class Complex{ double real, imag; public: Complex(double r=0, double i=0): real(r), imag(i){ } friend istream& operator>>(istream& in, Complex& c); //已实现 friend ostream& operator<<(ostream& out, const Complex& c);//已实现 friend Complex operator+(const Complex& c1, const Complex& c2); friend Complex operator-(const Complex& c1, const Complex& c2); Complex& operator+=(const Complex& c); Complex& operator-=(const Complex& c); };#include <iostream> using namespace std; int main() { Complex c1, c2; cin >> c1 >> c2; cout << c1 + c2 << endl; cout << c1 - c2 << endl; c1 += c2; cout << c1 << endl; c1 -= c2; cout << c1 << endl; return 0; } /* 请在这里填写答案，类的详细定义已由系统给出，并重载了输入输出运算符，你只需要写出需要重载的算术运算符函数即可 */

重载的算术运算符函数如下所示：

Complex operator+(const Complex& c1, const Complex& c2){
    return Complex(c1.real+c2.real, c1.imag+c2.imag);
}

Complex operator-(const Complex& c1, const Complex& c2){
    return Complex(c1.real-c2.real, c1.imag-c2.imag);
}

Complex& Complex::operator+=(const Complex& c){
    real += c.real;
    imag += c.imag;
    return *this;
}

Complex& Complex::operator-=(const Complex& c){
    real -= c.real;
    imag -= c.imag;
    return *this;
}

其中，`operator+` 重载了加法运算符，返回两个复数相加的结果；`operator-` 重载了减法运算符，返回两个复数相减的结果；`operator+=` 重载了复合赋值加法运算符，将一个复数加上另一个复数并返回结果；`operator-=` 重载了复合赋值减法运算符，将一个复数减去另一个复数并返回结果。

相关问题

#include<iostream> using namespace std; class Complex { private: double real; double imag; public: Complex(double r=0.0,double i=0.0) { real = r; imag = i; } friend Complex operator + (Complex c1, Complex c2); friend Complex operator - (Complex c1, Complex c2); void display(); }; Complex Complex:: operator +(Complex c1, Complex c2) { Complex c; c.real = c1.real + c2.real; c.imag = c1.imag + c2.imag; return c; } Complex Complex:: operator -(Complex c1, Complex c2) { Complex c; c.real = c1.real - c2.real; c.imag = c1.imag - c2.imag; return c; } void Complex::display() { cout << "(" << real << "," << imag << ")" << endl; } int main() { Complex c1(4, 3), c2(2, 1), c3; cout << "c1="; c1.display(); cout << "c2="; c2.display(); c3 = c1 - c2; cout << "c3="; c3.display(); c3 = c1 + c2; cout << "c3="; c3.display(); return 0; } 存在的问题

代码中存在以下问题：

1. 缺少头文件：需要添加头文件 `#include<iostream>`。

2. 命名空间使用不规范：应该避免在头文件中使用 `using namespace std;`，而是应该在使用标准库的时候显式地使用 `std::`。

3. 运算符重载函数的定义方式不正确：应该将运算符重载函数定义为类的成员函数，或者定义为友元函数。在代码中，运算符重载函数应该写成 `Complex Complex::operator+(Complex c2)` 和 `Complex Complex::operator-(Complex c2)`。

4. 运算符重载函数的参数传递方式不正确：在运算符重载函数中，需要将当前对象作为一个参数传入。在代码中，应该将运算符重载函数定义为友元函数，并且将两个对象作为参数传入，在函数中分别访问它们的私有成员变量。

5. 类方法的定义方式不规范：在定义类方法时，应该将方法的实现写在类定义的外面，而不是写在类定义内部。

6. 对象的初始化方式不规范：在定义对象时，应该避免使用默认构造函数的方式进行初始化，而是应该使用带参数的构造函数进行初始化。在代码中，应该将 `Complex c1(4, 3), c2(2, 1), c3;` 改为 `Complex c1(4, 3), c2(2, 1), c3(0, 0);`。

