求谜之一元二次方程

#include<iostream>
#include<cstdio>

#include<cmath>
using namespace std;

int main()
{
    double a,b,c,x1,x2;
    scanf("%lf%lf%lf",&a,&b,&c);
    if(b*b>4*a*c)
    {
        x1=(0-b+sqrt(b*b-4*a*c))/(2*a);
        x2=(0-b-sqrt(b*b-4*a*c))/(2*a);
        if(x1<x2)
        {
            printf("x1=%.5lf;x2=%.5lf\n",x1,x2);
        }
        else if(x1>x2)
        {
            printf("x1=%.5lf;x2=%.5lf\n",x2,x1);
        }
    }
    else if(b*b==4*a*c)
    {
        x1=(0-b)/(2*a);
        printf("x1=x2=%.5lf\n",x1);
    }
    else if(b*b<4*a*c)
    {
        cout<<"No answer!"<<endl;
    }
    return 0;
}