static stop_t *make_stops (const float *tab, int n,
const float *vals, int nval, int *nstop_out)
{
int i;
stop_t *stops = NEWA (stop_t, nval + 1);
for (i = 0; i < nval; i++) {
stop_t *stop = stops + i;
stop->val = vals[i];
stop->no = i;
stop->n_gt = stop->n_eq = 0;
}
{ /* lower sentinel to count values below the lowest val and NaNs */
stop_t *stop = stops + nval;
stop->val = -1e30; /* -1.0/0.0 does not work ?? */
stop->no = -1;
stop->n_gt = stop->n_eq = 0;
}
qsort (stops, nval + 1, sizeof (stop_t), &cmp_stops_for_increasing);
for(i=1;i<nval+1;i++) assert(stops[i-1].val<=stops[i].val);
assert (stops[0].no == -1 || !isfinite(stops[0].val));
/* handle duplicate vals */
int nstop = nval + 1;
i = 1;
while (i < nstop) {
if (stops[i].val == stops[i - 1].val) {
int copied_no = stops[i].no;
/* shift array */
memmove (stops + i, stops + i + 1, (nstop - i - 1) * sizeof (stop_t));
nstop--;
stops[nstop].no = copied_no;
stops[nstop].copy_from_no = stops[i - 1].no;
} else i++;
}
for (i = 0; i < n; i++) {
float v = tab[i];
/* bisection, property: stops[t0].val <= v < stops[t1].val
* NaNs will be counted in stops[0].n_gt */
int t0 = 0, t1 = nstop;
while (t0 + 1 != t1) {
int med = (t0 + t1) / 2;
if (stops[med].val <= v)
t0 = med;
else
t1 = med;
}
if (stops[t0].val < v)
stops[t0].n_gt++;
else /* NaN's and other weird values here... */
stops[t0].n_eq++;
}
*nstop_out = nstop;
return stops;
}
void
plot_full_sets_grouped (
bitmap_t * fset_mask, /* IN - subset of full-sets to plot */
struct cinfo * cip, /* IN - compatibility info */
enum plot_size plot_size /* IN - size of plot to produce */
)
{
int i;
int j;
int n;
int nleft;
int kmasks;
int nmasks;
int nplot;
bitmap_t * left;
bitmap_t * tmask;
int * plist;
struct full_set * fsp;
struct pset * pts;
char * cp1;
char * cp2;
char fsnums [110];
char fsnum [8];
char title [120];
n = cip -> num_edges;
nmasks = cip -> num_edge_masks;
kmasks = cip -> num_vert_masks;
left = NEWA (nmasks, bitmap_t);
tmask = NEWA (kmasks, bitmap_t);
plist = NEWA (n, int);
/* Make a local copy of all full sets left to plot. */
for (i = 0; i < nmasks; i++) {
left [i] = fset_mask [i];
}
nleft = n;
while (nleft > 0) {
begin_plot (plot_size);
for (i = 0; i < kmasks; i++) {
tmask [i] = 0;
}
nplot = 0;
cp1 = &fsnums [sizeof (fsnums)];
*--cp1 = '\0';
for (i = n - 1; i >= 0; i--) {
if (NOT BITON (left, i)) continue;
/* Skip full set "i" if not disjoint */
/* with all others in this plot... */
fsp = cip -> full_trees [i];
pts = fsp -> terminals;
for (j = 0; j < pts -> n; j++) {
if (BITON (tmask, pts -> a [j].pnum)) break;
}
if (j < pts -> n) continue;
(void) sprintf (fsnum, "%lu", (int32u) i);
for (cp2 = fsnum; *cp2 NE '\0'; cp2++) {
}
/* Stop if label does not fit! */
if ((cp2 - fsnum) + 2 > (cp1 - fsnums)) break;
while (cp2 > fsnum) {
*--cp1 = *--cp2;
}
*--cp1 = ' ';
*--cp1 = ',';
plist [nplot++] = i;
CLRBIT (left, i);
--nleft;
fsp = cip -> full_trees [i];
fst_comment (fsp);
draw_fst (fsp, cip);
pts = fsp -> terminals;
for (j = 0; j < pts -> n; j++) {
SETBIT (tmask, pts -> a [j].pnum);
}
}
(void) printf ("\tPlot_Terminals\n");
(void) sprintf (title,
"FST%s %s.",
(nplot > 1) ? "s" : "",
cp1 + 2);
end_plot (title);
}
page_break ();
free ((char *) plist);
free ((char *) tmask);
