C++ 代码

#include<bits/stdc++.h>
using namespace std;
double a,b,c;
int main()
{
    cin>>a>>b>>c;
    double der=b*b-4*a*c;
    if(a==0||der<0)cout<<"Impossivel calcular";
    else if(der==0)
    {
        cout<<"R1 = "<<fixed<<setprecision(5)<<(sqrt(der)-b)/(2*a)<<endl;
        cout<<"R2 = "<<fixed<<setprecision(5)<<(sqrt(der)-b)/(2*a);
    }
    else
    {
        cout<<"R1 = "<<fixed<<setprecision(5)<<(sqrt(der)-b)/(2*a)<<endl;
        cout<<"R2 = "<<fixed<<setprecision(5)<<(-sqrt(der)-b)/(2*a);
    }
    return 0;
}