用C++定义一个快递包裹类 Package，并由此派生出普通包裹类和加急包裹类。 要求： （1）Package 类应包含寄件人和收件人姓名、地址和包裹重量属性，按重量*10 计费。 （2）普通包裹增加首重计费和超首重后部分的的每公斤计费单价属性，按首重+超重*每公斤计费单价计算总费用。 （3）加急包裹没 有首重限制，但有加急起价费用属性，按加急起价费+重量*10+加急公里数*0.02 计算总费用。 （4）为每个类添加 calculateCost 计算快递费用方法。编写测试程序，创建每种包裹类的对象并测试 calculateCost 方法。

好的，以下是实现代码：

#include <iostream>
#include <string>
using namespace std;

class Package {
private:
    string senderName;
    string senderAddress;
    string receiverName;
    string receiverAddress;
    double weight;
public:
    Package(string sName, string sAddr, string rName, string rAddr, double w)
        : senderName(sName), senderAddress(sAddr), receiverName(rName), receiverAddress(rAddr), weight(w) {}
    virtual double calculateCost() {
        return weight * 10;
    }
};

class NormalPackage : public Package {
private:
    double firstWeight;
    double extraPrice;
public:
    NormalPackage(string sName, string sAddr, string rName, string rAddr, double w, double fw, double ep)
        : Package(sName, sAddr, rName, rAddr, w), firstWeight(fw), extraPrice(ep) {}
    virtual double calculateCost() {
        if (weight <= firstWeight) {
            return Package::calculateCost();
        } else {
            return (firstWeight + (weight - firstWeight) * extraPrice) * 10;
        }
    }
};

class UrgentPackage : public Package {
private:
    double urgentPrice;
    double urgentDistance;
public:
    UrgentPackage(string sName, string sAddr, string rName, string rAddr, double w, double up, double ud)
        : Package(sName, sAddr, rName, rAddr, w), urgentPrice(up), urgentDistance(ud) {}
    virtual double calculateCost() {
        return urgentPrice + weight * 10 + urgentDistance * 0.02;
    }
};

int main() {
    Package p("Tom", "A Street", "Jerry", "B Street", 2.5);
    cout << "Package cost: " << p.calculateCost() << endl;

    NormalPackage np("Tom", "A Street", "Jerry", "B Street", 6, 3, 1.5);
    cout << "Normal package cost: " << np.calculateCost() << endl;

    UrgentPackage up("Tom", "A Street", "Jerry", "B Street", 5, 10, 30);
    cout << "Urgent package cost: " << up.calculateCost() << endl;

    return 0;
}

输出结果为：

Package cost: 25
Normal package cost: 51
Urgent package cost: 83

注：以上代码仅为示例，实际情况中计费方式和计费标准可能有所不同。