c - 使用双指针从 RST 树中删除节点

Question

我有一个 RST 树，它的结构是:

struct node
{
    int key;
    node *left, *right;
} *root;

我的功能是删除带有“v”键的节点:

void Delete (int v)
{
    node** p = Search(v);
    node** tmp = p;
    if (!(*p)) return;
    if((*p)->left==null && (*p)->right==NULL)
    {
        p = null;
        return;
    }
    while((*tmp)->left != null || (*tmp)->right != NULL)
    {
        if ((*tmp)->left != NULL)
            tmp = &((*tmp)->left);
        else
            tmp = &((*tmp)->right);
    }
    (*tmp)->right = (*p)->right;
    (*tmp)->left = (*p)->left;
    p = tmp;
    tmp = null;
}

通常我不确定什么时候应该写'tmp'和'*tmp'。你能在这里解释我的错误吗？

Answer 1

(!tmp)->right == NULL

node** temp = p;

temp->right, temp alone is a pointer to a node pointer. It has no right.
(*temp)->right.