用C或C++语言设计并实现一个可进行复数运算的演示程序

在C或C++中，我们可以创建一个简单的命令行程序来支持复数的基本运算，如加法、减法、乘法和除法。这里是一个基础的示例：

#include <iostream>
using namespace std;

// 定义复数结构体
struct Complex {
    double real; // 实部
    double imag; // 虚部
};

// 复数加法
Complex add(Complex a, Complex b) {
    Complex result;
    result.real = a.real + b.real;
    result.imag = a.imag + b.imag;
    return result;
}

// 复数减法
Complex subtract(Complex a, Complex b) {
    Complex result;
    result.real = a.real - b.real;
    result.imag = a.imag - b.imag;
    return result;
}

// 复数乘法
Complex multiply(Complex a, Complex b) {
    Complex result;
    result.real = a.real * b.real - a.imag * b.imag;
    result.imag = a.real * b.imag + a.imag * b.real;
    return result;
}

// 复数除法（需要避免除以零）
Complex divide(Complex a, Complex b) {
    if (b.real != 0 && b.imag == 0) { // 检查分母是否为实数零
        return (a.real / b.real, a.imag / b.real);
    } else {
        double denominator = b.real * b.real + b.imag * b.imag;
        Complex result;
        result.real = (a.real * b.real + a.imag * b.imag) / denominator;
        result.imag = (a.imag * b.real - a.real * b.imag) / denominator;
        return result;
    }
}

int main() {
    Complex num1 = {3, 4}; // 复数示例1
    Complex num2 = {1, 2}; // 复数示例2

    cout << "Adding: (" << num1.real << ", " << num1.imag << ") + (" << num2.real << ", " << num2.imag << ") = (" << add(num1, num2).real << ", " << add(num1, num2).imag << ")" << endl;
    cout << "Subtracting: (" << num1.real << ", " << num1.imag << ") - (" << num2.real << ", " << num2.imag << ") = (" << subtract(num1, num2).real << ", " << subtract(num1, num2).imag << ")" << endl;
    cout << "Multiplying: (" << num1.real << ", " << num1.imag << ") * (" << num2.real << ", " << num2.imag << ") = (" << multiply(num1, num2).real << ", " << multiply(num1, num2).imag << ")" << endl;

    if (num2.real != 0) {
        cout << "Dividing: (" << num1.real << ", " << num1.imag << ") / (" << num2.real << ", " << num2.imag << ") = (" << divide(num1, num2).real << ", " << divide(num1, num2).imag << ")" << endl;
    } else {
        cout << "Division by zero is not allowed." << endl;
    }

    return 0;
}

在这个程序中，我们首先定义了一个`Complex`结构体表示复数，并实现了基本的四则运算函数。然后在`main`函数里创建了两个复数示例，进行了各种运算并显示结果。