完善下列代码#define N 3; class CHouse { private: char mName[20]; //地址 float mPrice; //单价 float mArea; //面积 public: float getprice() { return mPrice; } float getarea() { return mArea; } void set(char* name, float price, float area); //修改房屋参数 CHouse(char* name=0,float price=0,float area=0); //构造函数 friend ifstream& operator>> (ifstream &is, CHouse &house); //从文件中读取一个房屋参数 friend ostream& operator<< (ostream &is, CHouse &house); }; class CBuilding //大楼 { private: CHouse *mHouse; int mNums; int size; public: CBuilding(int m = N) { mHouse = new CHouse[m]; size = m; mNums = 0; } float Total(); //计算大楼所有房屋的总价值 void AddHouse(char* name,float price,float area); //加入房屋到大楼中,注意空间是否超出 void ReadData(char* filename); //将大楼信息从文件中读取 friend ostream& operator<< (ostream &is, CBuilding & cb); ~CBuilding(); }; void main() { CBuilding Building; Building.ReadData("data.txt"); Building.AddHouse("507",23000,80); cout<<Building<<endl; }

这段代码中存在一个问题：在宏定义 N 的后面有一个分号，应该将它改为：

#define N 3

另外，还需要完善 CHouse 类中的 set 方法和构造函数，代码如下：

void set(char* name, float price, float area)
{
    strcpy(mName, name);
    mPrice = price;
    mArea = area;
}

CHouse(char* name = 0, float price = 0, float area = 0)
{
    if (name != 0)
    {
        strcpy(mName, name);
    }
    mPrice = price;
    mArea = area;
}

在 CBuilding 类中，需要完善 AddHouse 方法、Total 方法、<< 运算符重载函数和析构函数。具体代码如下：

void AddHouse(char* name, float price, float area)
{
    if (mNums >= size)
    {
        cout << "Add Error: The building is full!" << endl;
        return;
    }
    mHouse[mNums++].set(name, price, area);
}

float Total()
{
    float total = 0;
    for (int i = 0; i < mNums; i++)
    {
        total += mHouse[i].getprice() * mHouse[i].getarea();
    }
    return total;
}

ostream& operator<<(ostream& os, CBuilding& cb)
{
    os << "Building Info: " << endl;
    for (int i = 0; i < cb.mNums; i++)
    {
        os << "House " << i + 1 << ": " << cb.mHouse[i].getprice() << " * " << cb.mHouse[i].getarea() << " = " << cb.mHouse[i].getprice() * cb.mHouse[i].getarea() << endl;
    }
    os << "Total Value: " << cb.Total() << endl;
    return os;
}

CBuilding::~CBuilding()
{
    delete[] mHouse;
}