title: Find all routes from source to destination in google maps
body: <p>I am developing an app for local bus system and as per requirement, a bus can have multiple routes from one location to other. So i have to implement methodology like</p>
  
  <ol>
  <li>fetch user's current location</li>
  <li>get destination from user and accordingly show user all possible routes to destination</li>
  <li>show all paths on map simulataneously with optimal shortest path highlighted with different color.</li>
  </ol>
  
  <p>currently, I have progressed to basic application having functionality</p>
  
  <ol>
  <li>get user's current location and pin point it with marker on google map</li>
  <li>getting single path to destination (using google maps api)</li>
  <li>plotting it on map by polyline. I have used one tutorial that implements navigation from source to destination.</li>
  </ol>
  
  <p>Now I have to find all possible routes from source to destination. searched for answer but most answers referred to apply single path which I have already done. Any help will be much more appreciated.. Thanks in advance...</p>