#include <string>
#include <iostream>
using namespace std;
class PurchaseRequest {
public:
    double Amount;       // 一个采购的金额
    int Number;              // 采购单编号
    string Purpose;        // 采购目的
};
class Approver {              // 审批者类
public:
    Approver(){    successor = NULL;    }
    virtual void ProcessRequest(PurchaseRequest aRequest)
    {
        if (successor != NULL){  successor->ProcessRequest(aRequest);    }
    }
    void SetSuccessor(Approver *aSuccesssor){ successor = aSuccesssor; }
private:
      Approver* successor;
};
class Congress : public Approver {
public:
    void ProcessRequest(PurchaseRequest aRequest){
        if(aRequest.Amount >= 500000){    /* 决定是否审批的代码省略 */    }
        else   Approver::ProcessRequest(aRequest);
    }
};
class Director : public Approver {
public:
    void ProcessRequest(PurchaseRequest aRequest){  /* 此处代码省略 */    }
};
class President : public Approver {
public:
    void ProcessRequest(PurchaseRequest aRequest){  /* 此处代码省略 */  }
};
class VicePresident : public Approver {
public:
    void ProcessRequest(PurchaseRequest aRequest){  /* 此处代码省略 */   }
};
void main(){
    Congress Meeting;  
    VicePresident VPre;  
    Director Dir;  
    President Pre;      
    // 构造责任链
    Meeting.SetSuccessor(NULL);        
    VPre.SetSuccessor(&Pre);
    Pre.SetSuccessor(&Meeting);
    Dir.SetSuccessor(&VPre);
    
    PurchaseRequest aRequest;     // 构造一采购审批请求
    cin >> aRequest.Amount;   // 输入采购请求的金额
    
    Dir.ProcessRequest(aRequest);     // 开始审批
    return ;
}
07年下半年软设最后一题，这个搞不懂了，不知怎么传来传去的，希望那位高手能解答一下，万分感激了！