Note that in traversing a tree, at any point in the traversal, a node can be the root of a new subtree.

注意在穿越树中，任何的点，一个节点都可能是新的子树的根。

youdao

Note that in traversing a tree, at any point in the traversal, a node can be the root of a new subtree.

注意在穿越树中，任何的点，一个节点都可能是新的子树的根。

youdao