if you imagine the grid as being on a table, you can walk around the table and directions will change relative to you while still making sense. you can look at the table from above, or crawl underneath it, or view it through a mirror

for a chess board, up down left right is different depending on whether you're black or white. maybe you're viewing it from the side. it's the same game regardless.

[0, 0] is top left corner, and [N - 1, N - 1] is bottom right corner.

Does it matter? Pick one you like, if you must.

Every solution has a link titled Fork, you can use it to create a fork of the solution and tests, so you can mess with it as much as you want, without submitting.

And what is the expected result of that test you propose?