tag:blogger.com,1999:blog-20310719431789785562024-03-06T02:06:40.418+00:00 detuned radioUnknownnoreply@blogger.comBlogger435125tag:blogger.com,1999:blog-2031071943178978556.post-45936753930185845132023-02-10T22:21:00.001+00:002023-02-10T22:21:07.342+00:00Puzzle 362 Penalty HeyawakeIt's been a good long while dearest reader, but here's something I came up with on a bit of a whim. Come to think of it, lots of things about this post are a bit scatter-gun. For one, Puzzle 361 remains unpublished. For two I don't know if this means I'll be posting anything other than quick ideas in the near future (not that I suppose I ever posted anything other than relatively quick ideas).<div><br /></div><div>But yes. All that aside, the idea of this puzzle is to apply the usual rules of Heyawake. There is one further constraint to add to the mix: you must not be able to draw a loop in the unshaded squares.</div><div><br /></div><div>The easiest consequence of this is that there cannot be any 2x2 blocks of unshaded squares, but there are a couple more of logical consequences/solving heuristics to consider. I'm not sure how many of them make it into this puzzle, or whether it's something that is really worth exploring in all that much detail, or even indeed whether this is a particularly helpful name of the variation... but it will have to do for now. Enjoy!<br />
<blockquote><b> #362 Penalty Heyawake</b> – rated <b>5/10 [Medium]</b><div><div class="separator" style="clear: both;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiuGLoiGBlZTECDty03Trd1B8U0TMba6YyrdxDu4hKgVp6Hj9XRTH_YgDvLJbUF_u3BGAWn_2ZKxLuHyqWkxVBsjni1OIiTMkNdUd5iZ3uTYwVj6vt_8B8vS_YpyJKgD86AWRgDxOISetkXfxJ32aqmCK43retLJkQVjYjiR3IQCwtwnSFUU2c8IWhoeg/s363/362p-he.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="363" data-original-width="363" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiuGLoiGBlZTECDty03Trd1B8U0TMba6YyrdxDu4hKgVp6Hj9XRTH_YgDvLJbUF_u3BGAWn_2ZKxLuHyqWkxVBsjni1OIiTMkNdUd5iZ3uTYwVj6vt_8B8vS_YpyJKgD86AWRgDxOISetkXfxJ32aqmCK43retLJkQVjYjiR3IQCwtwnSFUU2c8IWhoeg/s320/362p-he.png" width="320" /></a></div></div></blockquote><br />
<a href="https://tcollyer.blogspot.com/p/copyright-statement.html" rel="nofollow" target="_blank">All puzzles © Tom Collyer 2009-23</a>.</div>Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-2031071943178978556.post-73280123520525430222022-10-30T20:54:00.005+00:002022-10-30T21:51:52.176+00:00Unofficial Championship Host's GuidebookBefore I get going, a couple of quick note to self: <div><br /></div><div><ol style="text-align: left;"><li>Move this somewhere more permanent on the blog, and dig up other similar posts!</li><li>Finish the post!</li></ol><div><br /></div><div>I don't know exactly how much appetite there is for this kind of post, but I don't think it's of no interest at all. Hopefully it's of more interest than the existing WPF guidebook that exists somewhere on the internet, but that I am not interested enough in to find and link to right now.</div><div><br /></div><div>The best approach to this kind of thing is to somehow work backwards from a successful outcome. To that end, I will draw on my many experiences as a competition participant as well as my experience as a competition organiser to run through all the things a participant tends to experience at a well-run event.</div><div><br /></div><div>These then can be regrouped from an organiser's point of view.<span><a name='more'></a></span></div><div><br /></div><h3 style="text-align: left;">Leading up to the event</h3><div>Firstly a participant needs to be vaguely aware of the basics of the competition; namely the location of the hotel and the dates of the competition. The associated costs of the competition should also be advertised well in advance. </div><div><br /></div><div><i>Tasks:</i></div><div><ul style="text-align: left;"><li>Set up an organising committee, and a holding company for the event (this could be an existing puzzle association). This company should have its own bank account.</li><li>Set up an event budget.</li><li>Set up a project plan.</li><li>Conduct negotiations with a venue to the extent you can fix a date.</li><li>Set up a website to provide basic information. It is likely the website will also be useful in handling registrations (see below)</li><li>Set up event branding (usually a logo).</li></ul><div>With regards to the organising committee: this can be flexible depending on the specifics of the tasks in hand. My advice would be to have at least three different roles as a minimum:</div><div><ul style="text-align: left;"><li>Committee Chair/Overall Project Leader</li><li>WSC Competition Director</li><li>WPC Competition Director</li></ul><div>At the risk of repeating myself, these should be three different people.</div></div><div><br /></div><div>A participant then needs to be aware of how it is they are going to be able to attend. This will depend on various national qualification schemes. There needs to be enough time that the competition organisers allow national organisers to both organise qualifiers and then also to confirm the teams.</div></div><div><br /></div><div><i>Tasks:</i></div><div><ul style="text-align: left;"><li>Clearly communicate the dates of the competition.</li><li>Clearly communicate registration deadlines for the competition.</li><li>Clearly communicate the extent to which you will facilitate transfers from airports/railway stations etc.</li><li>Indicate roughly to what extent "unofficial" participation (guests, B team, C team etc) will be possible.</li></ul><div>The registration itself is best handled with designated team captains from each participating country. This gives rise to the following tasks.</div></div><div><br /></div><div><i>Tasks:</i></div><div><ul style="text-align: left;"><li>Record arrival/departure travel information.</li><li>Translate this information into a plan for transfers.</li><li>Record any other special requests and liaise with the hotel accordingly.</li><li>Ensure there are plans and policies in place to ensure the safeguarding of any children (i.e. explicitly require they travel with a responsible adult).</li><li>Manage registration cashflows, including communication of receipt.</li><li>Manage other correspondence, including official invitation letters and anything else that will aid competitors obtaining any necessary travel visas.</li></ul><div>There are generally a lot of participants and teams to liaise with, so it is highly recommended that the registration process involves at least some level of automation of data capture and management. The cashflows are also very important, as it may well be that there are large sums of money due to the hotel before any competitor fees start coming in. The following tasks are therefore something participants don't really see</div></div><div><br /></div><div><i>Tasks:</i></div><div></div><div><ul style="text-align: left;"><li>Managing any bridging loans the event requires (typically these are covered by individuals, although the WPF has also fulfilled this role historically).