Putting a guard on when loading a map

Attach a wall at the point of loading map data.

• Top, bottom, left, right become for d in [-1, +1, -WIDTH, +WIDTH]:.
• The distance that can be moved at one time determines the width SENTINEL of the wall.
• Only SENTINEL is shifted for the starting point, etc.
  • Note that sometimes it is originally 1-origin.

https://github.com/nishio/atcoder/blob/master/libs/readMap.py

Addendum in PAST5

• PAST5E I used to just read one, but this problem required me to read "two different widths of guard."

  • In addition, only one side is rotated, which is the source of the bug.
  • I made it a class, and I also made the rotation a method.

• PAST5H

  • It was necessary not to construct a grid graph.

• PAST5G "Maybe we could make a library of places to graph in terms of adjacencies," he wrote, but we should avoid graphing in the first place.

• Put the map in a 1D array

I made something that reads numpy before. - One-dimensional array with guard

• But if you think about it, when dealing with this kind of data, it is usually a random access to the map with subscripts.
• It is better to have it in a list than to wait with numpy because
  • see NUMPY subscript access is slow.

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