用c语言编写程序解一元二次方程

下面是一个简单的 C 语言程序，用于解一元二次方程：

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

int main() {
    double a, b, c, x1, x2, discriminant, realPart, imaginaryPart;
    printf("Enter coefficients a, b and c: ");
    scanf("%lf %lf %lf", &a, &b, &c);

    discriminant = b * b - 4 * a * c;

    if (discriminant > 0) {
        x1 = (-b + sqrt(discriminant)) / (2 * a);
        x2 = (-b - sqrt(discriminant)) / (2 * a);
        printf("Roots are real and different.\n");
        printf("x1 = %.2lf and x2 = %.2lf\n", x1 , x2);
    }
    else if (discriminant == 0) {
        x1 = -b / (2 * a);
        printf("Roots are real and same.\n");
        printf("x1 = x2 = %.2lf\n", x1);
    }
    else {
        realPart = -b / (2 * a);
        imaginaryPart = sqrt(-discriminant) / (2 * a);
        printf("Roots are complex and different.\n");
        printf("x1 = %.2lf+%.2lfi and x2 = %.2lf-%.2lfi\n", realPart, imaginaryPart, realPart, imaginaryPart);
    }

    return 0;
}

运行程序后，程序会提示您输入方程的系数 a、b 和 c。然后，程序会计算方程的判别式，并根据判别式的值输出方程的根。如果判别式为正，则方程有两个实根。如果判别式为零，则方程有一个实根。如果判别式为负，则方程有两个复根。