free ((char *) left);
}
static
void
compute_grid_graph (
bitmap_t * tmap, /* IN - valid set of terminals */
bitmap_t * fset_mask, /* IN - valid FSTs */
struct cinfo * cip /* IN - compatibility info */
)
{
int i;
int j;
int k;
int nverts;
int nverts2;
int v1;
int spi;
int32u * gridp;
coord_t coord;
dist_t prev_coord;
int prev_index;
struct pset * tmp;
char buf1 [128];
char buf2 [128];
nverts = cip -> num_verts;
grid.nt = nverts;
grid.ns = 0;
grid.x_coord = NEWA (nverts, coord_t);
grid.y_coord = NEWA (nverts, coord_t);
grid.xindex = NEWA (nverts, int);
grid.yindex = NEWA (nverts, int);
/* Compute map giving index of each terminal in sequence when */
/* sorted by increasing X coordinate. */
tmp = NEW_PSET (nverts);
tmp -> n = nverts;
for (i = 0; i < nverts; i++) {
tmp -> a [i] = cip -> pts -> a [i];
}
sort_x_inc (tmp);
prev_coord = INF_DISTANCE;
prev_index = -1;
for (i = 0; i < nverts; i++) {
coord = tmp -> a [i].x;
grid.x_coord [i] = coord;
j = tmp -> a [i].pnum;
if (coord NE prev_coord) {
prev_index = i;
}
grid.xindex [j] = prev_index;
prev_coord = coord;
}
/* Compute map giving index of each terminal in sequence when */
/* sorted by increasing Y coordinate. */
tmp -> n = nverts;
for (i = 0; i < nverts; i++) {
tmp -> a [i] = cip -> pts -> a [i];
}
sort_y_inc (tmp);
prev_coord = INF_DISTANCE;
prev_index = -1;
for (i = 0; i < nverts; i++) {
coord = tmp -> a [i].y;
grid.y_coord [i] = tmp -> a [i].y;
j = tmp -> a [i].pnum;
if (coord NE prev_coord) {
prev_index = i;
}
grid.yindex [j] = prev_index;
prev_coord = coord;
}
free ((char *) tmp);
/* Allocate and zero matrix to hold the grid... */
nverts2 = (nverts + 1) * nverts;
grid.gridp = NEWA (nverts2, int32u);
for (i = 0; i < nverts2; i++) {
grid.gridp [i] = 0;
}
grid.gridp += nverts;
/* Set vertex number for each terminal in the grid... */
for (i = 0; i < nverts; i++) {
if (NOT BITON (tmap, i)) {
/* Should not have any duplicate terminals! */
fatal ("compute_grid_graph: Bug 1.");
}
j = grid.xindex [i];
k = grid.yindex [i];
grid.gridp [k * nverts + j] = i + 1;
}
draw_full_sets_on_grid (fset_mask, cip);
identify_steiner_points ();
/* Count every edge... */
count_edges = TRUE;
number_of_edges = 0;
gridp = grid.gridp;
for (i = 0; i < nverts; i++) {
for (j = 0; j < nverts; j++, gridp++) {
v1 = (*gridp & GMASK);
if (v1 EQ 0) continue;
if ((*gridp & RIGHT_EDGE) NE 0) {
edge_right (gridp, v1, i, j, 0, cip);
}
if ((*gridp & UP_EDGE) NE 0) {
edge_up (gridp, v1, i, j, 0, cip);
}
if ((j > 0) AND ((gridp [-1] & RIGHT_EDGE) NE 0)) {
edge_left (gridp, v1, i, j, 0, cip);
}
if ((i > 0) AND ((gridp [-nverts] & UP_EDGE) NE 0)) {
edge_down (gridp, v1, i, j, 0, cip);
}
}
}
/* Output total number of vertices, plus number of terminals. */
if (Print_ORLibrary_Format) {
printf ("%d %d\n", nverts + grid.ns, number_of_edges);
}
if (Print_SteinLib_Format) {
printf ("33d32945 STP File, STP Format Version 1.00\n"
"Section Comment\n"
"Name \"%s\"\n"
"Creator \"GeoSteiner\"\n"
"Remark \"Reduced graph from FST generator\"\n"
"End\n\n"
"Section Graph\n"
"Nodes %d\n"
"Edges %d\n",
cip -> description, nverts + grid.ns, number_of_edges);
}
/* Output every edge... */
count_edges = FALSE;
gridp = grid.gridp;
for (i = 0; i < nverts; i++) {
for (j = 0; j < nverts; j++, gridp++) {
