编辑代码

#include<stdio.h>
#include<math.h>
int main()
{
    double x1,x2,a,b,c,disc;
    scanf("%lf%lf%lf",&a,&b,&c);
    if(b*b-4*a*c<0)
       printf("无实根\n");
    else if(b*b-4*a*c==0)
    printf("%.2lf\n",(-b+sqrt(b*b-4*a*c))/(2*a));
    else if(b*b-4*a*c>0)
    printf("%4.2f\n%4.2f\n",(-b+sqrt(b*b-4*a*c)/(2*a)),(-b-sqrt(b*b-4*a*c))/(2*a)));

    return 0;
}