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.
Explanation: Maximum amount of money the thief can rob = 3 + 3 + 1 = 7.
/ \ \
1 3 1
Explanation: Maximum amount of money the thief can rob = 4 + 5 = 9.
# Definition for a binary tree node. # class TreeNode: # def __init__(self, x): # self.val = x # self.left = None # self.right = None class Solution: def rob(self, root: TreeNode) -> int: def superrob(node): # returns tuple of size two (now, later) # now: max money earned if input node is robbed # later: max money earned if input node is not robbed # base case if not node: return (0, 0) # get values left, right = superrob(node.left), superrob(node.right) # rob now now = node.val + left + right # rob later later = max(left) + max(right) return (now, later) return max(superrob(root))