v1 = (*gridp & GMASK);
if (v1 EQ 0) continue;
if ((*gridp & RIGHT_EDGE) NE 0) {
edge_right (gridp, v1, i, j, 0, cip);
}
if ((*gridp & UP_EDGE) NE 0) {
edge_up (gridp, v1, i, j, 0, cip);
}
if ((j > 0) AND ((gridp [-1] & RIGHT_EDGE) NE 0)) {
edge_left (gridp, v1, i, j, 0, cip);
}
if ((i > 0) AND ((gridp [-nverts] & UP_EDGE) NE 0)) {
edge_down (gridp, v1, i, j, 0, cip);
}
}
}
/* Write terminals (and coordinates in STP-format) */
if (Print_ORLibrary_Format) {
printf ("%d\n", nverts);
for (i = 0; i < nverts; i++) {
printf ("%d\n", i+1);
}
}
if (Print_SteinLib_Format) {
printf ("End\n\n"
"Section Terminals\n"
"Terminals %d\n",
nverts);
for (i = 0; i < nverts; i++) {
printf ("T %d\n", i+1);
}
printf ("End\n\n"
"Section Coordinates\n");
/* Output coordinates of each terminal... */
for (i = 0; i < nverts; i++) {
coord_to_string (buf1,
cip -> pts -> a [i].x,
&(cip -> scale));
coord_to_string (buf2,
cip -> pts -> a [i].y,
&(cip -> scale));
printf ("DD %d %s %s\n", i+1, buf1, buf2);
}
/* Output coordinates of each steiner point... */
spi = nverts+1;
gridp = grid.gridp;
for (i = 0; i < nverts; i++) {
for (j = 0; j < nverts; j++, gridp++) {
if ((*gridp & GMASK) > nverts) {
coord_to_string (buf1,
grid.x_coord [j],
&(cip -> scale));
coord_to_string (buf2,
grid.y_coord [i],
&(cip -> scale));
printf ("DD %d %s %s\n",
spi, buf1, buf2);
spi++;
}
}
}
printf ("End\n\n"
"EOF\n");
}
free ((char *) (grid.gridp - nverts));
free ((char *) grid.yindex);
free ((char *) grid.xindex);
free ((char *) grid.y_coord);
free ((char *) grid.x_coord);
}
struct constraint *
add_cutset_to_list (
bitmap_t * cutset, /* IN - new cutset to add */
struct constraint * cutlist, /* IN - list to add to */
double * x, /* IN - current LP solution */
bitmap_t * vert_mask, /* IN - set of valid terminals */
bitmap_t * edge_mask, /* IN - set of valid hyperedges */
struct cinfo * cip /* IN - compatibility info */
)
{
int i;
int j;
int nedges;
int nmasks;
int num_in_cut;
int count;
int * vp1;
int * vp2;
struct constraint * p;
struct constraint ** hookp;
bitmap_t * cut_edges;
double z;
nedges = cip -> num_edges;
nmasks = cip -> num_edge_masks;
cut_edges = NEWA (nmasks, bitmap_t);
memset (cut_edges, 0, nmasks * sizeof (*cut_edges));
count = 0;
z = 0.0;
for (i = 0; i < cip -> num_edges; i++) {
if (NOT BITON (edge_mask, i)) continue;
num_in_cut = 0;
vp1 = cip -> edge [i];
vp2 = cip -> edge [i + 1];
while (vp1 < vp2) {
j = *vp1++;
if (BITON (cutset, j)) {
++num_in_cut;
}
}
if (num_in_cut <= 0) {
/* this hyperedge resides entirely */
/* outside of the cut... doesn't span! */
continue;
}
if (num_in_cut >= cip -> edge_size [i]) {
/* this hyperedge resides entirely */
/* within the cut... doesn't span! */
continue;
}
SETBIT (cut_edges, i);
++count;
z += x [i];
}
/* Check for an all-zero cutset. These occasionally */
/* happen because of numeric issues... */
if (count <= 0) {
/* Empty cutset! OOOPS! */
#if 1
tracef (" %% WARNING! empty cutset!\n");
#endif
free ((char *) cut_edges);
return (cutlist);
}
if (z >= 1.0 - FUZZ) {
#if 1
tracef (" %% WARNING! bogus cutset!\n");
#endif
free ((char *) cut_edges);
return (cutlist);
}
/* If this new cutset is a superset of an existing one, */
/* then there is nothing to add, and nothing to delete. */
