// 트리 노드 삭제
void deleteNode(Tree *RBT, Node *node)
{
Node *successor, *fixupNode;
Node *left = node->left;
Node *right = node->right;
Node *p = node->parent;
int nColor = node->color;
// child 0, 1 : 왼쪽노드 없는 경우
if (left == RBT->NIL)
{
fixupNode = right;
transPlant(RBT, node, right);
}
// child 1 : 오른쪽노드 없는 경우
else if (right == RBT->NIL)
{
fixupNode = left;
transPlant(RBT, node, left);
}
// child 2 : 자식노드 2개인 경우 -> successor를 삭제하는 것으로 가정
else
{
successor = findSuccessor(RBT, right);
nColor = successor->color;
fixupNode = successor->right;
// fixupNode를 successor의 자리에 이식
transPlant(RBT, successor, fixupNode);
successor->right = node->right;
successor->right->parent = successor;
// successor를 node의 자리에 이식
transPlant(RBT, node, successor);
successor->left = node->left;
successor->left->parent = successor;
successor->color = node->color;
}
// 삭제 노드의 색이 BLACK인 경우 Violation 발생
if (nColor == BLACK)
{
treeDelFixUp(RBT, fixupNode);
}
// 메모리 영역 해방시켜줌
free(node);
return;
}
//Delete Node
void deleteWord(WordBST* bst, Word* z) {
Word* y = z;
Word *x, *xParent;
int yOriginalColor = y->color;
if (z->left == NULL) {
x = z->right;
xParent = z->parent;
transPlant(bst, z, z->right);
}
else if (z->right == NULL) {
x = z->left;
xParent = z->parent;
transPlant(bst, z, z->left);
}
else {
y = findMinWord(z->right);
yOriginalColor = y->color;
x = y->right;
xParent = y->parent;
if (y->parent == z) {
xParent = y;
}
else {
transPlant(bst, y, y->right);
y->right = z->right;
y->right->parent = y;
}
transPlant(bst, z, y);
y->left = z->left;
y->left->parent = y;
y->color = z->color;
}
if (yOriginalColor == 0) {
WorddeleteFixUp(bst, x, xParent);
}
freeWord(z);
}
