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Java Constructors: Actual and formal argument lists differ in length

So I was given an assignment in which I had to find and fix many errors in a somewhat large and sloppy code. I'm down to what looks to be the last one and I can't find the solution to this one. I've read similar scenarios where people get the same mistake but I can't relate them to my code. This is where I get the error: Temp = new BinaryNode(AId,AValue); saying
constructor BinaryNode in class BinaryNode cannot be applied to given
types;
Btree Class
package evidencia2datos;
public class BTree {
private BinaryNode Root;
private int NoOfNodes;
private BTree()
{
Root = null;
NoOfNodes = 0;
}
//operaciones
public boolean IsEmpty() //busca valor en NoOfNodes
{
return(NoOfNodes == 0);
}
public BinaryNode gRoot()
{
return Root;
}
public int Count() //valor de NoOfNodes
{
return NoOfNodes;
}
//size del arbol
public int Size(BinaryNode ATree)
{
if (ATree == null)
return 0;
else
return(1 + Size(ATree.gLeft()) + Size(ATree.gRight()));
}
//niveles
public int Height(BinaryNode ATree)
{
if (ATree == null)
return 0;
else
return (1 + Math.max(Height(ATree.gLeft()), Height(ATree.gRight())));
}
//traversales
public void PreOrder(BinaryNode ATree)
{
if (ATree != null)
{
System.out.println(ATree.gData());
PreOrder(ATree.gLeft());
PreOrder(ATree.gRight());
}
}
public void InOrder(BinaryNode ATree)
{
if (ATree != null)
{
InOrder(ATree.gLeft());
System.out.println(ATree.gData());
InOrder(ATree.gRight());
}
}
public void PostOrder(BinaryNode ATree)
{
if (ATree != null)
{
PostOrder(ATree.gLeft());
PostOrder(ATree.gRight());
System.out.println(ATree.gData());
}
}
//insertar valores
public void Insert(int AId, Object AValue)
{
BinaryNode Temp,Current,Parent;
if(Root == null)//tree is empty
{
Temp = new BinaryNode(AId,AValue);
Root = Temp;
NoOfNodes++;
}
else//tree is not empty
{
Temp = new BinaryNode(AId,AValue);
Current = Root;
while(true)//never ending while loop
{
Parent = Current;
if(AId < Current.gKey())
{//go left
Current = Current.gLeft();
if (Current == null)
{
Parent.sLeft(Temp);
NoOfNodes++;
return;//jump out of loop
}
}
else
{ //go right
Current = Current.gRight();
if(Current == null)
{
Parent.sRight(Temp);
NoOfNodes++;
return;
}
}
}
}
}
//search
public BinaryNode Find(int AKey)
{
BinaryNode Current = null;
if(!IsEmpty())
{
Current = Root; //start search at top of tree
while(Current.gKey() != AKey)
{
if(AKey < Current.gKey())
Current = Current.gLeft();
else
Current = Current.gRight();
if(Current == null)
return null;
}
}
return Current;
}
//succesor
public BinaryNode GetSuccessor(BinaryNode ANode)
{
BinaryNode Current,Successor,SuccessorParent;
Successor = ANode;
SuccessorParent = ANode;
Current = ANode.gRight();
while(Current !=null)
{
SuccessorParent = Successor;
Successor = Current;
Current = Current.gLeft();
}
if(Successor != ANode.gRight())
{
SuccessorParent.sLeft(Successor.gRight());
Successor.sRight(ANode.gRight());
}
return Successor;
}
public boolean Delete (int AKey)
{
BinaryNode Current, Parent;
boolean IsLeftChild = true;
Current = Root;
Parent = Root;
while (Current.gKey() != AKey)
{
Parent = Current;
if (AKey < Current.gKey())
{
IsLeftChild = true;
Current = Current.gLeft();
}
else
{
IsLeftChild = false;
Current = Current.gRight();
}
if(Current == null)
return false;
}
// if no children delete the node
if (Current.gLeft() == null && Current.gRight() == null)
{
if (Current == Root)
Root = Current.gLeft();
else
if (IsLeftChild)
Parent.sLeft(Current.gRight());
else
Parent.sRight(Current.gRight());
}
// if no right child replace with left subtree
else
{
if (Current.gRight() == null)
{
if (Current == Root)
Root = Current.gRight();
else
if (IsLeftChild)
Parent.sLeft(Current.gLeft());
else
Parent.sRight(Current.gLeft());
}
// if no left child replace with right subtree
else
{
if (Current.gLeft() == null)
{
if (Current == Root)
Root = Current.gLeft();
else
if (IsLeftChild)
Parent.sLeft(Current.gRight());
else
Parent.sRight(Current.gRight());
}
// two children so replace in order of successor
else
{
BinaryNode Successor = GetSuccessor(Current);
if (Current == Root)
Root = Successor;
else
if (IsLeftChild)
Parent.sLeft(Successor);
else
Parent.sRight(Successor);
Successor.sLeft(Current.gLeft());
}
}
}
NoOfNodes--;
return true;
}
public static void main(String[] args) {
BTree MyTree = new BTree();
BinaryNode NodeAt;
MyTree.Insert(12,"Jorge");
MyTree.Insert(4,"Andres");
MyTree.Insert(11,"Javier");
MyTree.Insert(1,"Jose");
MyTree.Insert(100,"Paty");
MyTree.Delete(1);
MyTree.InOrder(MyTree.gRoot());
NodeAt = MyTree.Find(11);
if(NodeAt !=null)
System.out.println("Data in Node with Key 11 = " + NodeAt.gData());
System.exit(0);
}
}
BinaryNode Class
package evidencia2datos;
public class BinaryNode {
private int Key;
private Object Data;
private BinaryNode Left;
private BinaryNode Right;
public BinaryNode()
{
java.util.Scanner scaniar = new java.util.Scanner(System.in);
System.out.print("Enter in Key Value: ");
Key = scaniar.nextInt();
System.out.print("Enter in data: ");
Data = scaniar.nextInt();
Left = null;
Right = null;
}
//get
public int gKey()
{
return Key;
}
public Object gData()
{
return Data;
}
public BinaryNode gLeft()
{
return Left;
}
public BinaryNode gRight()
{
return Right;
}
//set
public void sKey(int AValue)
{
Key = AValue;
}
public void sData(Object AValue)
{
Data = AValue;
}
public void sLeft( BinaryNode AValue)
{
Left = AValue;
}
public void sRight( BinaryNode AValue)
{
Right = AValue;
}
}

