Defining Square Spin

Lets play a game!

The aim of this game is to transform one image into another using the least amount of moves possible. Here is what a move consists of:

  1. You get to pick a square of any size in the grid.
  2. You then get to rotate the square around its midpoint as much as you want as long as it fits back into the grid.
  3. This is where your move terminates and the resulting image can no longer be modified unless you take another turn.

Here is an example of two valid moves Transforming what looks like a plus into a weird F

Problem #1: Sun and Moon

I'm a little tired after defining the game and it's too bright outside for me to have a nap, can you make it nighttime for me?

Can you please get rid of this sun and replace it with a moon

Get a 7x7 grid to work with here

  • $\begingroup$ Let me know if this type of puzzle already exists $\endgroup$ – Adam Apr 12 at 12:15
  • $\begingroup$ Would of been nice to use black background if you used yellow lines and red. $\endgroup$ – Overmind Apr 12 at 12:49
  • $\begingroup$ When making similar drawings I always use black background because all colors are significantly more visible like that. The alternative is uglier (white background and ugly darker colors). $\endgroup$ – Overmind Apr 12 at 12:53
  • $\begingroup$ @Overmind I recreated the images using your colour scheme and they do look more appealing however against the backdrop of this website it looked a little off. I also have plans to add complications to this puzzle type and that colour scheme may get in the way of that. I've found that adding a black border to the yellow is slightly better, anyway, thanks for the feedback! $\endgroup$ – Adam Apr 12 at 14:05
  • $\begingroup$ Various types of gray are also good for sites with white background. They were pretty much a good solution for old forums/boards. $\endgroup$ – Overmind Apr 15 at 5:11

It can be done in

8 moves.

You start by noting

that the problem has a symmetry. You can split this up into 4 different pieces, where each piece contains 4 colored parts,

as shown in:

enter image description here

Perform these moves on the sun, you can get to the situation:

This action rotates the lower left 2 by 2 block,

to become:

The second move rotates the 2 by 2 block of column 2 and 3 and row 2 and 3 of the selected blue zone.

You now obtain

Repeating this for the next zones will get you to obtain the moon in 8 steps, starting from the sun.

  • 1
    $\begingroup$ Good job! However it's possible to do it in less moves believe it or not! $\endgroup$ – Adam Apr 12 at 12:44
  • $\begingroup$ I thought so, @Adam. ;) I'll think about it! $\endgroup$ – KevinT Apr 12 at 12:46

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