题解 | 计算一元二次方程

#include <stdio.h>


int main() {
    float a, b, c, d, x1, x2, s, w, q, e;

    while (scanf("%f %f %f", &a, &b, &c) != EOF) { 
        d = b*b-4.0*a*c;
        if (a != 0) {
            if (d > 0) {
                x1 = (-b+sqrt(d))/(2*a);
                x2 = (-b-sqrt(d))/(2*a);
                q =x1 - x2;
                if(q <= 0)    printf("x1=%.2f;x2=%.2f'n",x1,x2);
                else printf("x1=%.2f;x2=%.2f\n",x2,x1);
            }
            else if(d < 0){
                s = (-b)/ 2 / a;
                w = sqrt(-d)/2/a;
                if(s==-0.00) {
                    s=0.00;
                    printf("x1=%.2f-%.2fi;x2=%.2f+%0.2fi\n",s,w,s,w);
                }
                else {
                    printf("x1=%.2f-%.2fi;x2=%.2f+%0.2fi\n",s,w,s,w);
                }
                
            }
            else {
                x1 = x2 = -b/ 2/a;
                if (x1== -0.00 || x2 == -0.00) {
                    x1=x2=0.00;
                     printf("x1=x2=%.2f\n", x1);
                }
                else printf("x1=x2=%.2f\n", x1);
            }
       

        
        } 

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