Problem

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.

使用拆分数组的方法

    public int rob(int[] nums) {
        if (nums == null || nums.length == 0) {
            return 0;
        }
        if (nums.length == 1) {
            return nums[0];
        }

        int[] dp = new int[nums.length + 1];
        dp[0] = 0;
        dp[1] = nums[0];

        for (int i = 2; i < nums.length; i++) {
            dp[i] = Math.max(dp[i - 1], dp[i - 2] + nums[i - 1]);
        }

        int res1 = dp[nums.length - 1];
        dp[1] = nums[1];

        for (int i = 2; i < nums.length; i++) {
            dp[i] = Math.max(dp[i - 1], dp[i - 2] + nums[i]);
        }

        return Math.max(res1, dp[nums.length - 1]);
    }