You can create a new BinaryNode constructor which takes two arguments
BinaryNode (){
...
}
//Este es el nuevo constructor, como se puede observar
//toma dos argumentos
BinaryNode (int k, Object d){
key = k;
data = d;
...
}
I hope this will help you.

Couting leaves in a binary tree

I have been trying to figure out why my countingLeaves method cannot be found when I call it from my tester class.
My compiler gives me the error TreeTester.java:25: error: cannot find symbol
countLeaves();
^
symbol: method countLeaves()
location: class TreeTester
public class BinarySearchTree
{
private Node root;
public BinarySearchTree()
{
root = null;
}
public void add(Comparable obj)
{
Node newNode = new Node();
newNode.data = obj;
newNode.left = null;
newNode.right = null;
if (root == null) { root = newNode; }
else { root.addNode(newNode); }
}
public boolean find(Comparable obj)
{
Node current = root;
while (current != null)
{
int d = current.data.compareTo(obj);
if (d == 0) { return true; }
else if (d > 0) { current = current.left; }
else { current = current.right; }
}
return false;
}
public void remove(Comparable obj)
{
Node toBeRemoved = root;
Node parent = null;
boolean found = false;
while (!found && toBeRemoved != null)
{
int d = toBeRemoved.data.compareTo(obj);
if (d == 0) { found = true; }
else
{
parent = toBeRemoved;
if (d > 0) { toBeRemoved = toBeRemoved.left; }
else { toBeRemoved = toBeRemoved.right; }
}
}
if (!found) { return; }
if (toBeRemoved.left == null || toBeRemoved.right == null)
{
Node newChild;
if (toBeRemoved.left == null)
{
newChild = toBeRemoved.right;
}
else
{
newChild = toBeRemoved.left;
}
if (parent == null) // Found in root
{
root = newChild;
}
else if (parent.left == toBeRemoved)
{
parent.left = newChild;
}
else
{
parent.right = newChild;
}
return;
}
Node smallestParent = toBeRemoved;
Node smallest = toBeRemoved.right;
while (smallest.left != null)
{
smallestParent = smallest;
smallest = smallest.left;
}
toBeRemoved.data = smallest.data;
if (smallestParent == toBeRemoved)
{
smallestParent.right = smallest.right;
}
else
{
smallestParent.left = smallest.right;
}
}
public void print()
{
print(root);
System.out.println();
}
private static void print(Node parent)
{
if (parent == null) { return; }
print(parent.left);
System.out.print(parent.data + " ");
print(parent.right);
}
public int countLeaves(Node node)
{
if(node == null)
return 0;
else if(node.left == null && node.right == null)
{
return 1;
}
else
{
return countLeaves(node.left) + countLeaves(node.right);
}
}
class Node
{
public Comparable data;
public Node left;
public Node right;
public void addNode(Node newNode)
{
int comp = newNode.data.compareTo(data);
if (comp < 0)
{
if (left == null) { left = newNode; }
else { left.addNode(newNode); }
}
else if (comp > 0)
{
if (right == null) { right = newNode; }
else { right.addNode(newNode); }
}
}
}
}
The tester class used
public class TreeTester
{
public static void main(String[] args)
{
BinarySearchTree t = new BinarySearchTree();
t.add("D");
t.add("B");
t.add("A");
t.add("C");
t.add("F");
t.add("E");
t.add("I");
t.add("G");
t.add("H");
t.add("J");
t.remove("A"); // Removing leaf
t.remove("B"); // Removing element with one child
t.remove("F"); // Removing element with two children
t.remove("D"); // Removing root
t.print();
System.out.println("Expected: C E G H I J");
countLeaves(t);
}
}

The countLeaves needs a Node, not a BinarySearchTree.
You may add a method in BinarySearchTree as this:
Node getRoot(){return root;}
Amd use countLeaves(t.getRoot()).

The countLeaves needs a Node, not a BinarySearchTree.

