add the following methods to binary tree... public void breadthFirstTraversal()

Question

add the following methods to binary tree...

public void breadthFirstTraversal() (displays the nodes in breadth-first traversal)
public in height() ( returns the height of this binary tree, the number of the nodes in the longest path of the root to a leaf)


This is the binary tree code to add the methods to...

public class BinaryTree<E extends Comparable<E>>
extends AbstractTree<E> implements Cloneable {
protected TreeNode<E> root;
protected int size = 0;

/** Create a default binary tree */
public BinaryTree() {
}

/** Create a binary tree from an array of objects */
public BinaryTree(E[] objects) {
for (int i = 0; i < objects.length; i++)
insert(objects[i]);
}

/** Returns true if the element is in the tree */
public boolean search(E e) {
TreeNode<E> current = root; // Start from the root

while (current != null) {
if (e.compareTo(current.element) < 0) {
current = current.left;
}
else if (e.compareTo(current.element) > 0) {
current = current.right;
}
else // element matches current.element
return true; // Element is found
}

return false;
}

/** Insert element o into the binary tree
* Return true if the element is inserted successfully */
public boolean insert(E e) {
if (root == null)
root = createNewNode(e); // Create a new root
else {
// Locate the parent node
TreeNode<E> parent = null;
TreeNode<E> current = root;
while (current != null)
if (e.compareTo(current.element) < 0) {
parent = current;
current = current.left;
}
else if (e.compareTo(current.element) > 0) {
parent = current;
current = current.right;
}
else
return false; // Duplicate node not inserted

// Create the new node and attach it to the parent node
if (e.compareTo(parent.element) < 0)
parent.left = createNewNode(e);
else
parent.right = createNewNode(e);
}

size++;
return true; // Element inserted
}

protected TreeNode<E> createNewNode(E e) {
return new TreeNode<E>(e);
}

/** Inorder traversal from the root*/
public void inorder() {
inorder(root);
}

/** Inorder traversal from a subtree */
protected void inorder(TreeNode<E> root) {
if (root == null) return;
inorder(root.left);
System.out.print(root.element + " ");
inorder(root.right);
}

/** Postorder traversal from the root */
public void postorder() {
postorder(root);
}

/** Postorder traversal from a subtree */
protected void postorder(TreeNode<E> root) {
if (root == null) return;
postorder(root.left);
postorder(root.right);
System.out.print(root.element + " ");
}

/** Preorder traversal from the root */
public void preorder() {
preorder(root);
}

/** Preorder traversal from a subtree */
protected void preorder(TreeNode<E> root) {
if (root == null) return;
System.out.print(root.element + " ");
preorder(root.left);
preorder(root.right);
}

/** Inner class tree node */
public static class TreeNode<E extends Comparable<E>> {
E element;
TreeNode<E> left;
TreeNode<E> right;

public TreeNode(E e) {
element = e;
}
}

/** Get the number of nodes in the tree */
public int getSize() {
return size;
}

/** Returns the root of the tree */
public TreeNode<E> getRoot() {
return root;
}

/** Returns a path from the root leading to the specified element */
public java.util.ArrayList<TreeNode<E>> path(E e) {
java.util.ArrayList<TreeNode<E>> list =
new java.util.ArrayList<TreeNode<E>>();
TreeNode<E> current = root; // Start from the root

while (current != null) {
list.add(current); // Add the node to the list
if (e.compareTo(current.element) < 0) {
current = current.left;
}
else if (e.compareTo(current.element) > 0) {
current = current.right;
}
else
break;
}

return list; // Return an array of nodes
}

/** Delete an element from the binary tree.
* Return true if the element is deleted successfully
* Return false if the element is not in the tree */
public boolean delete(E e) {
// Locate the node to be deleted and also locate its parent node
TreeNode<E> parent = null;
TreeNode<E> current = root;
while (current != null) {
if (e.compareTo(current.element) < 0) {
parent = current;
current = current.left;
}
else if (e.compareTo(current.element) > 0) {
parent = current;
current = current.right;
}
else
break; // Element is in the tree pointed by current
}

if (current == null)
return false; // Element is not in the tree

// Case 1: current has no left children
if (current.left == null) {
// Connect the parent with the right child of the current node
if (parent == null) {
root = current.right;
}
else {
if (e.compareTo(parent.element) < 0)
parent.left = current.right;
else
parent.right = current.right;
}
}
else {
// Case 2: The current node has a left child
// Locate the rightmost node in the left subtree of
// the current node and also its parent
TreeNode<E> parentOfRightMost = current;
TreeNode<E> rightMost = current.left;

while (rightMost.right != null) {
parentOfRightMost = rightMost;
rightMost = rightMost.right; // Keep going to the right
}

// Replace the element in current by the element in rightMost
current.element = rightMost.element;

// Eliminate rightmost node
if (parentOfRightMost.right == rightMost)
parentOfRightMost.right = rightMost.left;
else
// Special case: parentOfRightMost == current
parentOfRightMost.left = rightMost.left;
}

size--;
return true; // Element inserted
}

/** Obtain an iterator. Use inorder. */
public java.util.Iterator iterator() {
return inorderIterator();
}

/** Obtain an inorder iterator */
public java.util.Iterator inorderIterator() {
return new InorderIterator();
}

// Inner class InorderIterator
class InorderIterator implements java.util.Iterator {
// Store the elements in a list
private java.util.ArrayList<E> list =
new java.util.ArrayList<E>();
private int current = 0; // Point to the current element in list

public InorderIterator() {
inorder(); // Traverse binary tree and store elements in list
}

/** Inorder traversal from the root*/
private void inorder() {
inorder(root);
}

/** Inorder traversal from a subtree */
private void inorder(TreeNode<E> root) {
if (root == null)return;
inorder(root.left);
list.add(root.element);
inorder(root.right);
}

/** Next element for traversing? */
public boolean hasNext() {
if (current < list.size())
return true;

return false;
}

/** Get the current element and move cursor to the next */
public Object next() {
return list.get(current++);
}

/** Remove the current element and refresh the list */
public void remove() {
delete(list.get(current)); // Delete the current element
list.clear(); // Clear the list
inorder(); // Rebuild the list
}
}

/** Remove all elements from the tree */
public void clear() {
root = null;
size = 0;
}

public Object clone() {
BinaryTree<E> tree1 = new BinaryTree<E>();

copy(root, tree1);

return tree1;
}

private void copy(TreeNode<E> root, BinaryTree<E> tree) {
if (root != null) {
tree.insert(root.element);
copy(root.left, tree);
copy(root.right, tree);
}
}
}

Explanation / Answer

public int height()
{
  return height(root);
}

/**
* returns the height of the given node
*/
private int height(TreeNode<E> root)
{
  // break case
  if(root == null)
{
  return 0;
}

  // otherwise search down left and right trees
  return 1 + (int)Math.max(height(root.left), height(root.right));
}

public void breadthFirstTraversal()
{
  // add nodes to Queue in breadthfirst order
  Queue<TreeNode<E>> queue = newLinkedList<TreeNode<E>>();

  if(root != null)
{
queue.add(root);
}

  while(!queue.isEmpty())
{
  TreeNode<E> temp = queue.remove();

  System.out.println(temp);

  if(temp.left != null)
{
queue.add(temp.left);
}
  if(temp.right != null)
{
queue.add(temp.right);
}
}
}

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.