for left and right subtree height allowed values for ( lh - rh ) are 1 , - 1 , 0
lh = height ( root . left ) NEW_LINE rh = height ( root . right ) NEW_LINE if ( abs ( lh - rh ) <= 1 ) and isBalanced ( root . left ) is True and isBalanced ( root . right ) is True : NEW_LINE INDENT return True NEW_LINE DEDENT