static void printCommonElements ( int mat [ ] [ ] ) {
  Map < Integer , Integer > mp = new HashMap < > ( ) ;
  for ( int j = 0 ;
  j < N ;
  j ++ ) mp . put ( mat [ 0 ] [ j ] , 1 ) ;
  for ( int i = 1 ;
  i < M ;
  i ++ ) {
    for ( int j = 0 ;
    j < N ;
    j ++ ) {
      if ( mp . get ( mat [ i ] [ j ] ) != null && mp . get ( mat [ i ] [ j ] ) == i ) {
        mp . put ( mat [ i ] [ j ] , i + 1 ) ;
        if ( i == M - 1 ) System . out . print ( mat [ i ] [ j ] + " " ) ;
      }
    }
  }
}

static void printCommonElements ( int mat [ ] [ ] ) { Map < Integer , Integer > mp = new HashMap < > ( ) ; for ( int j = 0 ; j < N ; j ++ ) mp . put ( mat [ 0 ] [ j ] , 1 ) ; for ( int i = 1 ; i < M ; i ++ ) { for ( int j = 0 ; j < N ; j ++ ) { if ( mp . get ( mat [ i ] [ j ] ) != null && mp . get ( mat [ i ] [ j ] ) == i ) { mp . put ( mat [ i ] [ j ] , i + 1 ) ; if ( i == M - 1 ) System . out . print ( mat [ i ] [ j ] + " ▁ " ) ; } } } }
(method_declaration (modifiers) type: (void_type) name: (identifier) parameters: (formal_parameters (formal_parameter type: (integral_type) name: (identifier) dimensions: (dimensions))) body: (block (local_variable_declaration type: (generic_type (type_identifier) (type_arguments (type_identifier) (type_identifier))) declarator: (variable_declarator name: (identifier) value: (object_creation_expression type: (generic_type (type_identifier) (type_arguments)) arguments: (argument_list)))) (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 (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (array_access array: (array_access array: (identifier) index: (decimal_integer_literal)) index: (identifier)) (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: (block (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: (block (if_statement condition: (parenthesized_expression (binary_expression left: (binary_expression left: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (array_access array: (array_access array: (identifier) index: (identifier)) index: (identifier)))) right: (null_literal)) right: (binary_expression left: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (array_access array: (array_access array: (identifier) index: (identifier)) index: (identifier)))) right: (identifier)))) consequence: (block (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (array_access array: (array_access array: (identifier) index: (identifier)) index: (identifier)) (binary_expression left: (identifier) right: (decimal_integer_literal))))) (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (binary_expression left: (identifier) right: (decimal_integer_literal)))) consequence: (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (binary_expression left: (array_access array: (array_access array: (identifier) index: (identifier)) index: (identifier)) right: (string_literal))))))))))))))