#include<iostream> using namespace std; class Complex { private: int real, imag; public: Complex(int r, int i) { real = r, imag = i; } Complex operator+(Complex& c1, Complex& c2); }; int main() { Complex c1(1, 2), c2(5, 6); Complex temp = c1 + c2; }指出错误并说明原因

这段代码存在一个错误，错误在于 Complex 类中的 operator+ 函数的定义方式。应该将其定义为类的成员函数或者定义为全局函数并传递 Complex 对象作为参数，而不是将两个 Complex 对象作为参数。

修改后的代码如下：

#include<iostream> 
using namespace std; 

class Complex { 
private: 	
    int real, imag; 
public: 	
    Complex(int r, int i) { real = r, imag = i; } 	
    Complex operator+(Complex& c); 
}; 

Complex Complex::operator+(Complex& c) {
    Complex temp(real + c.real, imag + c.imag);
    return temp;
}

int main() { 	
    Complex c1(1, 2), c2(5, 6); 	
    Complex temp = c1 + c2; 
}

在修改后的代码中，operator+ 函数被定义为 Complex 类的成员函数，使用 this 指针访问对象成员变量，创建一个新的 Complex 对象 temp 并将其作为返回值。这样，代码就可以正确地编译和运行了。

相关问题

#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 */

根据代码中的提示，需要重载类 `Complex` 的算术运算符。假设 `Complex` 类的定义如下：

class Complex {
public:
    Complex(double r = 0, double i = 0) : real(r), imag(i) {}
    Complex operator+(const Complex& other) const {
        return Complex(real + other.real, imag + other.imag);
    }
    Complex operator-(const Complex& other) const {
        return Complex(real - other.real, imag - other.imag);
    }
    Complex& operator+=(const Complex& other) {
        real += other.real;
        imag += other.imag;
        return *this;
    }
    Complex& operator-=(const Complex& other) {
        real -= other.real;
        imag -= other.imag;
        return *this;
    }
    friend istream& operator>>(istream& is, Complex& c) {
        is >> c.real >> c.imag;
        return is;
    }
    friend ostream& operator<<(ostream& os, const Complex& c) {
        os << c.real << "+" << c.imag << "i";
        return os;
    }
private:
    double real, imag;
};

则需要重载的算术运算符函数如下：

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

Complex operator/(const Complex& c1, const Complex& c2) {
    double denominator = c2.real * c2.real + c2.imag * c2.imag;
    double real = (c1.real * c2.real + c1.imag * c2.imag) / denominator;
    double imag = (c1.imag * c2.real - c1.real * c2.imag) / denominator;
    return Complex(real, imag);
}

其中，`operator*` 重载了乘法运算符，`operator/` 重载了除法运算符。它们都返回一个新的 `Complex` 对象，表示两个 `Complex` 对象的乘积或商。需要注意的是，除法运算符除数不能为零，此处没有进行特判。在实际使用中，需要根据实际情况进行处理。

#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;
}