Singly Linked List: Removing

Trying to write a method that removes all instances of a value from a singly linked list, but it doesn't appear to be working.
I tried to accomodate for whether or not the head contains the value, but I'm not sure whether or not this is the correct way to do so:
public void remove (int value)
{
if (head.value == value)
{
head = head.next;
count--;
}
IntegerNode temp=head;
while (temp !=null)
{
if (temp.next != null)
{
if (temp.next.value == value)
{
temp.next = temp.next.next;
count--;
}
}
temp=temp.next;
}
}
Is there something apparent wrong with my code?

Here the implementation of linked list with add and remove methods with test.
public class ListDemo {
public static void main(String[] args) {
MyList list = new MyList();
list.addToEnd(1);
list.addToEnd(2);
list.addToEnd(3);
list.removeByValue(2);
list.removeByValue(3);
}
}
class MyList {
private IntegerNode head;
private int count = 0;
public void addToEnd(int value) {
if(head == null) {
head = new IntegerNode(value);
count = 1;
head.next = null;
return;
}
IntegerNode current = head;
while (current.next != null) {
current = current.next;
}
IntegerNode node = new IntegerNode(value);
node.next = null;
count++;
current.next = node;
}
public void removeByValue(int value) {
if (count == 0) {
return;
} else if (count == 1) {
if (head.value == value) {
count = 0;
head = null;
}
} else {
IntegerNode current = this.head;
IntegerNode next = current.next;
while (next != null) {
if (next.value == value) {
if (next.next == null) {
current.next = null;
count--;
return;
} else {
current.next = next.next;
count--;
}
}
next = next.next;
}
}
}
}
class IntegerNode {
IntegerNode(int value) {
this.value = value;
}
IntegerNode next;
int value;
}

here is different ways to delete from Linked list
public Node removeAtFront()
{
Node returnedNode = null;
if(rootNode !=null)
{
if(rootNode.next !=null)
{
Node pointer = rootNode;
returnedNode = rootNode;
pointer = null;
rootNode = rootNode.next;
}
else
{
Node pointer = rootNode;
returnedNode = rootNode;
pointer = null;
rootNode = rootNode.next;
System.out.println("removing the last node");
}
}else
{
System.out.println("the linkedlist is empty");
}
return returnedNode;
}
public Node removeAtBack()
{
Node returnedNode = null;
if(rootNode != null)
{
//Remove the commented line if you wish to keep 1 node as minimum in the linked list
//if(rootNode.next !=null)
//{
Node pointer = new students();
pointer = rootNode;
while(pointer.next.next !=null)
{
pointer=pointer.next;
}
returnedNode = pointer.next.next;
pointer.next.next = null;
pointer.next = null;
//}
//else
//{
// System.out.println("cant remove the last node because its the root node");
//}
}
else
{
System.out.println("the linkedlist is empty");
}
return returnedNode;
}
public Node removeNode(String name)
{
Node returnedNode = null;
if(rootNode !=null)
{
Node pointer = new students();
Node previous = new students();
pointer = rootNode;
while(pointer !=null)
{
if(pointer.name.equals(name))
{
previous.next = pointer.next;
returnedNode = pointer;
pointer = null;
break;
}
else
{
previous = pointer;
pointer = pointer.next;
}
}
}
else
{
System.out.println("the linkedlist is empty");
}
return returnedNode;
}
public boolean isEmpty() {
return rootNode == null;
}

You need to track where you have been in the list rather than where you are going. Like this:
public void remove (int value)
{
IntegerNode current = head;
while (current !=null)
{
if (current.value == value)
{
if (head == current)
{
head = current.next;
}
else
{
head.next = current.next;
}
count--;
}
current=current.next;
}
}

