step 1: calculate the maximum attacks in eight directions; step 2: if there is obstacle in any one of the eight direction, which one smaller is the distance. def queensAttack(n, k, r_q, c_q, obstacles): # Write your code here dir_dis = {(0,1):n-c_q, (0,-1):c_q - 1, (1, 0): n-r_q, (-1, 0): r_q - 1, (-1, -1):min(r_q - 1, c_q - 1), (1, 1):min(n-r_q, n-c_q), (1, -1): min(n-r_q, c_q-1), (-1, 1):min(r_q-1, n-c_q) } for ro, co in obstacles: dx = ro - r_q dy = co - c_q if dx == 0 or dy == 0 or abs(dx) == abs(dy): dis = abs(dx) if abs(dx) == abs(dy) else max(abs(dx), abs(dy)) di = (dx/dis, dy/dis) dir_dis[di] = min(dir_dis[di], dis - 1) return sum(dir_dis.values())