Bridges #539 · 11×11

• 11×11grid
• 23islands
• 34bridges
• 9double routes

Bridges #539 is a 11×11 grid at hard level with 23 islands. The solution lays 34 bridges along 25 routes, and 9 of those routes carry a double bridge. The largest number on the map is 6.

You can start without any guessing: 5 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.

7 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.

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.