题解 | #计算一元二次方程#

#include<stdio.h>
#include<math.h>

int main()
{
    float a, b, c, det, z;
    while(scanf("%f %f %f", &a, &b, &c)!=EOF)
    if (a != 0)
    {
        det = b * b - 4 * a * c;
        if (det > 0)
            printf("x1=%.2f;x2=%.2f\n", (-b - sqrt(det)) / 2.0 / a, (-b + sqrt(det)) / 2.0 / a);
        else 
            if (det == 0)
            {

                if (b == 0)
                    printf("x1=x2=%.2f\n", b);
                else
                    printf("x1=x2=%.2f\n", -b / 2.0 / a);
            }
            else
                printf("x1=%.2f-%.2fi;x2=%.2f+%.2fi\n", -b / 2.0 / a, fabs(sqrt(-det)/2.0/a), -b / 2.0 / a, fabs(sqrt(-det) / 2.0 / a));
    }
    else
        printf("Not quadratic equation\n");

    return 0;
}