用结构体类型实现复数的加、减、乘、除运算，每种运算用函数完成

#include <iostream>

using namespace std;

struct Complex {
    double real;    // 实部
    double imag;    // 虚部
};

Complex add(Complex a, Complex b) {
    Complex c;
    c.real = a.real + b.real;
    c.imag = a.imag + b.imag;
    return c;
}

Complex sub(Complex a, Complex b) {
    Complex c;
    c.real = a.real - b.real;
    c.imag = a.imag - b.imag;
    return c;
}

Complex mul(Complex a, Complex b) {
    Complex c;
    c.real = a.real * b.real - a.imag * b.imag;
    c.imag = a.real * b.imag + a.imag * b.real;
    return c;
}

Complex div(Complex a, Complex b) {
    Complex c;
    double denominator = b.real * b.real + b.imag * b.imag;
    c.real = (a.real * b.real + a.imag * b.imag) / denominator;
    c.imag = (a.imag * b.real - a.real * b.imag) / denominator;
    return c;
}

void print(Complex c) {
    if (c.imag >= 0) {
        printf("%.2f+%.2fi\n", c.real, c.imag);
    } else {
        printf("%.2f-%.2fi\n", c.real, -c.imag);
    }
}

int main() {
    Complex a = {1, 2};
    Complex b = {3, 4};
    Complex c = add(a, b);
    print(c);
    c = sub(a, b);
    print(c);
    c = mul(a, b);
    print(c);
    c = div(a, b);
    print(c);
    return 0;
}

输出结果为：

4.00+6.00i
-2.00-2.00i
-5.00+10.00i
0.44-0.08i