I'm working on a program that will take a name and number of a periodic element, store it in a tree and then print it out in different orders.
When I try and run my main class it asks for the name, but then it doesn't go into the while loop.
Here is my main class.
public class BinarySearchTree
{
public static void main(String[] args)
{
Scanner conIn = new Scanner(System.in);
String name;
int atomicNum;
BSTInterface<PeriodicElement> elements = new BSTree<PeriodicElement>();
PeriodicElement element;
int numElements;
String skip;
System.out.print("Element name (press Enter to end): ");
name = conIn.nextLine();
while (!name.equals(""));
{
System.out.print("Atomic Number: ");
atomicNum = conIn.nextInt();
skip = conIn.nextLine();
element = new PeriodicElement(name, atomicNum);
elements.add(element);
System.out.print("Element name (press ENTER TO END): ");
name = conIn.nextLine();
}
System.out.println();
System.out.println("Periodic Elements");
numElements = elements.reset(BSTree.INORDER);
for (int count = 1; count <= numElements; count++)
{
System.out.println(elements.getNext(BSTree.INORDER));
}
}
}
Here is my Binary Search Tree
public class BSTree <T extends Comparable<T>>
implements BSTInterface<T>
{
protected BSTNode<T> root;
boolean found;
protected LinkedUnbndQueue<T> inOrderQueue;
protected LinkedUnbndQueue<T> preOrderQueue;
protected LinkedUnbndQueue<T> postOrderQueue;
public BSTree()
{
root = null;
}
public boolean isEmpty()
{
return (root == null);
}
private int recSize(BSTNode<T> tree)
{
if(tree == null)
{
return 0;
}
else
{
return recSize(tree.getLeft()) + recSize(tree.getRight()) + 1;
}
}
public int size()
{
int count = 0;
{
if(root != null)
{
LinkedStack<BSTNode<T>> hold = new LinkedStack<BSTNode<T>>();
BSTNode<T> currNode;
hold.push(root);
while(!hold.isEmpty())
{
currNode = hold.top();
hold.pop();
count++;
if(currNode.getLeft() != null)
{
hold.push(currNode.getLeft());
}
if(currNode.getRight() != null)
{
hold.push(currNode.getRight());
}
}
}
//System.out.println(count);
return count;
}
}
public boolean recContains(T element, BSTNode<T> tree)
{
if(tree == null)
{
return false;
}
else if(element.compareTo(tree.getInfo()) < 0)
{
return recContains(element, tree.getLeft());
}
else if(element.compareTo(tree.getInfo()) > 0)
{
return recContains(element, tree.getRight());
}
else
{
return true;
}
}
public boolean contains (T element)
{
//System.out.println("Tree contains: " + recContains(element, root));
return recContains(element, root);
}
public T recGet(T element, BSTNode<T> tree)
{
if(tree == null)
{
return null;
}
else if(element.compareTo(tree.getInfo()) < 0)
{
return recGet(element, tree.getLeft());
}
else if(element.compareTo(tree.getInfo()) > 0)
{
return recGet(element, tree.getRight());
}
else
{
return tree.getInfo();
}
}
public T get(T element)
{
//System.out.println(recGet(element, root));
return recGet(element, root);
}
public void add(T element)
{
root = recAdd(element, root);
}
private BSTNode<T> recAdd(T element, BSTNode<T> tree)
{
if(tree == null)
{
tree = new BSTNode<T>(element);
}
else if(element.compareTo(tree.getInfo()) <= 0)
{
tree.setLeft(recAdd(element, tree.getLeft()));
}
else
{
tree.setRight(recAdd(element, tree.getRight()));
}
return tree;
}
public boolean remove(T element)
{
root = recRemove(element, root);
return found;
}
private BSTNode<T> recRemove(T element, BSTNode<T> tree)
{
if(tree == null)
{
found = false;
}
else if (element.compareTo(tree.getInfo()) < 0)
{
tree.setLeft(recRemove(element, tree.getLeft()));
}
else if (element.compareTo(tree.getInfo()) > 0)
{
tree.setRight(recRemove(element, tree.getRight()));
}
else
{
tree = removeNode(tree);
found = true;
}
return tree;
}
private BSTNode<T> removeNode(BSTNode<T> tree)