</li><li>Explore options for event sponsorship, and any other kind of financial support.</li></ul></div><h3 style="text-align: left;">Immediately before the event</h3><div>Once a prospective participant has registered, paid up and sorted out travel, the next thing on their mind will be the competition itself. The first sight they see of this are the instruction booklets. In theory, typically the instruction booklets are published two weeks before the start of the competition. In practice, typically things are running behind schedule and two weeks sounds like a very generous allowance!</div><div><br /></div><div>There is some consideration to be given to the publication of the instructions. In the two weeks leading up to the event there is a small subset of participants who are able to dedicate significant time and effort into understanding the more novel elements of the competition by constructing for themselves a set of example puzzles that go beyond what has been communicated by the instruction booklets.</div><div><br /></div><div>It may well be that the competition directors take a view on how fair this is. One option available to them is to communicate what the novel elements of the competition will be ahead of the official instruction booklet.</div><div><br /></div><div>Anyhow, I begin to digress. Let's get back to the tasks at hand. In 2014, the publication of the instruction booklets happened at the same time as print deadlines for both the instruction booklets and the puzzle booklets. This brings into focus the following activities that need special focus from the competition directors.</div><div><br /></div><div>The most important task is not always obvious:</div><div><br /></div><div><i>Tasks:</i></div><div><ul style="text-align: left;"><li>Work out a detailed schedule for the competition week, including individual competition time, team competition time, play-off time, break times, meal times, and socialising times.</li><li>From here you can begin designing your competition round structure.</li></ul><div>In my opinion, designing to a timetable is critical. It will involve avoiding subtle mistakes like having too much puzzle solving in the day, reducing team rounds to after-thoughts and allowing insufficient time to socialise and debrief with other competitors on the puzzles you have just solved. In recent years (since 2017 perhaps) the total puzzle solving time of the week has grown and I don't think this is necessary to maintain the integrity of the competition. I think we've probably passed the optimal total solving time and so my philosophy here is that less is more.</div></div><div><br /></div><div>Beyond that, the tasks of a competition director also include:</div><div><br /></div><div><i>Tasks:</i></div><div><ul style="text-align: left;"><li>Obtaining competition puzzles.</li><li>Maintaining a set of puzzle rules.</li><li>Maintaining a set of example puzzles. (Ideally these should be full size and not totally trivial)</li><li>Drawing up puzzle grids for each of: example puzzles, competition puzzles, competition solutions. (There is much more to say on this).</li><li>Having a system to dynamically generate competition rounds in booklet form.</li></ul><div>This last point is going to be critical to get right if you are interested in saving yourself a lot of time. I use a LaTeX system that draws puzzle rules from a common source to ensure consistency of wording and examples in the competition and instruction booklets. I have heard of many other competition organisers doing something similar.</div></div><div><br /></div><div>In an ideal world you have this hooked up to a testing database, which ensures the correct points and totals are assigned consistently between the competition and instruction booklets.</div><div><br /></div><div>The tasks relating to testing I have kept separate as obviously testing is super important to ensuring your competition is successful. The main dimensions to testing a puzzle are as follows:</div><div><ul style="text-align: left;"><li>How many solutions does it have? [The answer is either: None, One or Many]</li><li>If the answer is one, what was the solving time?</li><li>If the answer is one, does this match the corresponding solution?</li><li>If the answer is one, did the solve require any "high-variance" type deductions?</li></ul><div>Ideally you will apply this schema to both competition puzzles and example puzzles. Obviously if you need to compromise effort that you should focus efforts on the competition puzzles as the main priority.</div></div><div><br /></div><div><div><i>Tasks:</i></div><div><ul><li>Finding a group of reliable test solvers</li><li>Testing prospective puzzles in their original format (pass 1)</li><li>Testing prospective puzzles in their redrawn format (pass 2)</li><li>Testing prospective puzzles in their redrawn format against the solutions in their redrawn format (pass 3)</li><li>Liaising with authors where one of the (at least!) three passes reveals a puzzle does not have exactly one solution.</li><li>Finding a mechanism to translate testing times into points allocations.</li><li>Keeping points allocations consistent across different rounds.</li><li>Finalise an early-completed-round bonus points allocation consistent with the overall points allocation.</li><li>Reviewing points allocations and making manual interventions where necessary. This will be necessary at some point.</li><li>Reviewing final round structures.</li></ul></div></div><div>The competition director needs to be intimately familiar with each and every puzzle in the competition. My opinion is they MUST have solved each puzzle in the competition a minimum of three times. Ideally the rest of the testing pool will have done the same. Note that wherever you redraw puzzles, mistakes happen, and therefore they MUST test puzzles after the redrawing process. Any typos identified here will send you back to square one. There will be typos.</div><div><br /></div><div>The last tasks after round design involve bringing everything together.</div><div><br /></div><div><i>Tasks:</i></div><div><ul style="text-align: left;"><li>Confirming competition hall rules (for both participants and non-participants).</li><li>Confirming play-off formats and rules.</li><li>Final review of every puzzle booklet as drawn up on computer.</li><li>Final review of the instruction booklet as drawn up on computer.</li></ul><div>The rest is then printing and publishing. There are still things to think about.</div></div><div><br /></div><div><i>Tasks:</i></div><div><ul style="text-align: left;"><li>Confirm whether colour printing is required.</li><ul><li>If colour printing is required, have you considered colour-blindness?</li></ul><li>Confirm paper quality (i.e. not glossy, not too thin etc)</li><li>Confirm paper size. Usually this is A4, however if you are based in North America this may well be Letter. Needless to say the paper size you are printing on needs to match the specification of whatever software you have used to draw up the booklets.