@Override
public void insert(int newValue) {
// Empty tree
if (this.parent == null && !hasValue) {
this.value = newValue;
this.hasValue = true;
return;
}
if (this.value == newValue) return;
int direction = newValue < value ? LEFT : RIGHT;
BinarySearchTree child = children[direction];
if (child == null) {
children[direction] = new BinarySearchTree(this, newValue);
if (children[direction ^ 1] != null) ++height;
} else {
child.insert(newValue);
}
}
@Override
public void delete(int delVal) {
int numChildren = numChildren();
// Root node
if (this.parent == null && this.value == delVal && numChildren == 0) {
this.hasValue = false;
return;
}
if (value == delVal) {
// System.out.println("Deleting " + value + " with numChildren = " + numChildren);
if (numChildren == 2) {
BinarySearchTree successor = children[RIGHT].findMin();
this.value = successor.value;
successor.delete(successor.value);
} else if (numChildren == 1) {
BinarySearchTree child = children[LEFT] != null ? children[LEFT] : children[RIGHT];
// Check if root
if (parent != null) {
int directionFromParent = this.equals(parent.children[LEFT]) ? LEFT : RIGHT;
parent.children[directionFromParent] = child;
}
child.parent = this.parent;
} else {
int directionFromParent = this.equals(parent.children[LEFT]) ? LEFT : RIGHT;
parent.children[directionFromParent] = null;
this.parent = null;
}
}
int direction = delVal < value ? LEFT : RIGHT;
BinarySearchTree child = children[direction];
if (child != null) child.delete(delVal);
}