//finds route to target location and returns a pointer to the board that found it
Node* find_solution (Node *start, int height_coordinate, int width_coordinate){
hash *hash_array = create_hash_table (HASH_TABLE_SIZE);
set_hash_table (hash_array);
Node *current, *previous, *parent;
int target_found = 0;
current = start;
parent = start;
while (!target_found){
previous = current;
current->next = allocate_new_node (parent, previous);
if (find_next_move (hash_array, start, current->next, parent->board, current->next->board) == 0){
if (parent->next == NULL){
printf("Couldn't find a solution\n");
exit (1);
}
parent = parent->next;
current->next->parent = parent;
copy_board (current->next->board, parent->board);
}
target_found = check_for_target (current->next->board, height_coordinate, width_coordinate);
current = current->next;
}
return current;
}
node *get_node_1(const char *message_id, unsigned int group_id,
int get_new) {
int string_length = strlen(message_id);
int search = hash(message_id, string_length, node_table_length);
int offset = 0;
node *g;
#if 0
printf("Entering node '%s', %d\n", message_id, group_id);
#endif
previous_instance_node = 0;
while (1) {
offset = node_table[search];
if (! offset)
break;
else if (offset && ! strcmp(message_id,
get_string(nodes[offset].message_id)))
break;
if (search++ >= node_table_length)
search = 0;
}
if (! offset)
return allocate_new_node(message_id, group_id, search);
else {
g = &nodes[offset];
/* Try to find the parent in the same group. */
while (1) {
if (g->group_id == group_id)
return g;
previous_instance_node = g->id;
if (g->next_instance == 0)
break;
g = &nodes[g->next_instance];
}
if (get_new)
return allocate_new_node(message_id, group_id, search);
else
/* We didn't find any, so we just return the first instance of the
parent. */
return &nodes[offset];
}
}
node * add_child(node *parent, int value) {
if(parent == NULL){
return NULL;
}
if(parent->node_number > MAX_CHILD_NODES) {
return NULL;
}
new_child_node = allocate_new_node(value);
if(new_child_node != NULL) {
parent->children[parent->node_number] = new_child_node;
parent->node_number++;
}
return new_child_node;
}
