title: How to make a distance matrix for traveling salesman problem using most cost effective way?
body: <p>We are trying find the optimum route for given sets of addresses. Here optimum route meanibg going every address using shortest distance, We are using Traveling salesman approach to solve this, the problem is to work this algorithm perfectly we need distance between every pair of addresses. we can get the distance matrix using Google distance matrix/mapbox/distancematrix.ai/nextbillion.ai or any other 3rd party services. But these services are expensive.Suppose if we work with 100 addresses,then our distance matrix  shape would be <code>100*100</code>, so getting these <code>10000 pair</code> of distance would cost us around <code>20$</code> (for google it would cost <code>50$</code> !!!!).</p>
  <p>How can we solve this problem using most <strong>cost effective</strong> way?</p>