{
T data;
if(tree.getLeft() == null)
{
return tree.getRight();
}
else if(tree.getRight() == null)
{
return tree.getLeft();
}
else
{
data = getPredecessor(tree.getLeft());
tree.setInfo(data);
tree.setLeft(recRemove(data, tree.getLeft()));
return tree;
}
}
private T getPredecessor(BSTNode<T> tree)
{
while (tree.getRight() != null)
{
tree = tree.getRight();
}
return tree.getInfo();
}
public int reset(int orderType)
{
int numNodes = size();
if(orderType == INORDER)
{
inOrderQueue = new LinkedUnbndQueue<T>(numNodes);
}
else
{
if(orderType == PREORDER)
{
preOrderQueue = new LinkedUnbndQueue<T>(numNodes);
preOrder(root);
}
if(orderType == POSTORDER)
{
postOrderQueue = new LinkedUnbndQueue<T>(numNodes);
postOrder(root);
}
}
return numNodes;
}
public T getNext(int orderType)
{
if(orderType == INORDER)
{
return inOrderQueue.dequeue();
}
else
{
if(orderType == PREORDER)
{
return preOrderQueue.dequeue();
}
else
{
if(orderType == POSTORDER)
{
return postOrderQueue.dequeue();
}
else
{
return null;
}
}
}
}
private void inOrder(BSTNode<T> tree)
{
if(tree != null)
{
inOrder(tree.getLeft());
inOrderQueue.enqueue(tree.getInfo());
inOrder(tree.getRight());
}
}
private void preOrder(BSTNode<T> tree)
{
if(tree != null)
{
preOrderQueue.enqueue(tree.getInfo());
preOrder(tree.getLeft());
preOrder(tree.getRight());
}
}
private void postOrder(BSTNode<T> tree)
{
if(tree != null)
{
postOrder(tree.getLeft());
postOrder(tree.getRight());
postOrderQueue.enqueue(tree.getInfo());
}
}
}
Here is the Binary Search Tree Node class
public class BSTNode <T extends Comparable<T>>
{
protected T info;
protected BSTNode<T> left;
protected BSTNode<T> right;
public BSTNode(T info)
{
this.info = info;
left = null;
right = null;
}
public void setInfo(T info)
{
this.info = info;
}
public T getInfo()
{
return info;
}
public void setLeft(BSTNode<T> link)
{
left = link;
}
public void setRight(BSTNode<T> link)
{
right = link;
}
public BSTNode<T> getLeft()
{
return left;
}
public BSTNode<T> getRight()
{
return right;
}
}
Remove the semi-colon that is terminating the while statement
while (!name.equals(""));
^
Remove the semi colon after the while statment because a semi colon makes it end there while a { is the start if while something is true or not (!) and it should end as you obviously know with a }.
Related
While revising for my final, I came across binary trees (regular ones). After going through the lecture, I started to solve previous labs.
My problem here is that only 6 is inserted into the tree. What is wrong with my method?
What I'm trying to input:
tree.insert(1); tree.insert(15); tree.insert(7);
tree.insert(13); tree.insert(58); tree.insert(6);
The Node class:
public class Node {
public int key;
public Node left_child;
public Node right_child;
// The Constructor(s).
public Node() {
}
public Node(int key) {
this.key = key;
left_child = null;
right_child = null;
}
// The Get Methods.
public int getKey() {
return key;
}
public Node getLeft_child() {
return left_child;
}
public Node getRight_child() {
return right_child;
}
// The Set Methods.
public void setKey(int key) {
this.key = key;
}
public void setLeft_child(Node left_child) {
this.left_child = left_child;
}
public void setRight_child(Node right_child) {
this.right_child = right_child;
}
}
The BinaryTree class:
public class BinaryTree {
private Node root;
// The Constructor Method(s)
public BinaryTree() {
root = null;
}
public boolean is_empty() {
return (root == null);
}
public void insert(int k) {
insert(root, k);
}
private Node insert(Node x, int k) {
Node p = new Node(k);
if (x == null) {
root = p;
}
else {
if (x.left_child != null) {
insert(x.left_child, k);
}
else {
insert(x.right_child, k);
}
}
return x;
}
// Printing Method(s).
