连问带写

#include <stdio.h>
#include <math.h>

#pragma warning(disable:4996)

#define EPS 0.000000001


int main()
{
	double a = 0.0, b = 0.0, c = 0.0;
	scanf("%lf %lf %lf", &a, &b, &c);
	if ((a > -EPS) && (a<EPS))
	{
		printf("不是一元二次方程\n");
	}
	else
	{
		double disc = b*b - 4 * a*c;
		if ((disc > -EPS) && (disc < EPS))
		{
			printf("两个相等的实根:%lf %lf\n", -b / (2 * a), -b / (2 * a));
		}
		else if (disc > 0)
		{
			printf("有两个不相等的实根:%lf %lf\n",
				(-b + sqrt(disc)) / (2 * a),
				(-b - sqrt(disc)) / (2 * a));
		}
		else
		{
			printf("有两个共轭复根\n");
		}
	}
	return 0;
}