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/* glpapi15.c (basic graph and network routines) */
/***********************************************************************
* This code is part of GLPK (GNU Linear Programming Kit).
*
* Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008,
* 2009, 2010, 2011, 2013 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 "env.h"
#include "glpsdf.h"
#include "prob.h"
#define xfprintf glp_format
/* CAUTION: DO NOT CHANGE THE LIMITS BELOW */
#define NV_MAX 100000000 /* = 100*10^6 */
/* maximal number of vertices in the graph */
#define NA_MAX 500000000 /* = 500*10^6 */
/* maximal number of arcs in the graph */
/***********************************************************************
* NAME
*
* glp_create_graph - create graph
*
* SYNOPSIS
*
* glp_graph *glp_create_graph(int v_size, int a_size);
*
* DESCRIPTION
*
* The routine creates a new graph, which initially is empty, i.e. has
* no vertices and arcs.
*
* The parameter v_size specifies the size of data associated with each
* vertex of the graph (0 to 256 bytes).
*
* The parameter a_size specifies the size of data associated with each
* arc of the graph (0 to 256 bytes).
*
* RETURNS
*
* The routine returns a pointer to the graph created. */
static void create_graph(glp_graph *G, int v_size, int a_size)
{ G->pool = dmp_create_pool();
G->name = NULL;
G->nv_max = 50;
G->nv = G->na = 0;
G->v = xcalloc(1+G->nv_max, sizeof(glp_vertex *));
G->index = NULL;
G->v_size = v_size;
G->a_size = a_size;
return;
}
glp_graph *glp_create_graph(int v_size, int a_size)
{ glp_graph *G;
if (!(0 <= v_size && v_size <= 256))
xerror("glp_create_graph: v_size = %d; invalid size of vertex "
"data\n", v_size);
if (!(0 <= a_size && a_size <= 256))
xerror("glp_create_graph: a_size = %d; invalid size of arc dat"
"a\n", a_size);
G = xmalloc(sizeof(glp_graph));
create_graph(G, v_size, a_size);
return G;
}
/***********************************************************************
* NAME
*
* glp_set_graph_name - assign (change) graph name
*
* SYNOPSIS
*
* void glp_set_graph_name(glp_graph *G, const char *name);
*
* DESCRIPTION
*
* The routine glp_set_graph_name assigns a symbolic name specified by
* the character string name (1 to 255 chars) to the graph.
*
* If the parameter name is NULL or an empty string, the routine erases
* the existing symbolic name of the graph. */
void glp_set_graph_name(glp_graph *G, const char *name)
{ if (G->name != NULL)
{ dmp_free_atom(G->pool, G->name, strlen(G->name)+1);
G->name = NULL;
}
if (!(name == NULL || name[0] == '\0'))
{ int j;
for (j = 0; name[j] != '\0'; j++)
{ if (j == 256)
xerror("glp_set_graph_name: graph name too long\n");
if (iscntrl((unsigned char)name[j]))
xerror("glp_set_graph_name: graph name contains invalid "
"character(s)\n");
}
G->name = dmp_get_atom(G->pool, strlen(name)+1);
strcpy(G->name, name);
}
return;
}
/***********************************************************************
* NAME
*
* glp_add_vertices - add new vertices to graph
*
* SYNOPSIS
*
* int glp_add_vertices(glp_graph *G, int nadd);
*
* DESCRIPTION
*
* The routine glp_add_vertices adds nadd vertices to the specified
* graph. New vertices are always added to the end of the vertex list,
* so ordinal numbers of existing vertices remain unchanged.
*
* Being added each new vertex is isolated (has no incident arcs).
