一元二次方程ax2+bx+c=0，从键盘输入a、b、c的值后，计算并输出两个根的值，结果保留三位小数。（考虑delt>0、delt=0、delt<0三种情况

当输入a、b、c的值后，可以通过判断delt的值来确定方程的根的情况。当delt>0时，方程有两个不相等的实根，可以通过求根公式计算得到；当delt=0时，方程有两个相等的实根，可以通过求根公式计算得到；当delt<0时，方程没有实根，可以通过求根公式计算得到虚根。具体实现可以参考下面的代码：

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

int main() {
    float a, b, c, delt, x1, x2, realPart, imagPart;
    printf("Please enter the coefficients a, b, c: ");
    scanf("%f %f %f", &a, &b, &c);
    delt = b * b - 4 * a * c;
    if (delt > 0) {
        x1 = (-b + sqrt(delt)) / (2 * a);
        x2 = (-b - sqrt(delt)) / (2 * a);
        printf("The equation has two distinct real roots: x1 = %.3f, x2 = %.3f\n", x1, x2);
    } else if (delt == 0) {
        x1 = x2 = -b / (2 * a);
        printf("The equation has two equal real roots: x1 = x2 = %.3f\n", x1);
    } else {
        realPart = -b / (2 * a);
        imagPart = sqrt(-delt) / (2 * a);
        printf("The equation has two complex roots: x1 = %.3f + %.3fi, x2 = %.3f - %.3fi\n", realPart, imagPart, realPart, imagPart);
    }
    return 0;
}