Algorithm & Data Structure

Recent breakthroughs in algorithms, data structures, and theoretical CS.

zSort: Stable Distribution Sort using Z-Score Partitioning

arXiv:2605.14419 · May 2026

An adaptive stable sorting algorithm using z-score-based partitioning that avoids the traditional "stability tax." Achieves 3x–4.5x speedups over comparison-based stable sorts while matching the throughput of unstable algorithms.

GSAR-Tree: Global Structure-Aware R-Tree using Deep RL and Self-Play

ScienceDirect · 2026

Replaces heuristic R-Tree construction with deep reinforcement learning + self-play. The RL agent learns globally optimal insertion decisions, reducing node accesses by 37.9%–1193.8% on real-world OpenStreetMap data.

Zip-zip Trees: Making Zip Trees More Balanced, Biased, Compact, or Persistent

Algorithmica · Jun 2026 · Tarjan et al.

Overcomes key bias in zip trees using only O(log log n) bits per node. Matches treap expected depth, with support for history independence, biased variants, and partial persistence — all with O(n) space overhead.