for (p = cutlist; p NE NULL; p = p -> next) {
if (is_subset (p -> mask, cut_edges, nmasks)) {
free (cut_edges);
return (cutlist);
}
}
/* Delete all current cutsets which have this new one */
/* as a subset. */
hookp = &cutlist;
while ((p = *hookp) NE NULL) {
if (p -> type NE CT_CUTSET) {
hookp = &(p -> next);
}
else if (is_subset (cut_edges, p -> mask, nmasks)) {
*hookp = p -> next;
free ((char *) (p -> mask));
free ((char *) p);
}
else {
hookp = &(p -> next);
}
}
p = NEW (struct constraint);
p -> next = NULL;
p -> iteration = 0;
p -> type = CT_CUTSET;
p -> mask = cut_edges;
*hookp = p;
return (cutlist);
}
int
main (
int argc,
char ** argv
)
{
int i;
int nedges;
int nmasks;
int fpsave;
bitmap_t * edge_mask;
bitmap_t * all_fsets_mask;
bitmap_t * no_fsets_mask;
int count;
char tbuf [20];
char title [128];
struct cinfo cinfo;
fpsave = set_floating_point_double_precision ();
setbuf (stdout, NULL);
decode_params (argc, argv);
init_tables ();
read_phase_1_data (&cinfo);
edge_mask = cinfo.initial_edge_mask;
convert_cpu_time (cinfo.p1time, tbuf);
printf (" %% Phase 1: %s seconds\n", tbuf);
/* Prepare for plotting all terminals. */
define_Plot_Terminals (cinfo.pts, &cinfo.scale);
nedges = cinfo.num_edges;
nmasks = cinfo.num_edge_masks;
all_fsets_mask = NEWA (nmasks, bitmap_t);
no_fsets_mask = NEWA (nmasks, bitmap_t);
for (i = 0; i < nmasks; i++) {
all_fsets_mask [i] = 0;
no_fsets_mask [i] = 0;
}
for (i = 0; i < nedges; i++) {
SETBIT (all_fsets_mask, i);
}
if (Print_Points) {
if ((cinfo.description NE NULL) AND
(cinfo.description [0] NE '\0')) {
strcpy (title, cinfo.description);
}
else {
sprintf (title, "%lu points", (int32u) cinfo.num_verts);
}
overlay_plot_subset (title, no_fsets_mask, &cinfo, BIG_PLOT);
}
if (Print_Full_Sets) {
plot_full_sets (all_fsets_mask, &cinfo, SMALL_PLOT);
}
if (Print_Grouped_Full_Sets) {
plot_full_sets_grouped (all_fsets_mask, &cinfo, SMALL_PLOT);
}
if (Print_Overlaid_Full_Sets) {
sprintf (title,
"All FSTs: %lu points, %s seconds",
(int32u) cinfo.num_verts, tbuf);
overlay_plot_subset (title, edge_mask, &cinfo, BIG_PLOT);
}
restore_floating_point_precision (fpsave);
exit (0);
}
color_image_t * color_image_png_load( FILE* fp, const char* file_name )
{
// read the header
png_byte header[8];
fread(header, 1, 8, fp);
if (png_sig_cmp(header, 0, 8))
{
fprintf(stderr, "error: %s is not a PNG.\n", file_name);
fclose(fp);
return 0;
}
png_structp png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
if (!png_ptr)
{
fprintf(stderr, "error: png_create_read_struct returned 0.\n");
fclose(fp);
return 0;
}
// create png info struct
png_infop info_ptr = png_create_info_struct(png_ptr);
if (!info_ptr)
{
fprintf(stderr, "error: png_create_info_struct returned 0.\n");
png_destroy_read_struct(&png_ptr, (png_infopp)NULL, (png_infopp)NULL);
fclose(fp);
return 0;
}
// create png info struct
png_infop end_info = png_create_info_struct(png_ptr);
if (!end_info)
{
fprintf(stderr, "error: png_create_info_struct returned 0.\n");
png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp) NULL);
fclose(fp);
return 0;
}
// the code in this if statement gets called if libpng encounters an error
if (setjmp(png_jmpbuf(png_ptr))) {
fprintf(stderr, "error from libpng\n");
