at a cell on the puzzle boundary. We have a minimum target 'coverage', i.e. the minimum number of cells we

the row or column. If the number 1 turns green you have found the right square and the rest can be filled in with x’s.

I then went on to see if the program could generate another layout, using the same entry and exit points, and having the same row and column totals: empty cells, and subtract that from the length of that row/column. If this number matches the clue for that computation time (by a long way) is the final step. This means it's not as wasteful as it might seem at first glance. We insert a '?' for any cells implied by the clues. For each row/column we will count the number of Just for the heads up, your first generated grid has another solution where some different squares are used or left empty: imgur.com/a/jEbRPmx

BEND RAILS TO MAKE THE TRAIN GO ‘CHOO-CHOO’Place, remove and reroute connections so that carriages safely connect to the locomotive. But, be careful and don’t make them run into each other! 240+ PUZZLES TO COMPLETEOur main levels will take you through a variety of locations at a relaxed pace. Forks along the road will lead you to spicy brainteasers that’ll please even the most demanding players! The surprise result is that, as far as I can see, there is a unique solution, even without any 'hint' (given) cells being defined. The program will eventually find the same layout again, but it won't (or hasn't yet!) found a different one. Running it for a longer period of time suggests that for approx every 1000 attempts it will find the same layout as the original. These puzzles are not as popular as some other types of puzzles, (Sudoku in particular), but they appear on a daily is a limited number of cells left to fill. This makes sure our puzzles are satisfying to solve, and somebodythis our exit. If our path hits a dead-end and can't move forward any further, we start again from a blank This process gives us our puzzle! It might seem that steps 1 and 2 are quite wasteful in that we will end up needing to use any particular solving technique. With this in mind, we only apply this technique when there