static int countPairsWithDiffK ( int arr [ ] , int n , int k ) {
  int count = 0 , i ;
  Arrays . sort ( arr ) ;
  for ( i = 0 ;
  i < n - 1 ;
  i ++ ) if ( binarySearch ( arr , i + 1 , n - 1 , arr [ i ] + k ) != - 1 ) count ++ ;
  return count ;
}

static int countPairsWithDiffK ( int arr [ ] , int n , int k ) { int count = 0 , i ; Arrays . sort ( arr ) ; for ( i = 0 ; i < n - 1 ; i ++ ) if ( binarySearch ( arr , i + 1 , n - 1 , arr [ i ] + k ) != - 1 ) count ++ ; return count ; }
(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: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal)) declarator: (variable_declarator name: (identifier))) (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier)))) (for_statement init: (assignment_expression left: (identifier) right: (decimal_integer_literal)) condition: (binary_expression left: (identifier) right: (binary_expression left: (identifier) right: (decimal_integer_literal))) update: (update_expression (identifier)) body: (if_statement condition: (parenthesized_expression (binary_expression left: (method_invocation name: (identifier) arguments: (argument_list (identifier) (binary_expression left: (identifier) right: (decimal_integer_literal)) (binary_expression left: (identifier) right: (decimal_integer_literal)) (binary_expression left: (array_access array: (identifier) index: (identifier)) right: (identifier)))) right: (unary_expression operand: (decimal_integer_literal)))) consequence: (expression_statement (update_expression (identifier))))) (return_statement (identifier))))