</li><li>Confirm print quality (i.e. not laser printed so that the ink can be erased)</li><li>Confirm layout. The gold standard here is not to print puzzles back-to-back within booklets in case solvers ink from one side of the page seeps through to the other; however perhaps compromises need to be made in relation to the printing budget.</li></ul></div><h3 style="text-align: left;">During the event</h3><div>[to do when I'm feeling less tired, ill and drained]</div></div><div>[to cover the following]</div><div><ul style="text-align: left;"><li>Event Signage</li><li>Volunteers/event staff</li><li>Goody bags, including t-shirts.</li><li>Competition hall set-up</li><li>Audio-Visual Requirements</li><li>Seating Plans</li><li>Food and Refreshments</li><li>Non-competition events (football, karaoke, evening entertainment)</li><li>Excursions</li><li>Photographs</li><li>Individual Rounds</li><li>Team Rounds</li><li>Grading</li><li>Solutions</li><li>Scoring System</li><li>Communication of Results</li><li>Play-Offs</li><li>Prizes</li><li>Press Conferences/Media Relations</li><li>Liaising with the WPF (e.g. for GP play-offs)</li></ul></div>Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-2031071943178978556.post-1513478383535722472022-10-25T18:26:00.001+01:002022-10-25T18:26:11.562+01:00WSPC 22: AftermathSo the intention wasn’t to leave the last post as something of a cliffhanger, but it turns out I didn’t really have the energy to do updates during the week. <div><br /></div><div><div>The first thing to say is that the week was a bit of a rollercoaster. There were some unpleasant lows I won’t speak more about, but they left me feeling greatly saddened and robbed me of both self-esteem and proper sleep during the week. That’s never ideal when you want to be at peak mental sharpness, to say the least.</div><div><br /></div><div>But overall it was great to return to things after 3 long years away. The puzzle solving itself also had its ups and downs; that’s usually the case but this year I was well within my usual abilities. I do think the WPC in particular will go down as a classic vintage. The 3 years away has given the opportunity for a new generation of solvers and authors to break through, and it has been a real delight to meet some of them and start new friendships. And of course to meet dear old friends once again.</div></div><div><br /></div><div>I’ll be doing some posts with the added benefit of hindsight when I’m back to London. These will probably focus more on the highs as I think it’s about time to put the aforementioned lows behind now. </div>Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-2031071943178978556.post-68927172945404134062022-10-18T02:29:00.002+01:002022-10-18T02:29:40.869+01:00WSPC 22: OuchI didn’t get around to finish posting yesterday, having been totally drained of all energy: mental, physical, emotional. It seems cruel that insomnia now prevents me from finding rest and peace for the night. <div><br /></div><div>I don’t know if I’ll keep posting through the rest of the week. To be honest, yesterday hit me pretty hard, as I’m sure anyone reading this is beginning to realise. I really wanted to make a good year of it, and I thought I was supposed to be reasonably good at this stuff, but everything seems to be falling apart and I can’t seem to process any of it. I’m in a pretty low place, feeling helpless and useless and in need of a hug. </div>Unknownnoreply@blogger.com4tag:blogger.com,1999:blog-2031071943178978556.post-63240326088171336102022-10-17T12:54:00.002+01:002022-10-17T12:54:45.491+01:00WSPC 22: Day 1On to the first day of competition at the world sudoku championships. I started the day full of excitement, but perhaps not quite with a level of mental sharpness ready to start the competition. <div><br /></div><div>We’re up to lunch now and I’m licking my wounds; the morning’s solving counts as one of the more chastening experiences I have had in 15+ years of solving. </div><div><br /></div><div>I’ll edit in more later, but for now I am at least comforted by the general consensus in the room that it has been hard! Seriously hard! Hard enough to make me wonder whether having a non-zero round represents a good achievement now. I will be even more studiously avoiding anything looking like scores or a leaderboard from now on. That was always going to be the case, but the readjusting of expectations this morning has hit me hard and left me low and disappointed. </div><div><br /></div><div>The first round was classics only, and I think the only way to look at things is an acceptance I choked. I got one puzzle done, tried enough twice, convinced myself there was an unresolvable contradiction and from there on in I was making errors left right and centre. </div><div><br /></div><div>The rounds after were disappointing in many ways. The second was looking ok, but ended up spending a lot of time on a puzzle without being able to finish it. Round 3 had a combination of 1 and 2’s woes, wasting a large amount of time on a puzzle I was convinced could not have a solution. Round 4 was just hard all round - no contradictions this time, but also not much in the way of puzzles solved either. I think I might have one. </div><div><br /></div><div>The morning ended with round 5, a very large samurai sudoku with 14 overlapping grids. Speaking with others this was also very hard, but I finally managed to get a good round under my belt. I’ll claim 11/14 completed grids in the 30 minutes - which is going to be close to my round 1-4 scores combined if there are no errors. Let’s hope not!</div><div><br /></div><div>As far as the contenders are going, I don’t really have a feel for things. I had a nice chat with the ever-kind Tiit Vunk about the mental side of long distance running - he’s not feeling the pressure too much this year and is instead focussing on enjoying all the puzzles he’s able to solve. I’m not sure many are finishing rounds, or even close to, but performance of the day goes to Kota Morinishi - he got that Samurai out in what I think was 18 minutes. 14 9x9 grids in 18 minutes! And that’s with what felt like the requirement to place numbers in about 8 of them before you could really get going. I think I heard Tantan declare with roughly 5 to go as well, but I think given how things have gone so far I can imagine Kota being an imperious position at the front of the pack. </div><div><br /></div><div>On to the afternoon!