Vehicle Routing with Cross-Docking

The Vehicle Routing Problem with Cross-Docking is a variant of the classic vehicle routing problem. In this case a cross dock is used to consolidate loads to maximize the utilization of the fleet of vehicles. The dataset presented here was originally developed for the paper "Vehicle routing with cross-docking" published in Journal of Operational Research Society, vol 60, issue 12, pp 1708-1718 (2009).A link to the technical report of the paper is provided here. The section on Data from page 13 provides a description of the data.DESCRIPTION OF DATA FILESEach VRPCD instance corresponds to two data files: the location file (e.g. Data50_d.txt) and time windows: (e.g. Data50_d_tw.txt)The format of location file:It contains n+2 lines:- the first line:number of requests, vehicle capacity, start time for each vehicle, end time for each vehicle, vehicle speed, preparation time for unloading/reloading, time for unloading/reloading each pallet- the second line (terminal information): id, xccord, yccord, xccord, yccord, demandthe rest (request information)for each request i (i=1,...,n): request id, xccord of delivery node, yccord of delivery node, xccord of pickup node, yccord of pickup node, demand of the request The format of time windows file:It contains n linesfor each request i (i=1,...,n): earliest service time for the delivery node, latest service time for the delivery node, earliest service time for the pickup node, latest service time for the pickup node,

带交叉装卸的车辆路径问题（Vehicle Routing Problem with Cross-Docking）是经典车辆路径问题的一类变体。此类问题通过交叉码头整合货物载荷，以最大化车队的装载利用率。本数据集最初为发表于《Journal of Operational Research Society》2009年第60卷第12期、页码范围1708-1718的论文《Vehicle routing with cross-docking》所开发，本文附带了该论文技术报告的链接，其中第13页的数据章节对本数据集进行了详细说明。

### 数据文件格式说明
每个带交叉装卸的车辆路径问题实例对应两个数据文件：位置文件（例如"Data50_d.txt"）与时间窗口文件（例如"Data50_d_tw.txt"）。

1. 位置文件格式
该文件共包含n+2行：
- 第一行：请求总数、车辆额定载货量、单车辆的作业开始时间、单车辆的作业结束时间、车辆行驶速度、装卸作业准备时长、单个托盘的装卸作业耗时；
- 第二行（终端节点信息）：节点ID、x坐标、y坐标、x坐标、y坐标、节点需求量；
- 剩余行（请求信息）：针对每个请求i（i=1,2,…,n），依次包含请求ID、配送节点的x坐标、配送节点的y坐标、取货节点的x坐标、取货节点的y坐标、该请求的货物需求量。

2. 时间窗口文件格式
该文件共包含n行，针对每个请求i（i=1,2,…,n），依次包含配送节点的最早服务时间、配送节点的最晚服务时间、取货节点的最早服务时间、取货节点的最晚服务时间。