题解 | #计算一元二次方程#

#include <stdio.h>
#include<math.h>
int main() {
    float a, b,c,sum,x,y,x1,y1;
    while (scanf("%f %f %f", &a, &b,&c) != EOF) 
    {
       if(a==0)
       {
        printf("Not quadratic equation\n");
       }
         else
         {
           sum=pow(b,2)-4*a*c;
           x=(-b+sqrtf(sum))/(2.0*a);
           y=(-b-sqrtf(sum))/(2.0*a);
               if(sum==0&&x!=0)
              {
                 printf("x1=x2=%.2f\n",x);
              }
               else  if(sum==0&&x==0)
              {
                  printf("x1=x2=0.00\n");
              }
         else  if(sum>0)
         {
            printf("x1=%.2f;x2=%.2f\n",y,x);
         }
         else if(sum<0)
         {
            printf("x1=%.2f-%.2fi;x2=%.2f+%.2fi\n",-b/(2*a),sqrt(-sum)/(2*a),-b/(2*a),sqrt(-sum)/(2*a));
         }
       }
    }
    return 0;
}