The New Sudoku Players' Forum

[RFB]

I find creating the set of pencil marks quite tedious and error prone.

Would it be possible to have an option to generate a set of pencil marks and when a big number is entered remove the corresponding marks from the row, column and box. This would eliminate some of the non-skilled drudge work.

It would, of course, still leave the user the more complicated logic to recognize and eliminate manually more complex possibles such a X wings.

[johnp]

I only found this program today and like it.

I agree with the idea of automated pencil marks. Whether or not the big number should clear the appropriate ones, I am not sure. Probably it would make completing the puzzle quicker.

[Pappocom]

I'm not so sure this would be a good idea ... but I'm willing to be guided by what others think.

It would be easy for the programmer (i.e., me!) to implement, of course. But wouldn't the temptation be for the solver to always use it, and then, what's left to do? Do you think there could be such a thing as getting too much help? It is a puzzle, after all.

I think the better course for a solver is to try to reduce the number of pencilmarks you need, not add to the number of pencilmarks you have to process.

You get more enjoyment if you are not tied up with the mechanical scanning of columns of pencilmarks. Try to recognize the hallmarks of a likely place where a breakthrough can be made, and then be alert for those hallmarks.

- Wayne

[joolslee]

I have to disagree that deleting pencil marks is simply "unskilled drudge work" - as my understanding of the puzzles has grown so has the number of pencil marks I am able to delete enabling me to get past 'stuck' points in puzzles I'd given up on. It has been part of the learning process for me and added to the satisfaction/enjoyment. I guess it's a personal thing, maybe an option for automatic deletion might be a desirable choice for some.

[RFB]

I have to disagree that deleting pencil marks is simply "unskilled drudge work" - as my understanding of the puzzles has grown so has the number of pencil marks I am able to delete enabling me to get past 'stuck' points in puzzles I'd given up on. It has been part of the learning process for me and added to the satisfaction/enjoyment. I guess it's a personal thing, maybe an option for automatic deletion might be a desirable choice for some.

I was certainly not trying to claim that all pencil mark deletion was drudge work. The whole skill of Sudoku is in reducing the list of possibilities down to a single certainty. However once you have determined that one value for a cell removing the value from the remaining pencil marks in the row/column/box is very straightforward and could be left to a computer without diminishing the intellectual exercise.

[Animator]

Automatic pencil marks (and/or the removal of it) could allow complexer puzzles though...

When I solve a puzzle more difficult then 'Very Hard' (or sometimes Very Hard too) I usually use some other self written programs, one to show the possibilities of a number/row/column/box, and one to generate all the possibilities (about the same as pencilmarks), then I go on modifying the pencilmarks and use another program to highlitght the possibilities of a number...

I could ofcourse do all this myself, it's just applying the rules, nothing difficult about that, but usually I make a lot mistakes then

Update: just for the record, it only adds them, it does not remove any pencilmarks, it only applies the most basic row/column/box constraint which everyone can do...

[shakers]

As a pencilmark user (pencilmarks anonymous, anyone? ) I certainly do NOT think they should be automated. Yes, it can be annoying if you miss one, but that's humans for you.

Using the computer to do the puzzle should only be in lieu of using a paper and pencil - if you want a pencilmark you should put it in; if it's no longer needed you should delete it.

If the computer's going to, in effect, solve the puzzle for you by showing you the candidates for the cells, why are you bothering doing the puzzle in the first place?

[RFB]

I think the better course for a solver is to try to reduce the number of pencilmarks you need, not add to the number of pencilmarks you have to process.

You get more enjoyment if you are not tied up with the mechanical scanning of columns of pencilmarks. Try to recognize the hallmarks of a likely place where a breakthrough can be made, and then be alert for those hallmarks.

- Wayne

I do try to reduce try to fill in as many cells as I can using the restrictions imposed by the original clue numbers and before starting to work with pencil marks on the most complete rows columns boxes. My brain isn't good enough to hold too many possibilities in memory at once
From experience I have found that having started down the pencil mark route I need to fill in the complete set of marks for a cell - If I come back to a cell and it is has incomplete information then I am likely to make invalid assumptions. Even so I often find that I have pencil marked almost the entire puzzle before finding the breakthrough spot

Obviously I need to spend more time re-reading the solving guides
but I supose my problem is 'how do you spot a pair or an x wing etc. without a full set of pencil marks to know where the possibles are '

[Batteneye]

This is the 3rd time I've tried to contribute to this discussion. Don't know where my messages are flying off to.

I think that automated pencil marks would be a good option to have, but with the facility to turn them off. Also, a 'notepad' area left of each row and under each column so that the user could key in the missing numbers.

i do not think we should be permitted to have the program automatically remove pencil marks when we key
t in a big number.

[Guest]

Many years ago there was a great DOS game called Sherlock (later ported to Windows) and the player board was similar in principle to Sudoku.

Sherlock printed a board and each tile offered all possible results for that tile as mini-tiles (equivalent to 3x3 Pencil Marks). When you were sure that a tile was a given value you'd click the mini-tile (equivalent to setting a Big Number) and when you did that, all other mini-tiles (horizontally in the case of Sherlock) would disappear. They could be reset by right-clicking, if you later found you'd got a wrong value.

In this way I'd love to see an option to create a fresh board pre-populated with Pencil Marks (with the pre-defined Big Numbers removed) -- this would save a good 3 to 5 minutes of time "setting up" the board in the way that I find most natural to play.

Basically, I would like to remove Pencil Marks as I discover the board, rather than add Pencil Marks to every blank tile before I start playing.

[Batteneye]

I've written out a spreadsheet in Excel with all the pencil marks in. It's quicker to cross them out than put them in every time before tackling a puzzle. If anyone wants a copy, get in touch.

[Cellach]

I do most of my sudoku on paper (printed out from the program) but I wouldn't want the program to remove unwanted pencil marks for me - that would be too easy. If it was made an option, I'd keep it turned off, like the wrong number in red function.

Cellach

[Guest]

I don't agree with automated pencil marks, as said it is a puzzle - and it's good try use them as little as possible. I think that all pencil marks should be automaticly removed when they become redundant - it seems a waste of time to have to manualy remove them all.

[kratos]

Surely the whole point of a popular puzzle is to make it attractive to as many as possible. If pencil marks could be turned off or on at will then what's the harm? Or are some of you not certain enough about resisting temptation?

Just in case it's not clear, I'm in favour of having the ability there, and of updating them when a big number is entered. (Again, removable at will.)

[Batteneye]

Kratos,

Can't reach you privately re your request for the spreadsheet. Your address is described as unrouteable (permanent error)

Batteneye