题解 | #计算一元二次方程#

#include <stdio.h>
#include<math.h>
int main() {
    float a, b , c;
    while (scanf("%f %f %f", &a, &b,&c) != EOF) { // 注意 while 处理多个 case
        // 64 位输出请用 printf("%lld") to 
        float derta = b*b-4*a*c;
        float x1 ,x2;
        if(a==0)

        {
            printf("Not quadratic equation");
        }
        else
        {
            if(derta==0)
            {
                x1=-b/(2*a)+0;
                printf("x1=x2=%.2f\n",x1);
            }
            else if(derta>0)
            {
                x1=(-b-sqrt(b*b-4*a*c))/(2*a);
                x2=(-b+sqrt(b*b-4*a*c))/(2*a);
                printf("x1=%.2f;x2=%.2f",x1,x2);
            }
            else {
                 if(b!=0)
            {
                printf("x1=%.2f-%.2fi;x2=%.2f+%.2fi\n",-b/(2*a),sqrt(-(b*b-4*a*c))/(2*a),-b/(2*a),sqrt(-(b*b-4*a*c))/(2*a));
            }
            else if(b==0)
            {
                printf("x1=0.00-%.2fi;x2=0.00+%.2fi\n",sqrt(-(b*b-4*a*c))/(2*a),sqrt(-(b*b-4*a*c))/(2*a));
            }
            }
        }
    }
    return 0;
}