编程求一元二次方程ax2+bx+c=0的根

#include "iostream"
#include "cmath"
using namespace std;
int main(){
double a,b,c;
double delta,x1,x2;
int sign,stop;
cout<<"输入3个系数a(a!=0),b,c"<<endl;
cin>>a>>b>>c;
if(a==0){
cout<<"a不能等于0!!!!不然这就不是一元二次方程式了"<<endl;
exit(0);
}
delta=b*b-4*a*c;
if(delta==0){
cout<<"方程有两个实根：x1=x2="<<-b/(2*a)<<endl;
}
else{
if(delta>0) sign=1;
else sign=0;
delta=sqrt(fabs(delta));
x1=-b/(2*a);
x2=delta/(2*a);
if(sign){
cout<<"方程有两个不同的实根：x1="<<x1+x2<<"   x2="<<x1-x2<<endl;
}
else{
cout<<"方程无实根，有两个不同的复数根：x1="<<x1<<"+i"<<x2<<"   x2="<<x1<<"-i"<<x2<<endl;
}
}
}