/* Naively choose the move that will shrink the most dots. */
mask_t choose_move_greedy(grid_t grid, int allow_shrinkers, int *no_moves) {
mask_t move = EMPTY_MASK;
int i, num_dots, max_dots = -1;
int num_moves;
move_list_t moves;
get_moves(grid, allow_shrinkers, &num_moves, moves);
*no_moves = 0;
if (SHOULD_SHRINK_RANDOM(num_moves, allow_shrinkers)) {
*no_moves = 1;
return random_mask();
}
for (i = 0; i < num_moves; i++) {
grid_t new_grid;
memcpy(new_grid, grid, sizeof(grid_t));
num_dots = apply_move(new_grid, moves[i]);
if (num_dots > max_dots) {
max_dots = num_dots;
move = moves[i];
}
}
return move;
}
void pancake::init_masks(uint8 n)
{
hord_masks_.clear();
ord_lookups_ = 0; // add_mask will increase this correctly
for (int i = 0; i < n; ++i){
add_mask(random_mask(time(NULL)+i));
}
}
/* heuristic = score ** uncertainty_of_board
* where uncertainty_of_board = (sum of certainty_of_dots) / num_dots
* uncertainty_of_dot | 1/4 if shrunk by cycle
* | 1/5 if shrunk by a regular move
* | 1 otherwise
*/
void _choose_move(grid_t grid, int allow_shrinkers, int turns_remaining, int certainty, float *value, mask_t *move, int *no_moves) {
float best_value = -1;
mask_t best_move = EMPTY_MASK;
int i, num_moves;
move_list_t moves;
get_moves(grid, allow_shrinkers, &num_moves, moves);
if (certainty == 720 && SHOULD_SHRINK_RANDOM(num_moves, allow_shrinkers)) {
*move = random_mask();
*value = num_dots(*move);
*no_moves = 1;
return;
}
for (i = 0; i < num_moves; i++) {
int score;
float value;
grid_t new_grid;
if (turns_remaining > 1 || HAS_CYCLE(moves[i])) {
memcpy(new_grid, grid, sizeof(grid_t));
score = apply_move(new_grid, moves[i]);
} else {
score = num_dots(moves[i]);
}
value = pow(score, certainty / 720.0);
if (turns_remaining > 1) {
int next_certainty = certainty - score * (HAS_CYCLE(moves[i]) ? 15 : 16);
float next_value;
mask_t next_move;
_choose_move(new_grid, allow_shrinkers, turns_remaining - 1, next_certainty, &next_value, &next_move, NULL);
value += next_value;
}
if (value > best_value) {
best_value = value;
best_move = moves[i];
}
}
*value = best_value;
*move = best_move;
}
