Java/com/study/demo4/Cardeliverycalculator.java

package com.study.demo4;

class CarDeliveryCalculator implements DeliveryFeeCalculator {
  @Override
  public double calculateFee(double distance) {
    if (distance <= 5) {
      return 10.0; // 起步价
    }
    return 10.0 + (distance - 5) * 2.0;
  }
}