struct media_entity *
media_entity_graph_walk_next(struct media_entity_graph *graph)
{
if (stack_top(graph) == NULL)
return NULL;
while (link_top(graph) < stack_top(graph)->num_links) {
struct media_entity *entity = stack_top(graph);
struct media_link *link = &entity->links[link_top(graph)];
struct media_entity *next;
if (!(link->flags & MEDIA_LNK_FL_ENABLED)) {
link_top(graph)++;
continue;
}
next = media_entity_other(entity, link);
if (next == stack_peek(graph)) {
link_top(graph)++;
continue;
}
link_top(graph)++;
stack_push(graph, next);
}
return stack_pop(graph);
}
void set_row_node(unsigned long grid_origin, piece_t *piece, unsigned long column, node_t *left) {
row_node->row_node->grid_origin = grid_origin;
row_node->row_node->piece = piece;
row_node->row_node->column = &nodes[column];
link_left(row_node, left);
link_top(row_node, tops[column]);
tops[column] = row_node++;
nodes[column].rows++;
}
/**
* media_entity_graph_walk_next - Get the next entity in the graph
* @graph: Media graph structure
*
* Perform a depth-first traversal of the given media entities graph.
*
* The graph structure must have been previously initialized with a call to
* media_entity_graph_walk_start().
*
* Return the next entity in the graph or NULL if the whole graph have been
* traversed.
*/
struct media_entity *
media_entity_graph_walk_next(struct media_entity_graph *graph)
{
if (stack_top(graph) == NULL)
return NULL;
/*
* Depth first search. Push entity to stack and continue from
* top of the stack until no more entities on the level can be
* found.
*/
while (link_top(graph) < stack_top(graph)->num_links) {
struct media_entity *entity = stack_top(graph);
struct media_link *link = &entity->links[link_top(graph)];
struct media_entity *next;
/* The link is not enabled so we do not follow. */
if (!(link->flags & MEDIA_LNK_FL_ENABLED)) {
link_top(graph)++;
continue;
}
/* Get the entity in the other end of the link . */
next = media_entity_other(entity, link);
if (WARN_ON(next->id >= MEDIA_ENTITY_ENUM_MAX_ID))
return NULL;
/* Has the entity already been visited? */
if (__test_and_set_bit(next->id, graph->entities)) {
link_top(graph)++;
continue;
}
/* Push the new entity to stack and start over. */
link_top(graph)++;
stack_push(graph, next);
}
return stack_pop(graph);
}
/**
* media_entity_graph_walk_next - Get the next entity in the graph
* @graph: Media graph structure
*
* Perform a depth-first traversal of the given media entities graph.
*
* The graph structure must have been previously initialized with a call to
* media_entity_graph_walk_start().
*
* Return the next entity in the graph or NULL if the whole graph have been
* traversed.
*/
struct media_entity *
media_entity_graph_walk_next(struct media_entity_graph *graph)
{
if (stack_top(graph) == NULL)
return NULL;
/*
* Depth first search. Push entity to stack and continue from
* top of the stack until no more entities on the level can be
* found.
