message: Update house-robber.py
diff: class Solution(object):
  # @param num, a list of integer
  # @return an integer
  - def rob(self, num):
  - if len(num) == 0:
  - return 0
  -
  - if len(num) == 1:
  - return num[0]
  -
  - num_i, num_i_1 = max(num[1], num[0]), num[0]
  - for i in xrange(2, len(num)):
  - num_i_1, num_i_2 = num_i, num_i_1
  - num_i = max(num[i] + num_i_2, num_i_1)
  -
  - return num_i
  -
  - def rob2(self, nums):
  + def rob(self, nums):
  """
  :type nums: List[int]
  :rtype: int
  