</div>Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-2031071943178978556.post-21754989310989536742022-10-16T22:50:00.001+01:002022-10-16T22:51:10.499+01:00WSPC 22: Day 0So I was hoping to post a bit more earlier today but now I’ll keep it brief. The official arrivals day started pleasantly with breakfast with old friends from Poland on the organising team. It’s like 3 years of madness that have past since we all last met in 2019 washed away - and pretty much references to “last year” throughout the day as people arrived became an agreed standard. <div><br /></div><div>It was nice to share stories from fellow championship organisers - our efforts date back a few years now to 2014 - but also a little sobering to hear about the impact of the Russian invasion of Ukraine on Poland, particularly with regards to military logistics. Later meeting some of the Japanese team brought tales of longer flight times due to diversions around Russian airspace. This year, there is no Russian presence at the championships as there usually would be, although a good friend from Belarus did manage to make it. These issues of course are far bigger than a puzzle championship, but that doesn’t mean they should not be discussed or shied away from. </div><div><br /></div><div>After a walk through some nearby woods in the crisp autumn sunshine, the rest of the day was spent in the hotel greeting a steady stream of arrivals. The UK team is all here now and looking forward to the competition. I’m curious to see how newcomer Jack does at his first competition, and I was pleased to tease Cracking The Cryptic’s Mark Goodliffe that he was probably the most famous person here, with his 500,000+ follows. Probably enough to outdo the likes of Will Shortz, even if he has had cameos on the Simpsons and his I met your mother. </div><div><br /></div><div>Perhaps my favourite time of the day was spent well with my good friend of many years now and anlso general all-round Chinese phenomenon Tantan Dai. I’m probably not totally partial here, but I think she is a narrow favourite for the Sudoku title ahead of the likes of Estonia’s Tiit Vunk and serial world champion from Japan Kota Morinishi. Those three are all mind-blowingly talented as well as being really good decent people in a way that it is hard to do justice - whoever comes out on top will be a worthy winner - but this year I’ll be firmly rooting for Tantan!</div><div><br /></div><div>No surprises in the evenings Q&A - although the team rounds sound like they might be eventful. More to come tomorrow!</div>Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-2031071943178978556.post-26595837501588891202022-10-16T00:02:00.000+01:002022-10-16T00:02:28.884+01:00WSPC 22: Day -1So here’s to the revival of detuned radio’s championship reports! I don't have a laptop with me this year however I’ll see what I can do tapping things out on a phone. I don’t think I’ll be in depth with all the gory details as I once was, and I think I’ll try to be at least somewhat journalistic about proceedings, aiming at an audience who sort of knows what puzzles are but don’t really know what the world championships are all about. <div><br /></div><div>I am here, finally, in Krakow. About 4 hours late, and sorely missing the company of others I’d hoped to catch this evening who have very sensibly gone to bed. I have sworn many times never to fly Wizz Air again, but I think this time is probably the last. I look forward to an epic fight to claim my rightful €250 when I get back home. </div><div><br /></div><div>To set the scene about the championships, I can share some of my day idly spent staring at a phone within the confines of Gatwick airport. </div><div><br /></div><div>At both the WSC: <a href="https://www.wspc2022.com/wsc">https://www.wspc2022.com/wsc</a> and the WPC: <a href="https://www.wspc2022.com/wpc">https://www.wspc2022.com/wpc</a> there is about as much variety in sudoku and logic puzzle grids that you could hope to throw a forest worth of sticks at. (Maybe that should be pencils?). I encourage my dearest readers to follow those links, scroll down to view the instruction booklets, and prepare yourselves.</div><div><br /></div><div>I have been doing these things since 2007, so I reckon I qualify as a seasoned pro at these things by now; but I doubt you will be that much more bewildered by it all than I am. I suppose I’ve done just enough reading to at least understand all the rules now, but there will be more than a few types that I will encounter for the first time when it really matters, in the competition itself. </div><div><br /></div><div>I might save more on the puzzles themselves for tomorrow. It’s getting late and there’s a long week ahead. I’m glad to be back at championships for the first time since 2019, to seeing old friends once again, and also to see how well the competitive juices get going again. My thanks also to the organisers for all they have already done in preparation - I was there in 2014 and once you’ve been through that, you certainly have my solidarity!</div>Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-2031071943178978556.post-22923688515405744332022-05-30T21:28:00.031+01:002022-05-30T22:52:36.563+01:00pzprPT Masyu experimentI thought I'd try the same thing as the previous post using the <a href="https://semiexp.net/pzprrt/index.html" rel="nofollow" target="_blank">pzprRT</a> interface - this time with Masyu. <div><br /></div><div>UPDATE: I managed to put out 15 puzzles, which seems absolutely insane to me. I had speculated that the interface might be a bit more fiddly with Masyu, because you can't just type in numbers - however what won through is the fact that you need far fewer clues to get a valid Masyu puzzle. So there we go, churn out a puzzle in an average of 2 minutes. Make of that what you will!<div><br /></div><div><b>Puzzle 1</b>: 21:32 - <a href="https://puzz.link/p?mashu/10/10/16020200033ii000903009222003030160" rel="nofollow" target="_blank">https://puzz.link/p?mashu/10/10/16020200033ii000903009222003030160</a></div><div><br /></div><div>Solved in 0'50. A fairly tricky puzzle in the end, although enabled with a repetition of my favourite diagonal pairs in the corner.</div><div><br /></div><div><b>Puzzle 2</b>: 21:34 - <a href="https://puzz.link/p?mashu/10/10/0000o10021i30010900i64020000360i00" rel="nofollow" target="_blank">https://puzz.link/p?mashu/10/10/0000o10021i30010900i64020000360i00</a></div><div><br /></div><div>Solved in 0'44. Mostly smooth, although a couple of tricky deductions. My initial impressions are this has been a bit more successful than the Slitherlink experiment to come up with puzzles that don't feel too artificial.</div><div><br /></div><div><b>Puzzle 3</b>: 21:36 - <a href="https://puzz.link/p?mashu/10/10/090109i61033300i900360920000961200" rel="nofollow" target="_blank">https://puzz.link/p?mashu/10/10/090109i61033300i900360920000961200</a></div><div><br /></div><div>Solved in 1'41. This is the first one I feel like I missed something - maybe too early to say if that points at a computer generated hallmark, although I didn't really like this as much.</div><div><br /></div><div><b>Puzzle 4</b>: 21:38 - <a href="https://puzz.link/p?mashu/10/10/10200b03i3010122033006000b03i130i0" rel="nofollow" target="_blank">https://puzz.link/p?mashu/10/10/10200b03i3010122033006000b03i130i0</a></div><div><br /></div><div>Solved in 0'33. The theme suffered in order to get something unique out, but this was a lovely smooth puzzle to solve. I might try and rescue this at a later date!