title: Add Two Numbers Without Using Arithmetic Operators
signature: addTwoNumbersWithoutUsingArithmeticOperators(x, y) {
test_code: import 'dart:convert';
  
  // SOLUTION CODE
  // ============================================
  PLACEHOLDER_CODE_BODY
  
  // TESTING CODE 
  // ============================================
  bool validateSolution(int actual, int expected){
      return actual.toString() == expected.toString();
  }
  
  String driver(x, y, int expected){
      try
      {
          if (validateSolution(PLACEHOLDER_FN_NAME(x, y), expected)){
              return "PASSED";
          }
          return "FAILED";
      }catch(exception_object){
          return exception_object.runtimeType.toString();
      }
  }
  
  int main() {
  
      print("TEST-0...${driver(
          56, 60, 
          116)
      }");
  
      print("TEST-1...${driver(
          17, 44, 
          61)
      }");
  
      print("TEST-2...${driver(
          73, 96, 
          169)
      }");
  
      print("TEST-3...${driver(
          75, 3, 
          78)
      }");
  
      print("TEST-4...${driver(
          27, 54, 
          81)
      }");
  
      print("TEST-5...${driver(
          61, 1, 
          62)
      }");
  
      print("TEST-6...${driver(
          65, 63, 
          128)
      }");
  
      print("TEST-7...${driver(
          22, 19, 
          41)
      }");
  
      print("TEST-8...${driver(
          61, 9, 
          70)
      }");
  
      print("TEST-9...${driver(
          97, 23, 
          120)
      }");
  
      return 0;
  }
source_py: def add_two_numbers_without_using_arithmetic_operators(x, y):
      while (y != 0):
          carry = (x & y)
          x = (x ^ y)
          y = (carry << 1)
      return x
source_cpp: int add_two_numbers_without_using_arithmetic_operators(int x, int y) {
    while ( y != 0 ) {
      int carry = x & y;
      x = x ^ y;
      y = carry << 1;
    }
    return x;
  }