- Thoughts.
- It’s stacked, so you can’t just remember the colors on the edges, because after they disappear, the colors inside appear.
- There are up to 50 balls and 2^50 options.
- Whether or not it is always okay to erase when you can.
- It’s easy if you can prove you can turn it off.
- If you can’t erase it, you can always erase it next time by putting it in such a way that the same color as the next color among the three colors on the left, right and current color is exposed.
- This way, if the length is 2, the next is 1 or 3, and that 3 is always 2 next
- Solve the short sequence by force and see if it looks OK.
- I think I can make it about 2^21.
- Official Explanation
- No, there is a user commentary: https://kort0n.hatenablog.com/entry/2020/01/08/002039
- The above procedure can maintain less than 3 pieces at all times.
- No need to go through a complicated state because it can maintain it until the end of the station.
- The logic is: [Optimal solution because it matches the lower boundary.
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