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AVL Tree Insertion.java
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AVL Tree Insertion.java
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class Solution {
public Node insertToAVL(Node node, int data) {
if (node == null) {
return new Node(data);
}
if (node.data > data) {
node.left = insertToAVL(node.left, data);
}
else if (node.data < data) {
node.right = insertToAVL(node.right, data);
}
node.height = Math.max(height(node.left), height(node.right)) + 1;
int diff = height(node.left) - height(node.right);
if (diff > 1) { // Left subtree is higher
if (data < node.left.data) {
return rightRotate(node);
}
else if (data > node.left.data) { // LR rotation
node.left = leftRotate(node.left);
return rightRotate(node);
}
}
else if (diff < -1) { // Right subtree is higher
if (data < node.right.data) { // RL rotation
node.right = rightRotate(node.right);
return leftRotate(node);
}
else if (data > node.right.data) {
return leftRotate(node);
}
}
return node;
}
public Node leftRotate(Node a) {
Node b = a.right;
Node t2 = b.left;
b.left = a;
a.right = t2;
a.height = Math.max(height(a.left), height(a.right)) + 1;
b.height = Math.max(height(b.left), height(b.right)) + 1;
return b;
}
public Node rightRotate(Node a) {
Node b = a.left;
Node t2 = b.right;
b.right = a;
a.left = t2;
a.height = Math.max(height(a.left), height(a.right)) + 1;
b.height = Math.max(height(b.left), height(b.right)) + 1;
return b;
}
public int height(Node node) {
if (node == null) {
return 0;
}
else {
return node.height;
}
}
}