title: Travelling Salesman Problem Constraint Representation
body: <p>I read a couple of articles and sample code about how to solve TSP with Genetic Algorithms and Ant Colony Optimization etc. But everything I found didn't include time (window) constraints, eg. "I have to be at customer x before 12am)" and assumed symmetry. </p>
  
  <p>Can somebody point me into the direction of some sample code or articles that explain how I can add constraints to TSP and how I can represent those in code.</p>
  
  <p>Thanks!</p>