Homework SourseObjective Binary Search Tree traversal 2 points Use traversa
Objective: Binary Search Tree traversal (2 points) Use traversal.pptx as guidance to write a program to build a binary search tree Dictionary. Input records from inventory.txt. Both key and Element of BST have the same data from each input record. Provide Add, Delete and Retrieve functions for user to access the database. Reject duplicate record when add a new record. Modify BST.java to add printpostOrder, printpreOrder methods. At the end, display inorder, postorder and preorder of the tree.
public interface BinNode<E> {
/** Get and set the element value */
public E element();
public void setElement(E v);
/** @return The left child */
public BinNode<E> left();
/** @return The right child */
public BinNode<E> right();
/** @return True if a leaf node, false otherwise */
public boolean isLeaf();
}
import java.lang.Comparable;
/** Binary Search Tree implementation for Dictionary ADT */
class BST<Key extends Comparable<? super Key>, E>
implements Dictionary<Key, E> {
private BSTNode<Key,E> root; // Root of the BST
int nodecount; // Number of nodes in the BST
/** Constructor */
BST() { root = null; nodecount = 0; }
/** Reinitialize tree */
public void clear() { root = null; nodecount = 0; }
/** Insert a record into the tree.
@param k Key value of the record.
@param e The record to insert. */
public void insert(Key k, E e) {
root = inserthelp(root, k, e);
nodecount++;
}
// Return root
public BSTNode getRoot()
{
return root;
}
/** Remove a record from the tree.
@param k Key value of record to remove.
@return The record removed, null if there is none. */
public E remove(Key k) {
E temp = findhelp(root, k); // First find it
if (temp != null) {
root = removehelp(root, k); // Now remove it
nodecount--;
}
return temp;
}
/** Remove and return the root node from the dictionary.
@return The record removed, null if tree is empty. */
public E removeAny() {
if (root == null) return null;
E temp = root.element();
root = removehelp(root, root.key());
nodecount--;
return temp;
}
/** @return Record with key value k, null if none exist.
@param k The key value to find. */
public E find(Key k) { return findhelp(root, k); }
/** @return The number of records in the dictionary. */
public int size() { return nodecount; }
private E findhelp(BSTNode<Key,E> rt, Key k) {
if (rt == null) return null;
if (rt.key().compareTo(k) > 0)
return findhelp(rt.left(), k);
else if (rt.key().compareTo(k) == 0) return rt.element();
else return findhelp(rt.right(), k);
}
/** @return The current subtree, modified to contain
the new item */
private BSTNode<Key,E> inserthelp(BSTNode<Key,E> rt,
Key k, E e) {
if (rt == null) return new BSTNode<Key,E>(k, e);
if (rt.key().compareTo(k) > 0)
rt.setLeft(inserthelp(rt.left(), k, e));
else
rt.setRight(inserthelp(rt.right(), k, e));
return rt;
}
/** Remove a node with key value k
@return The tree with the node removed */
private BSTNode<Key,E> removehelp(BSTNode<Key,E> rt,Key k) {
if (rt == null) return null;
if (rt.key().compareTo(k) > 0)
rt.setLeft(removehelp(rt.left(), k));
else if (rt.key().compareTo(k) < 0)
rt.setRight(removehelp(rt.right(), k));
else { // Found it
if (rt.left() == null) return rt.right();
else if (rt.right() == null) return rt.left();
else { // Two children
BSTNode<Key,E> temp = getmin(rt.right());
rt.setElement(temp.element());
rt.setKey(temp.key());
rt.setRight(deletemin(rt.right()));
}
}
return rt;
}
private BSTNode<Key,E> getmin(BSTNode<Key,E> rt) {
if (rt.left() == null) return rt;
return getmin(rt.left());
}
private BSTNode<Key,E> deletemin(BSTNode<Key,E> rt) {
if (rt.left() == null) return rt.right();
rt.setLeft(deletemin(rt.left()));
return rt;
}
private void printhelp(BSTNode<Key,E> rt) {
if (rt == null) return;
printhelp(rt.left());
