graph_t* MatrixToGraph(double *adjac_mtx_ptr, int iGraphOrder)
{
int i, j, idx;
graph_t *ptrGraph;
/* Initialize the graph that we want to return. */
ptrGraph = graph_new(iGraphOrder);
/* Loop through the adjacency matrix to create the graph. We assume
* that the adjacency matrix is symmetric and only consider the super-
* diagonals of the matrix. */
/* The indexing here seems flipped, but it's due to the translation
* between MATLAB and C element ordering. */
for (j = 0; j < iGraphOrder; j++)
for (i = j + 1; i < iGraphOrder; i++)
{
/* The matrix adj_mtx is stored as a 1-dimensional array, so
* we must convert the coordinate (i, j) to the corresponding
* 1-dimensional index. */
idx = j + i * iGraphOrder;
/* If the entry of the adjacency matrix is a 1, we want to add
* an edge to our graph. */
if(adjac_mtx_ptr[idx] == 1)
GRAPH_ADD_EDGE(ptrGraph, i, j);
}
/* Just to be cautios, ensure that we've produced a valid graph. */
ASSERT(graph_test(ptrGraph, NULL));
return ptrGraph;
}
boolean graph_write_dimacs_binary(graph_t *g, char *comment,FILE *fp) {
char *buf;
char *header=NULL;
int headersize=0;
int headerlength=0;
int i,j;
ASSERT((sizeof(setelement)*8)==ELEMENTSIZE);
ASSERT(graph_test(g,NULL));
ASSERT(fp!=NULL);
buf=malloc(MAX(1024,g->n/8+1));
header=malloc(1024);
header[0]=0;
headersize=1024;
if (comment) {
strcpy(buf,"c ");
strncat(buf,comment,1000);
strcat(buf,"\n");
STR_APPEND(buf);
}
sprintf(buf,"p edge %d %d\n",g->n,graph_edge_count(g));
STR_APPEND(buf);
for (i=0; i < g->n; i++) {
if (g->weights[i]!=1) {
sprintf(buf,"n %d %d\n",i+1,g->weights[i]);
STR_APPEND(buf);
}
}
fprintf(fp,"%d\n",(int)strlen(header));
fprintf(fp,"%s",header);
free(header);
for (i=0; i < g->n; i++) {
memset(buf,0,i/8+1);
for (j=0; j<i; j++) {
if (GRAPH_IS_EDGE_FAST(g,i,j)) {
buf[j/8] |= SET_BIT_MASK(7-j%8);
}
}
fwrite(buf,1,i/8+1,fp);
}
free(buf);
return TRUE;
}
/*
* graph_write_dimacs_ascii()
*
* Writes an ASCII dimacs-format file of graph g, with comment, to the
* file stream fp.
*
* Returns TRUE if successful, FALSE if an error occurred.
*/
boolean graph_write_dimacs_ascii(graph_t *g, char *comment, FILE *fp) {
int i,j;
ASSERT((sizeof(setelement)*8)==ELEMENTSIZE);
ASSERT(graph_test(g,NULL));
ASSERT(fp!=NULL);
if (comment)
fprintf(fp,"c %s\n",comment);
fprintf(fp,"p edge %d %d\n",g->n,graph_edge_count(g));
for (i=0; i < g->n; i++)
if (g->weights[i]!=1)
fprintf(fp,"n %d %d\n",i+1,g->weights[i]);
for (i=0; i < g->n; i++)
for (j=0; j<i; j++)
if (GRAPH_IS_EDGE_FAST(g,i,j))
fprintf(fp,"e %d %d\n",i+1,j+1);
return TRUE;
}
int main(int argc, char *argv[]) {
graph_t *g;
set_t s;
if (argc!=2) {
fprintf(stderr,"%s <dimacs_file>\n",argv[0]);
return 1;
}
g=graph_read_dimacs_file(argv[1]);
if (g==NULL)
return 1;
ASSERT(graph_test(g,stderr));
s=clique_find_single(g,0,0,FALSE,NULL);
set_print(s);
return 0;
}
