题解 | #计算一元二次方程#

#include <math.h>

void calculation(double a, double b, double c)               //解方程函数
{
    double x1,x2;
    double x1i;          //虚部
    double delta;
    if(a)
    {
        delta = pow(b,2) - 4 * a * c;
        if(delta == 0)
        {
            x1 = x2 = (-b + sqrt(delta))/(2 * a);
            printf("x1=x2=%.2f\n",x1);
        }
        else if(delta > 0)
        {
            x1 = (-b - sqrt(delta))/(2 * a);
            x2 = (-b + sqrt(delta))/(2 * a);
            printf("x1=%.2f;x2=%.2f\n",x1,x2);
        }
        else
        {
            x1 = (-b)/(2 * a);
            x1i = sqrt(-delta)/(2 * a);
            printf("x1=%.2f-%.2fi;x2=%.2f+%.2fi\n",x1,x1i,x1,x1i);
        }
    }
    else
    {
        printf("Not quadratic equation\n");
    }
}

int main()
{
    double a,b,c;
    while(scanf("%lf %lf %lf",&a,&b,&c) != EOF)
    {
        calculation(a, b, c);
    }
    return 0;
}