题解 | #计算一元二次方程#

#include <stdio.h>
#include <math.h>
int main() {
    float a, b, c;
    float delt = 0;
    while(scanf("%f%f%f",&a,&b,&c)!=EOF)
    {
        if(a == 0)
            printf("Not quadratic equation");
        else
        {
            if(b*b-4*a*c == 0)
            {
                float d = 0-b/(2*a);
                if(0.000000==d)
                {
                    printf("x1=x2=%.2f\n",0.00);
                }
                else
                {
                    printf("x1=x2=%.2f\n",-b/2.0/a);
                }

            }
            else if(b*b-4*a*c>0)
            {
                delt = b*b-4*a*c;
                printf("x1=%.2f;x2=%.2f\n",(0-b-sqrt(delt))/(2*a),(0-b+sqrt(delt))/(2*a));
            }
            else
            {
                delt = b*b-4*a*c;
                printf("x1=%.2f-%.2fi;x2=%.2f+%.2fi\n",
                0-b/(2*a),sqrt(0-delt)/(2*a),0-b/(2*a),sqrt(0-delt)/(2*a));
            }
        }
    }

    return 0;
}