试题五

阅读以下说明和C++代码，填补代码中的空缺，将解答填入答题纸的对应栏。

    [说明]

    在股票交易中，股票代理根据客户发出的股票操作指示进行股票的买卖操作。其类图如下图所示，相应的C++代码附后。

类图

    [C++代码]

    #include＜iostream＞

    #include＜string＞

    #include＜vector＞

    using namespace std;

    class Stock {

    private:

    string name;    int quantity;

    public:

    Stock(string name,int quantity) {this-＞name=name; this-＞quantity

    =quantity;}

    void buy（ ） {cout＜＜"[买进]股票名称:"＜＜name＜＜",数量:"＜＜quantity＜＜

    endl;}

    void sell（ ） {cout＜＜"[卖出]股票名称:"＜＜name＜＜",数量:"＜＜quantity

    ＜＜endl;}

    };

    clasS order{

    public:

    virtual void execute（ ）=0;

    };

    class BuyStock:___（ ）___ {

    private:

    Stock* stock;

    public:

    BuyStock(Stock* stock){__（ ）____ =stock;  }

    void execute（ ）{    stock一＞buy（ ）;    }

    };

    //类SellStock的实现与BuyStock类似,此处略

    class Broker{

    private:

    vector＜Order*＞ orderList;

    public:

    void takeOrder(___（ ）___ order)(    orderLiSt.push back(order);}

    void placeorders（ ）  {

    for(int i=0;i＜orderList.Size（ ）; i++){___（ ）___ -＞execute（ ）;}

    0rderLiSt.clear（ ）;

    }

    };

    class StockCommand{

    public:

    VOid main（ ）{

    Stock* aStock=new Stock("股票A",10);

    Stock*bStock=new Stock("股票B",20);

    Order*buyStockOrder=new BuyStock(aStock);

    Order* sellStockOrder=new SellStock(bStock);

    Broker* broker=new Broker（ ）;

    broker-＞takeOrder(buyStockorder);

    broker-＞takeOrder(sellStockOrder);

    broker-＞ ___（ ）___ （ ）;

    }

    };

    int main（ ）{

    StockCommand* stockCommand=new StockCommand（ ）;

    StockCommand-＞main（ ）;

    delete StoCkCommand;

    }