写出在不带头结点的单链表上第i位置删除和插入一个结点的算法(C语言

在不带头节点的单链表上，第i位置删除和插入操作的C语言算法可以这样实现：

### 删除第i个节点 (Delete Node at Position i)

void deleteNode(struct Node** head, int i) {
    if (*head == NULL || i <= 0) return; // 验证链表是否为空或索引越界

    struct Node* temp = *head;
    struct Node* prev = NULL;

    if (i == 1) { // 如果是要删除头节点
        *head = temp->next;
        free(temp);
        return;
    }

    for (int j = 1; temp != NULL && j < i; j++) {
        prev = temp;
        temp = temp->next;
    }

    if (temp == NULL) return; // 如果索引超出列表长度

    prev->next = temp->next;
    free(temp); // 释放要删除的节点
}

### 插入新节点到第i个位置 (Insert Node at Position i)

void insertNodeAtPosition(struct Node** head, int i, int data) {
    if (*head == NULL) { // 列表为空，直接插入作为头节点
        struct Node* newNode = (struct Node*)malloc(sizeof(struct Node));
        newNode->data = data;
        newNode->next = NULL;
        *head = newNode;
        return;
    }

    struct Node* newNode = (struct Node*)malloc(sizeof(struct Node));
    newNode->data = data;
    newNode->next = NULL;

    if (i <= 0) { // 插入在头部
        newNode->next = *head;
        *head = newNode;
        return;
    }

    struct Node* temp = *head;
    for (int j = 1; j < i; j++) {
        if (temp->next == NULL) {
            printf("Error: Index out of range.\n");
            return;
        }
        temp = temp->next;
    }

    newNode->next = temp->next;
    temp->next = newNode;
}