#include <iostream>
#include <cmath>
using namespace std;
double * checkRoot(double a, double b, double c){
static double arr[2] = {-1,-1};
if(b*b-4*a*c >= 0){
double d = sqrt(b*b-4*a*c);
arr[0] = (-b+d)/(2*a);
arr[1] = (-b-d)/(2*a);
}
return arr;
}
int main() {
double a=2.0, b=5, c=3.1;
double *arr;
arr = checkRoot(a,b,c);
cout << *arr<< endl;
cout << *(arr+1)<< endl;
return 0;
}