title: Efficient Way To Multiply With 7
signature: function efficient_way_to_multiply_with_7(n)
test_code: using Printf
  
  # SOLUTION CODE
  # ============================================
  PLACEHOLDER_CODE_BODY
  
  # TESTING CODE 
  # ============================================
  function validate_solution(actual, expected)
      return actual == expected
  end
  
  function driver(n, expected)
      try
  
          if validate_solution(PLACEHOLDER_FN_NAME(n), expected)
              return "PASSED";
          end
          return "FAILED";
      catch exception_obj
          return string(Base.typename(typeof(exception_obj)).wrapper);
      end
  end
  
  function main()
      
      result = driver(41, 287);
      @printf("TEST-0...%s\n",result);
      
      result = driver(42, 294);
      @printf("TEST-1...%s\n",result);
      
      result = driver(62, 434);
      @printf("TEST-2...%s\n",result);
      
      result = driver(4, 28);
      @printf("TEST-3...%s\n",result);
      
      result = driver(31, 217);
      @printf("TEST-4...%s\n",result);
      
      result = driver(75, 525);
      @printf("TEST-5...%s\n",result);
      
      result = driver(5, 35);
      @printf("TEST-6...%s\n",result);
      
      result = driver(75, 525);
      @printf("TEST-7...%s\n",result);
      
      result = driver(85, 595);
      @printf("TEST-8...%s\n",result);
      
      result = driver(19, 133);
      @printf("TEST-9...%s\n",result);
      
  end
  
  main()
source_py: def efficient_way_to_multiply_with_7(n):
      return ((n << 3) - n)
source_cpp: long efficient_way_to_multiply_with_7(long n) {
    return ( ( n << 3 ) - n );
  }