求一元二次方程 

 的根，通过键盘输入a、b、c，根据△的值输出对应x1和x2的值(保留一位小数)(用if语句完成)。 

//一元二次方程的实现
#include <stdio.h>
#include <math.h>
#include <stdlib.h>
int main()
{
	double a, b, c, delta, x1=0,x2=0,x3;
	char i = 0;
	printf("请输入一元二次方程的系数： ");
	scanf_s("%lf%lf%lf", &a, &b, &c);
	delta = b * b - 4 * a * c;
	x3 = -b / (2 * a);
	if (delta == 0)
	{
		x1 = x2 = -b / (2 * a);
		printf("x1=%.f,x2=%.f", x1, x2);
	}
	else if (delta > 0)
	{
		x1 = (-b / 2 * a) + sqrt(b * b - 4 * a * c) / (2 * a);
		x2 = (-b / 2 * a) - sqrt(b * b - 4 * a * c) / (2 * a);
		printf("x1=%.f,x2=%.f", x1, x2);
	}
	else if (delta < 0)
	{
		x1 =  sqrt(fabs(b * b - 4 * a * c))/ (2 * a);
		x2 = sqrt(fabs(b * b - 4 * a * c))/ (2 * a);
		printf("x1=%.f+%.fi,x2=%.f-%.fi", x3, x1,x3,x2);
	}
	return 0;
}