CheckIfTwoNodesAreSiblings.java

public class CheckIfTwoNodesAreSiblings {
	public boolean sameParents(Node root, Node x, Node y){
		if(root==null) return false;

		return ((root.left==x && root.right==y) ||root.left==y && root.right==x ||sameParents(root.left,x,y) || sameParents(root.right,x,y));
	}
	public static void main (String[] args) throws java.lang.Exception
	{
		Node root = new Node(1);
		Node x1 = new Node(2);
		Node y1 = new Node(3);
		root.left = x1;
		root.right = y1;
		root.left.left = new Node(4);
		root.right.left = new Node(6);
		Node x2 = new Node(7);
		Node y2 = new Node(9);
		root.right.left.left = new Node(8);
		root.right.left.right = y2;
		root.left.left.left = x2;

		CheckIfTwoNodesAreSiblings i  = new CheckIfTwoNodesAreSiblings();
		System.out.println("Node " + x1.data + " and Node " + y1.data + " are siblings??? " + i.sameParents(root, x1, y1));
		System.out.println("Node " + x2.data + " and Node " + y2.data + " are siblings??? " + i.sameParents(root, x2, y2));
	}
}
class Node{
	int data;
	Node left;
	Node right;
	public Node(int data){
		this.data = data;
		this.left = null;
		this.right = null;
	}
}