printVisit(rt.element());
printhelp(rt.right());
}
private StringBuffer out;
public String toString() {
out = new StringBuffer(400);
printhelp(root);
return out.toString();
}
private void printVisit(E it) {
out.append(it + \"\ \");
}
}
class BSTNode<Key, E> implements BinNode<E> {
private Key key; // Key for this node
private E element; // Element for this node
private BSTNode<Key,E> left; // Pointer to left child
private BSTNode<Key,E> right; // Pointer to right child
/** Constructors */
public BSTNode() {left = right = null; }
public BSTNode(Key k, E val)
{ left = right = null; key = k; element = val; }
public BSTNode(Key k, E val,
BSTNode<Key,E> l, BSTNode<Key,E> r)
{ left = l; right = r; key = k; element = val; }
/** Get and set the key value */
public Key key() { return key; }
public void setKey(Key k) { key = k; }
/** Get and set the element value */
public E element() { return element; }
public void setElement(E v) { element = v; }
/** Get and set the left child */
public BSTNode<Key,E> left() { return left; }
public void setLeft(BSTNode<Key,E> p) { left = p; }
/** Get and set the right child */
public BSTNode<Key,E> right() { return right; }
public void setRight(BSTNode<Key,E> p) { right = p; }
/** @return True if a leaf node, false otherwise */
public boolean isLeaf()
{ return (left == null) && (right == null); }
}
public interface Dictionary<Key, E> {
/** Reinitialize dictionary */
public void clear();
/** Insert a record
@param k The key for the record being inserted.
@param e The record being inserted. */
public void insert(Key k, E e);
/** Remove and return a record.
@param k The key of the record to be removed.
@return A maching record. If multiple records match
\"k\", remove an arbitrary one. Return null if no record
with key \"k\" exists. */
public E remove(Key k);
/** Remove and return an arbitrary record from dictionary.
@return the record removed, or null if none exists. */
public E removeAny();
/** @return A record matching \"k\" (null if none exists).
If multiple records match, return an arbitrary one.
@param k The key of the record to find */
public E find(Key k);
/** @return The number of records in the dictionary. */
public int size();
};
//
inventory.txt
traverse
CT16C1288B
DT14B1225F
MI15B1250A
MI15B1251A
HO03N1095A
HY07D1095BQ
KI04D2593C
DG12A1240AQ
HY03G2593BQ
TO30A1310A
HO03N1095AQ
HO01H1351C
HO01H1350C
FT18A1288B
LR15A1000A
BM12E1000A
VW02B3113A
NI23H1230AQ
LX03D2503A
LX03D2502A
LX03D2502A
VW22A3113B
VW22B3113A
Solution
Please find below the java program to implement a binary search tree Dictionary:
BST.java:
------------
import java.lang.Comparable;
/** A Binary Search Tree implementation for Dictionary ADT */
class BST<Key extends Comparable<? super Key>, E>
implements Dictionary<Key, E> {
private BSTNode<Key,E> root; // Root of the BST
int nodecount; // Number of nodes in the BST
/** Constructor */
BST() { root = null; nodecount = 0; }
/** Reinitialize tree */
public void clear() { root = null; nodecount = 0; }
/** Insert a record into the tree.
@param k Key value of the record.
@param e The record to insert. */
public void insert(Key k, E e) {
root = inserthelp(root, k, e);
nodecount++;
}
/** Remove a record from the tree.
@param k Key value of record to remove.
@return The record removed, null if there is none. */
public E remove(Key k) {
E temp = findhelp(root, k); // First find it
if (temp != null) {
root = removehelp(root, k); // Now remove it
nodecount--;
}
return temp;
}
/** Remove and return the root node from the dictionary.
@return The record removed, null if tree is empty. */
public E removeAny() {
if (root == null) return null;
E temp = root.element();
root = removehelp(root, root.key());
nodecount--;
return temp;
}
/** @return Record with key value k, null if none exist.
