from collections import deque class Solution: def xorTree(self, root: TreeNode, op: List[List[int]]) -> TreeNode: hashdict = self.cengxu(root) for idx, number in op: node = hashdict[idx] self.singlexor(node, number) return root def singlexor(self, node, number): if not node: return node.val = node.val ^ number self.singlexor(node.left, number) self.singlexor(node.right, number) return def cengxu(self, root): deq = deque([root]) ans = {} while deq: size = len(deq) path = {} for _ in range(size): node = deq.popleft() path[node.val] = node node.val = 0 if node.left: deq.append(node.left) if node.right: deq.append(node.right) ans.update(path) return ans