Tricky pointer basics explained | Inserting an element into a binary search tree

insert.cpp

tree_node* insert(tree_node* n, int value)
{
    if (n == NULL)
    {
        return NULL;
    }
    
    tree_node** x = &n;

    while ((*x) != NULL)
    {
        if (value == (*x)->data)
        {
            return *x;
        }

        if (value < (*x)->data)
        {
            (*x) = (*x)->left;
        }
        else
        {
            (*x) = (*x)->right;
        }
    }
    
    *x = new tree_node();
    (*x)->data = value;
    (*x)->right = (*x)->left = NULL;
    return (*x);
}