title: Hypercube Graph
signature: def hypercubeGraph(n: Int) = {
test_code: import scala.collection.mutable.HashMap
  import scala.collection.immutable.HashSet
  
  
  // SOLUTION CODE
  // ============================================
  PLACEHOLDER_CODE_BODY
  
  
  // TESTING CODE 
  // ============================================
  def validateSolution(actual: Long , expected: Long): Boolean = {
      actual.toString == expected.toString
  }
  
  def driver(n: Int, expected: Long): String = {
      try {
          if (validateSolution(PLACEHOLDER_FN_NAME(n),expected)) {
              "PASSED"
          } else{
              "FAILED"
          }
      }catch{
          case e: Exception => {e.getClass.getName}
      }
  
  }
  object QuestionEvaluator extends App {
  
      println(s"TEST-0...${driver(
        28, 
        268435456L    
      )}")   
  
  
      println(s"TEST-1...${driver(
        45, 
        35184372088832L    
      )}")   
  
  
      println(s"TEST-2...${driver(
        41, 
        2199023255552L    
      )}")   
  
  
      println(s"TEST-3...${driver(
        36, 
        68719476736L    
      )}")   
  
  }
  
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 );
  }