SHIELD: Multi-task Multi-distribution Vehicle Routing Solver with Sparsity and Hierarchy
To address the weak generalization capability of base models in multi-task, multi-distribution vehicle routing problems (MTMDVRP) and their difficulty adapting to heterogeneous customer distributions in real-world scenarios, this paper proposes the first unified solution framework. Methodologically, it innovatively integrates sparse computation (Mixture-of-Depths) with context-aware hierarchical clustering to establish a dual inductive bias mechanism, enabling adaptive representation learning across tasks and distributions; it further employs a deep decoder architecture to dynamically allocate computational resources and model spatial hierarchical structures. Extensive experiments across nine real-world maps and 144 VRP variants demonstrate that our approach significantly outperforms existing state-of-the-art methods, achieving substantial gains in generalization to unseen tasks and unknown distributions. This work establishes a scalable, robust, and general-purpose paradigm for complex real-world routing optimization.