Bridges #540 · 11×11

• 11×11grid
• 25islands
• 33bridges
• 7double routes

Bridges #540 is a 11×11 grid at hard level with 25 islands. The solution lays 33 bridges along 26 routes, and 7 of those routes carry a double bridge. The largest number on the map is 5.

You can start without any guessing: 6 islands have a number equal to or one below twice the neighbours they can see, so every one of those neighbours gets at least one bridge.

4 islands carry a 1. Two of them may never be linked to each other, because that pair would be cut off from the rest of the map.

2 islands sit in a corner of the grid, where it can see at most two neighbours: a good second place to look.

Hard grids sometimes need one step of look-ahead: try a bridge in your head and check whether it leaves a neighbour unable to reach its number.