Code:
import java.util.Scanner;
class SBBST
{
SBBST left, right;
int data;
int height;
public SBBST()
{
left = null;
right = null;
data = 0;
height = 0;
}
public SBBST(int n)
{
left = null;
right = null;
data = n;
height = 0;
}
}
class SelfBalancingBinarySearchTree
{
private SBBST root;
public SelfBalancingBinarySearchTree()
{
root = null;
}
public boolean isEmpty()
{
return root == null;
}
public void clear()
{
root = null;
}
public void insert(int data)
{
root = insert(data, root);
}
private int height(SBBST t)
{
return t == null ? -1 : t.height;
}
private int max(int lhs, int rhs)
{
return lhs > rhs ? lhs : rhs;
}
private SBBST insert(int x, SBBST t)
{
if (t == null)
t = new SBBST(x);
else if (x < t.data)
{
t.left = insert(x, t.left);
if (height(t.left) - height(t.right) == 2)
if (x < t.left.data)
t = rotateWithLeftChild(t);
else
t = doubleWithLeftChild(t);
} else if (x > t.data)
{
t.right = insert(x, t.right);
if (height(t.right) - height(t.left) == 2)
if (x > t.right.data)
t = rotateWithRightChild(t);
else
t = doubleWithRightChild(t);
} else
;
t.height = max(height(t.left), height(t.right)) + 1;
return t;
}
private SBBST rotateWithLeftChild(SBBST k2)
{
System.out.println("Left Rotation Performed");
SBBST k1 = k2.left;
k2.left = k1.right;
k1.right = k2;
k2.height = max(height(k2.left), height(k2.right)) + 1;
k1.height = max(height(k1.left), k2.height) + 1;
return k1;
}
private SBBST rotateWithRightChild(SBBST k1)
{
//System.out.println("Right Rotation Performed");
SBBST k2 = k1.right;
k1.right = k2.left;
k2.left = k1;
k1.height = max(height(k1.left), height(k1.right)) + 1;
k2.height = max(height(k2.right), k1.height) + 1;
return k2;
}
private SBBST doubleWithLeftChild(SBBST k3)
{
System.out.println("Left Rotation Performed");
k3.left = rotateWithRightChild(k3.left);
return rotateWithLeftChild(k3);
}
private SBBST doubleWithRightChild(SBBST k1)
{
//System.out.println("Right Rotation Performed");
k1.right = rotateWithLeftChild(k1.right);
return rotateWithRightChild(k1);
}
public int countNodes()
{
return countNodes(root);
}
private int countNodes(SBBST r)
{
if (r == null)
return 0;
else
{
int l = 1;
l += countNodes(r.left);
l += countNodes(r.right);
return l;
}
}
public boolean search(int val)
{
return search(root, val);
}
private boolean search(SBBST r, int val)
{
boolean found = false;
while ((r != null) && !found)
{
int rval = r.data;
if (val < rval)
r = r.left;
else if (val > rval)
r = r.right;
else
{
found = true;
break;
}
found = search(r, val);
}
return found;
}
public void inorder()
{
inorder(root);
}
private void inorder(SBBST r)
{
if (r != null)
{
inorder(r.left);
System.out.print(r.data + " ");
inorder(r.right);
}
}
public void preorder()
{
preorder(root);
}
private void preorder(SBBST r)
{
if (r != null)
{
System.out.print(r.data + " ");
preorder(r.left);
preorder(r.right);
}
}
public void postorder()
{
postorder(root);
}
private void postorder(SBBST r)
{
if (r != null)
{
postorder(r.left);
postorder(r.right);
System.out.print(r.data + " ");
}
}
}
public class Left_Rotation_BST
{
public static void main(String[] args)
{
Scanner scan = new Scanner(System.in);
SelfBalancingBinarySearchTree sbbst = new SelfBalancingBinarySearchTree();
System.out.println("Self Balancing Tree\n");
System.out.println("Inset first 10 Elements");
int N = 10;
for (int i = 0; i < N; i++)
{
sbbst.insert(scan.nextInt());
System.out.println("\nPre-order :");
sbbst.preorder();
System.out.println("\nIn-order :");
sbbst.inorder();
System.out.println("\nPost-order :");
sbbst.postorder();
System.out.println();
}
scan.close();
}
}
Output:
Self Balancing Tree
Inset first 10 Elements
10
Pre-order :
10
In-order :
10
Post-order :
10
9
Pre-order :
10 9
In-order :
9 10
Post-order :
9 10
8
Left Rotation Performed
Pre-order :
9 8 10
In-order :
8 9 10
Post-order :
8 10 9
7
Pre-order :
9 8 7 10
In-order :
7 8 9 10
Post-order :
7 8 10 9
6
Left Rotation Performed
Pre-order :
9 7 6 8 10
In-order :
6 7 8 9 10
Post-order :
6 8 7 10 9
5
Left Rotation Performed
Pre-order :
7 6 5 9 8 10
In-order :
5 6 7 8 9 10
Post-order :
5 6 8 10 9 7
4
Left Rotation Performed
Pre-order :
7 5 4 6 9 8 10
In-order :
4 5 6 7 8 9 10
Post-order :
4 6 5 8 10 9 7
3
Pre-order :
7 5 4 3 6 9 8 10
In-order :
3 4 5 6 7 8 9 10
Post-order :
3 4 6 5 8 10 9 7
2
Left Rotation Performed
Pre-order :
7 5 3 2 4 6 9 8 10
In-order :
2 3 4 5 6 7 8 9 10
Post-order :
2 4 3 6 5 8 10 9 7
1
Left Rotation Performed
Pre-order :
7 3 2 1 5 4 6 9 8 10
In-order :
1 2 3 4 5 6 7 8 9 10
Post-order :
1 2 4 6 5 3 8 10 9 7
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