static int countKdivPairs ( int A [ ] , int n , int K ) {
  int [ ] freq = new int [ K ] ;
  int ans = 0 ;
  for ( int i = 0 ;
  i < n ;
  i ++ ) {
    int rem = A [ i ] % K ;
    if ( rem != 0 ) ans += freq [ K - rem ] ;
    else ans += freq [ 0 ] ;
    freq [ rem ] ++ ;
  }
  return ans ;
}

static int countKdivPairs ( int A [ ] , int n , int K ) { int [ ] freq = new int [ K ] ; int ans = 0 ; for ( int i = 0 ; i < n ; i ++ ) { int rem = A [ i ] % K ; if ( rem != 0 ) ans += freq [ K - rem ] ; else ans += freq [ 0 ] ; freq [ rem ] ++ ; } return ans ; }
(method_declaration (modifiers) type: (integral_type) name: (identifier) parameters: (formal_parameters (formal_parameter type: (integral_type) name: (identifier) dimensions: (dimensions)) (formal_parameter type: (integral_type) name: (identifier)) (formal_parameter type: (integral_type) name: (identifier))) body: (block (local_variable_declaration type: (array_type element: (integral_type) dimensions: (dimensions)) declarator: (variable_declarator name: (identifier) value: (array_creation_expression type: (integral_type) dimensions: (dimensions_expr (identifier))))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (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 (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (binary_expression left: (array_access array: (identifier) index: (identifier)) right: (identifier)))) (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (decimal_integer_literal))) consequence: (expression_statement (assignment_expression left: (identifier) right: (array_access array: (identifier) index: (binary_expression left: (identifier) right: (identifier))))) alternative: (expression_statement (assignment_expression left: (identifier) right: (array_access array: (identifier) index: (decimal_integer_literal))))) (expression_statement (update_expression (array_access array: (identifier) index: (identifier)))))) (return_statement (identifier))))