生成实现链表的增删查找c语言代码

在C语言中，我们可以使用结构体和指针来创建简单的链表数据结构，并实现增、删、查的操作。下面是一个基本的单向链表的简单实现：

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

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

// 创建新节点
Node* createNode(int data) {
    Node* newNode = (Node*)malloc(sizeof(Node));
    if (newNode == NULL) {
        printf("Memory allocation failed.\n");
        return NULL;
    }
    newNode->data = data;
    newNode->next = NULL;
    return newNode;
}

// 添加元素到链表尾部
void appendNode(Node** head, int data) {
    if (*head == NULL) {
        *head = createNode(data);
    } else {
        Node* current = *head;
        while (current->next != NULL) {
            current = current->next;
        }
        current->next = createNode(data);
    }
}

// 查找元素
Node* searchNode(Node* head, int key) {
    Node* current = head;
    while (current != NULL) {
        if (current->data == key) {
            return current;
        }
        current = current->next;
    }
    return NULL; // 如果未找到，返回NULL
}

// 删除节点
void deleteNode(Node** head, int key) {
    if (*head == NULL) {
        return;
    }

    if ((*head)->data == key) {
        Node* temp = *head;
        *head = (*head)->next;
        free(temp);
        return;
    }

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

int main() {
    Node* head = NULL;
    appendNode(&head, 10);
    appendNode(&head, 20);
    appendNode(&head, 30);

    Node* found = searchNode(head, 20);
    if (found) {
        printf("Found element: %d\n", found->data);
    } else {
        printf("Element not found.\n");
    }

    deleteNode(&head, 20);
    
    return 0;
}