C++单向链表实现详解

struct ListNode {
    int data;           // 数据字段，可根据需要改为其他类型
    ListNode* next;     // 指向下一个节点的指针
// 构造函数，方便初始化
ListNode(int val) : data(val), next(nullptr) {}
};

class SinglyLinkedList {
private:
    ListNode* head;  // 头节点指针
public:
// 构造函数
SinglyLinkedList() : head(nullptr) {}
// 析构函数：释放所有节点内存
~SinglyLinkedList() {
    while (head != nullptr) {
        ListNode* temp = head;
        head = head->next;
        delete temp;
    }
}

// 在链表头部插入新节点
void insertAtHead(int val) {
    ListNode* newNode = new ListNode(val);
    newNode->next = head;
    head = newNode;
}

// 在链表尾部插入新节点
void insertAtTail(int val) {
    ListNode* newNode = new ListNode(val);
    if (head == nullptr) {
        head = newNode;
        return;
    }
    ListNode* current = head;
    while (current->next != nullptr) {
        current = current->next;
    }
    current->next = newNode;
}

// 删除第一个值为val的节点
bool remove(int val) {
    if (head == nullptr) return false;

    if (head->data == val) {
        ListNode* temp = head;
        head = head->next;
        delete temp;
        return true;
    }

    ListNode* current = head;
    while (current->next != nullptr && current->next->data != val) {
        current = current->next;
    }

    if (current->next == nullptr) return false;

    ListNode* temp = current->next;
    current->next = temp->next;
    delete temp;
    return true;
}

// 查找某个值是否存在
bool find(int val) const {
    ListNode* current = head;
    while (current != nullptr) {
        if (current->data == val) return true;
        current = current->next;
    }
    return false;
}

// 打印整个链表
void print() const {
    ListNode* current = head;
    while (current != nullptr) {
        std::cout << current->data << " -> ";
        current = current->next;
    }
    std::cout << "nullptr" << std::endl;
}
};

#include 
using namespace std;
int main() {
SinglyLinkedList list;
list.insertAtTail(10);
list.insertAtTail(20);
list.insertAtHead(5);
list.print();  // 输出: 5 -> 10 -> 20 -> nullptr

list.remove(10);
list.print();  // 输出: 5 -> 20 -> nullptr

cout << "Contains 20? " << (list.find(20) ? "Yes" : "No") << endl;

return 0;
}