#include <iostream>
using namespace std;

// 復(fù)數(shù)類：實(shí)部 + 虛部i
class Complex {
private:
    double real; // 實(shí)部
    double imag; // 虛部
public:
    // 構(gòu)造函數(shù)
    Complex(double r = 0.0, double i = 0.0) : real(r), imag(i) {}

    // 成員函數(shù)重載 + 運(yùn)算符（左操作數(shù)是this，右操作數(shù)是c）
    Complex operator+(const Complex& c) const {
        // 不修改this和c，返回新的復(fù)數(shù)對(duì)象
        return Complex(real + c.real, imag + c.imag);
    }

    // 打印函數(shù)
    void print() const {
        cout << real << " + " << imag << "i" << endl;
    }
};

int main() {
    Complex c1(1.5, 2.5), c2(3.5, 4.5);
    Complex c3 = c1 + c2; // 等價(jià)于 c1.operator+(c2)
    c1.print(); // 1.5 + 2.5i（原對(duì)象未修改）
    c2.print(); // 3.5 + 4.5i（原對(duì)象未修改）
    c3.print(); // 5 + 7i（相加結(jié)果）
    return 0;
}

// 類內(nèi)聲明友元（如需訪問私有成員）
friend 返回值類型 operator+(const 類名& 左操作數(shù), const 類名& 右操作數(shù));

// 全局定義
返回值類型 operator+(const 類名& 左操作數(shù), const 類名& 右操作數(shù)) {
    // 實(shí)現(xiàn)相加邏輯
}

#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) {}

    // 聲明友元：支持 Complex + Complex
    friend Complex operator+(const Complex& c1, const Complex& c2);
    // 聲明友元：支持 int + Complex
    friend Complex operator+(int num, const Complex& c);
    // 聲明友元：支持 Complex + int（可選，對(duì)稱設(shè)計(jì)）
    friend Complex operator+(const Complex& c, int num);

    void print() const {
        cout << real << " + " << imag << "i" << endl;
    }
};

// 全局定義：Complex + Complex
Complex operator+(const Complex& c1, const Complex& c2) {
    return Complex(c1.real + c2.real, c1.imag + c2.imag);
}

// 全局定義：int + Complex
Complex operator+(int num, const Complex& c) {
    return Complex(num + c.real, c.imag);
}

// 全局定義：Complex + int
Complex operator+(const Complex& c, int num) {
    return Complex(c.real + num, c.imag);
}

int main() {
    Complex c1(1.5, 2.5);
    Complex c2 = 10 + c1; // int + Complex
    Complex c3 = c1 + 20; // Complex + int
    Complex c4 = c1 + c2; // Complex + Complex

    c2.print(); // 11.5 + 2.5i
    c3.print(); // 21.5 + 2.5i
    c4.print(); // 13 + 5i
    return 0;
}

#include <iostream>
using namespace std;

class Complex {
private:
    double real, imag;
public:
    Complex(double r = 0, double i = 0) : real(r), imag(i) {}

    // 重載 +=（成員函數(shù)，修改自身）
    Complex& operator+=(const Complex& c) {
        real += c.real;
        imag += c.imag;
        return *this; // 返回自身，支持鏈?zhǔn)讲僮鳎ㄈ?c1 += c2 += c3）
    }

    // 基于 += 重載 +（成員函數(shù)）
    Complex operator+(const Complex& c) const {
        Complex temp = *this; // 拷貝當(dāng)前對(duì)象
        temp += c; // 復(fù)用 += 邏輯
        return temp;
    }

    void print() const {
        cout << real << " + " << imag << "i" << endl;
    }
};

int main() {
    Complex c1(1, 2), c2(3, 4);
    c1 += c2; // c1 被修改：4 + 6i
    c1.print();

    Complex c3 = c1 + c2; // c3：7 + 10i
    c3.print();
    return 0;
}

#include <iostream>
#include <cstring>
using namespace std;

class MyString {
private:
    char* str;
    int len;
public:
    // 構(gòu)造函數(shù)
    MyString(const char* s = "") {
        len = strlen(s);
        str = new char[len + 1];
        strcpy(str, s);
    }

    // 析構(gòu)函數(shù)
    ~MyString() {
        delete[] str;
    }

    // 拷貝構(gòu)造（避免淺拷貝）
    MyString(const MyString& other) {
        len = other.len;
        str = new char[len + 1];
        strcpy(str, other.str);
    }

    // 重載 +：字符串拼接
    friend MyString operator+(const MyString& s1, const MyString& s2) {
        MyString temp;
        temp.len = s1.len + s2.len;
        delete[] temp.str; // 釋放默認(rèn)構(gòu)造的空字符串
        temp.str = new char[temp.len + 1];
        strcpy(temp.str, s1.str);
        strcat(temp.str, s2.str);
        return temp;
    }

    // 打印字符串
    void print() const {
        cout << str << endl;
    }
};

int main() {
    MyString s1("Hello"), s2(" World!");
    MyString s3 = s1 + s2;
    s3.print(); // Hello World!
    return 0;
}