题解 | #计算一元二次方程#

#include <stdio.h>
#include<math.h>
int main() {
   double a,b,c;
   while(~scanf("%lf%lf%lf",&a,&b,&c))
   {
   if(a==0)
   {
       printf("Not quadratic equation");
   }
   else if(a!=0)
   {
if((pow(b,2)-4*a*c)==0)
{ if((-1*b+sqrt(pow(b,2)-4*a*c))/(2*a)==0)
{
    printf("x1=x2=0.00");
}
else
    printf("x1=x2=%.2lf",(-1*b+sqrt(pow(b,2)-4*a*c))/(2*a));
    printf("\n");
   
}
else if((pow(b,2)-4*a*c)>0)
{
    
    printf("x1=%.2lf;x2=%.2lf",(-1*b-sqrt(pow(b,2)-4*a*c))/(2*a),(-1*b+sqrt(pow(b,2)-4*a*c))/(2*a));
    printf("\n");
}
else if((pow(b,2)-4*a*c)<0)
{
printf("x1=%.2lf-%.2lfi;x2=%.2lf+%.2lfi",-1*b/(2*a),sqrt(-1*(pow(b,2)-4*a*c))/(2*a),-1*b/(2*a),sqrt(-1*(pow(b,2)-4*a*c))/(2*a));
printf("\n");
}

   }}
    return 0;
}