inOrderIterator method cannot be applied to BinaryTreeNode<T>

Working on an InOrderIterator traversal method. I understand how to do this recursively but I keep getting this complier error.
inOrderIterator() in LinkedBinarySearchTree<T> cannot be applied to (BinaryTreeNode<T>)
Im not sure why I can't apply this method to that object. Any ideas?
Heres my method so far
public ArrayList<T> inOrderIterator()
{
ArrayList<T> myArr = new ArrayList<T>();
BinaryTreeNode<T> currentNode = this.root;
if(currentNode != null)
{
inOrderIterator(currentNode.getLeftChild());
myArr.add(currentNode.getElement());
inOrderIterator(currentNode.getRightChild());
}
return myArr;
}
LinkedBinarySearchTree.java
import jss2.exceptions.EmptyCollectionException;
import jss2.exceptions.ElementNotFoundException;
import java.util.ArrayList;
public class LinkedBinarySearchTree<T extends Comparable<T>>
{
private T elem;
BinaryTreeNode<T> root;
public LinkedBinarySearchTree (T element)
{
elem = element;
root = null;
}
public LinkedBinarySearchTree ()
{
root = null;
}
public void addToTree (T element)
{
//Check if root is null
if(root == null)
{
root.getElement().equals(element);
}
else
{
addToTreeHelper(root, element);
}
}
public void addToTreeHelper(BinaryTreeNode<T> node, T target)
{
BinaryTreeNode<T> child;
BinaryTreeNode<T> targetNode = new BinaryTreeNode<T>(target);
if(target.compareTo(node.getElement()) == -1)
{
child = node.getLeftChild();
if(child == null)
{
node.setLeftChild(targetNode);
}
else
{
addToTreeHelper(node.getLeftChild(), target);
}
}
else if(target.compareTo(node.getElement()) >= 0)
{
child = node.getRightChild();
if(child == null)
{
node.setRightChild(targetNode);
}
else
{
addToTreeHelper(node.getRightChild(), target);
}
}
}
//remove Element
public void removeElement(T target) throws Exception
{
BinaryTreeNode<T> node;
if(root.getElement() == null)
{
throw new EmptyCollectionException("tree is empty");
}
else if(target.compareTo(root.getElement()) == 0)
{
root = getReplacement(root);
}
else
{
node = removeElemHelper(root, target);
if(node == null)
{
throw new ElementNotFoundException ("not found "+target.toString());
}
}
}
//remove element helper
public BinaryTreeNode<T> removeElemHelper(BinaryTreeNode<T> node, T target)
{
BinaryTreeNode<T> result, child, replacement;
result = null;
if(node != null)
{
if(target.compareTo(node.getElement()) == -1)
{
child = node.getLeftChild();
if(child != null && target.compareTo(child.getElement()) == 0)
{
result = child;
replacement = getReplacement(child);
if(replacement == null)
{
node.setLeftChild(null);
}
else
{
node.setLeftChild(replacement);
}
}
else
{
result = removeElemHelper(child, target);
}
}
//
else if(target.compareTo(node.getElement()) == 1)
{
child = node.getRightChild();
if(child != null && target.compareTo(child.getElement()) == 0)
{
result = child;
replacement = getReplacement(child);
if(replacement == null)
{
node.setRightChild(null);
}
else
{
node.setRightChild(replacement);
}
}
else
{
result = removeElemHelper(child, target);
}
}
}
return result;
}
//replacement
public BinaryTreeNode<T> getReplacement(BinaryTreeNode<T> node)
{
BinaryTreeNode<T> result,leftChild, rightChild;
leftChild = node.getLeftChild();
rightChild = node.getRightChild();
if(node.getLeftChild() == null && node.getRightChild() == null)
{
result = null;
}
else if(node.getLeftChild() == null && node.getRightChild() != null)
{
result = node.getRightChild();
}
else if(node.getLeftChild() != null && node.getRightChild() == null)
{
result = node.getLeftChild();
}
else
{
result = findInorderSucessor(rightChild);
result.setLeftChild(leftChild);
result.setRightChild(rightChild);
}
return result;
}
//findInorderSucessor
private BinaryTreeNode<T> findInorderSucessor(BinaryTreeNode<T> node)
{
BinaryTreeNode<T> child = node.getLeftChild();
if(child == node)
{
return node;
}
else if(child.getLeftChild() == null)
{
child.setRightChild(node.getLeftChild());
}
return findInorderSucessor(child);
}
public ArrayList<T> inOrderIterator()
{
ArrayList<T> myArr = new ArrayList<T>();
BinaryTreeNode<T> currentNode = this.root;
if(currentNode != null)
{
inOrderIterator(currentNode.getLeftChild());
myArr.add(currentNode.getElement());
inOrderIterator(currentNode.getRightChild());
}
return myArr;
}
}

Look at your method declaration:
public ArrayList<T> inOrderIterator()
It doesn't have any parameters. But look how you're trying to invoke it:
inOrderIterator(currentNode.getRightChild());
... you're specifying an argument. There's no method which is applicable for that call.
I suspect you want to overload the method to have a private method accepting a node and a List<T> (the one you're building up), and then make your public method call that. For example:
public List<T> inOrderIterator() {
List<T> list = new ArrayList<T>();
inOrderIterator(list, this.root);
return list;
}
private void inOrderIterator(List<T> list, BinaryTreeNode<T> current) {
if (current == null) {
return;
}
inOrderIterator(current.getLeftChild());
list.add(current);
inOrderIterator(current.getRightChild());
}

Binary Search Tree - Java Implementation

I'm writing a program that utilizes a binary search tree to store data. In a previous program (unrelated), I was able to implement a linked list using an implementation provided with Java SE6. Is there something similar for a binary search tree, or will I need to "start from scratch"?

You can use a TreeMap data structure. TreeMap is implemented as a red black tree, which is a self-balancing binary search tree.

According to Collections Framework Overview you have two balanced tree implementations:
TreeSet
TreeMap