@param k The key value to find. */
public E find(Key k) { return findhelp(root, k); }
/** @return The number of records in the dictionary. */
public int size() { return nodecount; }
private E findhelp(BSTNode<Key,E> rt, Key k) {
if (rt == null) return null;
if (rt.key().compareTo(k) > 0)
return findhelp(rt.left(), k);
else if (rt.key().compareTo(k) == 0) return rt.element();
else return findhelp(rt.right(), k);
}
/** @return The current subtree, modified to contain
the new item */
private BSTNode<Key,E> inserthelp(BSTNode<Key,E> rt,
Key k, E e) {
if (rt == null) return new BSTNode<Key,E>(k, e);
if (rt.key().compareTo(k) > 0)
rt.setLeft(inserthelp(rt.left(), k, e));
else
rt.setRight(inserthelp(rt.right(), k, e));
return rt;
}
/** Remove a node with key value k
@return The tree with the node removed */
private BSTNode<Key,E> removehelp(BSTNode<Key,E> rt,Key k) {
if (rt == null) return null;
if (rt.key().compareTo(k) > 0)
rt.setLeft(removehelp(rt.left(), k));
else if (rt.key().compareTo(k) < 0)
rt.setRight(removehelp(rt.right(), k));
else { // Found it
if (rt.left() == null) return rt.right();
else if (rt.right() == null) return rt.left();
else { // Two children
BSTNode<Key,E> temp = getmin(rt.right());
rt.setElement(temp.element());
rt.setKey(temp.key());
rt.setRight(deletemin(rt.right()));
}
}
return rt;
}
private BSTNode<Key,E> getmin(BSTNode<Key,E> rt) {
if (rt.left() == null) return rt;
return getmin(rt.left());
}
private BSTNode<Key,E> deletemin(BSTNode<Key,E> rt) {
if (rt.left() == null) return rt.right();
rt.setLeft(deletemin(rt.left()));
return rt;
}
private void printhelp(BSTNode<Key,E> rt) {
if (rt == null) return;
printhelp(rt.left());
printVisit(rt.element());
printhelp(rt.right());
}
private StringBuffer out;
public String toString() {
out = new StringBuffer(100);
printhelp(root);
return out.toString();
}
private void printVisit(E it) {
out.append(it + \" \");
}
}
BSTNode.java:
------------------
/** Binary tree node implementation: Pointers to children
@param E The data element
@param Key The associated key for the record */
class BSTNode<Key, E> implements BinNode<E> {
private Key key; // Key for this node
private E element; // Element for this node
private BSTNode<Key,E> left; // Pointer to left child
private BSTNode<Key,E> right; // Pointer to right child
/** Constructors */
public BSTNode() {left = right = null; }
public BSTNode(Key k, E val)
{ left = right = null; key = k; element = val; }
public BSTNode(Key k, E val,
BSTNode<Key,E> l, BSTNode<Key,E> r)
{ left = l; right = r; key = k; element = val; }
/** Get and set the key value */
public Key key() { return key; }
public void setKey(Key k) { key = k; }
/** Get and set the element value */
public E element() { return element; }
public void setElement(E v) { element = v; }
/** Get and set the left child */
public BSTNode<Key,E> left() { return left; }
public void setLeft(BSTNode<Key,E> p) { left = p; }
/** Get and set the right child */
public BSTNode<Key,E> right() { return right; }
public void setRight(BSTNode<Key,E> p) { right = p; }
/** @return True if a leaf node, false otherwise */
public boolean isLeaf()
{ return (left == null) && (right == null); }
}
BinNode.java:
------------------
/** The ADT for binary tree nodes */
public interface BinNode<E> {
/** Get and set the element value */
public E element();
public void setElement(E v);
/** @return The left child */
public BinNode<E> left();
/** @return The right child */
public BinNode<E> right();
/** @return True if a leaf node, false otherwise */
public boolean isLeaf();
}
Dictionary.java:
--------------------
/** The Dictionary abstract class. */
public interface Dictionary<Key, E> {
/** Reinitialize dictionary */
public void clear();
/** Insert a record
@param k The key for the record being inserted.
@param e The record being inserted. */
public void insert(Key k, E e);
/** Remove and return a record.
@param k The key of the record to be removed.
@return A maching record. If multiple records match
\"k\", remove an arbitrary one. Return null if no record
with key \"k\" exists. */
public E remove(Key k);
/** Remove and return an arbitrary record from dictionary.
@return the record removed, or null if none exists. */
public E removeAny();
/** @return A record matching \"k\" (null if none exists).
If multiple records match, return an arbitrary one.
@param k The key of the record to find */
public E find(Key k);
/** @return The number of records in the dictionary. */
public int size();
};