下面是修改后的代码：

#include<iostream>

class Complex {
private:
    double real;
    double imag;
public:
    Complex(double r=0.0, double i=0.0) {
        real = r;
        imag = i;
    }
    Complex operator+(Complex c2);
    Complex operator-(Complex c2);
    void display();
};

Complex Complex::operator+(Complex c2) {
    Complex c;
    c.real = real + c2.real;
    c.imag = imag + c2.imag;
    return c;
}

Complex Complex::operator-(Complex c2) {
    Complex c;
    c.real = real - c2.real;
    c.imag = imag - c2.imag;
    return c;
}

void Complex::display() {
    std::cout << "(" << real << "," << imag << ")" << std::endl;
}

int main() {
    Complex c1(4, 3), c2(2, 1), c3(0, 0);
    std::cout << "c1=";
    c1.display();
    std::cout << "c2=";
    c2.display();
    c3 = c1 - c2;
    std::cout << "c3=";
    c3.display();
    c3 = c1 + c2;
    std::cout << "c3=";
    c3.display();
    return 0;
}

#include<iostream> using namespace std; class Complex { double real,imag; public: Complex(double r=0,double i=0):real(r),imag(i) {} //只是让代码看起来简短而已 double get_real() {return real;} double get_imag() {return imag;} void print_complex() {cout<<real<<"+"<<"j"<<imag<<endl;} Complex operator + (double a); Complex operator + (Complex x); friend ostream &operator << (ostream &out,Complex &A ); } ostream &operator << (ostream &out,Complex &A ) { out<<A.real<<"+"<<A.imag<<"j"; return out; } Complex Complex:: operator + (double a) { Complex m; m.real=real+a;//实数 m.imag=imag; return m; } Complex Complex::operator +(Complex x)//加不加都可以，引用调用 { Complex t; t.imag=imag+x.imag; t.real=real+x.real; return t; } int main() { Complex c1(1,2),c2(4,5),c3; c1=c1+4.2; //重载 复数类+整型 cout<<c1<<endl; cout<<c2<<endl; c3=c1+c2; //重载 复述类+复数类 cout<<c3<<endl; return 0; } 哪里有问题以及怎么解决

这段代码中有两个问题：

1. 在重载<<运算符时，应该将Complex对象作为常量引用传递，即：

friend ostream &operator << (ostream &out, const Complex &A );

2. 在Complex类的构造函数中，应该使用成员初始化列表来初始化real和imag成员变量，即：

Complex(double r=0, double i=0): real(r), imag(i) {}

修改后的代码如下：

#include<iostream> 
using namespace std; 

class Complex {      
    double real, imag; 
public:     
    Complex(double r=0, double i=0): real(r), imag(i) {}     
    double get_real() {return real;}     
    double get_imag() {return imag;}     
    void print_complex() {cout<<real<<"+"<<"j"<<imag<<endl;}     
    Complex operator + (double a);     
    Complex operator + (Complex x);  
    friend ostream &operator << (ostream &out, const Complex &A ); 
};  

ostream &operator << (ostream &out, const Complex &A ) {     
    out<<A.real<<"+"<<A.imag<<"j";     
    return out; 
}   

Complex Complex:: operator + (double a) {             
    Complex m;             
    m.real=real+a; //实数             
    m.imag=imag;             
    return m;         
} 

Complex Complex::operator +(Complex x) {             
    Complex t;             
    t.imag=imag+x.imag;             
    t.real=real+x.real;             
    return t;         
} 

int main() {     
    Complex c1(1,2),c2(4,5),c3;     
    c1=c1+4.2; //重载 复数类+整型     
    cout<<c1<<endl;     
    cout<<c2<<endl;     
    c3=c1+c2; //重载 复数类+复数类     
    cout<<c3<<endl;   
    return 0; 
}