c++怎么实现一个链表_C++数据结构之单链表的创建与操作

struct ListNode {
    int data;               // 数据域，存储整型数据
    ListNode* next;         // 指针域，指向下一个节点
    ListNode(int val) : data(val), next(nullptr) {}  // 构造函数
};

void insertAtHead(ListNode*& head, int val) {
    ListNode* newNode = new ListNode(val);
    newNode->next = head;
    head = newNode;
}

void insertAtTail(ListNode*& head, int val) {
    ListNode* newNode = new ListNode(val);
    if (!head) {
        head = newNode;
        return;
    }
    ListNode* cur = head;
    while (cur->next) {
        cur = cur->next;
    }
    cur->next = newNode;
}

void printList(ListNode* head) {
    ListNode* cur = head;
    while (cur) {
        cout << cur->data << " -> ";
        cur = cur->next;
    }
    cout << "nullptr" << endl;
}

void deleteByValue(ListNode*& head, int val) {
    if (!head) return;
    if (head->data == val) {
        ListNode* temp = head;
        head = head->next;
        delete temp;
        return;
    }
    ListNode* cur = head;
    while (cur->next && cur->next->data != val) {
        cur = cur->next;
    }
    if (cur->next) {
        ListNode* temp = cur->next;
        cur->next = cur->next->next;
        delete temp;
    }
}

void freeList(ListNode*& head) {
    while (head) {
        ListNode* temp = head;
        head = head->next;
        delete temp;
    }
}