COMBHelper: A Neural Approach to Reduce Search Space for Graph Combinatorial Problems
This work addresses efficiency issues in combinatorial optimization for applications like traffic optimization and job matching, though it is incremental as it builds on existing algorithms with neural enhancements.
The paper tackles the problem of large search spaces in graph combinatorial optimization, which slows down traditional algorithms, by introducing COMBHelper, a neural method that uses a Graph Neural Network to prune the search space, resulting in at least a 2x speedup for these algorithms.
Combinatorial Optimization (CO) problems over graphs appear routinely in many applications such as in optimizing traffic, viral marketing in social networks, and matching for job allocation. Due to their combinatorial nature, these problems are often NP-hard. Existing approximation algorithms and heuristics rely on the search space to find the solutions and become time-consuming when this space is large. In this paper, we design a neural method called COMBHelper to reduce this space and thus improve the efficiency of the traditional CO algorithms based on node selection. Specifically, it employs a Graph Neural Network (GNN) to identify promising nodes for the solution set. This pruned search space is then fed to the traditional CO algorithms. COMBHelper also uses a Knowledge Distillation (KD) module and a problem-specific boosting module to bring further efficiency and efficacy. Our extensive experiments show that the traditional CO algorithms with COMBHelper are at least 2 times faster than their original versions.