第九周实验报告（五）

#include <iostream>     using namespace std;    class CEquation  {  private:        double a;     // 未知数系数         double b;     // 常数项         char unknown; // 未知数的符号     public:        CEquation(double aa=0,double bb=0);        friend istream &operator >> (istream &in,CEquation &e);        friend ostream &operator << (ostream &out,CEquation &e);        double Solve();        char getUnknown();  };    CEquation::CEquation(double aa,double bb)  {      aa = a;        bb = b;  }    istream &operator >> (istream &in,CEquation &e)  {      char f1, f2;        in >> e.a >> e.unknown >> e.b >> f1 >> f2;        return in;  }    ostream &operator << (ostream &out,CEquation &e)  {      if(e.b < 0)      out << e.a << e.unknown << e.b << "=" << "0" << endl;        else          out << e.a << e.unknown << "+" <<e.b << "=" << "0" << endl;        return out;  }    double CEquation::Solve()  {      double x;        x = b * (-1) / a;        return x;  }  char CEquation::getUnknown()  {      return unknown;  }    int main()  {      CEquation e1, e2;        cout<<"请输入一元一次方程(输入格式：3x-8=0)：";        cin>>e1;   //在两次测试中，分别输入3x-8=0和5s+18=0         cout<<"方程为："<<e1;        cout<<"方程的解为："<<e1.getUnknown()<<"="<<e1.Solve()<<endl; //对两次测试，分别输出x=...和s=...         e1.Solve();            cout<<"请输入一元一次方程(输入格式：3x-8=0)：";        cin>>e2;   //在两次测试中，分别输入3x-8=0和5s+18=0         cout<<"方程为："<<e2;        cout<<"方程的解为："<<e2.getUnknown()<<"="<<e2.Solve()<<endl; //对两次测试，分别输出x=...和s=...         e2.Solve();        system("pause");        return 0;  }  

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