import random #評価関数: z = 1000*x+2000*y def criterion(x, y): stock_c=w-0.75*(x)-2/7*(y) stock_d=h-0.25*(x)-5/7*(y) z=1000*x+2000*y if stock_c<0 or stock_d<0 or x<0 or y<0: z=-z return z #粒子の位置の更新を行う関数 def update_position(x, y, vx, vy): stock_c=w-0.75*(x+vx)-2/7*(y+vy) stock_d=h-0.25*(x+vx)-5/7*(y+vy) if stock_c<0 or stock_d<0 or x+vx<0 or y+vy<0: new_x = x new_y = y else: new_x = x + vx new_y = y + vy return new_x, new_y #粒子の速度の更新を行う関数 def update_velocity(x, y, vx, vy, p, g, w=0.5, ro_max=1): #パラメーターroはランダムに与える ro1 = random.uniform(0, ro_max) ro2 = random.uniform(0, ro_max) #粒子速度の更新を行う new_vx = w * vx + ro1 * (p["x"] - x) + ro2 * (g["x"] - x) new_vy = w * vy + ro1 * (p["y"] - y) + ro2 * (g["y"] - y) return new_vx, new_vy def main(): N = 1000 #粒子の数 x_min, x_max = 0, 2*w y_min, y_max = 0, 2*h #粒子位置, 速度, パーソナルベスト, グローバルベストの初期化を行う ps = [{"x": random.uniform(x_min, 0.7*w), "y": random.uniform(y_min, 0.7*h)} for i in range(N)] vs = [{"x": 0.0, "y": 0.0} for i in range(N)] personal_best_positions = list(ps) personal_best_scores = [criterion(p["x"], p["y"]) for p in ps] # best_particle = np.argmax(personal_best_scores) best_particle = personal_best_scores.index(max(personal_best_scores)) global_best_position = personal_best_positions[best_particle] T = 500 #制限時間(ループの回数) for t in range(T): for n in range(N): x, y = ps[n]["x"], ps[n]["y"] vx, vy = vs[n]["x"], vs[n]["y"] p = personal_best_positions[n] #粒子の位置の更新を行う new_x, new_y = update_position(x, y, vx, vy) ps[n] = {"x": new_x, "y": new_y} #粒子の速度の更新を行う new_vx, new_vy = update_velocity( new_x, new_y, vx, vy, p, global_best_position) vs[n] = {"x": new_vx, "y": new_vy} #評価値を求め, パーソナルベストの更新を行う score = criterion(new_x, new_y) if score > personal_best_scores[n]: personal_best_scores[n] = score personal_best_positions[n] = {"x": new_x, "y": new_y} #グローバルベストの更新を行う # best_particle = np.argmax(personal_best_scores) best_particle = personal_best_scores.index(max(personal_best_scores)) global_best_position = personal_best_positions[best_particle] #最適解 # print(global_best_position) # print(round(new_x,5), round(new_y,5)) print(max(personal_best_scores)) if __name__ == '__main__': w, h=[int(i) for i in input().split()] main()