Knowledge quizzes
Test your understanding and review explained answers.
Block, threshold, disjoint, and line index contracts
Check four range-index invariants, costs, and boundaries.
Coordinate ranks, order selection, offline windows, and grid sums
Check multiplicity, offline order, and rectangle boundaries.
Postings, positions, trigrams, and lexicon contracts
Check four text-index structures and their exact query meanings.
Eviction, expiry, handles, and heap contracts
Check frequency ties, stale deadlines, recycled slots, and wider heap paths.
Frequent items, distinct counts, and stream samples
Check bounded candidates, count errors, register merges, and sampling probability.
Approximate membership under mutation
Test balanced deletion, generation growth, blocked probes, and fingerprint rollback.
Priority-queue merge, monotonicity, and extremes
Check tree carries, pairing passes, radix buckets, and stale twin-heap entries.
Spatial grids, quadtrees, boxes, and code ranges
Check moving-cell ownership, region boundaries, box pruning, and Morton intervals.
Gap buffers, ropes, and blocked sequences
Check cursor movement, path sharing, block ownership, and cumulative offsets.
Compact integer sets, postings, and tries
Check encoding boundaries, exact membership, checkpoint seeks, and term flags.
Arenas, free spans, buddies, and slab slots
Check lifetime, contiguous fit, merge rules, and stale-handle rejection.
Hash tries, term trees, routes, and directories
Check collision identity, terminal terms, longest prefixes, and split rules.