[LeetCode] 337. House Robber III

轉自LeetCode

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.

<Solution>

198. House Robber 的衍生題，資料結構變成 binary tree

想法如下

• 每個節點都有選與不選兩種狀況。如果該節點被選，則它的兩個子節點就不能被選；反之，他兩個子節點可以被選

• 樹的資料結構，加上有選與不選的狀況，使用 recursive 來解

• 回傳一個 int[]，第一個位置放包含該節點的最佳解，第二個位置放不包含該節點的最佳解

code 如下

Java(參考解法)

kotlin