// 抽象父类Vehicle
abstract class Vehicle {
    public abstract void run();
}

// 子类Car
class Car extends Vehicle {
    @Override
    public void run() {
        System.out.println("小汽车在公路上行驶");
    }
}

// 子类Bike
class Bike extends Vehicle {
    @Override
    public void run() {
        System.out.println("自行车在非机动车道行驶");
    }
}

// 子类Truck
class Truck extends Vehicle {
    @Override
    public void run() {
        System.out.println("卡车在货运道路行驶");
    }
}

// 主类
public class VehicleTest {
    public static void main(String[] args) {
        // 创建Vehicle数组，存放不同车辆
        Vehicle[] vehicles = {
            new Car(),
            new Bike(),
            new Truck()
        };

        // 遍历调用run()
        System.out.println("=== 车辆行驶测试 ===");
        for (Vehicle v : vehicles) {
            v.run();
        }
    }
}