用C语言或Qbasic语言解：一元二次方程求根

#include <stdio.h>
#include <math.h>
main()
{
float a,b,c,disc,x1,x2,realpart,imagpart;
scanf("%f,%f,%f",&a,&b,&c);
printf("The equation:");
if (fabs(a)<=le-6)
printf("is not quadratic");
else
disc=b*b-4*a*c;
if (fabs(disc)<=le-6))
printf("has two equal roots:%8.4f\n",-b/(2*a));
else if (disc>le-6)
{
x1=(-b+sqrt(disc))/(2*a);
x2=(-b-sqrt(disc))/(2*a);
printf("has distinct real roots:%8.4f and %8.4f\n",x1,x2);
}
else
{
realpart=-b/(2*b);
imagpart=sqrt(-disc)/(2*a);
printf("has complex roots:\n");
printf("%8.4f+%8.4fi\n",realpart,imagpart);
printf("%8.4f-%8.4fi\n",realpart,imagpart);
}
}

楼上的一些问题：
1.scanf("a=%f",&a);printf("\n");
改为：printf("a=");scanf("%