C语言创建一个单链表并要求能够实现查找、插入、删除、打印基本操作，链表数据由键盘读入完整代码

在C语言中创建一个简单的单链表，包括查找、插入、删除和打印操作，我们需要定义链表结构体、相关的函数以及主程序来完成这些任务。下面是一个基础示例：

#include <stdio.h>
#include <stdlib.h>

// 定义链表节点结构
typedef struct Node {
    int data;
    struct Node* next;
} Node;

// 初始化链表为空
Node* createList() {
    return NULL;
}

// 查找元素
Node* search(Node* head, int target) {
    Node* current = head;
    while (current != NULL) {
        if (current->data == target)
            return current;
        current = current->next;
    }
    return NULL; // 如果未找到目标元素，则返回NULL
}

// 插入元素
void insert(Node** head, int value) {
    Node* newNode = (Node*)malloc(sizeof(Node));
    newNode->data = value;
    newNode->next = *head;
    *head = newNode;
}

// 删除元素
void delete(Node** head, int target) {
    if (*head == NULL)
        return;
    
    if ((*head)->data == target) {
        Node* temp = *head;
        *head = (*head)->next;
        free(temp);
        return;
    }

    Node* current = *head;
    while (current->next != NULL && current->next->data != target) {
        current = current->next;
    }
    if (current->next != NULL) {
        Node* toDelete = current->next;
        current->next = current->next->next;
        free(toDelete);
    }
}

// 打印链表
void printList(Node* head) {
    while (head != NULL) {
        printf("%d -> ", head->data);
        head = head->next;
    }
    printf("NULL\n");
}

int main() {
    Node* head = createList();

    // 输入数据并插入
    int n, value;
    printf("Enter number of elements: ");
    scanf("%d", &n);
    for (int i = 0; i < n; i++) {
        printf("Enter element %d: ", i+1);
        scanf("%d", &value);
        insert(&head, value);
    }

    // 打印链表
    printList(head);

    // 用户输入查询
    int target;
    printf("Search for an element (press -1 to quit): ");
    scanf("%d", &target);
    while (target != -1) {
        Node* found = search(head, target);
        if (found != NULL) {
            printf("Found element %d at position %ld.\n", target, (long)(found - head));
        } else {
            printf("Element not found in the list.\n");
        }
        printf("Search for an element (press -1 to quit): ");
        scanf("%d", &target);
    }

    return 0;
}