comefrom: <qiyuangong>143_Reorder_List_2.py
code: def reorderList( head):
      if head is None or head.next is None:
          return
      p1, p2 = head, head.next
      while p2 and p2.next:
          p1 = p1.next
          p2 = p2.next.next
      head2 = p1.next
      p1.next = None
      p2 = head2.next
      head2.next = None
      while p2:
          temp = p2.next
          p2.next = head2
          head2 = p2
          p2 = temp
      p1, p2 = head, head2
      while p1:
          temp = p1.next
          p1.next = p2
          p1 = p1.next
          p2 = temp
masked: def sample_funcname ( var_0 ) :
      if var_0 is None or var_0.next is None :
          return
      var_3 , var_4 = var_0 , var_0.next
      while var_4 and var_4.next :
          var_3 = var_3.next
          var_4 = var_4.next.next
      var_5 = var_3.next
      var_3.next = None
      var_4 = var_5.next
      var_5.next = None
      while var_4 :
          var_6 = var_4.next
          var_4.next = var_5
          var_5 = var_4
          var_4 = var_6
      var_3 , var_4 = var_0 , var_5
      while var_3 :
          var_6 = var_3.next
          var_3.next = var_4
          var_3 = var_3.next
          var_4 = var_6
  