/************************************
* BEST FIRST SEARCH IMPLEMENTATION *
************************************/
Bool do_best_first_search( void ) {
static Bool fc = TRUE; /*first round*/
static State S;
BfsNode *first;
int i, min = INFINITY;
Bool start = TRUE;
if ( fc ) {
make_state( &S, gnum_ft_conn );
S.max_F = gnum_ft_conn;
fc = FALSE;
}
lbfs_space_head = new_BfsNode();
lbfs_space_had = NULL;
for ( i = 0; i < BFS_HASH_SIZE; i++ ) {
lbfs_hash_entry[i] = NULL;
}
add_to_bfs_space( &ginitial_state, -1, NULL );
while ( TRUE ) {
if ( (first = lbfs_space_head->next) == NULL ) {
printf("\n\nbest first search space empty! problem proven unsolvable.\n\n");
return FALSE;
}
lbfs_space_head->next = first->next;
if ( first->next ) {
first->next->prev = lbfs_space_head;
}
if ( LESS( first->h, min ) ) {
min = first->h;
if ( start ) {
printf("\nadvancing to distance : %4d", min);
start = FALSE;
} else {
printf("\n %4d", min);
}
/*
* modified by JC: return ealier
*/
if(is_solved_state( &first->S )){
printf("\nstate have seen. return!\n");
break;
}
}
if ( first->h == 0 ) {
break;
}
get_A( &(first->S) );
for ( i = 0; i < gnum_A; i++ ) {
/*if(g_is_strong){*/
/*JC: dismiss invalid actions*/
int k;
Bool found = FALSE;
for(k = 0; k < gnum_IV; k++){
if(gA[i] == gInvActs[k].act){
found = TRUE;
break;
}
}
/*}*/
if(found) continue;
result_to_dest( &S, &(first->S), gA[i] );
add_to_bfs_space( &S, gA[i], first );
}
first->next = lbfs_space_had;
lbfs_space_had = first;
}
extract_plan( first );
return TRUE;
}
Bool do_best_first_search( void )
{
static Bool fc = TRUE;
static State S;
BfsNode *first;
int i, min = INFINITY;
Bool start = TRUE;
if ( fc ) {
make_state( &S, gnum_ft_conn );
fc = FALSE;
}
lbfs_space_head = new_BfsNode();
lbfs_space_had = NULL;
add_to_bfs_space( &ginitial_state, -1, NULL );
while ( TRUE ) {
if ( (first = lbfs_space_head->next) == NULL ) {
printf("\n\nbest first search space empty! problem proven unsolvable.\n\n");
return FALSE;
}
lbfs_space_head->next = first->next;
if ( first->next ) {
first->next->prev = lbfs_space_head;
}
if ( LESS( first->h, min ) ) {
min = first->h;
if ( start ) {
printf("\nadvancing to distance : %4d", min);
start = FALSE;
fflush(stdout);
} else {
printf("\n %4d", min);
fflush(stdout);
}
}
if ( first->h == 0 ) {
break;
}
get_A( &(first->S) );
for ( i = 0; i < gnum_A; i++ ) {
if ( !result_to_dest( &S, NULL, first, gA[i] ) ) continue;
add_to_bfs_space( &S, gA[i], first );
}
first->next = lbfs_space_had;
lbfs_space_had = first;
}
extract_plan( first );
return TRUE;
}
