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← Expansion Grid - Artificial Intelligence for Robotics

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Showing Revision 2 created 05/24/2016 by Udacity Robot.

  1. In the next programming quiz, I would like you to print out a table called expand,
  2. which does not exist right now.
  3. What expand is, is a table of the same size as grid
  4. that maintains at what step each node was expanded.
  5. So the very first node over here was expanded times 0.
  6. The second node to expand was this one over here: 1, 2, 3, 4, 5, 6, 7.
  7. In this table, every node that has never been expanded
  8. including all the obstacle nodes should have the value of -1.
  9. Like these guys over here - these are obstacles.
  10. And when a node is expanded, it should get a unique number
  11. that is incremented from expansion to expansion
  12. and counts from 0, in this case, all the way to 22 for reaching the goal stated.
  13. To give you a second example of how the quotes should work,
  14. let me block off the goal by adding 1 over here
  15. so there's an entire items that block the left side from the right side.
  16. Now the switch fails, and in the expansion list you find
  17. that all nodes on the right side have never been expanded.
  18. You get 0, 1, 2, 3, 4, 5, 6, 7, 8, 9.
  19. A little warning; this is not unique.
  20. Depending on how you break ties you might expand in a different order,
  21. so I don't expect your table to always look exactly the same way as this one over here.
  22. So for example, you might have 0, 2 over here, and 1 over here
  23. but what should be the case is when there is a full blockage
  24. the right side should just never expand.