</div><div><br /></div><div><b>Puzzle 5</b>: 21:40 - <a href="https://puzz.link/p?mashu/10/10/09i21000023j0i000ca0009219j0000930" rel="nofollow" target="_blank">https://puzz.link/p?mashu/10/10/09i21000023j0i000ca0009219j0000930</a></div><div><br /></div><div>Solved in 1'09. Solved nicely enough, but with a couple of moments to sit and think. But these aren't feeling so artificial to me. I wonder if that's because I'm a reasonably proficient Masyu solver and just get these things quicker than I do with Slitherlink? Or indeed if there's an upper limit as to how hard you can make Masyu?</div><div><br /></div><div><b>Puzzle 6</b>: 21:42 - <a href="https://puzz.link/p?mashu/10/10/209000i80030060j000169200409000i30" rel="nofollow" target="_blank">https://puzz.link/p?mashu/10/10/209000i80030060j000169200409000i30</a></div><div><br /></div><div>Solved in 0'26. Finally got an anti-symmetric one going, and it's just as good as any other in this style that I've ever written. Interesting!</div><div><br /></div><div><b>Puzzle 7</b>: 21:44 - <a href="https://puzz.link/p?mashu/10/10/00o0c02000i13i600010b60900302i1900" rel="nofollow" target="_blank">https://puzz.link/p?mashu/10/10/00o0c02000i13i600010b60900302i1900</a></div><div><br /></div><div>Solved in 0'27. On a roll with anti-symmetry. This one has a really nice design actually - maybe it compares favourably to most of the others in this style I've ever written. Hmmm!</div><div><br /></div><div><b>Puzzle 8</b>: 21:46 - <a href="https://puzz.link/p?mashu/10/10/00020910060909i00a2021100200i06090" rel="nofollow" target="_blank">https://puzz.link/p?mashu/10/10/00020910060909i00a2021100200i06090</a></div><div><br /></div><div>Solved in 0'49. I'm beginning to enjoy these! This one had a couple of my favourite patterns to get things going.</div><div><br /></div><div><b>Puzzle 9</b>: 21:48 - <a href="https://puzz.link/p?mashu/10/10/30i060200601002693300i391000136000" rel="nofollow" target="_blank">https://puzz.link/p?mashu/10/10/30i060200601002693300i391000136000</a></div><div><br /></div><div>Solved in 0'36. Fine again! A perfectly reasonable puzzle with a don't close the loop early theme.</div><div><br /></div><div><b>Puzzle 10</b>: 21:50 - <a href="https://puzz.link/p?mashu/10/10/20130300i0309960j0302060100i000990" rel="nofollow" target="_blank">https://puzz.link/p?mashu/10/10/20130300i0309960j0302060100i000990</a></div><div><br /></div><div>Solved in 0'35. Felt like a perfectly good themed puzzle that solved very smoothly to me.</div><div><br /></div><div><b>Puzzle 11</b>: 21:52 - <a href="https://puzz.link/p?mashu/10/10/0910910a39330c9c910a33a03113310990" rel="nofollow" target="_blank">https://puzz.link/p?mashu/10/10/0910910a39330c9c910a33a03113310990</a></div><div><br /></div><div>Solved in 1'24. Admittedly I guessed here - I wasn't expecting a puzzle with a random selection of white pearls to give anything other than something that needed guesswork.</div><div><br /></div><div><b>Puzzle 12</b>: 21:53 - <a href="https://puzz.link/p?mashu/10/10/600060i020i00000606260000620060i00" rel="nofollow" target="_blank">https://puzz.link/p?mashu/10/10/600060i020i00000606260000620060i00</a></div><div><br /></div><div>Solved in 0'30. I guess all-black pearl puzzles are always going to be less interesting.</div><div><br /></div><div><b>Puzzle 13</b>: 21:56 - <a href="https://puzz.link/p?mashu/10/10/1930020a30i009077700i03916060010o0" rel="nofollow" target="_blank">https://puzz.link/p?mashu/10/10/1930020a30i009077700i03916060010o0</a></div><div><br /></div><div>Solved in 0'52. This attempt at anti-symmetry didn't quite work out, but a perfectly decent puzzle!</div><div><br /></div><div><b>Puzzle 14</b>: 21:58 - <a href="https://puzz.link/p?mashu/10/10/0062014000042160i0109000o199200000" rel="nofollow" target="_blank">https://puzz.link/p?mashu/10/10/0062014000042160i0109000o199200000</a></div><div><br /></div><div>Solved in 0'37. Another nice solve!</div><div><br /></div><div><b>Puzzle 15</b>: 22:00 - <a href="https://puzz.link/p?mashu/10/10/020100226i0030bi00ci2000a330060300" rel="nofollow" target="_blank">https://puzz.link/p?mashu/10/10/020100226i0030bi00ci2000a330060300</a></div></div><div><br /></div><div>Solved in 0'36 - more antisymmetry and solved well enough.</div>Unknownnoreply@blogger.com4tag:blogger.com,1999:blog-2031071943178978556.post-67753583174644185692022-05-29T15:00:00.111+01:002022-05-30T22:07:06.680+01:00pzprRT slitherlink experiment<div>Perhaps I'll reflect more on this after I finish the experiment - but for the time being I'm going to live-blog a slitherlink puzzle setting process which relies entirely on the hugely impressive <a href="https://semiexp.net/pzprrt/index.html" rel="nofollow" target="_blank">pzprRT</a> project. Let's see how many puzzles I can publish in the next 30 minutes...</div><div><br /></div><div><div>UPDATE: The answer is 9 puzzles, which feels like a lot for 30 minutes worth of work. I have now gone through and solved them all - they are unique and cover a surprising range of difficulty levels. Some of them are more fun to solve than others!</div><div><br /></div><div>Here are the puzzles:</div></div><div><br /></div><div><b>Puzzle 1:</b> 15:03 - <a href="https://puzz.link/p?slither/10/10/332b01co63cg635bkcg7251837bgck735cg25do32a321b" rel="nofollow" target="_blank">https://puzz.link/p?slither/10/10/332b01co63cg635bkcg7251837bgck735cg25do32a321b</a></div><div><br /></div><div>Solved in 1'02. The solve was a bit disjointed solving symmetric parts of the grid, but after that it was surprisingly smooth. Not the ugliest looking puzzle in the world either.</div><div><br /></div><div><div><b>Puzzle 2:</b> 15:06 - <a href="https://puzz.link/p?slither/10/10/1b0a122c2c1cdhbicdg06ch230bh81dgddidhb2c3b222c3b3d" rel="nofollow" target="_blank">https://puzz.link/p?slither/10/10/1b0a122c2c1cdhbicdg06ch230bh81dgddidhb2c3b222c3b3d</a></div></div><div><br /></div><div>Solved in 1'59. A smooth enough start to the puzzle, it got a bit fiddly at the end. Some interesting topological deductions in play here but it did feel somehow artificial.</div><div><br /></div><div><b>Puzzle 3: </b>15:09 - <a href="https://puzz.link/p?slither/10/10/gdch1ckdg111116aahd7706dh8286cchd511111bgdk1dhbb" rel="nofollow" target="_blank">https://puzz.link/p?slither/10/10/gdch1ckdg111116aahd7706dh8286cchd511111bgdk1dhbb</a></div><div><br /></div><div>Solved in 4'29. I didn't want to have to guess to solve any of these puzzles, but I ended up doing so here. There's probably a clever topological argument at play here, but this one definitely feels the most computer generated puzzle so far.</div><div><br /></div><div><b>Puzzle 4: </b>15:13 - <a href="https://puzz.link/p?slither/10/10/2b51bh2bh11bg26agbh2bc03b212bhac2bhcg52bg33dh2bh38d2b" rel="nofollow" target="_blank">https://puzz.link/p?slither/10/10/2b51bh2bh11bg26agbh2bc03b212bhac2bhcg52bg33dh2bh38d2b</a></div><div><br /></div><div>Solved in 3'13. Again needed to guess to finish things off at the end, so pretty hard. You can kind of see how I tried to build up a theme, and then compromised it quickly in order to get out the unique solution. Not amazing either.