programming-examples/java/Graph_Problems_Algorithms/Java Program to Implement Range Tree.java

/*This is a java program to implement Range Tree. A range tree on a set of 1-dimensional points is a balanced binary search tree on those points. The points stored in the tree are stored in the leaves of the tree; each internal node stores the largest value contained in its left subtree. A range tree on a set of points in d-dimensions is a recursively defined multi-level binary search tree. Each level of the data structure is a binary search tree on one of the d-dimensions. The first level is a binary search tree on the first of the d-coordinates. Each vertex v of this tree contains an associated structure that is a (d-1)-dimensional range tree on the last (d-1)-coordinates of the points stored in the subtree of v.*/

//This is a java program to implement Range Tree
import java.util.Random;
import java.util.Scanner;

class BSTNodes
{
    BSTNodes left, right;
    int      data;

    public BSTNodes()
    {
        left = null;
        right = null;
        data = 0;
    }

    public BSTNodes(int n)
    {
        left = null;
        right = null;
        data = n;
    }

    public void setLeft(BSTNodes n)
    {
        left = n;
    }

    public void setRight(BSTNodes n)
    {
        right = n;
    }

    public BSTNodes getLeft()
    {
        return left;
    }

    public BSTNodes getRight()
    {
        return right;
    }

    public void setData(int d)
    {
        data = d;
    }

    public int getData()
    {
        return data;
    }
}

class BST
{
    private BSTNodes root;

    public BST()
    {
        root = null;
    }

    public boolean isEmpty()
    {
        return root == null;
    }

    public void insert(int data)
    {
        root = insert(root, data);
    }

    private BSTNodes insert(BSTNodes node, int data)
    {
        if (node == null)
            node = new BSTNodes(data);
        else
            {
                if (data <= node.getData())
                    node.left = insert(node.left, data);
                else
                    node.right = insert(node.right, data);
            }
        return node;
    }

    public void delete(int k)
    {
        if (isEmpty())
            System.out.println("Tree Empty");
        else if (search(k) == false)
            System.out.println("Sorry " + k + " is not present");
        else
            {
                root = delete(root, k);
                System.out.println(k + " deleted from the tree");
            }
    }

    private BSTNodes delete(BSTNodes root, int k)
    {
        BSTNodes p, p2, n;
        if (root.getData() == k)
            {
                BSTNodes lt, rt;
                lt = root.getLeft();
                rt = root.getRight();
                if (lt == null && rt == null)
                    return null;
                else if (lt == null)
                    {
                        p = rt;
                        return p;
                    }
                else if (rt == null)
                    {
                        p = lt;
                        return p;
                    }
                else
                    {
                        p2 = rt;
                        p = rt;
                        while (p.getLeft() != null)
                            p = p.getLeft();
                        p.setLeft(lt);
                        return p2;
                    }
            }
        if (k < root.getData())
            {
                n = delete(root.getLeft(), k);
                root.setLeft(n);
            }
        else
            {
                n = delete(root.getRight(), k);
                root.setRight(n);
            }
        return root;
    }

    public int countNodes()
    {
        return countNodes(root);
    }

    private int countNodes(BSTNodes r)
    {
        if (r == null)
            return 0;
        else
            {
                int l = 1;
                l += countNodes(r.getLeft());
                l += countNodes(r.getRight());
                return l;
            }
    }

    public boolean search(int val)
    {
        return search(root, val);
    }

    private boolean search(BSTNodes r, int val)
    {
        boolean found = false;
        while ((r != null) && !found)
            {
                int rval = r.getData();
                if (val < rval)
                    r = r.getLeft();
                else if (val > rval)
                    r = r.getRight();
                else
                    {
                        found = true;
                        break;
                    }
                found = search(r, val);
            }
        return found;
    }

    public void inorder()
    {
        inorder(root);
    }

    private void inorder(BSTNodes r)
    {
        if (r != null)
            {
                inorder(r.getLeft());
                System.out.print(r.getData() + " ");
                inorder(r.getRight());
            }
    }

    public void preorder()
    {
        preorder(root);
    }

    private void preorder(BSTNodes r)
    {
        if (r != null)
            {
                System.out.print(r.getData() + " ");
                preorder(r.getLeft());
                preorder(r.getRight());
            }
    }

    public void postorder()
    {
        postorder(root);
    }

    private void postorder(BSTNodes r)
    {
        if (r != null)
            {
                postorder(r.getLeft());
                postorder(r.getRight());
                System.out.print(r.getData() + " ");
            }
    }
}

public class RangeTree
{
    public static void main(String[] args)
    {
        Scanner scan = new Scanner(System.in);
        BST bst = new BST();
        System.out
        .println("Range Tree in One Dimensional points(Binary Search Tree)\n");
        Random random = new Random();
        int N = 10;
        for (int i = 0; i < N; i++)
            bst.insert(Math.abs(random.nextInt(100)));
        char ch;
        do
            {
                System.out.print("Operations\n");
                System.out.println("1. Print Tree ");
                System.out.println("2. Delete");
                System.out.println("3. Search");
                System.out.println("4. Count Nodes");
                System.out.println("5. Check Empty");
                int choice = scan.nextInt();
                switch (choice)
                    {
                    case 1:
                        System.out.print("\nPost order : ");
                        bst.postorder();
                        System.out.print("\nPre order  : ");
                        bst.preorder();
                        System.out.print("\nIn order   : ");
                        bst.inorder();
                        break;
                    case 2:
                        System.out.println("Enter integer element to delete");
                        bst.delete(scan.nextInt());
                        break;
                    case 3:
                        System.out.println("Enter integer element to search");
                        System.out.println("Search result : "
                                           + bst.search(scan.nextInt()));
                        break;
                    case 4:
                        System.out.println("Nodes = " + bst.countNodes());
                        break;
                    case 5:
                        System.out.println("Empty status = " + bst.isEmpty());
                        break;
                    default:
                        System.out.println("Wrong Entry \n ");
                        break;
                    }
                System.out.println("\nDo you want to continue (Type y or n) \n");
                ch = scan.next().charAt(0);
            }
        while (ch == 'Y' || ch == 'y');
        scan.close();
    }
}

/*
Range Tree in One Dimensional points(Binary Search Tree)

Operations
1. Print Tree
2. Delete
3. Search
4. Count Nodes
5. Check Empty
1

Post order : 15 14 12 29 49 47 22 92 91 7
Pre order  : 7 91 22 12 14 15 47 29 49 92
In order   : 7 12 14 15 22 29 47 49 91 92
Do you want to continue (Type y or n)

y
Operations
1. Print Tree
2. Delete
3. Search
4. Count Nodes
5. Check Empty
2
Enter integer element to delete
7
7 deleted from the tree

Do you want to continue (Type y or n)

y
Operations
1. Print Tree
2. Delete
3. Search
4. Count Nodes
5. Check Empty
3
Enter integer element to search
91
Search result : true

Do you want to continue (Type y or n)

y
Operations
1. Print Tree
2. Delete
3. Search
4. Count Nodes
5. Check Empty
4
Nodes = 9

Do you want to continue (Type y or n)

y
Operations
1. Print Tree
2. Delete
3. Search
4. Count Nodes
5. Check Empty
5
Empty status = false

Do you want to continue (Type y or n)

n