+
+static void direction_to_coordinates(unsigned int direction, int* start_y, int* start_x) {
+
+ if (direction == north) {
+ *start_y = *start_y - 1;
+ } else if (direction == north_east) {
+ *start_y = *start_y - 1;
+ *start_x = *start_x + 1;
+ } else if (direction == east) {
+ *start_x = *start_x + 1;
+ } else if (direction == south_east) {
+ *start_y = *start_y + 1;
+ *start_x = *start_x + 1;
+ } else if (direction == south) {
+ *start_y = *start_y + 1;
+ } else if (direction == south_west) {
+ *start_y = *start_y + 1;
+ *start_x = *start_x - 1;
+ } else if (direction == west) {
+ *start_x = *start_x - 1;
+ } else if (direction == north_west) {
+ *start_y = *start_y - 1;
+ *start_x = *start_x - 1;
+ }
+}
+
+bool is_board_full(unsigned int pawn_array[board_size][board_size]) {
+
+ /* an alternate method is to test the round count vs. 60 */
+ for (int i = 1; i <= board_size; i++) {
+ for (int j = 1; j <= board_size; j++) {
+ if (is_box_type(i, j, pawn_array , empty)) {
+ return false;
+ }
+ }
+ }
+ return true;
+}
+
+unsigned int eval_winner(unsigned int nb_white, unsigned int nb_black) {
+
+ if (nb_white > nb_black) {
+ return player_two;
+ } else if (nb_white < nb_black) {
+ return player_one;
+ } else {
+ return 0;
+ }
+}
+
+static unsigned int reverse_one_direction(int y, int x, int direction, unsigned int current_player, unsigned int pawn_array[board_size][board_size]) {
+ unsigned int nb_pawns_reversed = 0;
+ int moving_y = y, moving_x = x;
+
+ /* count for pawns to reverse in the chosen direction */
+ direction_to_coordinates(direction, &moving_y, &moving_x);
+ while (true) {
+ if (!is_valid_coordinates(moving_y, moving_x) || is_box_type(moving_y, moving_x, pawn_array, empty)) {
+ return 0;
+ }
+ if (is_box_type(moving_y, moving_x, pawn_array, current_player)) {
+ break;
+ }
+ nb_pawns_reversed++;
+ direction_to_coordinates(direction, &moving_y, &moving_x);
+ }
+
+ /* now reverse the needed pawns */
+ if (nb_pawns_reversed > 0) {
+ moving_y = y, moving_x = x;
+ direction_to_coordinates(direction, &moving_y, &moving_x);
+ while (!is_box_type(moving_y, moving_x, pawn_array, current_player)) {
+ reverse_pawn(moving_y, moving_x, pawn_array);
+ direction_to_coordinates(direction, &moving_y, &moving_x);
+ }
+ }
+ return nb_pawns_reversed;
+}
+
+/* play the shot if legal and flip or reverse the necessary pawns */
+unsigned int valid_shot(int y, int x, unsigned int current_player, unsigned int pawn_array[board_size][board_size]) {
+ unsigned int nb_pawns_reversed = 0;
+
+ if (!is_valid_coordinates(y, x) || !is_box_type(y, x, pawn_array, empty)) {
+ return 0;
+ }
+
+ for (unsigned int direction = north; direction <= north_west; direction++) {
+ nb_pawns_reversed += reverse_one_direction(y, x, direction, current_player, pawn_array);
+ }
+
+ if (nb_pawns_reversed == 0) {
+ return 0;
+ }
+
+ set_pawn(y, x, current_player, pawn_array);
+ return nb_pawns_reversed;
+}