static HklTreeNode*
hkl_treenode_remove(HklTree* tree, HklTreeNode* node, HklString* key)
{
assert(node != NULL);
assert(key != NULL);
// If key < current node key, go left
if (hkl_string_compare(key, node->pair->key) < 0)
{
if (node->left != NULL)
{
if (!hkl_treenode_isred(node->left) && hkl_treenode_isred(node->left->left))
node = hkl_treenode_redleft(node);
node->left = hkl_treenode_remove(tree, node->left, key);
}
}
else
{
if (hkl_treenode_isred(node->left))
node = hkl_treenode_rotright(node);
if (hkl_string_compare(key, node->pair->key) == 0 && (node->right == NULL))
{
--tree->size;
hkl_treenode_free(node);
return NULL;
}
if (node->right != NULL)
{
if (!hkl_treenode_isred(node->right) && !hkl_treenode_isred(node->right->left))
node = hkl_treenode_redright(node);
if (hkl_string_compare(key, node->pair->key) == 0)
{
node->pair->value = hkl_treenode_findmin(node->right)->pair->value;
node->right = hkl_treenode_removemin(tree, node->right);
}
else
{
node->right = hkl_treenode_remove(tree, node->right, key);
}
}
}
return hkl_treenode_fixup(node);
}
static HklTreeNode* hkl_treenode_fixup(HklTreeNode* node)
{
assert(node != NULL);
if (hkl_treenode_isred(node->right))
node = hkl_treenode_rotleft(node);
if (hkl_treenode_isred(node->left) && hkl_treenode_isred(node->left->left))
node = hkl_treenode_rotright(node);
if (hkl_treenode_isred(node->left))
hkl_treenode_colorflip(node);
return node;
}
static HklTreeNode* hkl_treenode_removemin(HklTreeNode* node)
{
if (node->left == NULL)
{
hkl_treenode_free(node);
return NULL;
}
if (!hkl_treenode_isred(node->left) && !hkl_treenode_isred(node->left->left))
node = hkl_treenode_redleft(node);
node->left = hkl_treenode_removemin(node->left);
return hkl_treenode_fixup(node);
}
static HklTreeNode* hkl_treenode_move_pair(HklTreeNode* node, HklPair* pair)
{
assert(pair != NULL);
if (node == NULL)
return hkl_treenode_new_from_pair(pair);
if (hkl_treenode_isred(node->left) && hkl_treenode_isred(node->right))
hkl_treenode_colorflip(node);
int cmp = hkl_string_compare(node->pair->key, pair->key);
if (cmp == 0)
{
// This shouldnt happen since we only move into empty trees
assert(false);
node->pair = pair;
}
else if (cmp < 0) node->left = hkl_treenode_move_pair(node->left, pair);
else node->right = hkl_treenode_move_pair(node->right, pair);
if (hkl_treenode_isred(node->right) && !hkl_treenode_isred(node->left))
node = hkl_treenode_rotleft(node);
if (hkl_treenode_isred(node->left) && hkl_treenode_isred(node->left->left))
node = hkl_treenode_rotright(node);
return node;
}
static HklTreeNode*
hkl_treenode_insert(HklTree* tree, HklTreeNode* node, HklString* key, void* value)
{
assert(key != NULL);
// Insert in an empty node
if (node == NULL)
{
++tree->size;
return hkl_treenode_new(key, value);
}
if (hkl_treenode_isred(node->left) && hkl_treenode_isred(node->right))
hkl_treenode_colorflip(node);
int cmp = hkl_string_compare(node->pair->key, key);
if (cmp == 0) node->pair->value = value;
else if (cmp < 0) node->left = hkl_treenode_insert(tree, node->left, key, value);
else node->right = hkl_treenode_insert(tree, node->right, key, value);
if (hkl_treenode_isred(node->right) && !hkl_treenode_isred(node->left))
node = hkl_treenode_rotleft(node);
if (hkl_treenode_isred(node->left) && hkl_treenode_isred(node->left->left))
node = hkl_treenode_rotright(node);
return node;
}
static HklTreeNode* hkl_treenode_redright(HklTreeNode* node)
{
assert(node != NULL);
hkl_treenode_colorflip(node);
if (node->left != NULL && hkl_treenode_isred(node->left->left))
{
node = hkl_treenode_rotright(node);
hkl_treenode_colorflip(node);
}
return node;
}
