BinaryNode<ItemType>* rightRotate(BinaryNode<ItemType>* y) {
BinaryNode<ItemType>* x = y->getLeftChildPtr();
BinaryNode<ItemType>* T2 = x->getRightChildPtr();
x->setRightChildPtr(y);
y->setLeftChildPtr(T2);
y->setHeight(max(height(y->getLeftChildPtr()), height(y->getRightChildPtr()))+1);
x->setHeight(max(height(x->getLeftChildPtr()), height(x->getRightChildPtr()))+1);
return x;
}
BinaryNode<ItemType>* leftRotate(BinaryNode<ItemType>* x) {
BinaryNode<ItemType>* y = x->getRightChildPtr();
BinaryNode<ItemType>* T2 = y->getLeftChildPtr();
y->setLeftChildPtr(x);
x->setRightChildPtr(T2);
x->setHeight(max(height(x->getLeftChildPtr()), height(x->getRightChildPtr()))+1);
y->setHeight(max(height(y->getLeftChildPtr()), height(y->getRightChildPtr()))+1);
return y;
}
void BST::remove(int x)
{
/*Couple cases of removing an item
*1. Removing the root
*2. Removing a leaf
*3. Removing something in the middle
*/
//1
if (rootPtr->getItem()==x)
{
BinaryNode* toDelete = rootPtr;
rootPtr = rootPtr->getLeftChildPtr();
BinaryNode* rightChild = rootPtr->getRightChildPtr();
BinaryNode* leftChild = rootPtr->getLeftChildPtr();
delete toDelete;
while (leftChild->getrightChildPtr()!=nullptr)//keeps traversing down
{
leftChild = leftChild->getRightChildPtr();
}
leftChild = leftChild->setRightChildPtr(rightChild);
}
else
{
BinaryNode* parent = search(x, rootPtr, rootPtr);
int dir;
if (parent->getrightChildPtr()==x)
{
BinaryNode* toDelete = parent->getrightChildPtr();
dir =0;
}
else
{
BinaryNode* toDelete = parent->getLeftChildPtr();
dir=1;
}
//Now we encounter our next two cases:
//2. if it's a leaf
if (toDelete->getrightChildPtr==nullptr && toDelete->getLeftChildPtr==nullptr)
{
delete toDelete;
if (dir==0)
{
parent->setRightChildPtr(nullptr);
}
else
{
parent->setLeftChildPtr(nullptr);
}
}
//3. Something in the middle
BinaryNode* leftChild = toDelete->getLeftChildPtr();
BinaryNode* rightChild = toDelete->getRightChildPtr();
}
}