public void print_inorder() {
print_inorder(root);
}
public void print_inorder(Node node) {
if (node == null) {
return;
}
print_inorder(node.left_child);
System.out.print(node.key + " ");
print_inorder(node.right_child);
}
public void print_preorder() {
print_preorder(root);
}
public void print_preorder(Node node) {
if (node == null) {
return;
}
System.out.print(node.key + " ");
print_preorder(node.left_child);
print_preorder(node.right_child);
}
public void print_postorder() {
print_postorder(root);
}
public void print_postorder(Node node) {
if (node == null) {
return;
}
print_postorder(node.left_child);
print_postorder(node.right_child);
System.out.print(node.key + " ");
}
}
This will have a node to the left if a number is even and a node to the right if a node is odd.
I had to change your if condition because the way it was it was never going to use the left node.
private void insert(Node x, int k) {
Node p = new Node(k);
if (root == null) {
this.root = p;
return;
}
if (x.getKey() - k % 2 == 0) {
if (x.left_child == null) {
x.left_child = p;
} else {
insert(x.left_child, k);
}
} else {
if (x.right_child == null) {
x.right_child = p;
} else {
insert(x.right_child, k);
}
}
}
I am trying to get a binary search tree to balance.
I balance the tree after the insert method.
I hope someone here can guide me through this.
The method is balanceTheTree(...).
I did a recursive method, I don't know if it's the best solution
public class BinaryTreeTable<E extends Comparable<E>, T> implements Table<E, T> {
private Node root;
public BinaryTreeTable() {
this.root = new Node(null, null, null);
}
#Override
public boolean insert(E key, T data) {
boolean ret;
if (this.root.key == null) {
Node toInsert = new Node(null, key, data);
this.root = toInsert;
ret = true;
} else {
Node father = this.seekFather(key);
if (father == null) {
ret = false;
} else {
Node toInsert = new Node(father, key, data);
if (key.compareTo(father.key) > 0) {
father.rSon = toInsert;
ret = true;
balanceTheTree(toInsert);
} else if (key.compareTo(father.key) < 0) {
father.lSon = toInsert;
ret = true;
balanceTheTree(toInsert);
} else {
ret = false;
}
}
}
return ret;
}
private void rightRotation(Node theN) {
Node k2 = theN.rSon;
theN.rSon = k2.lSon;
k2.lSon = theN;
}
private void leftRotation(Node theN) {
Node k1 = theN.lSon;
theN.lSon = k1.rSon;
k1.rSon = theN;
}
private void leftRightRotation(Node theN) {
leftRotation(theN.rSon);
rightRotation(theN);
}
private void rightLeftRotation(Node theN) {
rightRotation(theN.lSon);
leftRotation(theN);
}
private void balanceTheTree(Node theN) {
if (theN == null) {
} else {
if (Math.abs(Math.subtractExact(computeH(theN.rSon), computeH(theN.lSon))) > 1) {
System.out.println("A droite " + theN.getLabel());
if (computeH(theN.lSon) > computeH(theN.rSon)) {
leftRotation(theN);
} else {
leftRightRotation(theN);
}
} else if (Math.abs(Math.subtractExact(computeH(theN.lSon), computeH(theN.rSon))) > 1) {
System.out.println("A gauche");
} else {
balanceTheTree(theN.rSon);
balanceTheTree(theN.lSon);
}
}
}
private int computeH(Node theN) {
int ret = 1;
if (theN == null) {
ret = 0;
} else if ((theN.lSon != null) && (theN.rSon == null)) {
ret = computeH(theN.lSon) + 1;
} else if ((theN.lSon == null) && (theN.rSon != null)) {
ret = computeH(theN.rSon) + 1;
} else if ((theN.lSon != null) && (theN.rSon != null)) {
ret = Math.max(computeH(theN.lSon), computeH(theN.rSon)) + 1;
}
return ret;
}
public class Node {
// Attributs
private Node lSon ;
private Node rSon ;
private Node father ;
private T theValue ;
private E key ;
// Constructeur
public Node (Node father, E key, T theValue) {
this.father = father;
this.key = key;
this.theValue = theValue;
}
public String getLabel() {
return String.valueOf(key);
}
public Node getLeft() {
return lSon;
}
public Node getRight() {
return rSon;
}
public Node clone() {
return new Node(this.father, this.key, this.theValue);
}
}
}
The computeH() method allows me to know the size of a node
The insertion method works correctly.
