#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):a(aa),b(bb){} friend istream &operator >> (istream &in,CEquation &e); friend ostream &operator << (ostream &out,CEquation &e); double Solve(); char getUnknown();};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;}istream &operator >> (istream &in,CEquation &e){ double d; char v; in >> e.a >> e.unknown >> e.b >> v>> d; return in;}ostream &operator << (ostream &out,CEquation &e){ if(e.b >= 0) { out << e.a << "x+" << e.b <<"="<<"0"; } else { out << e.a << "x" << e.b <<"="<<"0"; } return out;}double CEquation::Solve(){ double d; return ((-b)/a);}char CEquation::getUnknown(){ return unknown;}