LeetCode198 House Robber

You are a professional robber planning to rob houses along a street. Each house has a certain amount of money stashed, the only constraint stopping you from robbing each of them is that adjacent houses have security system connected and it will automatically contact the police if two adjacent houses were broken into on the same night.

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.

 这个题用动态规划。一条街上人家都有一定量的财产，如果有连着两家的东西被盗就会触发警报。如果你去偷一条街的东西，如何在不触发警报的情况下，得到更多的东西。求得动态公式就是：i是到i为止得到的最多的财产。那么取得方法就是，拿第i家和第i－2家的东西(dp[i-2]+nums[i])，或者不拿i家，拿i-1家的东西(dp[i-1)。比较哪个更多一些。

 1 public class HouseRobber198 {

 2     public int rob(int[] nums){

 3         if(nums == null || nums.length ==0){

 4             return 0;

 5         }

 6         

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

 8         dp[0] = 0;

 9         dp [1] = nums[0];

10         

11         for(int i = 2; i <=nums.length; i++){

12             dp[i] = Math.max(dp[i-2]+nums[i-1], dp[i-1]);

13         }

14         

15         return dp[nums.length];

16     }

17 }