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

int main(){
	float a, b, c, delta, x1, x2, shi, xu;
	while(1) {
		printf("请输入a, b, c 的值：");
		scanf("%f%f%f", &a, &b, &c);
		delta = pow(b, 2) - 4 * a * c;
		if (delta > 0) {
			x1 = (-b + sqrt(delta)) / (2 * a);
			x2 = (-b - sqrt(delta)) / (2 * a);
			printf("x1 = %.2f\nx2 = %.2f\n", x1, x2);
		} else if (delta == 0) {
			x1 = x2 = -b / (2 * a);
			printf("x = %.2f\n", x1);
		} else if (delta < 0) {
			shi = -b / (2 * a);
			xu = sqrt(-delta) / (2 * a);
			printf("x1 = %.2f + %.2fi\nx2 = %.2f - %.2fi\n", shi, xu, shi, xu);
		}
	}
	return 0;
}