Freeing linked structs in C

Okay so I have a Binary Search Tree built using only C structs and pointers because I'm insane and didn't want to use C++. Anyways, I've got some serious memory leaks since I'm assuming free(tree), tree being an instance of the struct below, doesn't free all the children of that tree.

Here is my node:

struct node{
    struct node* parent;
    struct node* left;
    struct node* right;
    int key; //the value of the node
};

and here is my bst:

struct bst{
    struct node* root;
    int elements; //number of nodes in the bst
};

So my question, is there any better way of doing this than recursively calling a delete function? for instance (writing this on the spot):

void delete_tree(开发者_如何学运维struct node* n){
    if(n == NULL) return;
    struct node* left = n->left;
    struct node* right = n->right;
    free(n);
    delete_tree(left);
    delete_tree(right);
}

I see absolutely nothing wrong with a recursive delete. You could use an iterative approach, but it wouldn't have any discernible benefits and would be harder to write.

By the way, you can simplify the code a little and remove the two local variables as so:

void delete_tree(struct node* n){
    if(n == NULL) return;
    delete_tree(n->left);
    delete_tree(n->right);
    free(n);
}

You are making the recursive calls but never actually call free. You probably need to verify if a node is a leaf node (maybe asking if both children are null) and call free on that node.