static int countTrees ( int n ) {
  int BT [ ] = new int [ n + 1 ] ;
  for ( int i = 0 ;
  i <= n ;
  i ++ ) BT [ i ] = 0 ;
  BT [ 0 ] = BT [ 1 ] = 1 ;
  for ( int i = 2 ;
  i <= n ;
  ++ i ) for ( int j = 0 ;
  j < i ;
  j ++ ) BT [ i ] += BT [ j ] * BT [ i - j - 1 ] ;
  return BT [ n ] ;
}

static int countTrees ( int n ) { int BT [ ] = new int [ n + 1 ] ; for ( int i = 0 ; i <= n ; i ++ ) BT [ i ] = 0 ; BT [ 0 ] = BT [ 1 ] = 1 ; for ( int i = 2 ; i <= n ; ++ i ) for ( int j = 0 ; j < i ; j ++ ) BT [ i ] += BT [ j ] * BT [ i - j - 1 ] ; return BT [ n ] ; }
(method_declaration (modifiers) type: (integral_type) name: (identifier) parameters: (formal_parameters (formal_parameter type: (integral_type) name: (identifier))) body: (block (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) dimensions: (dimensions) value: (array_creation_expression type: (integral_type) dimensions: (dimensions_expr (binary_expression left: (identifier) right: (decimal_integer_literal)))))) (for_statement init: (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) condition: (binary_expression left: (identifier) right: (identifier)) update: (update_expression (identifier)) body: (expression_statement (assignment_expression left: (array_access array: (identifier) index: (identifier)) right: (decimal_integer_literal)))) (expression_statement (assignment_expression left: (array_access array: (identifier) index: (decimal_integer_literal)) right: (assignment_expression left: (array_access array: (identifier) index: (decimal_integer_literal)) right: (decimal_integer_literal)))) (for_statement init: (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) condition: (binary_expression left: (identifier) right: (identifier)) update: (update_expression (identifier)) body: (for_statement init: (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) condition: (binary_expression left: (identifier) right: (identifier)) update: (update_expression (identifier)) body: (expression_statement (assignment_expression left: (array_access array: (identifier) index: (identifier)) right: (binary_expression left: (array_access array: (identifier) index: (identifier)) right: (array_access array: (identifier) index: (binary_expression left: (binary_expression left: (identifier) right: (identifier)) right: (decimal_integer_literal)))))))) (return_statement (array_access array: (identifier) index: (identifier)))))