*
* RETURNS
*
* The routine glp_add_vertices returns an ordinal number of the first
* new vertex added to the graph. */
int glp_add_vertices(glp_graph *G, int nadd)
{ int i, nv_new;
if (nadd < 1)
xerror("glp_add_vertices: nadd = %d; invalid number of vertice"
"s\n", nadd);
if (nadd > NV_MAX - G->nv)
xerror("glp_add_vertices: nadd = %d; too many vertices\n",
nadd);
/* determine new number of vertices */
nv_new = G->nv + nadd;
/* increase the room, if necessary */
if (G->nv_max < nv_new)
{ glp_vertex **save = G->v;
while (G->nv_max < nv_new)
{ G->nv_max += G->nv_max;
xassert(G->nv_max > 0);
}
G->v = xcalloc(1+G->nv_max, sizeof(glp_vertex *));
memcpy(&G->v[1], &save[1], G->nv * sizeof(glp_vertex *));
xfree(save);
}
/* add new vertices to the end of the vertex list */
for (i = G->nv+1; i <= nv_new; i++)
{ glp_vertex *v;
G->v[i] = v = dmp_get_atom(G->pool, sizeof(glp_vertex));
v->i = i;
v->name = NULL;
v->entry = NULL;
if (G->v_size == 0)
v->data = NULL;
else
{ v->data = dmp_get_atom(G->pool, G->v_size);
memset(v->data, 0, G->v_size);
}
v->temp = NULL;
v->in = v->out = NULL;
}
/* set new number of vertices */
G->nv = nv_new;
/* return the ordinal number of the first vertex added */
return nv_new - nadd + 1;
}
/**********************************************************************/
void glp_set_vertex_name(glp_graph *G, int i, const char *name)
{ /* assign (change) vertex name */
glp_vertex *v;
if (!(1 <= i && i <= G->nv))
xerror("glp_set_vertex_name: i = %d; vertex number out of rang"
"e\n", i);
v = G->v[i];
if (v->name != NULL)
{ if (v->entry != NULL)
{ xassert(G->index != NULL);
avl_delete_node(G->index, v->entry);
v->entry = NULL;
}
dmp_free_atom(G->pool, v->name, strlen(v->name)+1);
v->name = NULL;
}
if (!(name == NULL || name[0] == '\0'))
{ int k;
for (k = 0; name[k] != '\0'; k++)
{ if (k == 256)
xerror("glp_set_vertex_name: i = %d; vertex name too lon"
"g\n", i);
if (iscntrl((unsigned char)name[k]))
xerror("glp_set_vertex_name: i = %d; vertex name contain"
"s invalid character(s)\n", i);
}
v->name = dmp_get_atom(G->pool, strlen(name)+1);
strcpy(v->name, name);
if (G->index != NULL)
{ xassert(v->entry == NULL);
v->entry = avl_insert_node(G->index, v->name);
avl_set_node_link(v->entry, v);
}
}
return;
}
/***********************************************************************
* NAME
*
* glp_add_arc - add new arc to graph
*
* SYNOPSIS
*
* glp_arc *glp_add_arc(glp_graph *G, int i, int j);
*
* DESCRIPTION
*
* The routine glp_add_arc adds a new arc to the specified graph.
*
* The parameters i and j specify the ordinal numbers of, resp., tail
* and head vertices of the arc. Note that self-loops and multiple arcs
* are allowed.
*
* RETURNS
*
* The routine glp_add_arc returns a pointer to the arc added. */
glp_arc *glp_add_arc(glp_graph *G, int i, int j)
{ glp_arc *a;
if (!(1 <= i && i <= G->nv))
xerror("glp_add_arc: i = %d; tail vertex number out of range\n"
, i);
if (!(1 <= j && j <= G->nv))
xerror("glp_add_arc: j = %d; head vertex number out of range\n"
, j);
if (G->na == NA_MAX)
xerror("glp_add_arc: too many arcs\n");
a = dmp_get_atom(G->pool, sizeof(glp_arc));
a->tail = G->v[i];
a->head = G->v[j];
if (G->a_size == 0)
a->data = NULL;
else
{ a->data = dmp_get_atom(G->pool, G->a_size);
memset(a->data, 0, G->a_size);
}
a->temp = NULL;
a->t_prev = NULL;
a->t_next = G->v[i]->out;
if (a->t_next != NULL) a->t_next->t_prev = a;
a->h_prev = NULL;
a->h_next = G->v[j]->in;
if (a->h_next != NULL) a->h_next->h_prev = a;
G->v[i]->out = G->v[j]->in = a;
G->na++;
return a;
}
/***********************************************************************
* NAME
*
* glp_del_vertices - delete vertices from graph
*
* SYNOPSIS
*
* void glp_del_vertices(glp_graph *G, int ndel, const int num[]);
*
* DESCRIPTION
*
* The routine glp_del_vertices deletes vertices along with all
* incident arcs from the specified graph. Ordinal numbers of vertices
* to be deleted should be placed in locations num[1], ..., num[ndel],
* ndel > 0.
