Re:How to do a code review
by Tyr42 on Friday September 06, 2019 @02:52PM
(#20898635)
Here's a fun example from math which requires generalizing to get a good solution to.
Suppose you have a 2^n x 2^n sized courtyard. You have one 1x1 statue, and unlimited L pieces (2x2 with a corner missing).
You would like to have a layout which places the statue in one of the centermost tiles, and fill the rest with L pieces.
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Solution
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Define a layout function with allows for the empty tile to be in any corner. This is trivial for 2x2, as it's just an L peice.
By tiling these squares, you can solve for the next size up.
Put three with the hole in the center and fill in with an L piece to get the bigger square.
At the end, take 4 2^(n-1) squares and put the holes in the middle. Add one L and you are done.
What was the point of that?
By generalizing your solve function to have more outputs, it lets you build up a structure from it, in which it's easy to solve your actual goal.
Suppose you have a 2^n x 2^n sized courtyard. You have one 1x1 statue, and unlimited L pieces (2x2 with a corner missing).
You would like to have a layout which places the statue in one of the centermost tiles, and fill the rest with L pieces.
----------------
Solution
----------------
Define a layout function with allows for the empty tile to be in any corner. This is trivial for 2x2, as it's just an L peice.
By tiling these squares, you can solve for the next size up. Put three with the hole in the center and fill in with an L piece to get the bigger square.
At the end, take 4 2^(n-1) squares and put the holes in the middle. Add one L and you are done.
What was the point of that?
By generalizing your solve function to have more outputs, it lets you build up a structure from it, in which it's easy to solve your actual goal.