
- Use `Deque` and `ArrayDeque` instead of `Stack` - Use presized `ArrayList` instead of a dynamic `LinkedList` when possible - Don't create empty `HashSet` when `Collections.emptySet()` suffices - User `Collections.singletonList()` were apropriate
- Use `Deque` and `ArrayDeque` instead of `Stack` - Use presized `ArrayList` instead of a dynamic `LinkedList` when possible - Don't create empty `HashSet` when `Collections.emptySet()` suffices - User `Collections.singletonList()` were apropriate