Improved Approximation Algorithms for the Cumulative Vehicle Routing Problem
摘要
The Cumulative Vehicle Routing Problem (Cu-VRP) extends the classic Vehicle Routing Problem by incorporating fuel consumption considerations, which are crucial in transportation and logistics. In Cu-VRP with Stochastic Demands (Cu-VRPSD), the demand of each customer is unknown until the vehicle visits it. In this paper, we propose a randomized 2.5-approximation algorithm for splittable deliveries and a randomized 3.5-approximation algorithm for unsplittable deliveries, improving the best-known approximation ratios of 3.25 and 6, respectively. For Cu-VRP, since it is a special case of Cu-VRPSD, our algorithms also improve the best-known approximation ratios of 3.186 and 4, respectively. We apply our algorithms on the benchmark sets and the experimental results show that the quality of our computed solutions is much closer to optimality than the provable approximation ratio.