title: Sum Subsets Set Formed First N Natural Numbers
signature: function sum_subsets_set_formed_first_n_natural_numbers(n)
test_code: using Printf
  
  # SOLUTION CODE
  # ============================================
  PLACEHOLDER_CODE_BODY
  
  # TESTING CODE 
  # ============================================
  function validate_solution(actual, expected)
      return abs(actual - expected) < 1e-09
  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(26, 11777605632.0);
      @printf("TEST-0...%s\n",result);
      
      result = driver(35, 10823317585920.0);
      @printf("TEST-1...%s\n",result);
      
      result = driver(34, 5111011082240.0);
      @printf("TEST-2...%s\n",result);
      
      result = driver(22, 530579456.0);
      @printf("TEST-3...%s\n",result);
      
      result = driver(3, 24.0);
      @printf("TEST-4...%s\n",result);
      
      result = driver(25, 5452595200.0);
      @printf("TEST-5...%s\n",result);
      
      result = driver(22, 530579456.0);
      @printf("TEST-6...%s\n",result);
      
  end
  
  main()
source_py: def sum_subsets_set_formed_first_n_natural_numbers(n):
      return (((n * (n + 1)) / 2) * (1 << (n - 1)))
source_cpp: unsigned long long sum_subsets_set_formed_first_n_natural_numbers(int n) {
    return ( n * ( n + 1 ) / 2 ) * ( 1 << ( n - 1 ) );
  }