class BSTNode { int key; BSTNode left, right; public BSTNode(int item) { key = item; left = right = null; } } class BST_Tree { BSTNode root; BST_Tree() { // Constructor root = null; } boolean search(int key){ return (searchRec(root, key) != null); } public BSTNode searchRec(BSTNode root, int key) { if (root==null || root.key==key) return root; if (root.key > key) return searchRec(root.left, key); return searchRec (root.right, key); } void deleteKey(int key) { root = deleteRec(root, key); } /* A recursive function to insert a new key in BST */ BSTNode deleteRec(BSTNode root, int key) { /* Base Case: If the tree is empty */ if (root == null) return root; /* Otherwise, recur down the tree */ if (key < root.key) root.left = deleteRec(root.left, key); else if (key > root.key) root.right = deleteRec(root.right, key); // if key is same as root's key, then This is the target else { // node with only one child or no child if (root.left == null) return root.right; else if (root.right == null) return root.left; // node with two children: Get the inorder successor // (smallest in the right subtree) root.key = minValue(root.right); // Delete the inorder successor root.right = deleteRec(root.right, root.key); } return root; } int minValue(BSTNode root) { int minv = root.key; while (root.left != null) { minv = root.left.key; root = root.left; } return minv; } void insert(int key) { root = insertRec(root, key); } /* A recursive function to insert a new key in BST */ BSTNode insertRec(BSTNode root, int key) { /* If the tree is empty, return a new node */ if (root == null) { root = new BSTNode(key); return root; } /* Otherwise, recur down the tree */ if (key < root.key) root.left = insertRec(root.left, key); else if (key > root.key) root.right = insertRec(root.right, key); return root; } void inorder() { inorderRec(root); } // A utility function to do inorder traversal of BST void inorderRec(BSTNode root) { if (root != null) { inorderRec(root.left); System.out.print(root.key + " "); inorderRec(root.right); } } void preorder() { preorderRec(root); } void preorderRec(BSTNode root) { if (root != null) { System.out.print(root.key + " "); preorderRec(root.left); preorderRec(root.right); } } void postorder() { postorderRec(root); } void postorderRec(BSTNode root) { if (root != null) { postorderRec(root.left); postorderRec(root.right); System.out.print(root.key + " "); } } } public class BST_Recursive { public static void main(String[] args) { BST_Tree tree = new BST_Tree(); System.out.println("Build a tree by inserting :\n 50 30 20 40 70 60 80"); tree.insert(50); tree.insert(30); tree.insert(20); tree.insert(40); tree.insert(70); tree.insert(60); tree.insert(80); System.out.println("\nPre-order traversal of the given tree"); tree.preorder(); System.out.println("\nIn-order traversal of the given tree"); tree.inorder(); System.out.println("\nPost-order traversal of the given tree"); tree.postorder(); System.out.println("\n\nDelete 20"); tree.deleteKey(20); System.out.println("Inorder traversal of the modified tree"); tree.inorder(); System.out.println("\nDelete 30"); tree.deleteKey(30); System.out.println("Inorder traversal of the modified tree"); tree.inorder(); System.out.println("\nDelete 50"); tree.deleteKey(50); System.out.println("Inorder traversal of the modified tree"); tree.inorder(); System.out.println("\nSearch 70"); System.out.println("Found ? : " + tree.search(70) ); } } Task 1: Modify BST_Recursive.java to write a complete program to implement a spare-parts database with itemNo, price and description. Provide options to insert, search, delete, and show all items in order of itemNo.

class BSTNode {

int key;

BSTNode left, right;

public BSTNode(int item) {

key = item;

left = right = null;

}

}

class BST_Tree {

BSTNode root;

BST_Tree() { // Constructor

root = null;

}

boolean search(int key){

return (searchRec(root, key) != null);

}

public BSTNode searchRec(BSTNode root, int key) {

if (root==null || root.key==key)

return root;

if (root.key > key)

return searchRec(root.left, key);

return searchRec (root.right, key);

}

void deleteKey(int key) {

root = deleteRec(root, key);

}

/* A recursive function to insert a new key in BST */

BSTNode deleteRec(BSTNode root, int key) {

/* Base Case: If the tree is empty */

if (root == null) return root;

/* Otherwise, recur down the tree */

if (key < root.key)

root.left = deleteRec(root.left, key);

else if (key > root.key)

root.right = deleteRec(root.right, key);

// if key is same as root's key, then This is the target

else {

// node with only one child or no child

if (root.left == null)

return root.right;

else if (root.right == null)

return root.left;

// node with two children: Get the inorder successor

// (smallest in the right subtree)

root.key = minValue(root.right);

// Delete the inorder successor

root.right = deleteRec(root.right, root.key);

}

return root;

}

int minValue(BSTNode root) {

int minv = root.key;

while (root.left != null) {

minv = root.left.key;

root = root.left;

}

return minv;

}

void insert(int key) {

root = insertRec(root, key);

}

/* A recursive function to insert a new key in BST */

BSTNode insertRec(BSTNode root, int key) {

/* If the tree is empty, return a new node */

if (root == null) {

root = new BSTNode(key);

return root;

}

/* Otherwise, recur down the tree */

if (key < root.key)

root.left = insertRec(root.left, key);

else if (key > root.key)

root.right = insertRec(root.right, key);

return root;

}

void inorder() {

inorderRec(root);

}

// A utility function to do inorder traversal of BST

void inorderRec(BSTNode root) {

if (root != null) {

inorderRec(root.left);

System.out.print(root.key + " ");

inorderRec(root.right);

}

}

void preorder() {

preorderRec(root);

}

void preorderRec(BSTNode root) {

if (root != null) {

System.out.print(root.key + " ");

preorderRec(root.left);

preorderRec(root.right);

}

}

void postorder() {

postorderRec(root);

}

void postorderRec(BSTNode root) {

if (root != null) {

postorderRec(root.left);

postorderRec(root.right);

System.out.print(root.key + " ");

}

}

}

public class BST_Recursive {

public static void main(String[] args) {

BST_Tree tree = new BST_Tree();

System.out.println("Build a tree by inserting :\n 50 30 20 40 70 60 80");

tree.insert(50);

tree.insert(30);

tree.insert(20);

tree.insert(40);

tree.insert(70);

tree.insert(60);

tree.insert(80);

System.out.println("\nPre-order traversal of the given tree");

tree.preorder();

System.out.println("\nIn-order traversal of the given tree");

tree.inorder();

System.out.println("\nPost-order traversal of the given tree");

tree.postorder();

System.out.println("\n\nDelete 20");

tree.deleteKey(20);

System.out.println("Inorder traversal of the modified tree");

tree.inorder();

System.out.println("\nDelete 30");

tree.deleteKey(30);

System.out.println("Inorder traversal of the modified tree");

tree.inorder();

System.out.println("\nDelete 50");

tree.deleteKey(50);

System.out.println("Inorder traversal of the modified tree");

tree.inorder();

System.out.println("\nSearch 70");

System.out.println("Found ? : " + tree.search(70) );

}

}

Task 1:

Modify BST_Recursive.java to write a complete program to implement a spare-parts database with itemNo, price and description. Provide options to insert, search, delete, and show all items in order of itemNo.