png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
fclose(fp);
return 0;
}
// init png reading
png_init_io(png_ptr, fp);
// let libpng know you already read the first 8 bytes
png_set_sig_bytes(png_ptr, 8);
// read all the info up to the image data
png_read_info(png_ptr, info_ptr);
// variables to pass to get info
int bit_depth, color_type;
png_uint_32 temp_width, temp_height;
// get info about png
png_get_IHDR(png_ptr, info_ptr, &temp_width, &temp_height, &bit_depth, &color_type,
NULL, NULL, NULL);
// Update the png info struct.
png_read_update_info(png_ptr, info_ptr);
// Row size in bytes.
int rowbytes = png_get_rowbytes(png_ptr, info_ptr);
// Allocate the image_data as a big block, to be given to opengl
png_byte * image_data;
image_data = NEWA(png_byte, rowbytes * temp_height);
assert(image_data!=NULL);
// row_pointers is for pointing to image_data for reading the png with libpng
png_bytep * row_pointers = NEWA(png_bytep, temp_height);
assert(row_pointers!=NULL);
// set the individual row_pointers to point at the correct offsets of image_data
unsigned int i;
for (i = 0; i <temp_height; i++)
row_pointers[i] = image_data + i * rowbytes;
// read the png into image_data through row_pointers
png_read_image(png_ptr, row_pointers);
// copy into color image
color_image_t* image = color_image_new(temp_width,temp_height);
if( color_type==0 ) {
assert((unsigned)rowbytes == temp_width || !"error: not a proper gray png image");
for(i=0; i<temp_width*temp_height; i++)
image->c1[i] = image->c2[i] = image->c3[i] = image_data[i];
}
else if( color_type == 2 ) {
assert((unsigned)rowbytes == 3*temp_width || !"error: not a proper color png image");
for(i=0; i<temp_width*temp_height; i++) {
image->c1[i] = image_data[3*i+0];
image->c2[i] = image_data[3*i+1];
image->c3[i] = image_data[3*i+2];
}
} else
assert(!"error: unknown PNG color type" );
// clean up
png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
free(row_pointers);
return image;
}
struct constraint *
sec_flow_separator (
struct comp ** comp_hookp, /* IN/OUT - congested component(s) */
double * x, /* IN - the LP solution to separate */
bitmap_t * edge_mask, /* IN - subset of valid edges */
struct bbinfo * bbip, /* IN - branch-and-bound info */
struct constraint * cp /* IN - existing constraints */
)
{
int i;
int j;
int t;
int kmasks;
struct comp * comp;
struct cinfo * cip;
int * ip1;
int * ip2;
double z;
bitmap_t * S;
bitmap_t * RS;
cip = bbip -> cip;
#if 0
plot_lp_solution ("LP solution to separate", x, cip, BIG_PLOT);
#endif
S = NEWA (2 * cip -> num_vert_masks, bitmap_t);
RS = S + cip -> num_vert_masks;
for (;;) {
comp = *comp_hookp;
if (comp EQ NULL) break;
if (comp -> num_verts <= 0) {
/* Free up this component... */
*comp_hookp = comp -> next;
comp -> next = NULL;
free_congested_component (comp);
continue;
}
if (comp -> num_verts EQ 1) {
/* Because of the total-degree constraint, this */
/* cannot happen unless something is very wrong! */
fatal ("sec_flow_separator: Bug 1.");
}
if (comp -> num_verts <= SEC_ENUM_LIMIT) {
/* We have whittled this component down to */
/* something small. Use brute force on the */
/* rest... */
cp = enumerate_all_subtours (comp, cp, bbip);
/* Free up this component... */