Here is my simple binary search tree implementation in Java SE 1.8:
public class BSTNode
{
int data;
BSTNode parent;
BSTNode left;
BSTNode right;
public BSTNode(int data)
{
this.data = data;
this.left = null;
this.right = null;
this.parent = null;
}
public BSTNode()
{
}
}
public class BSTFunctions
{
BSTNode ROOT;
public BSTFunctions()
{
this.ROOT = null;
}
void insertNode(BSTNode node, int data)
{
if (node == null)
{
node = new BSTNode(data);
ROOT = node;
}
else if (data < node.data && node.left == null)
{
node.left = new BSTNode(data);
node.left.parent = node;
}
else if (data >= node.data && node.right == null)
{
node.right = new BSTNode(data);
node.right.parent = node;
}
else
{
if (data < node.data)
{
insertNode(node.left, data);
}
else
{
insertNode(node.right, data);
}
}
}
public boolean search(BSTNode node, int data)
{
if (node == null)
{
return false;
}
else if (node.data == data)
{
return true;
}
else
{
if (data < node.data)
{
return search(node.left, data);
}
else
{
return search(node.right, data);
}
}
}
public void printInOrder(BSTNode node)
{
if (node != null)
{
printInOrder(node.left);
System.out.print(node.data + " - ");
printInOrder(node.right);
}
}
public void printPostOrder(BSTNode node)
{
if (node != null)
{
printPostOrder(node.left);
printPostOrder(node.right);
System.out.print(node.data + " - ");
}
}
public void printPreOrder(BSTNode node)
{
if (node != null)
{
System.out.print(node.data + " - ");
printPreOrder(node.left);
printPreOrder(node.right);
}
}
public static void main(String[] args)
{
BSTFunctions f = new BSTFunctions();
/**
* Insert
*/
f.insertNode(f.ROOT, 20);
f.insertNode(f.ROOT, 5);
f.insertNode(f.ROOT, 25);
f.insertNode(f.ROOT, 3);
f.insertNode(f.ROOT, 7);
f.insertNode(f.ROOT, 27);
f.insertNode(f.ROOT, 24);
/**
* Print
*/
f.printInOrder(f.ROOT);
System.out.println("");
f.printPostOrder(f.ROOT);
System.out.println("");
f.printPreOrder(f.ROOT);
System.out.println("");
/**
* Search
*/
System.out.println(f.search(f.ROOT, 27) ? "Found" : "Not Found");
System.out.println(f.search(f.ROOT, 10) ? "Found" : "Not Found");
}
}
And the output is:
3 - 5 - 7 - 20 - 24 - 25 - 27 -
3 - 7 - 5 - 24 - 27 - 25 - 20 -
20 - 5 - 3 - 7 - 25 - 24 - 27 -
Found
Not Found

Here is a sample implementation:
import java.util.*;
public class MyBSTree<K,V> implements MyTree<K,V>{
private BSTNode<K,V> _root;
private int _size;
private Comparator<K> _comparator;
private int mod = 0;
public MyBSTree(Comparator<K> comparator){
_comparator = comparator;
}
public Node<K,V> root(){
return _root;
}
public int size(){
return _size;
}
public boolean containsKey(K key){
if(_root == null){
return false;
}
BSTNode<K,V> node = _root;
while (node != null){
int comparison = compare(key, node.key());
if(comparison == 0){
return true;
}else if(comparison <= 0){
node = node._left;
}else {
node = node._right;
}
}
return false;
}
private int compare(K k1, K k2){
if(_comparator != null){
return _comparator.compare(k1,k2);
}
else {
Comparable<K> comparable = (Comparable<K>)k1;
return comparable.compareTo(k2);
}
}
public V get(K key){
Node<K,V> node = node(key);
return node != null ? node.value() : null;
}
private BSTNode<K,V> node(K key){
if(_root != null){
BSTNode<K,V> node = _root;
while (node != null){
int comparison = compare(key, node.key());
if(comparison == 0){
return node;
}else if(comparison <= 0){
node = node._left;
}else {
node = node._right;
}
}
}
return null;
}
public void add(K key, V value){
if(key == null){
throw new IllegalArgumentException("key");
}
if(_root == null){
_root = new BSTNode<K, V>(key, value);
}
BSTNode<K,V> prev = null, curr = _root;
boolean lastChildLeft = false;
while(curr != null){
int comparison = compare(key, curr.key());
prev = curr;
if(comparison == 0){
curr._value = value;
return;
}else if(comparison < 0){
curr = curr._left;
lastChildLeft = true;
}
else{
curr = curr._right;
lastChildLeft = false;
}
}
mod++;
if(lastChildLeft){
prev._left = new BSTNode<K, V>(key, value);
}else {
prev._right = new BSTNode<K, V>(key, value);
}
}
private void removeNode(BSTNode<K,V> curr){
if(curr.left() == null && curr.right() == null){
if(curr == _root){
_root = null;
}else{
if(curr.isLeft()) curr._parent._left = null;
else curr._parent._right = null;
}
}
else if(curr._left == null && curr._right != null){
curr._key = curr._right._key;
curr._value = curr._right._value;
curr._left = curr._right._left;
curr._right = curr._right._right;
}
else if(curr._left != null && curr._right == null){
curr._key = curr._left._key;
curr._value = curr._left._value;
curr._right = curr._left._right;
curr._left = curr._left._left;
}
else { // both left & right exist
BSTNode<K,V> x = curr._left;
// find right-most node of left sub-tree
while (x._right != null){
x = x._right;
}
// move that to current
curr._key = x._key;
curr._value = x._value;
// delete duplicate data
removeNode(x);
}
}
public V remove(K key){
BSTNode<K,V> curr = _root;
V val = null;
while(curr != null){
int comparison = compare(key, curr.key());
if(comparison == 0){
val = curr._value;
removeNode(curr);
mod++;
break;
}else if(comparison < 0){
curr = curr._left;
}
else{
curr = curr._right;
}
}
return val;
}
public Iterator<MyTree.Node<K,V>> iterator(){
return new MyIterator();
}
private class MyIterator implements Iterator<Node<K,V>>{
int _startMod;
Stack<BSTNode<K,V>> _stack;
public MyIterator(){
_startMod = MyBSTree.this.mod;
_stack = new Stack<BSTNode<K, V>>();
BSTNode<K,V> node = MyBSTree.this._root;
while (node != null){
_stack.push(node);
node = node._left;
}
}
public void remove(){
throw new UnsupportedOperationException();
}
public boolean hasNext(){
if(MyBSTree.this.mod != _startMod){
throw new ConcurrentModificationException();
}
return !_stack.empty();
}
public Node<K,V> next(){
if(MyBSTree.this.mod != _startMod){
throw new ConcurrentModificationException();
}
if(!hasNext()){
throw new NoSuchElementException();
}
BSTNode<K,V> node = _stack.pop();
BSTNode<K,V> x = node._right;
while (x != null){
_stack.push(x);
x = x._left;
}
return node;
}
}
#Override
public String toString(){
if(_root == null) return "[]";
return _root.toString();
}
private static class BSTNode<K,V> implements Node<K,V>{
K _key;
V _value;
BSTNode<K,V> _left, _right, _parent;
public BSTNode(K key, V value){
if(key == null){
throw new IllegalArgumentException("key");
}
_key = key;
_value = value;
}
public K key(){
return _key;
}
public V value(){
return _value;
}
public Node<K,V> left(){
return _left;
}
public Node<K,V> right(){
return _right;
}
public Node<K,V> parent(){
return _parent;
}
boolean isLeft(){
if(_parent == null) return false;
return _parent._left == this;
}
boolean isRight(){
if(_parent == null) return false;
return _parent._right == this;
}
#Override
public boolean equals(Object o){
if(o == null){
return false;
}
try{
BSTNode<K,V> node = (BSTNode<K,V>)o;
return node._key.equals(_key) && ((_value == null && node._value == null) || (_value != null && _value.equals(node._value)));
}catch (ClassCastException ex){
return false;
}
}
#Override
public int hashCode(){
int hashCode = _key.hashCode();
if(_value != null){
hashCode ^= _value.hashCode();
}
return hashCode;
}
#Override
public String toString(){
String leftStr = _left != null ? _left.toString() : "";
String rightStr = _right != null ? _right.toString() : "";
return "["+leftStr+" "+_key+" "+rightStr+"]";
}
}
}

