C++计算并输出一元二次方程的根

二次方程 ax2+bx+c = 0 (其中a≠0），a 是二次项系数，bx 叫作一次项，b是一次项系数；c叫作常数项。
x 的值为：

根的判别式

示例

#include <iostream>
#include <cmath>
using namespace std;int main() {float a, b, c, x1, x2, discriminant, realPart, imaginaryPart;cout << "输入 a, b 和 c: ";cin >> a >> b >> c;discriminant = b*b - 4*a*c;if (discriminant > 0) {x1 = (-b + sqrt(discriminant)) / (2*a);x2 = (-b - sqrt(discriminant)) / (2*a);cout << "Roots are real and different." << endl;cout << "x1 = " << x1 << endl;cout << "x2 = " << x2 << endl;}else if (discriminant == 0) {cout << "实根相同：" << endl;x1 = (-b + sqrt(discriminant)) / (2*a);cout << "x1 = x2 =" << x1 << endl;}else {realPart = -b/(2*a);imaginaryPart =sqrt(-discriminant)/(2*a);cout << "实根不同："  << endl;cout << "x1 = " << realPart << "+" << imaginaryPart << "i" << endl;cout << "x2 = " << realPart << "-" << imaginaryPart << "i" << endl;}return 0;
}