House Robber 2

After robbing those houses on that street, the thief has found himself a new place for his thievery so that he will not get too much attention. This time, all houses at this place are arranged in a circle. That means the first house is the neighbor of the last one. Meanwhile, the security system for these houses remain the same as for those in the previous street.

Given a list of non-negative integers representing the amount of money of each house, determine the maximum amount of money you can rob tonight without alerting the police.

Solution

class Solution(object):
    def rob(self, nums):
        """
        :type nums: List[int]
        :rtype: int
        """
        def rob(nums):
            now = prev = 0
            for n in nums:
                now, prev = max(now, prev + n), now
            return now
        return max(rob(nums[len(nums) != 1:]), rob(nums[:-1]))