This program has a functions for
Add Node
Display BST(Inorder)
Find Element
Find Successor
class BNode{
int data;
BNode left, right;
public BNode(int data){
this.data = data;
this.left = null;
this.right = null;
}
}
public class BST {
static BNode root;
public int add(int value){
BNode newNode, current;
newNode = new BNode(value);
if(root == null){
root = newNode;
current = root;
}
else{
current = root;
while(current.left != null || current.right != null){
if(newNode.data < current.data){
if(current.left != null)
current = current.left;
else
break;
}
else{
if(current.right != null)
current = current.right;
else
break;
}
}
if(newNode.data < current.data)
current.left = newNode;
else
current.right = newNode;
}
return value;
}
public void inorder(BNode root){
if (root != null) {
inorder(root.left);
System.out.println(root.data);
inorder(root.right);
}
}
public boolean find(int value){
boolean flag = false;
BNode current;
current = root;
while(current!= null){
if(current.data == value){
flag = true;
break;
}
else if(current.data > value)
current = current.left;
else
current = current.right;
}
System.out.println("Is "+value+" present in tree? : "+flag);
return flag;
}
public void successor(int value){
BNode current;
current = root;
if(find(value)){
while(current.data != value){
if(value < current.data && current.left != null){
System.out.println("Node is: "+current.data);
current = current.left;
}
else if(value > current.data && current.right != null){
System.out.println("Node is: "+current.data);
current = current.right;
}
}
}
else
System.out.println(value+" Element is not present in tree");
}
public static void main(String[] args) {
BST b = new BST();
b.add(50);
b.add(30);
b.add(20);
b.add(40);
b.add(70);
b.add(60);
b.add(80);
b.add(90);
b.inorder(root);
b.find(30);
b.find(90);
b.find(100);
b.find(50);
b.successor(90);
System.out.println();
b.successor(70);
}
}