*
* Note that deleting vertices involves changing ordinal numbers of
* other vertices remaining in the graph. New ordinal numbers of the
* remaining vertices are assigned under the assumption that the
* original order of vertices is not changed. */
void glp_del_vertices(glp_graph *G, int ndel, const int num[])
{ glp_vertex *v;
int i, k, nv_new;
/* scan the list of vertices to be deleted */
if (!(1 <= ndel && ndel <= G->nv))
xerror("glp_del_vertices: ndel = %d; invalid number of vertice"
"s\n", ndel);
for (k = 1; k <= ndel; k++)
{ /* take the number of vertex to be deleted */
i = num[k];
/* obtain pointer to i-th vertex */
if (!(1 <= i && i <= G->nv))
xerror("glp_del_vertices: num[%d] = %d; vertex number out o"
"f range\n", k, i);
v = G->v[i];
/* check that the vertex is not marked yet */
if (v->i == 0)
xerror("glp_del_vertices: num[%d] = %d; duplicate vertex nu"
"mbers not allowed\n", k, i);
/* erase symbolic name assigned to the vertex */
glp_set_vertex_name(G, i, NULL);
xassert(v->name == NULL);
xassert(v->entry == NULL);
/* free vertex data, if allocated */
if (v->data != NULL)
dmp_free_atom(G->pool, v->data, G->v_size);
/* delete all incoming arcs */
while (v->in != NULL)
glp_del_arc(G, v->in);
/* delete all outgoing arcs */
while (v->out != NULL)
glp_del_arc(G, v->out);
/* mark the vertex to be deleted */
v->i = 0;
}
/* delete all marked vertices from the vertex list */
nv_new = 0;
for (i = 1; i <= G->nv; i++)
{ /* obtain pointer to i-th vertex */
v = G->v[i];
/* check if the vertex is marked */
if (v->i == 0)
{ /* it is marked, delete it */
dmp_free_atom(G->pool, v, sizeof(glp_vertex));
}
else
{ /* it is not marked, keep it */
v->i = ++nv_new;
G->v[v->i] = v;
}
}
/* set new number of vertices in the graph */
G->nv = nv_new;
return;
}
/***********************************************************************
* NAME
*
* glp_del_arc - delete arc from graph
*
* SYNOPSIS
*
* void glp_del_arc(glp_graph *G, glp_arc *a);
*
* DESCRIPTION
*
* The routine glp_del_arc deletes an arc from the specified graph.
* The arc to be deleted must exist. */
void glp_del_arc(glp_graph *G, glp_arc *a)
{ /* some sanity checks */
xassert(G->na > 0);
xassert(1 <= a->tail->i && a->tail->i <= G->nv);
xassert(a->tail == G->v[a->tail->i]);
xassert(1 <= a->head->i && a->head->i <= G->nv);
xassert(a->head == G->v[a->head->i]);
/* remove the arc from the list of incoming arcs */
if (a->h_prev == NULL)
a->head->in = a->h_next;
else
a->h_prev->h_next = a->h_next;
if (a->h_next == NULL)
;
else
a->h_next->h_prev = a->h_prev;
/* remove the arc from the list of outgoing arcs */
if (a->t_prev == NULL)
a->tail->out = a->t_next;
else
a->t_prev->t_next = a->t_next;
if (a->t_next == NULL)
;
else
a->t_next->t_prev = a->t_prev;
/* free arc data, if allocated */
if (a->data != NULL)
dmp_free_atom(G->pool, a->data, G->a_size);
/* delete the arc from the graph */
dmp_free_atom(G->pool, a, sizeof(glp_arc));
G->na--;
return;
}
/***********************************************************************
* NAME
*
* glp_erase_graph - erase graph content
*
* SYNOPSIS
*
* void glp_erase_graph(glp_graph *G, int v_size, int a_size);
*
* DESCRIPTION
*
* The routine glp_erase_graph erases the content of the specified
* graph. The effect of this operation is the same as if the graph
* would be deleted with the routine glp_delete_graph and then created
* anew with the routine glp_create_graph, with exception that the
* handle (pointer) to the graph remains valid. */
static void delete_graph(glp_graph *G)
{ dmp_delete_pool(G->pool);
xfree(G->v);
if (G->index != NULL) avl_delete_tree(G->index);
return;
}
void glp_erase_graph(glp_graph *G, int v_size, int a_size)
{ if (!(0 <= v_size && v_size <= 256))
xerror("glp_erase_graph: v_size = %d; invalid size of vertex d"
"ata\n", v_size);
if (!(0 <= a_size && a_size <= 256))
xerror("glp_erase_graph: a_size = %d; invalid size of arc data"
"\n", a_size);
delete_graph(G);
create_graph(G, v_size, a_size);
return;
}
/***********************************************************************
