题解 | #计算一元二次方程#

#include <stdio.h>
#include <math.h>
int main() {
    float delta;
    float a,b,c;
    float x1,x2;
    while(scanf("%f %f %f",&a,&b,&c)!=EOF)
    {
        delta=b*b-4*a*c;
        x1=(-b-sqrt(delta))/2/a;
         x2=(-b+sqrt(delta))/2/a;
        if(a!=0)
        {
            if(x1==0&&a>0)
            x1=-x1;
            else if(x1==0&&a<0)
            x1=x1;
            
            if(delta==0)
                {
                    printf("x1=x2=%.2f\n",x1);
                }
            else if(delta>0)
                {
                    printf("x1=%.2f;x2=%.2f\n",x1,x2);
                }
            else 
                {
                    
                printf("x1=%.2f-%.2fi;x2=%.2f+%.2fi\n",-b/2/a,sqrt(-delta)/2/a,-b/2/a,sqrt(-delta)/2/a);
                }
        }
        else {
        printf("Not quadratic equation");
        }
    }
    return 0;
}