1058：求一元二次方程

 

 

#include<iostream>
#include<cmath>
#include<cstdio>
using namespace std;
const double eps = 1e-6;
int main()
{
    double a,b,c,dis,x1,x2;
    cin>>a>>b>>c;
    dis = b*b-4*a*c;
    if (dis<-eps) cout<<"No answer!\n";
    else if (fabs(dis)<=eps) printf("x1=x2=%.5lf\n",(-b)/(2*a));
    else {
        x1=(-b+sqrt(dis))/(2*a);
        x2=(-b-sqrt(dis))/(2*a);
        if (x1>x2) { double t=x1; x1=x2; x2=t; }
        printf("x1=%.5lf;x2=%.5lf\n",x1,x2);
    }
    return 0;
}