/
HouseRobberIII.java
46 lines (40 loc) · 1.18 KB
/
HouseRobberIII.java
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/**
* Definition for a binary tree node.
* public class TreeNode {
* int val;
* TreeNode left;
* TreeNode right;
* TreeNode() {}
* TreeNode(int val) { this.val = val; }
* TreeNode(int val, TreeNode left, TreeNode right) {
* this.val = val;
* this.left = left;
* this.right = right;
* }
* }
*/
// https://leetcode.com/problems/house-robber-iii
class Solution {
public int rob(TreeNode root) {
return max(root, false, new HashMap<>());
}
int max(TreeNode root, boolean skip, Map<Pair<TreeNode, Boolean>, Integer> memo) {
if (root == null) {
return 0;
}
Pair<TreeNode, Boolean> p = new Pair<>(root, skip);
if (memo.containsKey(p)) {
return memo.get(p);
}
if (skip) {
return max(root.left, false, memo) + max(root.right, false, memo);
}
// We can now choose to skip this or not
int res = Math.max(
root.val + max(root.left, true, memo) + max(root.right, true, memo),
max(root.left, false, memo) + max(root.right, false, memo)
);
memo.put(p, res);
return res;
}
}