func_code: def reverse(a):
      i = 0
      j = len(a)
      if j % 2 == 0:
          while i < len(a) / 2:
              tmp = a[j]
              a[j] = a[i]
              a[i] = tmp
              i = i + 1
              j = j - 1
      else:
          while i < len(a) / 2 + 1:
              tmp = a[j]
              a[j] = a[i]
              a[i] = tmp
              i = i + 1
              j = j - 1