title: Efficient Way To Multiply With 7
signature: function efficientWayToMultiplyWith7($n) {
test_code: <?php
  
  
  // SOLUTION CODE 
  // ============================================
  PLACEHOLDER_CODE_BODY
  
  // TESTING CODE 
  // ============================================
  function validateSolution($actual, $expected){
      return serialize($actual) == serialize($expected);
  }
  
  function driver($n, $expected){
      try{
        if (validateSolution(PLACEHOLDER_FN_NAME($n), $expected)){
          return "PASSED";
        }
        return "FAILED";
      }
      catch (Exception $exception_obj) {
        return get_class($exception_obj);
      }
  }
  
  function main(){
      printf("TEST-0...%s\n",driver(
        41, 
        287));
      
      printf("TEST-1...%s\n",driver(
        42, 
        294));
      
      printf("TEST-2...%s\n",driver(
        62, 
        434));
      
      printf("TEST-3...%s\n",driver(
        4, 
        28));
      
      printf("TEST-4...%s\n",driver(
        31, 
        217));
      
      printf("TEST-5...%s\n",driver(
        75, 
        525));
      
      printf("TEST-6...%s\n",driver(
        5, 
        35));
      
      printf("TEST-7...%s\n",driver(
        75, 
        525));
      
      printf("TEST-8...%s\n",driver(
        85, 
        595));
      
      printf("TEST-9...%s\n",driver(
        19, 
        133));
      
  }
  
  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 );
  }