int maxPath(TreeNode tree) {
if (tree == null) {
return 0;
}
if (map.containsKey(tree)) {
return map.get(tree);
}
int res = tree.val;
int left = maxPath(tree.left);
int right = maxPath(tree.right);
int maxPath = max(left, right);
res = res + maxPath > 0 ? res + maxPath : 0;
map.put(tree, res);
return res;
}
