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

int main(void)
{
    int a,b,c;

    printf("请输入a,b,c\n");

    scanf("%d,%d,%d", &a,&b,&c);

    double delta =b*b-4*a*c;
    double x1,x2;
    if (delta > 0)
    {
        x1 = (-b + sqrt(delta)) / (2 * a);
        x2 = (-b - sqrt(delta)) / (2 * a);

        printf("该一元二次方程有两个解， x1=(-%d + √(%d)) / (2 * a) = %f ; x2 = (-%d - √(%d) / (2 * a))");
    }

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

        printf("该一元二次方程有一个唯一解， x1 = x2 = (-%d) / (2 * %d) = %f");
    }

    if (delta < 0)
    {
        printf("无解");
    }
    return 0;
}

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

int main(void)
{
    float a,b,c;

    printf("请输入a,b,c\n");

    scanf("%d %d %d", &a,&b,&c);

    float delta =b*b-4*a*c;
    float x1,x2;
    if (delta > 0)
    {
        x1 = (-b + sqrt(delta)) / (2 * a);
        x2 = (-b - sqrt(delta)) / (2 * a);

        printf("该一元二次方程有两个解， x1=(-%d + √(%d)) / (2 * a) = %f ; x2 = (-%d - √(%d) / (2 * a))");
    }

    if (delta == 0)//这孩子 真冒失！！！
    {
        x1 = (-1*b) / (2 * a);//怎么能直接写个-b？？？？？？？？？？？？
        x2 = x1;

        printf("该一元二次方程有一个唯一解， x1 = x2 = %f\n",x1);
    }

    if (delta < 0)
    {
        printf("无解");
    }
    return 0;
}