{"type":"ScholarlyArticle","title":"Efficient Optimization of Fixed-Length Paths","authors":[{"name":"Martino Ciaperoni","slug":"martino-ciaperoni","given":"Martino","family":"Ciaperoni","affiliation":""},{"name":"Nikolaos Tziavelis","slug":"nikolaos-tziavelis","given":"Nikolaos","family":"Tziavelis","affiliation":""},{"name":"Panagiotis Karras","slug":"panagiotis-karras","given":"Panagiotis","family":"Karras","affiliation":""}],"abstract":"Optimization problems such as Viterbi decoding and V-optimal histogram construction seek a path of exact length L through a state space that minimizes a cost function. These problems are traditionally solved using dynamic programming (DP). A best-first-search (BFS) solution is also applicable, yet requires maintaining a priority queue. In all cases, memory usage grows linearly with both state space size and path length. In this paper, we propose CompactBFS, a framework that limits the growth of the BFS priority queue to space-efficiently determine the exact optimal cost for a fixed-length path and then constructs such a path by a divide-and-conquer strategy that eliminates the memory overhead. We apply CompactBFS to Viterbi decoding, which remains relevant to speech recognition, and V-optimal histogram construction. Our experimental results demonstrate significant gains over state-of-the-art solutions in runtime and memory consumption.","doi":"10.24963/ijcai.2026/245","url":"https://ijcai.org/proceedings/2026/245","pdf":"https://ijcai.org/proceedings/2026/0245.pdf","markdown":"https://ijcai.org/proceedings/2026/245.md","bibtex":"https://ijcai.org/proceedings/2026/bibtex/245","volume":{"slug":"2026","title":"Proceedings of the Thirty-Fifth International Joint Conference on Artificial Intelligence","short_title":"IJCAI 2026","url":"https://ijcai.org/proceedings/2026/","year":2026,"location":"Bremen, Germany","dates":"15-21 August 2026","editors":"Diego Calvanese","isbn":"978-1-956792-09-6","publisher":"International Joint Conferences on Artificial Intelligence Organization","doi_prefix":"10.24963/ijcai.2026"},"section":"Constraint Satisfaction and Optimization","track":"Main Track","number":245,"pages":{"first":2199,"last":2207},"keywords":["Data Mining: Mining graphs","Data Mining: Big data and scalability","Natural Language Processing: Speech","Constraint Satisfaction and Optimization: Constraint optimization problems","Search: Combinatorial search and optimisation"],"videos":[],"references":[],"license_note":"Copyright International Joint Conferences on Artificial Intelligence."}