</div><div><br /></div><div><b>Puzzle 5: </b>15:17 - <a href="https://puzz.link/p?slither/10/10/b3321ao836dbg187126dgabhbdg812672dgb508ao3221cb" rel="nofollow" target="_blank">https://puzz.link/p?slither/10/10/b3321ao836dbg187126dgabhbdg812672dgb508ao3221cb</a></div><div><br /></div><div>Solved in 1'54. This one I remember trying to set by including a few patterns of clues I'm familiar with. It kind of works, but not entirely successfully. Definitely better than the previous two, but still with an undeniable artificial feeling to it.</div><div><br /></div><div><b>Puzzle 6: </b>15:21 - <a href="https://puzz.link/p?slither/10/10/g20271bgdgbg7202c75ci5c7c727a8c7ci75c2027cgagbg16202c" rel="nofollow" target="_blank">https://puzz.link/p?slither/10/10/g20271bgdgbg7202c75ci5c7c727a8c7ci75c2027cgagbg16202c</a></div><div><br /></div><div>Solved in 1'36. This one is largely easy and with a smooth solve, except for a fiddly end which kind of ruins things a bit. Again you can see how the initial visual theme got watered down a bit. I suspect it wouldn't take that much work on this to keep the theme stronger and have a more consistent solve.</div><div><br /></div><div><b>Puzzle 7: </b>15:23 - <a href="https://puzz.link/p?slither/10/10/3dj3d1bbi16516aj16751bl16571bj51651bid1b0cj3d" rel="nofollow" target="_blank">https://puzz.link/p?slither/10/10/3dj3d1bbi16516aj16751bl16571bj51651bid1b0cj3d</a></div><div><br /></div><div>Solved in 1'20. Basically a taburega puzzle for those familiar with the reference. Solves smoothly and with a couple of interesting moments, but always with the sense that the thing is one big gimmick.</div><div><br /></div><div><b>Puzzle 8:</b> 15:27 - <a href="https://puzz.link/p?slither/10/10/gag73bg27bg3627012chdg2c327dg0bg832c2cgch2238270dg62cg15bgb" rel="nofollow" target="_blank">https://puzz.link/p?slither/10/10/gag73bg27bg3627012chdg2c327dg0bg832c2cgch2238270dg62cg15bgb</a></div><div><br /></div><div>Solved in 2'16. This one felt very computer generated.</div><div><br /></div><div><b>Puzzle 9:</b> 15:30 - <a href="https://puzz.link/p?slither/10/10/jb580d8dpa3580dbblbb0880dap8a355adh" rel="nofollow" target="_blank">https://puzz.link/p?slither/10/10/jb580d8dpa3580dbblbb0880dap8a355adh</a></div><div><br /></div><div>Solved in 0'29. Nice to have an easy one, although that was always going to be the case using patterns like this. I suppose if I'm honest I'd have to say this one is fairly taburega-like as well.</div>Unknownnoreply@blogger.com3tag:blogger.com,1999:blog-2031071943178978556.post-1985619500662980522022-02-16T23:38:00.009+00:002022-02-17T22:51:05.095+00:00Results: Sudoku Design CompetitionHere's what you've all been waiting for dearest reader, the big reveal!<div><br /></div><div>Firstly, in a completely randomly generated order, here are your (mostly) esteemed and highly talented authors. I will be in touch over the next few days about the best way to send over the prizes.</div><div><br /></div><div>Entry A - 0403 came courtesy of <b>Yunus Emre Büyükkale</b></div><div>Entry B - 3233 came courtesy of <b>Tom Collyer</b> (yes, that use of the word "mostly" is there for a reason)</div><div>Entry C - 4235 came courtesy of <b>Anuraag Sahay</b></div><div>Entry D - 4438 came courtesy of <b>Jiri Hrdina</b></div><div>Entry E - 5308 came courtesy of <b>Sinchai Rungsangrattanakul</b></div><div>Entry F - 5617 came courtesy of <b>Yoshi Baroshi</b></div><div>Entry G - 6071 came courtesy of <b>Kumaresan R</b></div><div>Entry H - 6283 came courtesy of <b>Gareth Moore</b></div><div>Entry I - 7408 came courtesy of <b>Florian Wortmann</b></div><div>Entry J - 7704 came courtesy of <b>tamz29</b></div><div>Entry K - 9133 came courtesy of <b>Sam Cappleman-Lynes</b></div><div>Entry L - 9158 came courtesy of <b>Jack Lance</b></div><div><b><br /></b></div><div><div>[I will edit in a link to a permanent page on this blog to showcase the entries in all their glory, as well as update the PDF. For now the puzzles can be found:]</div><ul style="text-align: left;"><li>at the <a href="https://www.blogger.com/#">bottom of this post</a></li><li>in this <a href="https://www.blogger.com/#">PDF</a></li></ul></div><div>I have to say that I went to great lengths to draw up entries as soon I received them to anonymise them and leave until after the closing date, so that I had the best chance of not knowing whose puzzle I was solving as I was going through. The original idea with 3 picks for me was to roughly group into an easy, medium and hard puzzle, but it didn't quite work out that way in the end. The first three £25 prizes go to:</div><div><ul style="text-align: left;"><li>Entry D - <b>Jiri Hrdina</b></li></ul><div>I thought this was a wonderfully smooth-solving easy puzzle, setting up the obvious hidden pairs in boxes 2, 4, 6 and 8. These boxes together with box 5 then resolve themselves leaving the corners of the puzzle to be mopped up via some more hidden single. The sort of highly polished easy puzzle I really appreciate!</div></div><div><ul style="text-align: left;"><li>Entry H - <b>Gareth Moore</b></li></ul><div>I thought this puzzle moved away from an easy level in a very pleasing way, nicely setting up a naked triple half-way through the solve; this was definitely something that set this puzzle apart for me. </div><div><br /></div><div>But don't just take my word for it, one very experienced sudoku solver thought that:</div></div><blockquote><i>H - clearly a favourite. It has a nice solving path, not too easy / not ridiculously hard. ... It would be a good puzzle for the WSC finals or something.</i></blockquote><div><div><ul style="text-align: left;"><li>Entry L - <b>Jack Lance</b></li></ul></div><div>Last but certainly not least, as soon as I saw entry L I knew I had a winner on my hands. The symmetry of this puzzle is absolutely stunning with consecutive pairs arranged in Battenberg formation around the grid, attached to another consecutive pair for good measure. However what I find most pleasing about the symmetry is that it doesn't fall into the pastiched trap of a <a href="https://www.sudokuwiki.org/Gurths_Theorem" rel="nofollow" target="_blank">Gurth's Theorem</a> situation where you only get to solve half (or even a quarter) of a puzzle. Crucially with this puzzle different given digits in the grid are not rotational symmetric from other given digits, which breaks the symmetry and ensures the puzzle maintains an interesting, albeit easier solve. Absolutely beautiful - this is the single puzzle from the set that I wish I had written and in my eyes is now *the* definitive puzzle for this layout. For whatever that is worth :-)</div></div><div><br /></div><div>Finally, the last £25 went down to the public vote. My previous post announced that I would be disregarding votes from the authors themselves, but in the end this made no difference to the overall winner. Which is:</div><div><ul style="text-align: left;"><li>Entry G - <b>Kumaresan R</b></li></ul></div><div>Interestingly my dearest readers plumped for one of the Extra Hard puzzles, which i think neatly wraps up the set of prizes (I should add I had picked my favourites before I counted the votes - in theory an entry could have one two prizes). It must be said Extra Hard in this case comes with a bit of a health warning - you can use a uniqueness technique to turn this puzzle into a much smoother solve, however knowing that some solvers prefer not to use uniqueness if they can help it, this was how I felt I had to rate the puzzle.