*comp_hookp = comp -> next;
comp -> next = NULL;
free_congested_component (comp);
continue;
}
/* Find the LEAST congested vertex. this is the one */
/* we are going to try to force into the solution, */
/* since that is the one we would like to delete from */
/* the set afterward... */
t = find_least_congested_vertex (NULL, comp);
#if 0
tracef (" %% -------------------------"
"-------------------------\n"
" %% separating comp with %d verts, %d edges,"
" forcing vertex %d\n"
" %% -------------------------"
"-------------------------\n",
comp -> num_verts, comp -> num_edges,
comp -> rverts [t] [0]);
#endif
/* Find worst SEC violation involving vertex t. */
z = do_flow_problem (comp, t, S);
#if 0
#if 0
kmasks = cip -> num_vert_masks;
for (i = 0; i < kmasks; i++) {
RS [i] = 0;
}
for (i = 0; i < comp -> num_verts; i++) {
if (NOT BITON (S, i)) continue;
ip1 = comp -> rverts [i];
ip2 = comp -> rverts [i + 1];
while (ip1 < ip2) {
j = *ip1++;
SETBIT (RS, j);
}
}
print_mask (" %% S =", RS, cip -> num_verts);
#else
print_mask (" %% S =", S, comp -> num_verts);
#endif
tracef (" %% f(S) = %-24.15g\n", z);
#endif
if (z < (1.0 - FUZZ)) {
/* Add new violated constraint to the list... */
cp = check_component_subtour (S,
comp,
cp,
x,
edge_mask,
bbip);
}
/* We have found the worst violation (if any) involving */
/* vertex t. We can now eliminate t from further */
/* consideration... */
*comp_hookp = delete_vertex_from_component (t, comp);
}
free ((char *) S);
return (cp);
}
static
void
build_SEC_flow_formulation (
struct comp * comp, /* IN - congested component */
int t, /* IN - vertex to force */
struct sec_flow_info * flowp /* OUT - SEC flow formulation */
)
{
int i;
int j;
int k;
int nverts;
int nedges;
int nmasks;
int num_arcs;
int num_nodes;
int e;
int arc_num;
int num_used_edges;
int first_edge_node;
int * used_edges;
bitmap_t * unused_edge_mask;
struct flow_prob * prob;
int * ip1;
int * ip2;
int * ep1;
int * ep2;
int * vp1;
int * vp2;
int * outlist;
int * inlist;
int * srcp;
int * dstp;
double * capp;
int * counts;
int ** ptrs;
double sum;
nverts = comp -> num_verts;
nedges = comp -> num_edges;
/* Compute a list of all component edges that */
/* DO NOT contain the vertex "t". */
nmasks = BMAP_ELTS (nedges);
unused_edge_mask = NEWA (nmasks, bitmap_t);
for (i = 0; i < nmasks; i++) {
unused_edge_mask [i] = 0;
}
num_used_edges = nedges;
ep1 = comp -> vedges [t];
ep2 = comp -> vedges [t + 1];
while (ep1 < ep2) {
e = *ep1++;
SETBIT (unused_edge_mask, e);
--num_used_edges;
}
used_edges = NEWA (num_used_edges, int);
ep1 = used_edges;
for (i = 0; i < nedges; i++) {
if (BITON (unused_edge_mask, i)) continue;
*ep1++ = i;
}
free ((char *) unused_edge_mask);
if (ep1 NE (used_edges + num_used_edges)) {
/* lost count somewhere? */
fatal ("build_SEC_flow_formulation: Bug 1.");
}
/* Tally up the total number of nodes and arcs needed */
/* for the flow graph. For the sake of simplicity, we */
/* include a node for t, but there will be no arcs */
/* associated with it... */
/* One node per vertex. One source and one sink */
/* node. One node per USED edge. */
num_nodes = nverts + 2 + num_used_edges;
/* One arc per vertex, one arc per USED edge, */
/* plus one arc for each vertex of every USED edge. */
