第9周项目5-方程也是类

来源：互联网发布：mac windows截屏编辑：程序博客网时间：2024/06/06 06:27
#include <iostream>using namespace std;class CEquation{private:    double a;//未知数系数    double b;//常数项    char unknown;//代表未知数的符号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 c1,c2,c3,c4;    do    {        in>>e.a>>c1>>c2>>e.b>>c3>>c4;    }while(!((c1>='a'&&c1<='z')||c2=='+'||c2=='-'||c3=='='||c4=='0'));    if(c2=='-')        e.b=-e.b;    e.unknown=c1;    return in;}ostream &operator<<(ostream &out,CEquation &e){    out<<e.a<<e.unknown;    if(e.b>0)        out<<'+';    out<<e.b<<"=0"<<endl;    return out;}double CEquation::Solve(){    double x;    if(a==0)    {        if(b==0)            cout<<"任意数都为该方程的解"<<endl;        else            cout<<"该方程无解"<<endl;    }    x=-b/a;    return x;}char CEquation::getUnknown(){    return unknown;}int main(){    CEquation e;    cout<<"请输入方程（格式：ax-b=0,a、b为常数，x处是代表未知数的字母）：";    cin>>e;    cout<<"方程为："<<e;    cout<<"方程的解为："<<e.getUnknown()<<"="<<e.Solve()<<endl;    return 0;}
运行结果：
0 0