Solution2.java

import java.util.Arrays;

/// 198. House Robber
/// https://leetcode.com/problems/house-robber/description/
/// 动态规划
/// 时间复杂度: O(n^2)
/// 空间复杂度: O(n)
public class Solution2 {

    public int rob(int[] nums) {

        int n = nums.length;
        if(n == 0)
            return 0;

        // memo[i] 表示考虑抢劫 nums[i...n) 所能获得的最大收益
        int[] memo = new int[nums.length];
        memo[n - 1] = nums[n - 1];
        for(int i = n - 2 ; i >= 0 ; i --)
            for (int j = i; j < n; j++)
                memo[i] = Math.max( memo[i],
                                    nums[j] + (j + 2 < n ? memo[j + 2] : 0));

        return memo[0];
    }

    public static void main(String[] args) {

        int nums[] = {2, 1};
        System.out.println((new Solution2()).rob(nums));
    }
}