题解 | 计算一元二次方程

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

int main(void)
{
    float a = 0;
    float b = 0;
    float c = 0;

    float medi_value = 0.0;
    float result_1 = 0.0;
    float result_2 = 0.0;

    while (scanf("%f %f %f", &a, &b, &c) != EOF)
    {
        medi_value = powf(b, 2) - 4 * a * c;

        if (a == 0)
        {
            printf("Not quadratic equation");
        }
        else
        {
            if (medi_value == 0)
            {
                result_1 = result_2 = (-b) / (2 * a);
                result_1 = result_1 == -0.0 ? 0.00 : result_1;
                result_2 = result_2 == -0.0 ? 0.00 : result_2;
                printf("x1=x2=%.2f\n", result_1);
            }
            else if (medi_value > 0)
            {
                result_1 = ((-b) - sqrtf(medi_value)) / (2 * a);
                result_2 = ((-b) + sqrtf(medi_value)) / (2 * a);
                result_1 = result_1 == -0.0 ? 0.00 : result_1;
                result_2 = result_2 == -0.0 ? 0.00 : result_2;
                printf("x1=%.2f;x2=%.2f\n", result_1, result_2);
            }
            else
            {
                result_1 = (-b) / (2 * a);
                result_2 = sqrt(-medi_value) / (2 * a);
                result_1 = result_1 == -0.0 ? 0.00 : result_1;
                result_2 = result_2 == -0.0 ? 0.00 : result_2;
                printf("x1=%.2f-%.2fi;x2=%.2f+%.2fi\n", result_1, result_2, result_1, result_2);
            }
        }
    }
  
    return 0;
}