</div><div><br /></div><div>The author had this to say about the puzzle: </div><i><blockquote>Actually it is not hard but an advance technique is involved. Without this technique unique rectangle can be used to complete the puzzle.</blockquote></i><div>Whilst another solver said:<br /><blockquote><i>The puzzle I preferred requires a very unusual way of uniqueness, which once found solves the puzzle. Not sure for the 10/10 rating for difficulty since it was an easy spot, but surely 10/10 of cleverness!</i></blockquote><div>Narrowly losing out in the public vote (regardless of whether author votes were taken into account or not) were entries H and F. We've already discussed entry H, but entry F was the other Extra Hard entry from the set, and perhaps demonstrates that there is something of an appetite for more difficult puzzles.</div></div><div><br /></div><div>That's it for now - congratulations to all the participants and especially the 4 winners! I'll probably look to do some more of these fixed layout competitions with other puzzle style in the future, as I think it went down well with both those who submitted a puzzle as well as those who voted on them. </div>Unknownnoreply@blogger.com2tag:blogger.com,1999:blog-2031071943178978556.post-65175702725066352602022-02-15T10:43:00.001+00:002022-02-15T10:43:32.750+00:00Puzzle design competition: results soonThis will be the penultimate post regarding the puzzle design competition. I have decided my top 3 and will be republishing the puzzles with credit over the next couple of days. I hope you are all looking forward to finally being able to put names to puzzles!<div><br /></div><div>I had fewer votes (10) than entries (12), which I find very curious - I’d like to hear what factors might have been holding people back, even if it’s just speculation. To those who did vote, thank you very much for participating and leaving your comments, I am glad that you enjoyed this idea.</div><div><br /></div><div>Some of the 10 votes were from entrants, which I had assumed wouldn’t really matter given I was expecting far more votes than entries, however before tallying up the votes it seems like the only sensible thing to do is to disregard author votes. I can’t see how an individual vote for oneself would not be significant in these circumstances, and given not every author voted there is clear unfairness here in my eyes. </div>Unknownnoreply@blogger.com6tag:blogger.com,1999:blog-2031071943178978556.post-20197365161317353812022-02-12T13:31:00.005+00:002022-02-12T13:31:57.539+00:00Public vote closes soonA friendly reminder to all my dearest readers that the public vote for your favourite entries from the puzzle design competition is closing soon - 23:59 GMT on Monday 14th February. <div><br /></div><div>I don’t have all that many votes right now so it’s be good to change this over the next couple of days to see if we can settle on a clear winner. </div><div><br /></div><div>I hope everyone has been enjoying the puzzles so far!</div>Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-2031071943178978556.post-75415691113302949862022-02-04T18:24:00.003+00:002022-02-04T18:32:55.345+00:00Puzzle Design Competition - Public VoteHi everyone,<div><br /></div><div>In case you haven't already seen, I have published the anonymised entries of the Sudoku Fixed Layout Design Competition. Thanks once again to each of the authors who contributed a puzzle.</div><div><br /></div><div>The puzzles can be found:</div><div><ul style="text-align: left;"><li>at the <a href="https://tcollyer.blogspot.com/2022/02/puzzle-design-competition-anonymised.html" rel="nofollow" target="_blank">bottom of this post</a></li><li>in this <a href="https://drive.google.com/file/d/1cAHtZ9yNtZSfbBoMNiwrBUnkGsrZBc3Z/view?usp=sharing" rel="nofollow" target="_blank">PDF</a></li></ul>Please note that I haven't asked the authors whether they are happy to provide links to online solving tools, so please take this into consideration before transposing the puzzles and sharing.</div><div><br /></div><div>As a reminder, I will be awarding 3 x £25 prizes to my person favourites. The fourth £25 prize will be awarded to the winner of the public vote.</div><div><br /></div><div>In order to vote, you need to select your own 3 favourite entries and order them in preference. Your first preference will score 5 points, your second will score 3 points, and your 3rd will score 1 point. At the end I'll add up the points and whoever has the most will win.</div><div><br /></div><div><div><a href="https://forms.gle/Jii5hrfRNxk9BJKi8" rel="nofollow" target="_blank">https://forms.gle/Jii5hrfRNxk9BJKi8</a></div></div><div><br /></div><div>To ensure that people only vote once, the form requires you to be logged in to google. If this is a concern to you, please leave a comment and I'll see if there's another way that you're able to cast a vote.</div><div><br /></div><div>Closing date for votes will be: <b>23.59pm GMT on Monday 14th February</b>.</div>Unknownnoreply@blogger.com4tag:blogger.com,1999:blog-2031071943178978556.post-35364125140853719022022-02-01T19:07:00.004+00:002022-02-04T18:25:20.718+00:00Puzzle Design Competition - Anonymised EntriesI am pleased to announce there were a total of 12 entries to the Sudoku Fixed Layout Design Competition. Thank you very much to everyone who submitted an entry, I am honoured that each of you took the time to participate and I am super excited to get solving and judging what I am sure are going to be a truly extraordinary set of puzzles!<div><br /></div><div>I am in a bit of a rush at the time of the initial post - expect this post to updated, probably with a PDF attachment for your printing convenience. Please note that I haven't asked the authors whether they are happy to provide links to online solving tools, so please take this into consideration before transposing the puzzles and sharing.</div><div><br /></div><div>UPDATE: difficulty ratings have been added to the post below, and I have also put together a PDF file. Please note the difficulty ratings are based on my initial solves - a sample of 1 is not usually great for the purposes of testing so do take these with a pinch of a salt. It is fair to say that the two entries rated at 10 / 10 are significantly more difficult than the rest of the set however!</div><div><br /></div><div><a href="https://drive.google.com/file/d/1cAHtZ9yNtZSfbBoMNiwrBUnkGsrZBc3Z/view?usp=sharing" rel="nofollow" target="_blank">PDF of entries</a><br /><div><br /></div><div>Expect a further post in the next couple of days with the voting form and corresponding deadline (which will be in at least a week's time), but in the meantime I thought all my dearest readers would be very keen to get solving as well.