*/
while (link_top(graph) < stack_top(graph)->num_links) {
struct media_entity *entity = stack_top(graph);
struct media_link *link = &entity->links[link_top(graph)];
struct media_entity *next;
/* The link is not enabled so we do not follow. */
if (!(link->flags & MEDIA_LNK_FL_ENABLED)) {
link_top(graph)++;
continue;
}
/* Get the entity in the other end of the link . */
next = media_entity_other(entity, link);
/* Was it the entity we came here from? */
if (next == stack_peek(graph)) {
link_top(graph)++;
continue;
}
/* Push the new entity to stack and start over. */
link_top(graph)++;
stack_push(graph, next);
}
return stack_pop(graph);
}
int main(void) {
int r;
unsigned long grid_cells_n2, pieces_n, pieces_max, column_nodes_n1, column_nodes_n2, row_nodes_n, pieces_r, piece_f, piece_l, nodes_n, i, j, k;
scanf("%lu", &grid_rows);
if (!grid_rows) {
return EXIT_FAILURE;
}
scanf("%lu", &grid_columns1);
if (!grid_columns1) {
return EXIT_FAILURE;
}
grid_cells_n1 = grid_rows*grid_columns1;
grid_columns2 = grid_columns1+1;
grid_cells_n2 = grid_rows*grid_columns2;
grid_cells = malloc(grid_cells_n2+1);
if (!grid_cells) {
free_data(0UL);
return EXIT_FAILURE;
}
for (i = grid_columns1; i < grid_cells_n2; i += grid_columns2) {
grid_cells[i] = '\n';
}
grid_cells[grid_cells_n2] = 0;
scanf("%lu", &pieces_n);
if (!pieces_n) {
return EXIT_FAILURE;
}
pieces_max = pieces_n*8;
pieces = malloc(sizeof(piece_t)*pieces_max);
if (!pieces) {
return EXIT_FAILURE;
}
column_nodes_n1 = grid_cells_n1+pieces_n;
column_nodes_n2 = column_nodes_n1+1;
row_nodes_n = 0;
pieces_r = 0;
for (i = 0; i < pieces_n; i++) {
if (!read_piece(&pieces[pieces_r], i)) {
free_data(pieces_r);
return EXIT_FAILURE;
}
piece_f = pieces_r;
row_nodes_n += pieces[pieces_r].row_nodes_n;
pieces_r++;
j = 1;
do {
if (!rotate_piece(&pieces[pieces_r-1], &pieces[pieces_r])) {
free_data(pieces_r);
return EXIT_FAILURE;
}
r = compare_pieces(&pieces[piece_f], &pieces[pieces_r]);
for (k = piece_f+1; k < pieces_r && !r; k++) {
r = compare_pieces(&pieces[k], &pieces[pieces_r]);
}
if (!r) {
row_nodes_n += pieces[pieces_r].row_nodes_n;
pieces_r++;
j++;
}
else {
free_piece(&pieces[pieces_r]);
}
}
while (j < 4 && !r);
piece_l = pieces_r;
j = piece_f;
do {
if (!flip_piece(&pieces[j], &pieces[pieces_r])) {
free_data(pieces_r);
return EXIT_FAILURE;
}
r = compare_pieces(&pieces[piece_f], &pieces[pieces_r]);
for (k = piece_f+1; k < piece_l && !r; k++) {
r = compare_pieces(&pieces[k], &pieces[pieces_r]);
}
if (!r) {
row_nodes_n += pieces[pieces_r].row_nodes_n;
pieces_r++;
j++;
}
else {
free_piece(&pieces[pieces_r]);
}
}
while (j < piece_l && !r);
}
row_nodes = malloc(sizeof(row_node_t)*row_nodes_n);
if (!row_nodes) {
free_data(pieces_r);
return EXIT_FAILURE;
}
nodes_n = column_nodes_n2+row_nodes_n;
nodes = malloc(sizeof(node_t)*nodes_n);
if (!nodes) {
free_data(pieces_r);
return EXIT_FAILURE;
}
for (i = column_nodes_n2; i < nodes_n; i++) {
nodes[i].row_node = &row_nodes[i-column_nodes_n2];
}
tops = malloc(sizeof(node_t *)*column_nodes_n1);
if (!tops) {
free_data(pieces_r);
return EXIT_FAILURE;
}
header = &nodes[column_nodes_n1];
set_column_node(nodes, header);
for (i = 0; i < column_nodes_n1; i++) {
set_column_node(&nodes[i+1], &nodes[i]);
tops[i] = &nodes[i];
}
row_node = header+1;
for (i = 0; i < pieces_r; i++) {
print_piece(&pieces[i]);
set_piece_row_nodes(&pieces[i]);
}
for (i = 0; i < column_nodes_n1; i++) {
link_top(&nodes[i], tops[i]);
}
dlx_search();
printf("\nCost %lu\nSolutions %lu\n", cost, solutions);
free_data(pieces_r);
return EXIT_SUCCESS;
}