Reinforcement Learning Based Monte Carlo Tree Search for Temporal Path Discovery

An Attributed Dynamic Graph (ADG) contains multiple dynamic attributes associated with each edge. In ADG based applications, people usually can specify multiple constrains in the attributes to illustrate their requirements, such as the total cost, the total travel time and the stopover interval of a flight between two cities. This inspires a type of Multi-Constrained Temporal Path (MCTP) discovery in ADGs, which is a challenging NP-Complete problem. In order to deliver an efficient and effective temporal path discovery method to be used in real-time environment, we propose a Reinforcement Learning (RL) based, Monte Carlo Tree Search algorithm (RLMCTS). RL-MCTS uses a newly designed memory structure to address the challenges of Monte Carlo Tree Search (MCTS) in MCTP discovery. To the best of our knowledge, RL-MCTS is the first RL algorithm that supports path discovery in ADGs. The experimental results on ten real dynamic graphs demonstrate that our algorithm outperforms the state-of-the-art methods in terms of both efficiency and effectiveness.