求一元二次方程的解 （c语言）

#include<stdio.h>
#include<math.h>
int main()
{
	float a,b,c,disc,x1,x2,realpart,imagpart;
	scanf("%f%f%f",&a,&b,&c);
	printf("%0.2fx^2+%0.2fx+%0.2f=0\n",a,b,c);
	printf("The equation ");
	if(a==0)	//a=0
	{
		printf("is not a quadratic\n.");
	}
	else
	{
		disc=b*b-4*a*c;
		if(disc==0)	//△=0	
			 
			printf("has two equal real roots:%0.2f\n",-b/(2*a));	
		else 
			if(disc>0)	//△>0 
			{
				x1=(-b+sqrt(disc))/(2*a);
				x2=(-b-sqrt(disc))/(2*a);
				printf("has two distinct real roots:%0.2f and %0.2f\n",x1,x2);
			}
			else	//△<0 
			{
				realpart=-b/(2*a);
				imagpart=sqrt(-disc)/(2*a);
				printf("has two distinct complex roots:\n");
				printf("%0.2f+%0.2fi\n",realpart,imagpart);
				printf("%0.2f-%0.2fi\n",realpart,imagpart);
			}
	}
return 0;
}