Locks Puzzle
How to play
Turn all the lines to vertical to unlock the puzzle. When you click or tap a box you turn the lines in all the boxes in that row and column through 90o.This first puzzle is solved very easily in 4 clicks / taps (there’s a clue for you if you look carefully). However using the ‘New Puzzle’ key will creates a random layout which is more of a challenge.
If you are really stuck, as always in the Compendium, the method for solving the puzzle is explained below.
The starting puzzle is solved by clicking or tapping the four boxes that begin with having vertical lines in any order, like this
There are two ways to solve the random puzzles.
Solution 1
Start with the top left box. Look at the seven boxes in the row across and the column down. If the number of vertical lines is 0 or an even number click or tap this box. Do the same for each of the 16 boxes working across and down the board. You may need to work down the board more than once but the puzzle is always solved in 16 moves or sometimes less!
Solution 2
Make a note of all the boxes with horizontal lines and click or tap on each of these boxes working across and down the board and ignoring how the lines turn. Make a note of all the boxes which now have horizontal lines and click or tap on each of these in turn working down the board. You may need to go through the board more than twice but again the puzzle is always solved in 16 moves or less!
