Tents

Tents ("Tents and Trees") is a logic puzzle invented by Léon Balmaekers (Netherlands). The task is a grid of squares, some of them contain trees. The goal is to place tents in some of the remaining squares, in such a way that the following conditions are met:

• There are exactly as many tents as trees.
• The tents and trees can be matched up in such a way that each tent is directly adjacent (horizontally or vertically, but not diagonally) to its own tree. However, a tent may be adjacent to other trees as well as its own.
• No two tents are adjacent horizontally, vertically or diagonally.
• The number of tents in each row, and in each column, matches the numbers given round the sides of the grid.

Cross+A can solve puzzles from 3 x 3 to 30 x 30.