void rb_insertFixup(rbt *t, rbnode *n)
{
rbnode *y = NULL;
while (n->parent != NULL && n->parent->color == RED)
{
if (n->parent == getGrandParent(n)->link[0])
{
y = getUncle(n);
if (y != NULL && y->color == RED)
{
n->parent->color = BLACK;
y->color = BLACK;
n = getGrandParent(n);
if(n != NULL)
n->color = RED;
}
else
{
if (n == n->parent->link[1])
{
n = n->parent;
leftRotate(t, n);
}
n->parent->color = BLACK;
getGrandParent(n)->color = RED;
rightRotate(t, getGrandParent(n));
}
}
else
{
y = getUncle(n);
if (y != NULL && y->color == RED)
{
n->parent->color = BLACK;
y->color = BLACK;
n = getGrandParent(n);
if(n != NULL)
n->color = RED;
}
else
{
if (n == n->parent->link[0])
{
n = n->parent;
rightRotate(t, n);
}
n->parent->color = BLACK;
getGrandParent(n)->color = RED;
leftRotate(t, n->parent->parent);
}
}
}
// save us from a red violation at the root
(t->root)->color = BLACK;
}
void RedBlackTree::CheckInsert(RBNode* node)
{
if(node->parent == m_nil)
{
node->bRed = false;
return;
}
if(!node->parent->bRed)
{
return;
}
if(getUncle(node)->bRed)
{
node->parent->bRed = false;
getUncle(node)->bRed = false;
getGrandParent(node)->bRed = true;
CheckInsert(getGrandParent(node));
return;
}
if(node == node->parent->right && node->parent == getGrandParent(node)->left)
{
RotateLeft(node->parent);
node = node->left;
}
else if(node == node->parent->left && node->parent == getGrandParent(node)->right)
{
RotateRight(node->parent);
node = node->right;
}
node->parent->bRed = false;
getGrandParent(node)->bRed = true;
if(node == node->parent->left)
{
RotateRight(getGrandParent(node));
}
else
{
RotateLeft(getGrandParent(node));
}
}
void RedBlackTree::insertFixup(TreeNode * pNode)
{
if (pNode == m_pSentinel)
{
return; // impossible actually.
}
TreeNode * pUncle = m_pSentinel;
TreeNode * pGrandParent = NULL;
while (pNode != m_pRoot && red == pNode->parent->color)
{
pUncle = getUncle(pNode);
pGrandParent = getGrandParent(pNode);
if (pUncle != NULL && pUncle != m_pSentinel && pUncle->color == red)
{
pNode->parent->color = black;
pUncle->color = black;
pGrandParent->color = red;
pNode = pGrandParent;
}
else
{
if (pNode->parent == pGrandParent->left)
{
if (pNode == pNode->parent->right)
{
pNode = pNode->parent;
rotateLeft(pNode);
}
pNode->parent->color = black;
pGrandParent->color = red;
rotateRight(pGrandParent);
}
else
{
if (pNode == pNode->parent->left)
{
pNode = pNode->parent;
rotateRight(pNode);
}
pNode->parent->color = black;
pGrandParent->color = red;
rotateLeft(pGrandParent);
}
}
}
m_pRoot->color = black;
}
Node fix(Node root, Node n)
{
Node rval = root;
Node u, g;
while ( n->parent != tnull )
{
u = getUncle(n);
g = grandParent(n);
if ( n->parent->color == BLACK ) {
break;
}
// check what color the Uncle is
if ( u != tnull && u->color == RED ) {
n->parent->color = BLACK;
u->color = BLACK;
g->color = RED;
n = g;
// re-evaluate the current node
continue;
}
if ( (n == n->parent->right) && (n->parent == g->left) )
{
rotateLeft(n);
n = n->left;
} else if ( (n == n->parent->left) && (n->parent == g->right)) {
rotateRight(n);
n = n->right;
}
n->parent->color = BLACK;
g->color = RED;
if ( n == n->parent->left ) {
rotateRight(n->parent);
} else {
rotateLeft(n->parent);
}
n = n->parent;
break;
}
if ( n->parent == tnull ) {
rval = n;
}
rval->color = BLACK;
return rval;
}
