != b) + make_edge(csa, cv, offset + AA + Parr[cv - offset], + c1, c2); /* the intermediate edges */ + if (y < A) + connect(csa, offset, cv, x, y + 1); + if (y > 1) + connect(csa, offset, cv, x, y - 1); + if (x < A) + connect(csa, offset, cv, x + 1, y); + if (x > 1) + connect(csa, offset, cv, x - 1, y); + } + } + } + xfree(Parr); + return N; +} + +static void print_max_format(struct csa *csa, network *n, char *comm[], + int dim) +{ /* prints a network heading with dim lines of comments (no \n + needs at the ends) */ + int i, vnum, e_num; + edge *e; + vnum = n->vertnum; + e_num = n->edgenum; + if (G == NULL) + { for (i = 0; i < dim; i++) + xprintf("c %s\n", comm[i]); + xprintf("p max %7d %10d\n", vnum, e_num); + xprintf("n %7d s\n", n->source); + xprintf("n %7d t\n", n->sink); + } + else + { glp_add_vertices(G, vnum); + if (s != NULL) *s = n->source; + if (t != NULL) *t = n->sink; + } + for (i = 1; i <= e_num; i++) + { e = &n->edges[i]; + if (G == NULL) + xprintf("a %7d %7d %10d\n", e->from, e->to, (int)e->cap); + else + { glp_arc *a = glp_add_arc(G, e->from, e->to); + if (a_cap >= 0) + { double temp = (double)e->cap; + memcpy((char *)a->data + a_cap, &temp, sizeof(double)); + } + } + } + return; +} + +static void gen_free_net(network *n) +{ xfree(n->edges); + xfree(n); + return; +} + +int glp_rmfgen(glp_graph *G_, int *_s, int *_t, int _a_cap, + const int parm[1+5]) +{ struct csa _csa, *csa = &_csa; + network *n; + char comm[10][80], *com1[10]; + int seed, a, b, c1, c2, ret; + G = G_; + s = _s; + t = _t; + a_cap = _a_cap; + if (G != NULL) + { if (a_cap >= 0 && a_cap > G->a_size - (int)sizeof(double)) + xerror("glp_rmfgen: a_cap = %d; invalid offset\n", a_cap); + } + seed = parm[1]; + a = parm[2]; + b = parm[3]; + c1 = parm[4]; + c2 = parm[5]; + if (!(seed > 0 && 1 <= a && a <= 1000 && 1 <= b && b <= 1000 && + 0 <= c1 && c1 <= c2 && c2 <= 1000)) + { ret = 1; + goto done; + } + if (G != NULL) + { glp_erase_graph(G, G->v_size, G->a_size); + glp_set_graph_name(G, "RMFGEN"); + } + csa->rand = rng_create_rand(); + rng_init_rand(csa->rand, seed); + n = gen_rmf(csa, a, b, c1, c2); + sprintf(comm[0], "This file was generated by genrmf."); + sprintf(comm[1], "The parameters are: a: %d b: %d c1: %d c2: %d", + a, b, c1, c2); + com1[0] = comm[0]; + com1[1] = comm[1]; + print_max_format(csa, n, com1, 2); + gen_free_net(n); + rng_delete_rand(csa->rand); + ret = 0; +done: return ret; +} + +/**********************************************************************/ + +#if 0 +int main(int argc, char *argv[]) +{ int seed, a, b, c1, c2, i, parm[1+5]; + seed = 123; + a = b = c1 = c2 = -1; + for (i = 1; i < argc; i++) + { if (strcmp(argv[i], "-seed") == 0) + seed = atoi(argv[++i]); + else if (strcmp(argv[i], "-a") == 0) + a = atoi(argv[++i]); + else if (strcmp(argv[i], "-b") == 0) + b = atoi(argv[++i]); + else if (strcmp(argv[i], "-c1") == 0) + c1 = atoi(argv[++i]); + else if (strcmp(argv[i], "-c2") == 0) + c2 = atoi(argv[++i]); + } + if (a < 0 || b < 0 || c1 < 0 || c2 < 0) + { xprintf("Usage:\n"); + xprintf("genrmf [-seed seed] -a frame_size -b depth\n"); + xprintf(" -c1 cap_range1 -c2 cap_range2\n"); + } + else + { parm[1] = seed; + parm[2] = a; + parm[3] = b; + parm[4] = c1; + parm[5] = c2; + glp_rmfgen(NULL, NULL, NULL, 0, parm); + } + return 0; +} +#endif + +/* eof */