struct Node* buildLinkedList(int* arr, int n)
{
    //创建哨兵位
    struct Node* head = (struct Node*)malloc(sizeof(struct Node));
    head->link = NULL;

    struct Node* node = NULL;
    for (int i = 0; i < n; i++)
    {
        //循环创建每一个结点
        node = (struct Node*)malloc(sizeof(struct Node));
        node->data = arr[i];
        //连接
        node->link = head->link;
        head->link = node;
    }
    return head;
}
void printLinkedList(struct Node* head)
{
    //输出第一个值
    head = head->link;
    printf("%d", head->data);

    head = head->link;
    while (head)
    {
        printf(" %d", head->data);
        head = head->link;
    }
}