int8_t get_opponent_da(int16_t *d, int16_t *a);
int8_t get_opponent_xyda(int16_t *x, int16_t *y, int16_t *d, int16_t *a);
int16_t distance_from_opponent(int16_t x, int16_t y);
int8_t get_opponent_da(int16_t *d, int16_t *a);
int8_t get_opponent_xyda(int16_t *x, int16_t *y, int16_t *d, int16_t *a);
int16_t distance_from_opponent(int16_t x, int16_t y);