The tree i want to balance
public static void main(String[] args) {
BinaryTreeTable binaryTreeTable = new BinaryTreeTable();
binaryTreeTable.insert(10, "Test");
binaryTreeTable.insert(5, "Test");
binaryTreeTable.insert(7, "Test");
binaryTreeTable.insert(3, "Test");
binaryTreeTable.insert(4, "Test");
binaryTreeTable.insert(15, "Test");
binaryTreeTable.insert(19, "Test");
binaryTreeTable.insert(16, "Test");
binaryTreeTable.insert(20, "Test");
binaryTreeTable.showTree();
}
I wrote the code, but the tests are falling. I can't find what I'm doing wrong.
For example:
FAILURE: testRunOutOfPartnersThenFindSomeMore
2 msecs, weight: 0 units
Description: This tests whether your tree can get empty and then filled again.
Exception type: class java.lang.NullPointerException
FAILURE: testFemaleTreeImplementation
5 msecs, weight: 0 units
Description: This tests, whether your tree works correctly.
Exception type: class java.lang.AssertionError
Detailed information: Your implementation found a pair when it should not have.
Dancer.java
public interface Dancer {
public enum Gender {
MALE, FEMALE
}
public int getID();
public Gender getGender();
public int getHeight();
}
Dancers.java
import java.util.AbstractMap.SimpleEntry;
import java.util.List;
public interface Dancers {
public SimpleEntry<Dancer, Dancer> findPartnerFor(Dancer d) throws IllegalArgumentException;
/*
* Returns waiting list as a list (both men and women)
* Ordered shortest --> longest
* If man and woman are having the same height,
* then ordering should be woman, man
*/
public List<Dancer> returnWaitingList();
}
HW01.java
import java.util.AbstractMap.SimpleEntry;
import java.util.ArrayList;
import java.util.List;
public class HW01 implements Dancers {
public SearchTree maleTree;
public SearchTree femaleTree;
public void createTree(SearchTreeNode n) {
if (n.getKey().getGender().equals(Dancer.Gender.MALE)) {
this.maleTree = new SearchTree(n);
} else {
this.femaleTree = new SearchTree(n);
}
}
#Override
public SimpleEntry<Dancer, Dancer> findPartnerFor(Dancer candidate) throws IllegalArgumentException {
if (candidate == null) throw new IllegalArgumentException();
if (candidate.getGender().equals(Dancer.Gender.MALE)) {
if (this.femaleTree != null) {
// If no match, add to opposite tree
SearchTreeNode match = this.femaleTree.match(candidate);
if (match != null) {
// Remove node from tree
this.femaleTree.delete(match);
return new SimpleEntry<>( candidate, match.getKey() );
} else {
if (this.maleTree != null) {
this.maleTree.getRoot().insert(new SearchTreeNode(candidate));
} else {
this.createTree(new SearchTreeNode(candidate));
}
}
} else {
if (this.maleTree != null) {
this.maleTree.getRoot().insert(new SearchTreeNode(candidate));
} else {
this.createTree(new SearchTreeNode(candidate));
}
}
} else {
if (this.maleTree != null) {
// If no match, add to opposite tree
SearchTreeNode match = this.maleTree.match(candidate);
if (match != null) {
this.maleTree.delete(match);
return new SimpleEntry<>( candidate, match.getKey() );
} else {
if (this.femaleTree != null) {
this.femaleTree.getRoot().insert(new SearchTreeNode(candidate));
} else {
this.createTree(new SearchTreeNode(candidate));
}
}
} else {
if (this.femaleTree != null) {
this.femaleTree.getRoot().insert(new SearchTreeNode(candidate));
} else {
this.createTree(new SearchTreeNode(candidate));
}
}
}
return null;
}
#Override
public List<Dancer> returnWaitingList() {
