title: Hypercube Graph
signature: function hypercube_graph(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(28, 268435456);
      @printf("TEST-0...%s\n",result);
      
      result = driver(45, 35184372088832);
      @printf("TEST-1...%s\n",result);
      
      result = driver(41, 2199023255552);
      @printf("TEST-2...%s\n",result);
      
      result = driver(36, 68719476736);
      @printf("TEST-3...%s\n",result);
      
  end
  
  main()
source_py: def hypercube_graph(n):
      if (n == 1):
          return 2
      return (2 * hypercube_graph((n - 1)))
source_cpp: int hypercube_graph(int n) {
    if ( n == 1 ) return 2;
    return 2 * hypercube_graph ( n - 1 );
  }