private boolean checkSameParent(Node root, int a, int b) {
        if (root.left != null && root.right != null) {
            if ((root.left.data == a || root.left.data == b)
                    && (root.right.data == a || root.right.data == b)) {
                return true;
            }
        }
        return false;
    }
Little more efficient than other method since this guy does not need
another look up to see if parent is same for found nodes.
src/com/interview/tree/CousinNodes.java