The New Sudoku Players' Forum

[Scott H]

I recently got hooked on Slither Link (also known by several other names). Here are several sites I've found. Anyone know other good ones?

http://www.puzzle-loop.com/. Large archive, sizes 5x5 thru 25x30. Normal/Hard levels. Free registration. Online applet (but no undo). Hall of Fame for fast completion times. Also has nomogram (picture logic) and sudoku.

http://www.kwontomloop.com/ . Daily puzzles, free registration, archives, leaderboard. Difficulty increases thru the week. Online applet, can mark one state and undo to it. General puzzle level seems pretty hard to me.

http://www.pro.or.jp/~fuji/java/puzzle/numline/index-eng.html . Hirofumi Fujiwara's site. 34 puzzles, 10 graded difficult levels, sizes 10x10 - 45x30. Online app, try/undo ("hint") mode. Free, no registration. Also has nomogram, kakro, sudoku, sliding blocks.

http://www.puzzle.jp/en/ . Nikoli puzzle site. Easy practice puzzles, 10 free sample puzzles, app (has undo). Nice logic patterns in Solution Key (but work out patterns yourself before looking at it). Also has seven other Japanese logic puzzles, including kakuro, nomogram, and Light Up (a fun one).

$4/month subscribers to www.puzzle.jp get 3+ new puzzles per day. Has anyone tried this? Is this 3+ of each of of the 8 puzzles, or just 1 puzzle for 3 of 8 types? Do they have archives?

http://janko.at/Raetsel/Schlangenlinie/index.htm . German site, 300 puzzles. I haven't evaluated it. Any reviewers?

[motris]

Excellent set of links - I was just given the kwontomloop.com link at a recent puzzling event and am looking forward to trying it out.

Regarding Nikoli's site, you get ~3+ total puzzles each day (so ~90+ per month) total, not for each type, and they will be of various sizes and difficulties. There are certainly some puzzles they tend to emphasize more than others but it is not possible to give you an exact number on how many slitherlinks you'd get in a month although it is not 90, probably more like 15-20. They had a free trial at the start of the year for 5 days and that is my only experience with them so someone who is registered with them can correct me if I am wrong. I've bought plenty of Nikoli books and love their puzzles, but find the online site not as useful as I prefer the much bigger and more challenging puzzles and it seemed the 3 per day you get would rarely last me too long for the cost. (I should clarify, to be fair to Nikoli, that I do many many logic puzzles and as a WPC competitor am likely fairly fast at the smaller, say 14x24, slitherlink puzzles and other types like Kakuro - this does not mean that all people will share this experience and be frustrated with the amount of puzzles they do post.)

Regarding archives, after you sign up, you will begin to compile an archive for the puzzles on the days you are a member - they also have a few specialty puzzles that are always available. You do not, however, with membership, get access to the last several years of puzzles, which makes sense for their payment format as it would be too easy to join, print puzzles from the archives, and then quit.

[tilps]

The following link is for a free program which can generate slitherlink puzzles of varying difficulties and also non-square variants. Requies .net 2.0.
http://www.themissingdocs.net/downloads/LoopDeLoop.exe

Edit: changed url to site with better bandwidth.

[debanjanray2003]

I recently got hooked on Slither Link (also known by several other names). Here are several sites I've found. Anyone know other good ones?

http://www.puzzle-loop.com/. Large archive, sizes 5x5 thru 25x30. Normal/Hard levels. Free registration. Online applet (but no undo). Hall of Fame for fast completion times. Also has nomogram (picture logic) and sudoku.

How do you get solution?
http://www.kwontomloop.com/ . Daily puzzles, free registration, archives, leaderboard. Difficulty increases thru the week. Online applet, can mark one state and undo to it. General puzzle level seems pretty hard to me.

http://www.pro.or.jp/~fuji/java/puzzle/numline/index-eng.html . Hirofumi Fujiwara's site. 34 puzzles, 10 graded difficult levels, sizes 10x10 - 45x30. Online app, try/undo ("hint") mode. Free, no registration. Also has nomogram, kakro, sudoku, sliding blocks.

http://www.puzzle.jp/en/ . Nikoli puzzle site. Easy practice puzzles, 10 free sample puzzles, app (has undo). Nice logic patterns in Solution Key (but work out patterns yourself before looking at it). Also has seven other Japanese logic puzzles, including kakuro, nomogram, and Light Up (a fun one).

