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.

解题思路： 简单DP

class Solution {public:    int rob(vector<int>& nums) {        int dp1[1010], dp2[1010];        int n = nums.size();        if(n == 0) return 0;        if(n == 1) return nums[0];        dp1[0] = 0;        dp1[1] = nums[0];        for(int i = 2; i < n; ++i) {            dp1[i] = dp1[i-1];            dp1[i] = max(dp1[i], dp1[i-2] + nums[i-1]);        }        dp2[0] = 0;        dp2[1] = 0;        dp2[2] = nums[1];        for(int i = 3; i <= n; ++i) {            dp2[i] = dp2[i-1];            dp2[i] = max(dp2[i], dp2[i-2] + nums[i-1]);        }        return max(dp1[n-1], dp2[n]);    }};