num_arcs = nverts + num_used_edges;
for (i = 0; i < num_used_edges; i++) {
e = used_edges [i];
num_arcs += (comp -> everts [e + 1] - comp -> everts [e]);
}
/* Start filling in the flow problem instance... */
prob = &(flowp -> prob);
prob -> num_nodes = num_nodes;
prob -> num_arcs = num_arcs;
/* Assign node numbers for the source and sink nodes... */
prob -> source = nverts;
prob -> sink = nverts + 1;
first_edge_node = nverts + 2;
/* Now that we know how big the directed flow graph is, */
/* allocate storage for the various data structures... */
prob -> out = NEWA (num_nodes + 1, int *);
prob -> in = NEWA (num_nodes + 1, int *);
prob -> arc_src = NEWA (num_arcs, int);
prob -> arc_dst = NEWA (num_arcs, int);
prob -> capacity = NEWA (num_arcs, double);
outlist = NEWA (num_arcs, int);
inlist = NEWA (num_arcs, int);
/* Generate the arcs from the source node to each USED edge. */
srcp = prob -> arc_src;
dstp = prob -> arc_dst;
capp = prob -> capacity;
arc_num = 0;
for (i = 0; i < num_used_edges; i++) {
e = used_edges [i];
j = first_edge_node + i;
*srcp++ = prob -> source;
*dstp++ = j;
*capp++ = comp -> x [e];
++arc_num;
/* Generate the arcs from each edge node to the */
/* corresponding vertex nodes. These all have weight */
/* 2, which is essentially infinite. */
vp1 = comp -> everts [e];
vp2 = comp -> everts [e + 1];
while (vp1 < vp2) {
k = *vp1++;
*srcp++ = j;
*dstp++ = k;
*capp++ = 2.0;
++arc_num;
}
}
free ((char *) used_edges);
/* Now generate one arc from each vertex node to the sink */
/* node. These all have weight (Bi - 1), where Bi is the */
/* congestion level of vertex i. */
for (i = 0; i < nverts; i++) {
sum = -1.0;
ep1 = comp -> vedges [i];
ep2 = comp -> vedges [i + 1];
while (ep1 < ep2) {
e = *ep1++;
sum += comp -> x [e];
}
*srcp++ = i;
*dstp++ = prob -> sink;
*capp++ = sum;
++arc_num;
}
if (arc_num NE num_arcs) {
fatal ("build_SEC_flow_formulation: Bug 2.");
}
/* We have now specified the directed flow graph as a */
/* list of directed arcs. Time to construct the */
/* adjacency lists -- for each node we build a list of */
/* outgoing and incoming arc numbers. Do the outgoing */
/* lists first... */
counts = NEWA (num_nodes, int);
ptrs = NEWA (num_nodes, int *);
for (i = 0; i < num_nodes; i++) {
counts [i] = 0;
}
for (i = 0; i < num_arcs; i++) {
++(counts [prob -> arc_src [i]]);
}
ip1 = outlist;
for (i = 0; i < num_nodes; i++) {
ptrs [i] = ip1;
prob -> out [i] = ip1;
ip1 += counts [i];
}
prob -> out [i] = ip1;
for (i = 0; i < num_arcs; i++) {
j = prob -> arc_src [i];
ip1 = ptrs [j]++;
*ip1 = i;
}
/* Now do the incoming arc lists... */
for (i = 0; i < num_nodes; i++) {
counts [i] = 0;
}
for (i = 0; i < num_arcs; i++) {
++(counts [prob -> arc_dst [i]]);
}
ip1 = inlist;
for (i = 0; i < num_nodes; i++) {
ptrs [i] = ip1;
prob -> in [i] = ip1;
ip1 += counts [i];
}
prob -> in [i] = ip1;
for (i = 0; i < num_arcs; i++) {
k = prob -> arc_dst [i];
ip1 = ptrs [k]++;
*ip1 = i;
}
/* Free temporary memory used to build things... */
free ((char *) counts);
free ((char *) ptrs);
/* Initialize the buffers used to hold flow solutions */
/* and temporary data... */
create_flow_solution_data (prob, &(flowp -> soln));
create_flow_temp_data (prob, &(flowp -> temp));
}
