Pocket Overflow
Expert
Used by Smart Hint
If making a cell land would seal an empty cell in on all four sides, that trapped cell can't be a lone piece of sea with nowhere to connect — so it has to be land too. If taking both together overflows an island or joins two islands, the first cell was never land: it's sea.
- Sea
- Cells that establish the pattern
How it works
- One step further than Land Squeeze: instead of checking whether a land cell breaks something straight away, check what that land cell would FORCE next.
- Watch for a cell it would seal in — an empty square with land on all four sides. That square can't be sea, because a single sea cell cut off from every other one has no way to join the rest of the sea.
- So it must be land as well, and the two of them arrive together. If taking both overflows the island they'd join — or if the sealed square is hemmed in by two different islands, so it can't be land either — then the first cell was never land to begin with.
- It's sea.