第九周实验报告5

#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)
{
a = aa;
b = bb;
}
istream &operator >> (istream &in,CEquation &e)
{
char n, m ,z;
in >> e.a >> e.unknown >> n >> e.b >> m >> z;
while( m != '=' || z != '0')
{
cout <<"输入错误";
in >> e.a >> e.unknown >> n >> e.b >> m >> z;
}
if( n == '-')
{
e.b = -e.b ;
}
return in;
}

ostream &operator << (ostream &out,CEquation &e)
{
if( e.b > 0)
{
out << e.a << e.unknown << "+" << e.b << "=0";
}
else
{
out << e.a << e.unknown << e.b << "=0";
}
return out;
}

double CEquation::Solve()
{
double c;
c = ( -b)/a;
return c;
}

char CEquation::getUnknown()
{
return unknown;
}
int main()
{
CEquation e;
cout<<"请输入一元一次方程(输入格式：3x-8=0)：";
cin>>e;   //在两次测试中，分别输入3x-8=0和5s+18=0
cout<<"方程为："<<e;
cout<<"方程的解为："<<e.getUnknown()<<"="<<e.Solve()<<endl; //对两次测试，分别输出x=...和s=...
e.Solve();
system("pause");
return 0;
}