198. 打家劫舍
public int rob(int[] nums) { final int N = nums == null ? 0 : nums.length; if (N <= 0) { return 0; } int[] dp = new int[N]; dp[0] = Math.max(0, nums[0]); if (N == 1) { return dp[0]; } dp[1] = Math.max(0, Math.max(nums[0], nums[1])); for (int i = 2; i < N; i++) { dp[i] = Math.max(dp[i - 1], dp[i - 2] + nums[i]); } return dp[N - 1]; }