CODEWITHSUNDEEP
ctreebinary-search-treefree
Kyuu
Kyuu

Reputation: 1045

How to free a BST that contains a char pointer?

This is a node that im using to create a BST. How would I be able to free this tree. Below is an attempt of what I have tried but Im not too sure how to free str.

typedef struct tree_s tree_t;

struct tree_s 
{
    char *str;
    tree_t *left;
    tree_t *right;
};

void freeTree(tree_t *tree) {
    if (tree == NULL) 
    {
        return;
    }
    /* first delete both subtrees */
    freeTree(tree->left);
    free(tree->str);
    freeTree(tree->right);

    /* then delete the node */
    free(tree);
 }

Upvotes: 1

Views: 813

Answers (1)

user2736738
user2736738

Reputation: 30926

Just have a postorder traversal (that is what you are doing) and free() the memory allocated. [ free(str)] In your case free(tree->str); You have done it correctly. A more concise one

void preord(tree *root)
{
if(root)
{
   preord(root->left);
   preord(root->right);
   free(tree->str);
   free(tree);
}
}

Note: Once you know the node at which you are working currently is non-null then you can free the char * any time , only remember that the children must be freed before the parent.

Upvotes: 3

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