#include<iostream>
#include<string>
using namespace std;class company
{
public:company(string str){name = str;}void setName(string str){name = str;}string getName(){return name;}virtual void sale(){};virtual void buy(){};
private:string name;
};class chinaCompany:public company
{
public:chinaCompany(string str):company(str){};void sale(){cout<<getName()<<" sale sth"<<endl;}void buy(){cout<<getName()<<" buy sth"<<endl;}
};class AmericaCompany:public company
{
public:AmericaCompany(string str):company(str){};void sale(){cout<<getName()<<" sale sth"<<endl;}void buy(){cout<<getName()<<" buy sth"<<endl;}
};class companyUnion
{
public:companyUnion(){for(int i=0;i<10;i++)list[i]=0;maxlen=0;}void join(company *c){list[maxlen]=c;maxlen++;cout<<c->getName()<<" join the company union"<<endl;}int find(company *c){for(int i=0;i<maxlen;i++){if(c->getName() == list[i]->getName())return i;}return -1;}void business(company *from, company *to){int source = find(from);int dest = find(to);if(source == dest){cout<<"you can't sell goods to yourself"<<endl;return;}list[source]->sale();list[dest]->buy();}
private:company *list[10];int maxlen;
};int main()
{company *huawei = new chinaCompany("huawei");company *zet = new chinaCompany("ZET");company *cisco = new AmericaCompany("cisco");company *at = new AmericaCompany("AT&T");companyUnion *wto = new companyUnion();wto->join(huawei);wto->join(zet);wto->join(cisco);wto->join(at);cout<<endl;wto->business(huawei, zet);cout<<endl;wto->business(huawei, cisco);cout<<endl;wto->business(huawei, huawei);cout<<endl;wto->business(at, zet);cout<<endl;wto->business(cisco, zet);cout<<endl;wto->business(at, cisco);system("pause");return 0;
}

参考：http://www.cnblogs.com/mayvar/archive/2011/09/08/wanghonghua_201109080334.html