Here is the complete Implementation of Binary Search Tree In Java insert,search,countNodes,traversal,delete,empty,maximum & minimum node,find parent node,print all leaf node, get level,get height, get depth,print left view, mirror view
import java.util.NoSuchElementException;
import java.util.Scanner;
import org.junit.experimental.max.MaxCore;
class BSTNode {
BSTNode left = null;
BSTNode rigth = null;
int data = 0;
public BSTNode() {
super();
}
public BSTNode(int data) {
this.left = null;
this.rigth = null;
this.data = data;
}
#Override
public String toString() {
return "BSTNode [left=" + left + ", rigth=" + rigth + ", data=" + data + "]";
}
}
class BinarySearchTree {
BSTNode root = null;
public BinarySearchTree() {
}
public void insert(int data) {
BSTNode node = new BSTNode(data);
if (root == null) {
root = node;
return;
}
BSTNode currentNode = root;
BSTNode parentNode = null;
while (true) {
parentNode = currentNode;
if (currentNode.data == data)
throw new IllegalArgumentException("Duplicates nodes note allowed in Binary Search Tree");
if (currentNode.data > data) {
currentNode = currentNode.left;
if (currentNode == null) {
parentNode.left = node;
return;
}
} else {
currentNode = currentNode.rigth;
if (currentNode == null) {
parentNode.rigth = node;
return;
}
}
}
}
public int countNodes() {
return countNodes(root);
}
private int countNodes(BSTNode node) {
if (node == null) {
return 0;
} else {
int count = 1;
count += countNodes(node.left);
count += countNodes(node.rigth);
return count;
}
}
public boolean searchNode(int data) {
if (empty())
return empty();
return searchNode(data, root);
}
public boolean searchNode(int data, BSTNode node) {
if (node != null) {
if (node.data == data)
return true;
else if (node.data > data)
return searchNode(data, node.left);
else if (node.data < data)
return searchNode(data, node.rigth);
}
return false;
}
public boolean delete(int data) {
if (empty())
throw new NoSuchElementException("Tree is Empty");
BSTNode currentNode = root;
BSTNode parentNode = root;
boolean isLeftChild = false;
while (currentNode.data != data) {
parentNode = currentNode;
if (currentNode.data > data) {
isLeftChild = true;
currentNode = currentNode.left;
} else if (currentNode.data < data) {
isLeftChild = false;
currentNode = currentNode.rigth;
}
if (currentNode == null)
return false;
}
// CASE 1: node with no child
if (currentNode.left == null && currentNode.rigth == null) {
if (currentNode == root)
root = null;
if (isLeftChild)
parentNode.left = null;
else
parentNode.rigth = null;
}
// CASE 2: if node with only one child
else if (currentNode.left != null && currentNode.rigth == null) {
if (root == currentNode) {
root = currentNode.left;
}
if (isLeftChild)
parentNode.left = currentNode.left;
else
parentNode.rigth = currentNode.left;
} else if (currentNode.rigth != null && currentNode.left == null) {
if (root == currentNode)
root = currentNode.rigth;
if (isLeftChild)
parentNode.left = currentNode.rigth;
else
parentNode.rigth = currentNode.rigth;
}
// CASE 3: node with two child
else if (currentNode.left != null && currentNode.rigth != null) {
// Now we have to find minimum element in rigth sub tree
// that is called successor
BSTNode successor = getSuccessor(currentNode);
if (currentNode == root)
root = successor;
if (isLeftChild)
parentNode.left = successor;
else
parentNode.rigth = successor;
successor.left = currentNode.left;
}
return true;
}
private BSTNode getSuccessor(BSTNode deleteNode) {
BSTNode successor = null;
BSTNode parentSuccessor = null;
BSTNode currentNode = deleteNode.left;
while (currentNode != null) {
parentSuccessor = successor;
successor = currentNode;
currentNode = currentNode.left;
}
if (successor != deleteNode.rigth) {
parentSuccessor.left = successor.left;
successor.rigth = deleteNode.rigth;
}
return successor;
}
public int nodeWithMinimumValue() {
return nodeWithMinimumValue(root);
}
private int nodeWithMinimumValue(BSTNode node) {
if (node.left != null)
return nodeWithMinimumValue(node.left);
return node.data;
}
public int nodewithMaximumValue() {
return nodewithMaximumValue(root);
}
private int nodewithMaximumValue(BSTNode node) {
if (node.rigth != null)
return nodewithMaximumValue(node.rigth);
return node.data;
}
public int parent(int data) {
return parent(root, data);
}
private int parent(BSTNode node, int data) {
if (empty())
throw new IllegalArgumentException("Empty");
if (root.data == data)
throw new IllegalArgumentException("No Parent node found");
BSTNode parent = null;
BSTNode current = node;
while (current.data != data) {
parent = current;
if (current.data > data)
current = current.left;
else
current = current.rigth;
if (current == null)
throw new IllegalArgumentException(data + " is not a node in tree");
}
return parent.data;
}
public int sibling(int data) {
return sibling(root, data);
}
private int sibling(BSTNode node, int data) {
if (empty())
throw new IllegalArgumentException("Empty");
if (root.data == data)
throw new IllegalArgumentException("No Parent node found");
BSTNode cureent = node;
BSTNode parent = null;
boolean isLeft = false;
while (cureent.data != data) {
parent = cureent;
if (cureent.data > data) {
cureent = cureent.left;
isLeft = true;
} else {
cureent = cureent.rigth;
isLeft = false;
}
if (cureent == null)
throw new IllegalArgumentException("No Parent node found");
}
if (isLeft) {
if (parent.rigth != null) {
return parent.rigth.data;
} else
throw new IllegalArgumentException("No Sibling is there");
} else {
if (parent.left != null)
return parent.left.data;
else
throw new IllegalArgumentException("No Sibling is there");
}
}
public void leafNodes() {
if (empty())
throw new IllegalArgumentException("Empty");
