c++求解：定义一元二次方程类,数据成员为私有,求方程的根（虚根实根都要）

#include
#include
class LQuadEqu
{
double a,b,c; //方程为 aX^2+bX+c=0
double ReA,ImA; //存第一个根的实部ReA,和虚部ImA
double ReB,ImB; //存第2个根的实部和虚部
int rt; //rt=2有不等实根,rt=-2有不等虚根,rt=1有相等实根
public:
LQuadEqu(double aa,double bb,double cc);
//getResult用来取得方程的根,输入参数为指向存放各根的变量的指针,传指针是为了改值
//返回值为根的数目和类型 2有不等实根,-2有不等虚根,1有相等实根
int getResult(double *pReA,double *pImA,double *pReB,double *pImB);
};
LQuadEqu::LQuadEqu(double aa,double bb,double cc)
{
a=aa;b=bb;c=cc;
//计算公式为X=(-b+sqrt(b*b-4ac))/2/a和(-b-sqrt(b*b-4ac))/2/a
double tmp;
tmp = b*b-4*a*c;
if(tmp0)
{ //有不等实根
rt=2;
ImA=ImB=0;
ReA=(-b+sqrt(tmp))/2.0/a;
ReB=(-b-sqrt(tmp))/2.0/a;
}
else
{ //tmp==0 有相等实根
rt=1;
ImA=ImB=0;
ReA=ReB=-b/2.0/a;
}
}
int LQuadEqu::getResult(double *pReA,double *pImA,double *pReB,double *pImB)
{
*pReA=ReA; *pImA=ImA; *pReB=ReB; *pImB=ImB;
return rt;
}
void main ( )
{
double a,b,c,reA,imA,reB,imB;
int r;
printf("输入二次方程的参数a b cn");
scanf("%lf%lf%lf",&a,&b,&c);
printf("方程%f X^2 + %f X + %fn",a,b,c);
LQuadEqu lqe(a,b,c); //生成,计算
r = lqe.getResult(&reA,&imA,&reB,&imB); //取结果
if( r==2 )
printf("有两个不相等实根 %f %fn",reA,reB);
else if( r==-2 )
printf("有两个不相等虚根 (%f,%fi) (%f,%fi)n",reA,imA,reB,imB);
else
printf("有两个相等实根 %fn",reA);
getchar(); //使用者按任意键结束
}