添加 '进阶题'

进阶题

@@ -0,0 +1,46 @@
+// 抽象父类 Vehicle
+public abstract class Vehicle {
+    public abstract void run();
+}
+
+// 子类 Car
+public class Car extends Vehicle {
+    @Override
+    public void run() {
+        System.out.println("汽车在公路上行驶，速度 100km/h");
+    }
+}
+
+// 子类 Bike
+public class Bike extends Vehicle {
+    @Override
+    public void run() {
+        System.out.println("自行车在非机动车道骑行，速度 15km/h");
+    }
+}
+
+// 子类 Truck
+public class Truck extends Vehicle {
+    @Override
+    public void run() {
+        System.out.println("卡车在公路上缓慢行驶，速度 60km/h");
+    }
+}
+
+// 测试主类
+public class VehicleTest {
+    public static void main(String[] args) {
+        System.out.println("=== 进阶题测试 ===");
+        // 创建 Vehicle 数组，存放不同车辆
+        Vehicle[] vehicles = {
+            new Car(),
+            new Bike(),
+            new Truck()
+        };
+
+        // 遍历调用 run() 方法
+        for (Vehicle v : vehicles) {
+            v.run();
+        }
+    }
+}