题解 | #计算一元二次方程#

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

int main(){
    float a , b  , c;
    while(scanf("%f %f %f",&a,&b,&c) != EOF)
    {
        if(a != 0)
        {
            float deta = pow(b, 2) - 4 * a *c;
            if(deta >= 0)
            {
                float r1 = (-b + sqrt(deta)) / (2 * a);
                float r2 = (-b - sqrt(deta)) / (2 * a);
                if(deta > 0)
                {
                    printf("x1=%.2f;x2=%.2f\n",r2,r1);
                }
                else
                {
                    if(r1 == 0)
                    {
                        printf("x1=x2=0.00\n");
                    }
                    else 
                    {
                        printf("x1=x2=%.2f\n",r1);
                    }
                }
            }
            else
            {
                float shibu = (- b ) / (2.0 * a);
                float xubu = (sqrt(-deta)) / (2.0 * a);
                if(xubu < 0)
                {
                    xubu = - xubu;
                    printf("x1=%.2f-%.2fi;x2=%.2f+%.2fi\n",shibu,xubu,shibu,xubu);
                }
                else {
                printf("x1=%.2f-%.2fi;x2=%.2f+%.2fi\n", shibu, xubu, shibu, xubu);
                }
            }

        }else 
        printf("Not quadratic equation\n");
    }
    return 0;
}