public Node decode(Result r) {
        AtomicInteger x = new AtomicInteger(0);
        AtomicInteger y = new AtomicInteger(0);
        return decode(r, x, y);
    }
Date 11/01/2015
 @author Tushar

 Encode and decode binary tree using succinct encoding technique

References - http://www.geeksforgeeks.org/succinct-encoding-of-binary-tree/
https://en.wikipedia.org/wiki/Binary_tree#Succinct_encodings
src/com/interview/tree/SuccinctTree.java