Speller - unloading a trie - function doesn´t work properly

Question

I am trying to free a trie, but I can still see a lot of used memory after running valgrind. Could someone point me in the right direction? What could I change? I tried to draw it on paper and logically it makes sense to me, but obviously it doesn´t work properly. Thank you for any inputs!

bool destroy(node *tmp)
{
     // Going through all the children nodes
    for (int i = 0, number = 0; i < N; i++)
    {
        // If children node is not NULL, destroy it (recursion)
        if (tmp->children[i] != 0)
        {
            return destroy(tmp->children[i]);
        }
    }

    // At this point all the children nodes should be NULL
    // Free current node
    free(tmp);
    return true;
}

valgrind output:
==5374== HEAP SUMMARY:
==5374==     in use at exit: 3,808 bytes in 17 blocks
==5374==   total heap usage: 23 allocs, 6 frees, 14,352 bytes allocated

Answer 1

I supppose it should be

if (tmp -> children[j] != NULL)
{
  destroy(tmp -> children[j]);
}

For you are trying to check for NULL condition.

You should change it to a void function so that recursion can occur freely

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