Papers › Run Compressed Rank/Select for Large Alphabets
Run Compressed Rank/Select for Large Alphabets
José Fuentes-Sepúlveda, Juha Kärkkäinen, Dmitry Kosolobov, Simon J. Puglisi
The archive published only this paper's code-link row. Authors, date and abstract are from arXiv's metadata (CC0), read from the Kaggle arXiv metadata snapshot of 2026-09-12 where its title matched the archive's; the title is the archive's.
Given a string of length n that is composed of r runs of letters from the alphabet {0,1,…,σ-1} such that 2 ≤σ≤r, we describe a data structure that, provided r ≤n / log^(ω(1)) n, stores the string in rlognσ/r + o(rlognσ/r) bits and supports select and access queries in O(log(log(n/r))/loglogn) time and rank queries in O(log(log(nσ/r))/loglogn) time. We show that rlog(n(σ-1))/r - O(logn/r) bits are necessary for any such data structure and, thus, our solution is succinct. We also describe a data structure that uses (1 + ϵ)rlognσ/r + O(r) bits, where ϵ> 0 is an arbitrary constant, with the same query times but without the restriction r ≤n / log^(ω(1)) n. By simple reductions to the colored predecessor problem, we show that the query times are optimal in the important case r ≥2^(log^δ n), for an arbitrary constant δ> 0. We implement our solution and compare it with the state of the art, showing that the closest competitors consume 31-46% more space.
Code
Repository list and official/mentioned flags are the archive's, frozen 2025-07-28. Reachability, where shown, is from one Syntology probe window (2026-09-16 to 2026-09-18); repositories not probed show nothing. GitHub stars are not tracked.
Code Syntology ran Syntology
Not run by Syntology. Nothing on this page verifies that the listed code works.
Results from the paper archive 2025-07-28
No leaderboard rows for this paper in the archive.
Report a problem or propose a change · a person checks every report against the paper or source before anything changes; decisions are listed on /corrections