* NAME
*
* glp_delete_graph - delete graph
*
* SYNOPSIS
*
* void glp_delete_graph(glp_graph *G);
*
* DESCRIPTION
*
* The routine glp_delete_graph deletes the specified graph and frees
* all the memory allocated to this program object. */
void glp_delete_graph(glp_graph *G)
{ delete_graph(G);
xfree(G);
return;
}
/**********************************************************************/
void glp_create_v_index(glp_graph *G)
{ /* create vertex name index */
glp_vertex *v;
int i;
if (G->index == NULL)
{ G->index = avl_create_tree(avl_strcmp, NULL);
for (i = 1; i <= G->nv; i++)
{ v = G->v[i];
xassert(v->entry == NULL);
if (v->name != NULL)
{ v->entry = avl_insert_node(G->index, v->name);
avl_set_node_link(v->entry, v);
}
}
}
return;
}
int glp_find_vertex(glp_graph *G, const char *name)
{ /* find vertex by its name */
AVLNODE *node;
int i = 0;
if (G->index == NULL)
xerror("glp_find_vertex: vertex name index does not exist\n");
if (!(name == NULL || name[0] == '\0' || strlen(name) > 255))
{ node = avl_find_node(G->index, name);
if (node != NULL)
i = ((glp_vertex *)avl_get_node_link(node))->i;
}
return i;
}
void glp_delete_v_index(glp_graph *G)
{ /* delete vertex name index */
int i;
if (G->index != NULL)
{ avl_delete_tree(G->index), G->index = NULL;
for (i = 1; i <= G->nv; i++) G->v[i]->entry = NULL;
}
return;
}
/***********************************************************************
* NAME
*
* glp_read_graph - read graph from plain text file
*
* SYNOPSIS
*
* int glp_read_graph(glp_graph *G, const char *fname);
*
* DESCRIPTION
*
* The routine glp_read_graph reads a graph from a plain text file.
*
* RETURNS
*
* If the operation was successful, the routine returns zero. Otherwise
* it prints an error message and returns non-zero. */
int glp_read_graph(glp_graph *G, const char *fname)
{ glp_data *data;
jmp_buf jump;
int nv, na, i, j, k, ret;
glp_erase_graph(G, G->v_size, G->a_size);
xprintf("Reading graph from '%s'...\n", fname);
data = glp_sdf_open_file(fname);
if (data == NULL)
{ ret = 1;
goto done;
}
if (setjmp(jump))
{ ret = 1;
goto done;
}
glp_sdf_set_jump(data, jump);
nv = glp_sdf_read_int(data);
if (nv < 0)
glp_sdf_error(data, "invalid number of vertices\n");
na = glp_sdf_read_int(data);
if (na < 0)
glp_sdf_error(data, "invalid number of arcs\n");
xprintf("Graph has %d vert%s and %d arc%s\n",
nv, nv == 1 ? "ex" : "ices", na, na == 1 ? "" : "s");
if (nv > 0) glp_add_vertices(G, nv);
for (k = 1; k <= na; k++)
{ i = glp_sdf_read_int(data);
if (!(1 <= i && i <= nv))
glp_sdf_error(data, "tail vertex number out of range\n");
j = glp_sdf_read_int(data);
if (!(1 <= j && j <= nv))
glp_sdf_error(data, "head vertex number out of range\n");
glp_add_arc(G, i, j);
}
xprintf("%d lines were read\n", glp_sdf_line(data));
ret = 0;
done: if (data != NULL) glp_sdf_close_file(data);
return ret;
}
/***********************************************************************
* NAME
*
* glp_write_graph - write graph to plain text file
*
* SYNOPSIS
*
* int glp_write_graph(glp_graph *G, const char *fname).
*
* DESCRIPTION
*
* The routine glp_write_graph writes the specified graph to a plain
* text file.
*
* RETURNS
*
* If the operation was successful, the routine returns zero. Otherwise
* it prints an error message and returns non-zero. */
int glp_write_graph(glp_graph *G, const char *fname)
{ glp_file *fp;
glp_vertex *v;
glp_arc *a;
int i, count, ret;
xprintf("Writing graph to '%s'...\n", fname);
fp = glp_open(fname, "w"), count = 0;
if (fp == NULL)
{ xprintf("Unable to create '%s' - %s\n", fname, get_err_msg());
ret = 1;
goto done;
}
xfprintf(fp, "%d %d\n", G->nv, G->na), count++;
for (i = 1; i <= G->nv; i++)
{ v = G->v[i];
for (a = v->out; a != NULL; a = a->t_next)
xfprintf(fp, "%d %d\n", a->tail->i, a->head->i), count++;
}
#if 0 /* FIXME */
xfflush(fp);
#endif
if (glp_ioerr(fp))
{ xprintf("Write error on '%s' - %s\n", fname, get_err_msg());
ret = 1;
goto done;
}
xprintf("%d lines were written\n", count);
ret = 0;
done: if (fp != NULL) glp_close(fp);
return ret;
}
/* eof */