题解 | #计算一元二次方程#

#include<stdio.h>
#include<math.h>
int main()
{
    float a,b,c;
    double tmp,Num1,Num2;
    double v=0;
    while(scanf("%f %f %f",&a,&b,&c) != EOF)
    {
        if(a == 0.0)
        {
            printf("Not quadratic equation");
        }else
        {
            tmp = b*b-4.0*a*c;
            if(tmp > 0)
            {
                Num1 = (-b - sqrt(tmp))/(2*a);
                Num2 = (-b + sqrt(tmp))/(2*a);
                printf("x1=%.2lf;x2=%.2lf\n",Num1,Num2);
            }else if(tmp == 0)
            {
                Num1=-b/(2*a);
                printf("x1=x2=%.2lf\n",Num1);
            }else if(tmp < 0)
            {
                Num1=b/(-2*a);
                v=sqrt(-tmp)/(2*a);
                if(Num1==-0.00)
                {
                    Num1=0.00;
                }
                printf("x1=%.2lf-%.2lfi;x2=%.2lf+%.2lfi\n",Num1,v,Num1,v);
            }
        }
    }
}