#include<stdio.h>
#include<math.h>
int main()
{
    double a,b,c,disc,x1,x2,realpart,imagpart;
    scanf("%lf,%lf,%lf",&a,&b,&c);
    printf("The equation");
    if(fabs(a)<=le-6)
        printf("is not a quadratic\n");
    else
    {
        disc=b*b-4*a*c;
        if(fabs(disc)<=1e-6)
            printf("has two equal roots:%8.4f\n",-b/(2*a));
        else
        
            if(disc>1e-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*a);
                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);
            }
        

    }
    return 0;
}

错误是1e-6没有定义,但是这是指数形式的常量啊?还要怎么定义?

居然输入的是l,太像了,怪不得看不到,我把它当1了

是一个错误..