用头插法（或尾插法〉建立带头结点的单链表，对己建立的单链表实现插人、删除、查找和遍历等基本操作的代码

好的，下面是用头插法建立带头结点的单链表，并实现插入、删除、查找和遍历等基本操作的代码：

#include <iostream>
using namespace std;

// 定义单链表结点
struct ListNode {
    int val;
    ListNode* next;
    ListNode(int x) : val(x), next(NULL) {}
};

// 建立带头结点的单链表
ListNode* createList() {
    ListNode* head = new ListNode(0); // 头结点
    ListNode* p = head;
    int x;
    while (cin >> x) {
        ListNode* node = new ListNode(x);
        p->next = node;
        p = p->next;
    }
    return head;
}

// 插入结点
void insertNode(ListNode* head, int val) {
    ListNode* node = new ListNode(val);
    node->next = head->next;
    head->next = node;
}

// 删除结点
void deleteNode(ListNode* head, int val) {
    ListNode* p = head->next;
    ListNode* pre = head;
    while (p != NULL) {
        if (p->val == val) {
            pre->next = p->next;
            delete p;
            break;
        }
        pre = p;
        p = p->next;
    }
}

// 查找结点
ListNode* findNode(ListNode* head, int val) {
    ListNode* p = head->next;
    while (p != NULL) {
        if (p->val == val) {
            return p;
        }
        p = p->next;
    }
    return NULL;
}

// 遍历链表
void traverseList(ListNode* head) {
    ListNode* p = head->next;
    while (p != NULL) {
        cout << p->val << " ";
        p = p->next;
    }
    cout << endl;
}

int main() {
    ListNode* head = createList();
    traverseList(head);
    insertNode(head, 5);
    traverseList(head);
    deleteNode(head, 3);
    traverseList(head);
    ListNode* node = findNode(head, 2);
    if (node != NULL) {
        cout << "Found node: " << node->val << endl;
    } else {
        cout << "Node not found." << endl;
    }
    return 0;
}