Persistent structures: Keep all versions, query any version. Rollback Union-Find: Keep history stack, only access latest or rolled-back state. | | Persistent | Rollback | |---|---|---| | Query any version | Yes | No | | Space | | | | Implementation | Complex | Simple | | Path compression | No | No | Use rollback when you only need to undo, not query arbitrary past states.
Use persistence when you need random access to version history.