Question

Ok so I thought it was fixed, but I’m getting totally inconsistent results. I rewrote it kind of from scratch to start fresh and here are my results. I get no errors, no crashing, it just doesn’t remove them. It just totally messes up the tree and gives me a ton more leaves, and mixes everything up. Not sure where else to go

template <class T> void BST<T>::remove(struct Node<T>*& root, const T& x) {    Node<T>* ptr = root;    bool found = false;    Node<T>* parent;      while (ptr != NULL && !found)    {        if (x < ptr->data)        {            parent = ptr;            ptr = ptr->left;        }        else if (x > ptr->data)        {            parent = ptr;            ptr = ptr->right;        }        else            found = true;    }     if (found == false)        return;    else    {        if(ptr->left != NULL && ptr->right != NULL)        {            Node<T>* inOrderPtr = ptr->left;            parent = ptr;            while (inOrderPtr->right != NULL)            {                parent = inOrderPtr;                inOrderPtr = inOrderPtr->right;            }             ptr->data = inOrderPtr->data;            ptr = inOrderPtr;        }     Node<T>* subPtr = ptr->left;     if (subPtr == NULL)         subPtr = ptr->right;      else if (parent->left == ptr)         parent->left = subPtr;      else         parent->right = subPtr;      delete ptr;     } 

Answer 1

Are each T found in the tree unique? It looks like they are from your code…

It looks like this should work:

In the else case deleting the root node:

Node<T> *tmp_r = root->left; Node<T> *parent = root; while (tmp_r->right != NULL) {     parent = tmp_r;     tmp_r = tmp_r->right; } Node<T> *tmp_l = tmp_r; while (tmp_l->left != NULL)     tmp_l = tmp_l->left;  tmp_l->left = root->left; tmp_r->right = root->right; parent->right = NULL;  parent = root; root = tmp_r; delete parent;