题解 | #计算一元二次方程#

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