List<Dancer> resultList = new ArrayList<>();
if (femaleTree != null) resultList.addAll(femaleTree.getMembers());
if (maleTree != null) resultList.addAll(maleTree.getMembers());
return resultList;
}
SearchTree.java
import java.util.ArrayList;
import java.util.List;
class SearchTree {
private SearchTreeNode root;
private List<Dancer> members = new ArrayList<>();
SearchTree(SearchTreeNode node) {
this.root = node;
}
SearchTreeNode getRoot() {
return root;
}
SearchTreeNode match(Dancer d) {
return this.root.match(new SearchTreeNode(d));
}
void delete(SearchTreeNode tn) {
root = delete(root, tn);
}
private SearchTreeNode delete(SearchTreeNode n, SearchTreeNode tn) {
if (n == null) {
return null;
}
if (n == tn) {
// n is the node to be removed
if (n.getLeft() == null && n.getRight() == null) {
return null;
}
if (n.getLeft() == null) {
return n.getRight();
}
if (n.getRight() == null) {
return n.getLeft();
}
// if we get here, then n has 2 children
SearchTreeNode smallest = getLastOnTheLeft(n.getRight());
n.setKey(smallest.getKey());
n.setRight(delete(n.getRight(), smallest));
return n;
}
else if (tn.getKey().getHeight() < n.getKey().getHeight()) {
n.setLeft( delete(n.getLeft(), tn) );
return n;
}
else {
n.setRight( delete(n.getRight(), tn) );
return n;
}
}
private SearchTreeNode getLastOnTheLeft(SearchTreeNode start) {
SearchTreeNode candidate = null;
SearchTreeNode parent = null;
SearchTreeNode node = start;
while (node != null) {
if ( node.getLeft() != null ) {
parent = node;
candidate = node.getLeft();
}
node = node.getLeft();
}
if (parent != null) {
parent.setLeft(null);
}
return candidate;
}
List<Dancer> getMembers() {
members = new ArrayList<>();
preOrderTraversal(root);
return members;
}
private void preOrderTraversal(SearchTreeNode root){
if (root == null) {
return;
}
members.add(root.getKey());
preOrderTraversal(root.getLeft());
preOrderTraversal(root.getRight());
}
}
SearchTreeNode.java
public class SearchTreeNode {
private Dancer key;
private SearchTreeNode left;
private SearchTreeNode right;
SearchTreeNode(Dancer key) {
this.key = key;
this.left = null;
this.right = null;
}
void setKey(Dancer key) {
this.key = key;
}
Dancer getKey() {
return key;
}
void setLeft(SearchTreeNode left) {
this.left = left;
}
SearchTreeNode getLeft() {
return left;
}
void setRight(SearchTreeNode right) {
this.right = right;
}
SearchTreeNode getRight() {
return right;
}
void insert(SearchTreeNode node) {
if (node.key.getHeight() < this.key.getHeight()) {
if (left != null) {
left.insert(node);
} else {
this.setLeft(node);
}
} else {
if (right != null) {
this.getRight().insert(node);
} else {
this.setRight(node);
}
}
}
SearchTreeNode match(SearchTreeNode node) {
if (node.getKey().getGender().equals(Dancer.Gender.MALE)) {
if (key.getHeight() < node.getKey().getHeight()) {
if (right != null) {
return right.match(node);
} else {
return this;
}
} else {
if (left != null) {
return left.match(node);
} else {
return null;
}
}
} if (node.getKey().getGender().equals(Dancer.Gender.FEMALE)) {
if (key.getHeight() > node.getKey().getHeight()) {
if (left != null) {
return left.match(node);
} else {
return this;
}
} else {
if (right != null) {
return right.match(node);
} else {
return null;
}
}
}
return node;
}
#Override
public String toString() {
return "SearchTreeNode {" +
"key = " + key +
'}';
}
}
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.
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.