Large Language Model-Enhanced Algorithm Selection: Towards Comprehensive Algorithm Representation
Xingyu Wu, Yan Zhong, Jibin Wu, Bingbing Jiang, Kay Chen Tan
TL;DR
The paper tackles the challenge of algorithm selection by introducing AS-LLM, a framework that uses pretrained Large Language Models to extract rich, high-dimensional algorithm features from code or descriptive text and pairs them with problem representations via separate encoders. A feature-selection module and a cosine-based fusion/decision stage enable robust matching between problems and candidate algorithms, addressing the bidirectional nature of the problem-algorithm relationship. The authors derive a theoretical upper bound on model complexity through an inductive Rademacher complexity analysis and demonstrate empirical gains on the ASlib benchmark, with ablations confirming the value of algorithm features and feature selection. The work suggests that leveraging algorithm features via LLMs can improve generalization, particularly with larger algorithm portfolios, while also outlining data-quality and scalability considerations for real-world deployment.
Abstract
Algorithm selection, a critical process of automated machine learning, aims to identify the most suitable algorithm for solving a specific problem prior to execution. Mainstream algorithm selection techniques heavily rely on problem features, while the role of algorithm features remains largely unexplored. Due to the intrinsic complexity of algorithms, effective methods for universally extracting algorithm information are lacking. This paper takes a significant step towards bridging this gap by introducing Large Language Models (LLMs) into algorithm selection for the first time. By comprehending the code text, LLM not only captures the structural and semantic aspects of the algorithm, but also demonstrates contextual awareness and library function understanding. The high-dimensional algorithm representation extracted by LLM, after undergoing a feature selection module, is combined with the problem representation and passed to the similarity calculation module. The selected algorithm is determined by the matching degree between a given problem and different algorithms. Extensive experiments validate the performance superiority of the proposed model and the efficacy of each key module. Furthermore, we present a theoretical upper bound on model complexity, showcasing the influence of algorithm representation and feature selection modules. This provides valuable theoretical guidance for the practical implementation of our method.
