#define BOARD_WIDTH 7
#define BOARD_ROW_BYTES ((BOARD_WIDTH * 2) + 1)
#define BOARD_BYTES BOARD_ROW_BYTES * BOARD_ROW_BYTES

char EMPTY = ' ';

int neighbor_increments[] = {
  - BOARD_ROW_BYTES,
    1,
    BOARD_ROW_BYTES,
  - 1
};

// Board
void initialize_board(char* board);

void print_board(char* board);

void write_board(char* board, char* filename);

void read_board(char* board, char* filename);

// Moves
int is_allowed_placement(char* tile, int index, char* board);

int translate_coordinate(int index);

int is_center_index(int index);

int place_tile(char* tile, int index, char* board);

// Structures
void traverse_structure(char id, int index, char* board, char* structures);

void create_structure_mask(char* board, char* structures);

int evaluate_structure(int index, char* board, char* structures);