$4/month subscribers to www.puzzle.jp get 3+ new puzzles per day. Has anyone tried this? Is this 3+ of each of of the 8 puzzles, or just 1 puzzle for 3 of 8 types? Do they have archives?

http://janko.at/Raetsel/Schlangenlinie/index.htm . German site, 300 puzzles. I haven't evaluated it. Any reviewers?

[aclayton]

Regarding Nikoli's site http://www.puzzle.jp/en , I have been a completely satisfied subscriber for a little over 2 years. motris' descriptions of the puzzles supplied are accurate, there's a nice variation of difficulties and sizes, along with 8 puzzle types (they added Hitori last year and Heyawake this year). Every couple weeks they have a special "Time Trial" race where the winner gets a little prize, and this puzzle is usually very large and very hard. On initial subscription, you get access to the past 30 days' worth of puzzles, although recently they began offering a deal where new subscribers could immediately buy access to the last 6 months' worth of puzzles for a little more money.

All the applets are well-written, and the puzzles are all hand-made, with each puzzle's author given, which is nice because you can kind of get a sense of the style of each author. Also, the site saves the way every solver completed each puzzle, so you can check the solved list for your total completion time/method, other solvers' times, and even bring up their solve and watch how they did a puzzle real-time (or in FF if you like). I like to think of myself as a decent solver, but some of the solving times are unreal, and it's entertaining (and educating if you get stuck) to sit and watch one of those crazy solves happen.

I say all the above even though a few weeks ago they announced that the site would be closing this July 31. No real explanation is given, but I assume it must be related to low subscription rates. I'm somewhat surprised, since the $4/month seems pretty cheap to me for the large number of quality puzzles supplied, and especially since I assumed the sudoku/kakuro explosion in the UK and US would drive a few more people to their site, but it doesn't seem to have happened. I'm pretty heartbroken about it, as the site has been part of my daily routine/addiction for so long. Also it's disappointing for quality puzzles to be apparently ignored, even more so every time I see a magazine rack stuffed with trash sudoku magazines of junk computer-generated puzzles crapped out by every publisher who wants to bandwagon in on this "soduku" craze they heard about somewhere.

In any case, there's still another 3 months left for the site, so it's still a viable option in the short term (even better if you quick-buy the 6-month archive, probably 60-70+ of each puzzle type). Plus, if enough people sign up, maybe we can save it..

[tilps]

The following link is for a free program which can generate slitherlink puzzles of varying difficulties and also non-square variants. Requies .net 2.0.
http://www.themissingdocs.net/downloads/LoopDeLoop.exe

The latest version of this program now lets you play multiplayer games head to head over the internet.

Edit: changed link to refer to my other website which has much better bandwidth than my deadofnight site. Deadofnight direct download will continue to work for now, but not indefinitely. (The page which contains the link to LoopDeLoop.exe still exists on deadofnight.org and shall continue to do so)

[tso]

Though it can't compete with the Dead of Night LoopDeLoop, here is a good public domain generator:

http://www.chiark.greenend.org.uk/~sgtatham/puzzles/loopy.exe

[Lindy]

Regarding Nikoli's site closure mentioned above, Nikoli are in the process of developing a new site, www.nikoli.com. Seems like puzzles are going to be available daily.

[Sabreman64]

Though it can't compete with the Dead of Night LoopDeLoop, here is a good public domain generator:

http://www.chiark.greenend.org.uk/~sgtatham/puzzles/loopy.exe

That program is OK, but it seems to have a bit of a problem with solving puzzles entered into it. I tried entering a couple of easy 10x10 Nikoli puzzles and the program was unable to produce a complete solution.

[tilps]

Just thought I would drop by (since it seems people still click on my link here occasionally...) to mention that I've recently started work on a silverlight 4 version of LoopDeLoop, which works from your browser.

Its current address is http://www.themissingdocs.net/LoopDeLoop.html - case sensitive. If anyone tries it out successfully on a Mac I would be interested to hear.

[krazydad]

Just wanted to mention that I've created a set of unusual Slitherlinks, using non-grid tilings, such as Penrose, Altair, Cairo and so on.
You'll find my variety slitherlinks at Krazydad.com.

[Rob_UK]

I launched a website a few months ago at Slitherlink.com which offers a new free puzzle each day.

Puzzles generally come in sizes 10x10 on weekdays, and 10x18 at weekends, but on the last Sunday of the month you can play a big 14x24 puzzle. All previous puzzles are available to play in the archive, which now contains well over a hundred and counting. There are also leaderboards to compete on, an FAQ section and a forum.