C语言 解一元二次方程

# define _CRT_SECURE_NO_WARNINGS
# include 
# include 

int main(void)
{
	int a, b, c;
	double delta, x1, x2;
	char ch;

	do
	{
		printf("请输入一元二次方程的系数:n");

		printf("a = ");
		scanf("%d", &a);

		printf("b = ");
		scanf("%d", &b);

		printf("c = ");
		scanf("%d", &c);

		delta = b * b - 4 * a * c;

		if (delta > 0)
		{
			x1 = (-b + sqrt(delta)) / (2 * a);
			x2 = (-b - sqrt(delta)) / (2 * a);

			printf("该方程有两个不同的实根nx1 = %lfnx2 = %lf", x1, x2);
		}

		else if (delta == 0)
		{
			x1 = x2 = (-b) / (2 * a);

			printf("该方程有两个相同的实根nx1 = x2 = %lf", x1);
		}

		else
		{
			printf("该方程无实数根");
		}

		printf("n是否再来一次？（Y/N）");
		scanf(" %c", &ch);   //%c前一定要加空格！！！

	} while (ch == 'Y' || ch == 'y');
	return 0;
}