# Inversion Puzzle

You can describe your inversions however you like. I think an ordered grid from the center (n,m) is easy to understand (doesn't matter where to start due to radial symmetry), or an image

• Neat puzzle! Is there a reason why the black regions are not uniform? It's not important, but it makes the puzzle slightly harder to solve using an image editor because it breaks floodfilling. Apr 9, 2019 at 21:42
• Because I drew them in procreate. Thats a good point I'll remember that next time I make something like this Apr 9, 2019 at 21:45

My solution is

2 moves to make the inversions - was very slow to make this horrible graphic!

• Correct! Also works with most circles and sections Apr 9, 2019 at 22:49
• I would have drawn it quicker by making a fresh start with an 8 x 4 rectangular grid. I was able to floodfill the white areas with black but somehow not with black areas with white. Apr 9, 2019 at 22:51
• Black areas are shaded. Will make it easier next time. You can see the shading better here m.imgur.com/Sg5RLNi Apr 9, 2019 at 22:58
• My apologies to @PiIsNot3 because I inadvertently copied his final image, mistaking it for the one in the puzzle. Corrected. Apr 9, 2019 at 23:00

EDIT: I found an even better

2 inversion solution:

And of course, this is the optimal solution because you obviously can’t get to the end with only one inversion

Original answer: I can do it in

6 inversions

by

inverting a set of 4 non-adjacent big triangles (the ones that go BWBW or WBWB), then inverting the 2 black rings that result from that. (Will update with a visual later)

• Correct! Not sure who got it first but both correct Apr 9, 2019 at 22:51
• @ArtemLugin this was first with the 6 solution, I was working on the graphic for my 2 solution when PilsNot3 announced he had found a 2 solution. However I didn't post anything until mine was ready. Apr 10, 2019 at 7:11