game* evolve_torus(game* g) {
game* next = clone_game(g); //Clone game for evolution
int i, j, neighbor_cnt;
for (i = 0; i < g->rows; i++) {
for (j = 0; j < g->cols; j++) {
neighbor_cnt = neighbors_torus(g, i, j);
if (g->board[i][j] == ALIVE) { //ALIVE case
if (neighbor_cnt == 2 || neighbor_cnt ==3) {
; //Do nothing, stays alive
}
else {
next->board[i][j] = DEAD; //Else it dies
}
}
else { //DEAD case
if (neighbor_cnt == 3) { //If it has 3 living neighbors, it comes back to life
next->board[i][j] = ALIVE;
}
}
}
}
return next;
}
void evaluate_move(GAME *game, MOVE move, int *vector, int to_depth)
{
GAME *game2 = clone_game(game);
int window[MAX_PLAYERS];
memset(window, 0, sizeof(window));
apply_move(game2, move);
search_tree(game2, vector, to_depth, window, game2->current_player);
stack_pop(&game_stack, game2);
}
MOVE search_tree(GAME *game, int *best_vector, int to_depth, int *window_vector, int window_player)
{
MOVE moves[MAX_MOVES];
int num_moves;
int i;
MOVE best_move = MOVE_INVALID;
int player;
unsigned int hash;
if (to_depth <= 0 || game_is_over(game))
{
evaluate_game_immediate(game, best_vector);
return best_move;
}
#ifdef USE_TRANSPOSITION_TABLE_SEARCH
hash = hash_game(game) % TRANSPOSITION_TABLE_SIZE;
if (transposition_table[hash][0] != TABLE_UNUSED)
{
memcpy(best_vector, transposition_table[hash], sizeof(int)*MAX_PLAYERS);
hit_count++;
return best_move;
}
#endif
num_moves = generate_valid_moves(game, moves);
player = game->current_player;
for (i = 0; i < num_moves; i++)
{
GAME *game2 = clone_game(game);
int vector[MAX_PLAYERS];
MOVE move;
apply_move(game2, moves[i]);
node_count++;
move = search_tree(game2, vector, to_depth - 1, best_vector, player);
if (move == MOVE_INVALID)
move = moves[i];
if (i == 0 || vector[player] > best_vector[player])
{
memcpy(best_vector, vector, sizeof(vector));
best_move = moves[i];
}
stack_pop(&game_stack, game2);
/* Prune if this move is so good for the current player that
the potential value for the window player is less than
the window. */
if (vector[player] > parameters.total_score - window_vector[window_player])
{
break;
}
}
#ifdef USE_TRANSPOSITION_TABLE_SEARCH
memcpy(transposition_table[hash], best_vector, sizeof(int)*MAX_PLAYERS);
#endif
return best_move;
}
