求一元二次方程的根

程序填空，不要改变与输入输出有关的语句。
输入一个正整数repeat (0

#include 
#include 
int main(void)
{
    int repeat, ri;
    double a, b, c, d;

    scanf("%d", &repeat);
    for(ri = 1; ri <= repeat; ri++){
        scanf("%lf%lf%lf", &a, &b, &c);
        d = pow(b,2)-4*a*c;
		if(a==0 && b==0 && c==0)
			printf("参数都为零，方程无意义!\n");
			else if(a==0 && b==0 && c!=0)
				printf("a和b为0，c不为0，方程不成立\n");
				else if(a == 0)
					printf("x = %0.2f\n", -c/b);
					else if(d >= 0){
						printf("x1 = %0.2f\n", (-b+sqrt(d))/(2*a));
						printf("x2 = %0.2f\n", (-b-sqrt(d))/(2*a));
					}
					else {
						printf("x1 = %0.2f+%0.2fi\n", -b/(2*a), sqrt(-d)/(2*a));
						printf("x2 = %0.2f-%0.2fi\n", -b/(2*a), sqrt(-d)/(2*a));
					}
    }     
}