Hashi: join the islands with bridges
A Japanese logic puzzle (Hashiwokakero, “build bridges”): each island says how many bridges leave it, and together they must join up the whole archipelago.
- Each island has a number: how many bridges must reach it.
- Bridges run straight, across or down, between two neighbouring islands. There can be one or two between a pair, and bridges can’t cross.
- All islands must join up. Drag from one island towards another to lay a bridge, or tap the water between them: once for a bridge, twice for a double one, three times for none.