Build the PrimitiveEasy
Subtree of Another Tree
Write `is_subtree(root, sub)` returning `True` when `sub` appears as a subtree of `root` — matching a node and *all* of its descendants exactly.
This is two problems: an exact same-tree comparison, and trying it at every node. Say the complexity out loud: O(n * m). An empty `sub` is a subtree of anything, and a partial match is not a match — those two cases are where wrong answers show up.
What to expect: A timer starts when you begin. Edit the starter code, run it against the test suite as many times as you like, then finish when you're done. The reference solution and interviewer follow-up questions unlock only after you finish.