public void add(int x) {
BSTNode current = root;
if (x < 0) {
return;
}
if (root == null) {
root = new BSTNode(x);
return;
}
while (current.value != x) {
if (x < current.value) {
if (current.left == null) {
current.left = new BSTNode(x);
} else {
current = current.left;
}
} else {
if (current.right == null) {
current.right = new BSTNode(x);
} else {
current = current.right;
}
}
}
}
public boolean remove(int x) {
BSTNode current = root;
BSTNode parent = null;
boolean branch = true; // true =left, false =right
while (current != null) {
if (current.value == x) {
BSTNode bigson = current;
while (bigson.left != null || bigson.right != null) {
parent = bigson;
if (bigson.right != null) {
bigson = bigson.right;
branch = false;
} else {
bigson = bigson.left;
branch = true;
}
}
// System.out.println("Remove: current "+current.value+" parent "+parent.value+" bigson
// "+bigson.value);
if (parent != null) {
if (branch) {
parent.left = null;
} else {
parent.right = null;
}
}
if (bigson != current) {
current.value = bigson.value;
} else {;
}
return true;
}
parent = current;
// if (current.value <x ) { // THERE WAS ERROR
if (current.value > x) {
current = current.left;
branch = true;
} else {
current = current.right;
branch = false;
}
}
return false;
}