Builders guide robot pacman.pdf

}if ( walls & SOUTH )return 0;elsereturn 1;else // dir == W{if ( walls & WEST )return 0;elsereturn 1;}}void solve( int x, int y ){// maze solving algorithm to get to point pos from current position with fast floodingint queue_x[NUM_CELLS], queue_y[NUM_CELLS]; // holds queue of cells to calculate distanceint goal_distance[NUM_CELLS]; // holds each cell's distance from point posint neigh_cell_x, neigh_cell_y;int queue_count = 0, queue_index = 0, curr_cell_dist = 0; // for solving mazeint i;int curr_pos_dist, neigh_pos_dist; // for creating roadmapint curr_cell_x, curr_cell_y;// initialize frontier arrayfor ( i = 0; i < NUM_CELLS; i++ ){goal_distance[i] = 0xFF;}goal_distance[point_to_cell_number(x,y)] = curr_cell_dist;// add target point pos to queuequeue_x[0] = x;queue_y[0] = y;queue_count++;while(queue_count > 0){queue_count--;curr_cell_x = queue_x[queue_index];curr_cell_y = queue_y[queue_index];curr_cell_dist = goal_distance[point_to_cell_number(curr_cell_x, curr_cell_y)];queue_index++;if ( curr_cell_dist != 0xFF ){// check all neighbours for accessibilityif ( is_neighbour(curr_cell_x, curr_cell_y, N) ){neigh_cell_x = curr_cell_x;neigh_cell_y = curr_cell_y - 1;curr_cell_dist + 1;}if ( goal_distance[point_to_cell_number(neigh_cell_x, neigh_cell_y)] == 0xFF ){goal_distance[point_to_cell_number(neigh_cell_x, neigh_cell_y)] =}queue_x[queue_index + queue_count] = neigh_cell_x;queue_y[queue_index + queue_count] = neigh_cell_y;queue_count++;if ( is_neighbour(curr_cell_x, curr_cell_y, E) ){neigh_cell_x = curr_cell_x + 1;neigh_cell_y = curr_cell_y;curr_cell_dist + 1;}if ( goal_distance[point_to_cell_number(neigh_cell_x, neigh_cell_y)] == 0xFF ){goal_distance[point_to_cell_number(neigh_cell_x, neigh_cell_y)] =}queue_x[queue_index + queue_count] = neigh_cell_x;queue_y[queue_index + queue_count] = neigh_cell_y;queue_count++;if ( is_neighbour(curr_cell_x, curr_cell_y, S) ){neigh_cell_x = curr_cell_x;neigh_cell_y = curr_cell_y + 1;curr_cell_dist + 1;}if ( goal_distance[point_to_cell_number(neigh_cell_x, neigh_cell_y)] == 0xFF ){goal_distance[point_to_cell_number(neigh_cell_x, neigh_cell_y)] =}queue_x[queue_index + queue_count] = neigh_cell_x;queue_y[queue_index + queue_count] = neigh_cell_y;queue_count++;