c++ 链表拷贝

C++ 中的链表可以通过拷贝构造函数和赋值运算符进行拷贝。

拷贝构造函数：

class LinkedList {
public:
    // 节点类
    class Node {
    public:
        int data;
        Node* next;
        Node(int value) : data(value), next(nullptr) {}
    };
    
    // 拷贝构造函数
    LinkedList(const LinkedList& other) : head(nullptr) {
        if (other.head == nullptr) {
            return;
        }
        head = new Node(other.head->data);
        Node* p = head;
        Node* q = other.head->next;
        while (q != nullptr) {
            p->next = new Node(q->data);
            p = p->next;
            q = q->next;
        }
    }
    
    // ...
    
private:
    Node* head;
};

赋值运算符：

class LinkedList {
public:
    // 节点类
    class Node {
    public:
        int data;
        Node* next;
        Node(int value) : data(value), next(nullptr) {}
    };
    
    // 拷贝构造函数
    LinkedList(const LinkedList& other) : head(nullptr) {
        if (other.head == nullptr) {
            return;
        }
        head = new Node(other.head->data);
        Node* p = head;
        Node* q = other.head->next;
        while (q != nullptr) {
            p->next = new Node(q->data);
            p = p->next;
            q = q->next;
        }
    }
    
    // 赋值运算符
    LinkedList& operator=(const LinkedList& other) {
        if (this == &other) {
            return *this;
        }
        // 释放原有链表的内存
        Node* p = head;
        while (p != nullptr) {
            Node* q = p;
            p = p->next;
            delete q;
        }
        head = nullptr;
        // 拷贝新的链表
        if (other.head == nullptr) {
            return *this;
        }
        head = new Node(other.head->data);
        p = head;
        Node* q = other.head->next;
        while (q != nullptr) {
            p->next = new Node(q->data);
            p = p->next;
            q = q->next;
        }
        return *this;
    }
    
private:
    Node* head;
};
``