scip-routing

An exact VRPTW solver using PySCIPOpt. Intended to provide an easier starting point for research in exact methods for vehicle routing problems.

Installation

The easiest way to get started is to create a new conda environment using the env.yml file.

conda env create -f env.yml

The code implements two pricers, i.e. solvers for the resource constrained shortest path subproblem, one in python and a faster one in Rust. To use the Rust one, use maturin to build the code in rs_pricing

maturin develop --release 

Example

import cvrplib

from scip_routing.solver import VRPTWSolver
from scip_routing.utils import instance_graph

instance, sol = cvrplib.download('R101', solution=True)

instance_graph = instance_graph(instance)

solver = VRPTWSolver(
        graph=instance_graph,
        instance=instance,
        verbosity=2,
        pricing_strategy="rust", # "py" also can be used for the pure-python pricer
    )
solver.solve()