leafNode(root);
}
private void leafNode(BSTNode node) {
if (node == null)
return;
if (node.rigth == null && node.left == null)
System.out.print(node.data + " ");
leafNode(node.left);
leafNode(node.rigth);
}
public int level(int data) {
if (empty())
throw new IllegalArgumentException("Empty");
return level(root, data, 1);
}
private int level(BSTNode node, int data, int level) {
if (node == null)
return 0;
if (node.data == data)
return level;
int result = level(node.left, data, level + 1);
if (result != 0)
return result;
result = level(node.rigth, data, level + 1);
return result;
}
public int depth() {
return depth(root);
}
private int depth(BSTNode node) {
if (node == null)
return 0;
else
return 1 + Math.max(depth(node.left), depth(node.rigth));
}
public int height() {
return height(root);
}
private int height(BSTNode node) {
if (node == null)
return 0;
else
return 1 + Math.max(height(node.left), height(node.rigth));
}
public void leftView() {
leftView(root);
}
private void leftView(BSTNode node) {
if (node == null)
return;
int height = height(node);
for (int i = 1; i <= height; i++) {
printLeftView(node, i);
}
}
private boolean printLeftView(BSTNode node, int level) {
if (node == null)
return false;
if (level == 1) {
System.out.print(node.data + " ");
return true;
} else {
boolean left = printLeftView(node.left, level - 1);
if (left)
return true;
else
return printLeftView(node.rigth, level - 1);
}
}
public void mirroeView() {
BSTNode node = mirroeView(root);
preorder(node);
System.out.println();
inorder(node);
System.out.println();
postorder(node);
System.out.println();
}
private BSTNode mirroeView(BSTNode node) {
if (node == null || (node.left == null && node.rigth == null))
return node;
BSTNode temp = node.left;
node.left = node.rigth;
node.rigth = temp;
mirroeView(node.left);
mirroeView(node.rigth);
return node;
}
public void preorder() {
preorder(root);
}
private void preorder(BSTNode node) {
if (node != null) {
System.out.print(node.data + " ");
preorder(node.left);
preorder(node.rigth);
}
}
public void inorder() {
inorder(root);
}
private void inorder(BSTNode node) {
if (node != null) {
inorder(node.left);
System.out.print(node.data + " ");
inorder(node.rigth);
}
}
public void postorder() {
postorder(root);
}
private void postorder(BSTNode node) {
if (node != null) {
postorder(node.left);
postorder(node.rigth);
System.out.print(node.data + " ");
}
}
public boolean empty() {
return root == null;
}
}
public class BinarySearchTreeTest {
public static void main(String[] l) {
System.out.println("Weleome to Binary Search Tree");
Scanner scanner = new Scanner(System.in);
boolean yes = true;
BinarySearchTree tree = new BinarySearchTree();
do {
System.out.println("\n1. Insert");
System.out.println("2. Search Node");
System.out.println("3. Count Node");
System.out.println("4. Empty Status");
System.out.println("5. Delete Node");
System.out.println("6. Node with Minimum Value");
System.out.println("7. Node with Maximum Value");
System.out.println("8. Find Parent node");
System.out.println("9. Count no of links");
System.out.println("10. Get the sibling of any node");
System.out.println("11. Print all the leaf node");
System.out.println("12. Get the level of node");
System.out.println("13. Depth of the tree");
System.out.println("14. Height of Binary Tree");
System.out.println("15. Left View");
System.out.println("16. Mirror Image of Binary Tree");
System.out.println("Enter Your Choice :: ");
int choice = scanner.nextInt();
switch (choice) {
case 1:
try {
System.out.println("Enter Value");
tree.insert(scanner.nextInt());
} catch (Exception e) {
System.out.println(e.getMessage());
}
break;
case 2:
System.out.println("Enter the node");
System.out.println(tree.searchNode(scanner.nextInt()));
break;
case 3:
System.out.println(tree.countNodes());
break;
case 4:
System.out.println(tree.empty());
break;
case 5:
try {
System.out.println("Enter the node");
System.out.println(tree.delete(scanner.nextInt()));
} catch (Exception e) {
System.out.println(e.getMessage());
}
case 6:
try {
System.out.println(tree.nodeWithMinimumValue());
} catch (Exception e) {
System.out.println(e.getMessage());
}
break;
case 7:
try {
System.out.println(tree.nodewithMaximumValue());
} catch (Exception e) {
System.out.println(e.getMessage());
}
break;
case 8:
try {
System.out.println("Enter the node");
System.out.println(tree.parent(scanner.nextInt()));
} catch (Exception e) {
System.out.println(e.getMessage());
}
break;
case 9:
try {
System.out.println(tree.countNodes() - 1);
} catch (Exception e) {
System.out.println(e.getMessage());
}
break;
case 10:
try {
System.out.println("Enter the node");
System.out.println(tree.sibling(scanner.nextInt()));
} catch (Exception e) {
System.out.println(e.getMessage());
}
break;
case 11:
try {
tree.leafNodes();
} catch (Exception e) {
System.out.println(e.getMessage());
}
case 12:
try {
System.out.println("Enter the node");
System.out.println("Level is : " + tree.level(scanner.nextInt()));
} catch (Exception e) {
System.out.println(e.getMessage());
}
break;
case 13:
try {
System.out.println(tree.depth());
} catch (Exception e) {
System.out.println(e.getMessage());
}
break;
case 14:
try {
System.out.println(tree.height());
} catch (Exception e) {
System.out.println(e.getMessage());
}
break;
case 15:
try {
tree.leftView();
System.out.println();
} catch (Exception e) {
System.out.println(e.getMessage());
}
break;
case 16:
try {
tree.mirroeView();
} catch (Exception e) {
System.out.println(e.getMessage());
}
break;
default:
break;
}
tree.preorder();
System.out.println();
tree.inorder();
System.out.println();
tree.postorder();
} while (yes);
scanner.close();
}
}