单向链表增删改查的c代码

单向链表是一种线性的数据结构，每个节点包含数据和指向下一个节点的指针。以下是C语言中对单向链表进行增删改查的基本操作示例：

// 定义链表节点结构体
typedef struct Node {
    int data; // 节点的数据
    struct Node* next; // 指向下一个节点的指针
} Node;

// 创建新节点函数
Node* createNode(int value) {
    Node* newNode = (Node*)malloc(sizeof(Node));
    newNode->data = value;
    newNode->next = NULL;
    return newNode;
}

// 插入节点到链表头部
void insertAtStart(Node** head, int value) {
    Node* newNode = createNode(value);
    newNode->next = *head;
    *head = newNode;
}

// 插入节点到指定位置
void insertAfter(Node* current, int value) {
    if (current == NULL) {
        printf("Current node is null.\n");
        return;
    }
    Node* newNode = createNode(value);
    newNode->next = current->next;
    current->next = newNode;
}

// 删除节点
void deleteNode(Node** head, int key) {
    Node* temp = *head, *prev = NULL;
    if (temp != NULL && temp->data == key) {
        *head = temp->next;
        free(temp);
        return;
    }

    while (temp != NULL && temp->data != key) {
        prev = temp;
        temp = temp->next;
    }

    if (temp == NULL) {
        printf("Element not found in the list.\n");
        return;
    }
    prev->next = temp->next;
    free(temp);
}

// 查找节点
Node* findNode(Node* head, int key) {
    Node* current = head;
    while (current != NULL) {
        if (current->data == key)
            return current;
        current = current->next;
    }
    return NULL;
}

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