Leetcode House Robber II

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.

本题和House Robber差不多，分成两种情况来解决。第一家是不是偷了，如果偷了，那么最后一家肯定不能偷。

 class Solution(object):
     def rob(self, nums):
         """
         :type nums: List[int]
         :rtype: int
         """
         if not nums:
             return 0
         n = len(nums)
         if n == 1:
             return nums[0]
         if n == 2:
             return max(nums[0], nums[1])

         dp = [0]* n
         dp[0] = 0
         dp[1] = nums[1]

         for i in range(2,n):
             dp[i] = max(dp[i-2]+nums[i], dp[i-1])

         case1 = dp[-1]

         dp = [0]* (n-1)
         dp[0] = nums[0]
         dp[1] = nums[0]

         for i in range(2,n-1):
             dp[i] = max(dp[i-2]+nums[i], dp[i-1])

         case2 = dp[-1]

         return max(case1, case2)