测验程序总是评估答案是错误的

时间:2012-12-16 11:35:09

标签: c++

class Question{
  protected:
          int op1;
          int op2;
          string operate;
  public:
     Question();
};
class generateRandomQuiz:Question{
public: 
     generateRandomQuiz();
     int getp1();
     int getp2();
       string getOp();
}; 

class checkAnswer:generateRandomQuiz{
private:
      int Ans;
public:
     checkAnswer(int ans);
};

Question::Question()
 {
  op1=23;
 op2=12;
 operate="/";
 }

generateRandomQuiz::generateRandomQuiz():Question()
{
 op1=rand()%50;
 op2=rand()%50;
   string s="+-/*";
 int n=rand()%4;
 operate=s[n];
}

int generateRandomQuiz::getp1()
{
return op1;
}

int generateRandomQuiz::getp2()
{
return op2;
}

string generateRandomQuiz::getOp()
{
  return operate;
}

checkAnswer::checkAnswer(int ans):generateRandomQuiz()
{
Ans=ans;                       
string operate=getOp();
int op1=getp1();
int op2=getp2();
if (operate=="+")
{
     if (op1+op2==Ans)
    {
        cout<<"Your answer is correct."<<endl;
    }
    else
    {
        cout<<"You can do better next time."<<endl;
    }
}
if (operate=="-")
{
      if (op1-op2==Ans)
    {
        cout<<"Your answer is correct."<<endl;
    }
    else
    {
        cout<<"You can do better next time."<<endl;
    }
 }
 if (operate=="*")
{
    if (op1*op2==Ans)
    {
        cout<<"Your answer is correct."<<endl;
    }
    else
    {
        cout<<"You can do better next time."<<endl;
    }
}if (operate=="/")
{
    if (op1/op2==Ans)
    {
        cout<<"Your answer is correct."<<endl;
    }
    else
    {
        cout<<"You can do better next time."<<endl;
    }
  }                                                                
}
 int main()
{
  cout<<"This quiz is about evaluating an expression which is being generatedrandomly" 
   <<endl;

   generateRandomQuiz Q;
   int answer;
   int op1=Q.getp1();
   int op2=Q.getp2();
   string opr=Q.getOp();
   cout<<"What is: "<<op1<<op2<<op2<<"=?"<<endl;
   cin>>answer;
   checkAnswer A(answer);

system("PAUSE");
return 0;
}

我正在编写一个随机生成测验的程序,并要求用户提供这样的答案答案:什么是:15/43 =?操作员和数字是随机生成的。但是当我给出正确的答案时,即使这样,也会打印错误答案的评论。我写的条件很清楚。有人请指出来吗?谢谢

1 个答案:

答案 0 :(得分:2)

要检查答案,您依赖于checkAnswer 继承自 generateRandomQuiz这一事实。

但是当你真正检查答案时,你使用不同的实例而不是随机生成的测验,所以你不能通过做{{1}之类的东西来获得生成的测验}}。

通过这样做,您将获得默认构造值,并且由于您的构造函数执行随机化,您将得到完全不同的问题。所以检查机制是正确的,它只是检查一个不同的问题。我建议你重新考虑你的代码结构,它看起来很尴尬。