arXiv · 2607.23393
Key-Interval A*: Accelerating Grid Pathfinding via Structural Abstraction
Abstract
Existing exact methods for 4-connected grid pathfinding reduce online search, but often either retain fine-grained search states or require substantial preprocessing. This paper presents Key-Interval A* (KIA*), an optimal pathfinding algorithm that uses lightweight preprocessing to construct and search over a compact interval-level abstraction of free space. KIA* represents free space using intervals: maximal contiguous runs of traversable cells. It extracts key intervals that capture structural boundary changes and connects them through contiguous non-key regions. KIA* then performs A*-style search on the resulting key-interval graph and constructively reconstructs grid paths from interval chains, without cell-level local search. We prove the completeness and optimality of KIA* on 4-connected grids. Experiments on standard benchmarks show that KIA* preserves exact shortest-path lengths and achieves the fastest runtime on seven of eight benchmark groups, with the largest gains on structured and game maps.
Explore related subjects
Keep this discovery
Explore connections, maps & timelines
Taiquan Sui. 2026-07-25. Key-Interval A*: Accelerating Grid Pathfinding via Structural Abstraction. https://arxiv.org/abs/2607.23393
Cite the original work for its findings. Save a collection to share your selection of sources.