This is a Java Program to find minimum value of a Binary Search Tree. A binary search tree (BST), sometimes also called an ordered or sorted binary tree, is a node-based binary tree data structure which has the following properties:
i) The left subtree of a node contains only nodes with keys less than the node’s key.
ii) The right subtree of a node contains only nodes with keys greater than the node’s key.
iii) The left and right subtree must each also be a binary search tree.
iv) There must be no duplicate nodes.
Here is the source code of the Java program to minimum value of a Binary Search Tree. The Java program is successfully compiled and run on a Windows system. The program output is also shown below.
/*
* Java Program to Find the Minimum value of Binary Search Tree
*/
import java.util.Scanner;
/* Class BSTNode */
class BSTNode
{
BSTNode left, right;
int data;
/* Constructor */
public BSTNode()
{
left = null;
right = null;
data = 0;
}
/* Constructor */
public BSTNode(int n)
{
left = null;
right = null;
data = n;
}
}
/* Class BST */
class BST
{
private BSTNode root;
/* Constructor */
public BST()
{
root = null;
}
/* Functions to insert data */
public void insert(int data)
{
root = insert(root, data);
}
/* Function to insert data recursively */
private BSTNode insert(BSTNode node, int data)
{
if (node == null)
node = new BSTNode(data);
else
{
if (data <= node.data)
node.left = insert(node.left, data);
else
node.right = insert(node.right, data);
}
return node;
}
/* Function to return least value */
public int minValue()
{
return minValue(root);
}
/* Function to return least value recursively */
private int minValue(BSTNode r)
{
if (r.left == null)
return r.data;
return minValue(r.left);
}
public void inorder()
{
inorder(root);
}
private void inorder(BSTNode r)
{
if (r != null)
{
inorder(r.left);
System.out.print(r.data +" ");
inorder(r.right);
}
}
/* Function for preorder traversal */
public void preorder()
{
preorder(root);
}
private void preorder(BSTNode r)
{
if (r != null)
{
System.out.print(r.data +" ");
preorder(r.left);
preorder(r.right);
}
}
/* Function for postorder traversal */
public void postorder()
{
postorder(root);
}
private void postorder(BSTNode r)
{
if (r != null)
{
postorder(r.left);
postorder(r.right);
System.out.print(r.data +" ");
}
}
}
/* Class MinValueBST */
public class MinValueBST
{
public static void main(String[] args)
{
Scanner scan = new Scanner(System.in);
/* Creating object of BST */
BST bst = new BST();
System.out.println("Minimum Value of Binary Search Tree Test\n");
char ch;
/* Accept input */
do
{
System.out.println("Enter integer element to insert");
bst.insert( scan.nextInt() );
/* Display tree */
System.out.print("\nPost order : ");
bst.postorder();
System.out.print("\nPre order : ");
bst.preorder();
System.out.print("\nIn order : ");
bst.inorder();
System.out.println("\nDo you want to continue (Type y or n) \n");
ch = scan.next().charAt(0);
} while (ch == 'Y'|| ch == 'y');
System.out.println("\nMnimum value of the Binary Search Tree is : "+ bst.minValue());
}
}
Minimum Value of Binary Search Tree Test Enter integer element to insert 56 Post order : 56 Pre order : 56 In order : 56 Do you want to continue (Type y or n) y Enter integer element to insert 23 Post order : 23 56 Pre order : 56 23 In order : 23 56 Do you want to continue (Type y or n) y Enter integer element to insert 80 Post order : 23 80 56 Pre order : 56 23 80 In order : 23 56 80 Do you want to continue (Type y or n) y Enter integer element to insert 12 Post order : 12 23 80 56 Pre order : 56 23 12 80 In order : 12 23 56 80 Do you want to continue (Type y or n) y Enter integer element to insert 234 Post order : 12 23 234 80 56 Pre order : 56 23 12 80 234 In order : 12 23 56 80 234 Do you want to continue (Type y or n) y Enter integer element to insert 546 Post order : 12 23 546 234 80 56 Pre order : 56 23 12 80 234 546 In order : 12 23 56 80 234 546 Do you want to continue (Type y or n) y Enter integer element to insert 6 Post order : 6 12 23 546 234 80 56 Pre order : 56 23 12 6 80 234 546 In order : 6 12 23 56 80 234 546 Do you want to continue (Type y or n) y Enter integer element to insert 32 Post order : 6 12 32 23 546 234 80 56 Pre order : 56 23 12 6 32 80 234 546 In order : 6 12 23 32 56 80 234 546 Do you want to continue (Type y or n) n Mnimum value of the Binary Search Tree is : 6
