House Robber II

Note: This is an extension of House Robber.

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 

 

public class Solution {
    public int rob(int[] nums) {
        if (nums == null || nums.length == 0) {
        	return 0;
        }
        if (nums.length == 1) {
        	return nums[0];
        }
        if (nums.length == 2) {
        	return Math.max(nums[0], nums[1]);
        }
        return Math.max(rob1(nums, 0, nums.length-2), rob1(nums, 1, nums.length-1));
    }
    public int rob1(int[] nums, int s, int e) {
        int[] dp = new int[e-s+1];
        dp[0] = nums[s];
        dp[1] = Math.max(nums[s], nums[s+1]);
        for (int i = 2; i < dp.length; i++) {
			dp[i] = Math.max(dp[i-2] + nums[s+i], dp[i-1]);
		}
        return dp[dp.length-1];
    }
}