A*+BFHS: A Hybrid Heuristic Search Algorithm

No. 9: AAAI-22 Technical Tracks 9

Volume

Proceedings of the AAAI Conference on Artificial Intelligence, 36

AAAI Technical Track on Search and Optimization

We present a new algorithm called A*+BFHS for solving problems with unit-cost operators where A* and IDA* fail due to memory limitations and/or the existence of many distinct paths between the same pair of nodes. A*+BFHS is based on A* and breadth-first heuristic search (BFHS). A*+BFHS combines advantages from both algorithms, namely A*'s node ordering, BFHS's memory savings, and both algorithms' duplicate detection. On easy problems, A*+BFHS behaves the same as A*. On hard problems, it is slower than A* but saves a large amount of memory. Compared to BFIDA*, A*+BFHS reduces the search time and/or memory requirement by several times on a variety of planning domains.

10.1609/aaai.v36i9.21253