# House-Robber-III

The thief has found himself a new place for his thievery again. There is only one entrance to this area, called the “root.” Besides the root, each house has one and only one parent house. After a tour, the smart thief realized that “all houses in this place forms a binary tree”. It will automatically contact the police if two directly-linked houses were broken into on the same night.

Determine the maximum amount of money the thief can rob tonight without alerting the police.

Example 1:

 3
/ \

2 3
\
3 1

Maximum amount of money the thief can rob = 3 + 3 + 1 = 7.
Example 2:

 3
/ \

4 5
/ \
1 3 1

Maximum amount of money the thief can rob = 4 + 5 = 9.

• 不偷root:这意味着我们对root的孩子没有限制（即可以偷也可以不偷）。
• root：这意味着我们不能偷root的孩子。

dicuss中的解法大都是这个思路，只是写法不同而已，有一个写法比较有趣：