Question

in java, Write methods contains and remove for the BinarySearchTree class. Use methods find and delete to do the work.

Answer 1

1 public class BinarySearchTreel { /* Class containing left and right child of current node and key value*/ class Node { int key; Node left, right; 5 7 B 1 2 B public Node(int item) { key = item; left = right = null; } } 5 5 7 B // Root of BST Node root; // Constructor BinarySearchTree1() { root = null; } 3 1 5 5 70 3 // This method mainly calls deleteRec() void deleteKey(int key) { root = deleteRec(root, key); } 1 2 /* A recursive function to insert a new key in BST */ Node deleteRec(Node root, int key) { /* Base Case: If the tree is empty */ if (root null) return root; 1 5 5 7 3 * /* 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); 1 2 3 4 5 5 7 3 // if key is same as root's key, then this is the node // to be deleted else { // node with only one child or no child if (root.left == null) return root.right; else if (root.right == null) return root.left; 1 2 3 1 5 5 7 3 // 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; 1 2 3 4 } 5 7 3 public Node search (Node root, int key) { // Base Cases: root is null or key is present at root if (root==null || root.key==key)|| return root; 1 2 B 1 5 5 // val is greater than root's key if (root.key > key) return search(root.left, key); // val is less than root's key return search(root.right, key);

- int minValue (Node root) { int minv = root.key; while (root.left != null) { miny = root.left.key; root = root. left; } return minv; } // This method mainly calls insertRec() void insert(int key) { root = insertRec(root, key); } /* A recursive function to insert a new key in BST */ Node insertRec(Node root, int key) { /* If the tree is empty, return a new node */ if (root == null) { root = new Node(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 the (unchanged) node pointer */ return nont.

void inorder) { inorderRec(root); } // A utility function to do inorder traversal of BST void inorderRec(Node root) { if (root != null) { inorderRec(root.left); System.out.print(root.key + "); inorderRec(root.right); } } // Driver Program to test above functions public static void main(String[] args) { BinarySearchTree1 tree = new BinarySearchTree1(); /* Let us create following BST 50 / 30 70 / / 20 40 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("Inorder traversal of the given tree"); tree. inorder();

tree.insert(80); System.out.println("Inorder traversal of the given tree"); tree. inorder(); 151 152 153 154 155 156 157 158 159 System.out.println("\nDelete 20"); tree.deletekey (20); System.out.println("Inorder traversal of the modified tree"); tree. inorder(); 160 161 162 System.out.println("\nDelete 30"); tree.deleteKey(30); System.out.println("Inorder traversal of the modified tree"); tree. inorder(); 163 164 165 166 167 System.out.println("\nDelete 50"); tree.deletekey (50); System.out.println("Inorder traversal of the modified tree"); tree. inorder(); 168 169 170 } 171 172 } 173 Problems @ Javadoc Declaration Console X <terminated > BinarySearch Tree1 [Java Application] C:\Program Files\Java\jdk-14.0.2\bin\javaw.exe (29-Oct-2020, 9:42:13 am - 9:42:15 am) Inorder traversal of the given tree 20 30 40 50 60 70 80 Delete 20 Inorder traversal of the modified tree 30 40 50 60 70 80 Delete 30 Inorder traversal of the modified tree 40 50 60 70 80 Delete 50 Inorder traversal of the modified tree 40 60 70 80

source code:

public class BinarySearchTree1 {
   /* Class containing left and right child of current node and key value*/
class Node
{
int key;
Node left, right;
  
public Node(int item)
{
key = item;
left = right = null;
}
}
  
// Root of BST
Node root;
  
// Constructor
BinarySearchTree1()
{
root = null;
}
  
// This method mainly calls deleteRec()
void deleteKey(int key)
{
root = deleteRec(root, key);
}
  
/* A recursive function to insert a new key in BST */
Node deleteRec(Node 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 node
// to be deleted
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;
}
  
public Node search(Node root, int key)
{
// Base Cases: root is null or key is present at root
if (root==null || root.key==key)
return root;

// val is greater than root's key
if (root.key > key)
return search(root.left, key);

// val is less than root's key
return search(root.right, key);
}
  
int minValue(Node root)
{
int minv = root.key;
while (root.left != null)
{
minv = root.left.key;
root = root.left;
}
return minv;
}
  
// This method mainly calls insertRec()
void insert(int key)
{
root = insertRec(root, key);
}
  
/* A recursive function to insert a new key in BST */
Node insertRec(Node root, int key)
{
  
/* If the tree is empty, return a new node */
if (root == null)
{
root = new Node(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 the (unchanged) node pointer */
return root;
}
  
// This method mainly calls InorderRec()
void inorder()
{
inorderRec(root);
}
  
// A utility function to do inorder traversal of BST
void inorderRec(Node root)
{
if (root != null)
{
inorderRec(root.left);
System.out.print(root.key + " ");
inorderRec(root.right);
}
}
  
// Driver Program to test above functions
public static void main(String[] args)
{
BinarySearchTree1 tree = new BinarySearchTree1();
  
/* Let us create following BST
50
/ \
30 70
/ \ / \
20 40 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("Inorder traversal of the given tree");
tree.inorder();
  
System.out.println("\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();
}

}