</div><div><br /></div><div>Entries have been anonymised using four random digits as a reference. I will further update this page with a rough indication of difficult a bit later; for now I will add that, based on the authors' self-assessments, the difficult levels within the collection range from easy through to very difficult.</div><div><br /></div><div>The last thing to say is that I have run these puzzles through a computer checker to verify they solve uniquely only *after* I have redrawn into a standard format, so this should mean that there are no transposition errors below. If not, please let me know in the comments.</div><span><a name='more'></a></span><div><br /></div><div><b>Entry A - 0403</b></div><div><i>Rated 3 / 10 [Easy]</i></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/a/AVvXsEhT_iBq8rA90xBFNEmh7p0T7Cl1Xb12dwPL1oiytXkzfwHmxkeS7FOx4_kOBa8zp_FuJXwTLKzPp8qxmxWxp2buy4dW6Uc845xBPO646w6hCIDsP9Xrok3bY10Z6PnJ0ihOPc9HiU4zH28lT6e9wvJwNPAuEfFPKr51DyIV8uIRHBEygiA1tLE0rjnDWA=s435" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="435" data-original-width="435" height="320" src="https://blogger.googleusercontent.com/img/a/AVvXsEhT_iBq8rA90xBFNEmh7p0T7Cl1Xb12dwPL1oiytXkzfwHmxkeS7FOx4_kOBa8zp_FuJXwTLKzPp8qxmxWxp2buy4dW6Uc845xBPO646w6hCIDsP9Xrok3bY10Z6PnJ0ihOPc9HiU4zH28lT6e9wvJwNPAuEfFPKr51DyIV8uIRHBEygiA1tLE0rjnDWA=s320" width="320" /></a></div><div class="separator" style="clear: both; text-align: center;"><br /></div><div><b>Entry B - 3233</b></div><div><i>Rated 4 / 10 [Medium]</i></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/a/AVvXsEiEQuJmJBmXKvckS5s4WRi09HWv1sM0kytkBNNr-M6QV4S69K5ZvXEw88_n65h16Mqj56e6ohKPh_No9lB3A0dEAch5yvbGy1AHVn-9pJHeaGElVhFdB7L-RsZY8X4KrDGJqt-dUgm9LrUGTGyOjufSGppJbB813ehQrIfHNVQPEB2_7PCsLvVyr6PhtA=s435" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="435" data-original-width="435" height="320" src="https://blogger.googleusercontent.com/img/a/AVvXsEiEQuJmJBmXKvckS5s4WRi09HWv1sM0kytkBNNr-M6QV4S69K5ZvXEw88_n65h16Mqj56e6ohKPh_No9lB3A0dEAch5yvbGy1AHVn-9pJHeaGElVhFdB7L-RsZY8X4KrDGJqt-dUgm9LrUGTGyOjufSGppJbB813ehQrIfHNVQPEB2_7PCsLvVyr6PhtA=s320" width="320" /></a></div><div><b><br /></b></div><div><b>Entry C - 4235</b></div><div><i>Rated 4 / 10 [Medium]</i></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/a/AVvXsEj8tQ5R4fjO8hidk_CVujDrscbSid4Emwax_TxuwwHWvUEoDDlUJvOPRVzOubXGHI9VUqsINMQG4MimpRjzhduC0hIyk55BoBevkJxk9bcu8smPrxNfpDKKzHwKdiOconWDGl-h2WYEuJbnN7evtt4KZwE8P-nnOZOhGPU9wXztoDQQkfTOTO3osA1AoA=s435" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="435" data-original-width="435" height="320" src="https://blogger.googleusercontent.com/img/a/AVvXsEj8tQ5R4fjO8hidk_CVujDrscbSid4Emwax_TxuwwHWvUEoDDlUJvOPRVzOubXGHI9VUqsINMQG4MimpRjzhduC0hIyk55BoBevkJxk9bcu8smPrxNfpDKKzHwKdiOconWDGl-h2WYEuJbnN7evtt4KZwE8P-nnOZOhGPU9wXztoDQQkfTOTO3osA1AoA=s320" width="320" /></a></div><div><b><br /></b></div><div><b>Entry D - 4438</b></div><div><i>Rated 3 / 10 [Medium]</i></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/a/AVvXsEjKz7eV8eaNJvNKfTU-KpiZC3ALA_AntCugO0RNDLeh9uXYYqXDcSbw2n_wGQz7H_Q0EVtq5J3NvcG08Z-IebCIB1-zDCjMqK1fhzfjn6FVbj_zHY7LsrsUW3yjH190i6FWNnwiU3NSy0a-MjDpzk8Iiz_59HiY1224JGJ0GK1I7sqn9xOcbqC8hHmSZg=s435" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="435" data-original-width="435" height="320" src="https://blogger.googleusercontent.com/img/a/AVvXsEjKz7eV8eaNJvNKfTU-KpiZC3ALA_AntCugO0RNDLeh9uXYYqXDcSbw2n_wGQz7H_Q0EVtq5J3NvcG08Z-IebCIB1-zDCjMqK1fhzfjn6FVbj_zHY7LsrsUW3yjH190i6FWNnwiU3NSy0a-MjDpzk8Iiz_59HiY1224JGJ0GK1I7sqn9xOcbqC8hHmSZg=s320" width="320" /></a></div><div><br /></div><div><b>Entry E - 5308</b></div><div><i>Rated 5 / 10 [Medium]</i></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/a/AVvXsEiRrUnrkPWU_8S6CcxWXSZ8JTZ7rGrUz5x-3rkSQJv6C8hh8mh-2WKWtaQSi7qhyUo35SdHnSxcdWjlx_2ytn7aaE72cGRLPSpdT4-wrVRGciCBDgO1vwxvSYRNnH-q83rh5Ra3c5LyZrvEfmch6QqC6XYopyFyjqH8mYdrD2AEzxBbu3CkoRAYCiqgtQ=s435" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="435" data-original-width="435" height="320" src="https://blogger.googleusercontent.com/img/a/AVvXsEiRrUnrkPWU_8S6CcxWXSZ8JTZ7rGrUz5x-3rkSQJv6C8hh8mh-2WKWtaQSi7qhyUo35SdHnSxcdWjlx_2ytn7aaE72cGRLPSpdT4-wrVRGciCBDgO1vwxvSYRNnH-q83rh5Ra3c5LyZrvEfmch6QqC6XYopyFyjqH8mYdrD2AEzxBbu3CkoRAYCiqgtQ=s320" width="320" /></a></div><div><br /></div><div><b>Entry F - 5617</b></div><div><i>Rated 10 / 10 [Extra Hard]</i></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/a/AVvXsEhStEh8mHsiqYjO-8pD9R9r4zAR057tNUVfrIXQ6NvHqr_MijMYXrXbgwU0clXVrX_hNN_j5AiNhb6OdMbdNCtXLOsTjDBSdUqQNzngKgAyZ0eBlwSJ86e-oZFWps0hiaAY8NAJVkYeTtBLUE92iZ2Zoswd5nTQ8TTnNvZqn7SgFprH8oMjkFPH9NlyLA=s435" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="435" data-original-width="435" height="320" src="https://blogger.googleusercontent.com/img/a/AVvXsEhStEh8mHsiqYjO-8pD9R9r4zAR057tNUVfrIXQ6NvHqr_MijMYXrXbgwU0clXVrX_hNN_j5AiNhb6OdMbdNCtXLOsTjDBSdUqQNzngKgAyZ0eBlwSJ86e-oZFWps0hiaAY8NAJVkYeTtBLUE92iZ2Zoswd5nTQ8TTnNvZqn7SgFprH8oMjkFPH9NlyLA=s320" width="320" /></a></div><div><br /></div><div><b>Entry G - 6071</b></div><div><i>Rated 10 / 10 [Extra Hard]</i></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/a/AVvXsEjefpetI9fmE_xu8RxosiMZUKBeR3G-EZgpVWYms99aXMciQnvqelPwLhGbcPwNHF_7tptxXb28IATcPgezWWZLa6ZUO-UcTglEdDH4QTLd2Rcc9jqPONaMOCL-zy29s9p1Q7S7eSWYP5kFH4p8vjHxU6VSgMlCoxyAFh0WC9gd3-OfrVZi_pcK1WLu6Q=s435" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="435" data-original-width="435" height="320" src="https://blogger.googleusercontent.com/img/a/AVvXsEjefpetI9fmE_xu8RxosiMZUKBeR3G-EZgpVWYms99aXMciQnvqelPwLhGbcPwNHF_7tptxXb28IATcPgezWWZLa6ZUO-UcTglEdDH4QTLd2Rcc9jqPONaMOCL-zy29s9p1Q7S7eSWYP5kFH4p8vjHxU6VSgMlCoxyAFh0WC9gd3-OfrVZi_pcK1WLu6Q=s320" width="320" /></a></div><div><br /></div><div><b>Entry H - 6283</b></div><div><i>Rated 5 / 10 [Medium]</i></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/a/AVvXsEg2fUkZaXsf6kPlQTEIRhac_Mb17EN1dOHrkv8gfHWpkQpccdeISGerL7ptP0a44zcHbLHLCCZp1wTQNfIlJ9w147VSkbw9pjLozsx57odDPv0iGUd0HVtMvQptOcLS2NquBaLPsZRnwXeN4lSR1bbKDYy77H9BnB8SDK2swbNPd0sglWtoTZJiZIqaCQ=s435" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="435" data-original-width="435" height="320" src="https://blogger.googleusercontent.com/img/a/AVvXsEg2fUkZaXsf6kPlQTEIRhac_Mb17EN1dOHrkv8gfHWpkQpccdeISGerL7ptP0a44zcHbLHLCCZp1wTQNfIlJ9w147VSkbw9pjLozsx57odDPv0iGUd0HVtMvQptOcLS2NquBaLPsZRnwXeN4lSR1bbKDYy77H9BnB8SDK2swbNPd0sglWtoTZJiZIqaCQ=s320" width="320" /></a></div><div><br /></div><div><b>Entry I - 7408</b></div><div><i>Rated 5 / 10 [Medium]</i></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/a/AVvXsEibLlRfeARjR4QxRDhvbKfn90ZpJ1rLqBe4y5JRzmqTD-HswavFZeJT-ZBtYf5CSS31r1vDLVaFn7Zike96p9o0Q_6EsBHiFKOy7DZ-gyp_EyVvr1l2F3bbG0zUuu9eoz8FOVjYmOFS7le_48Gvd0Nmc29E6ZiI_aCaEKo9uVExMVSRnjKLD7qG3h9NBA=s435" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="435" data-original-width="435" height="320" src="https://blogger.googleusercontent.com/img/a/AVvXsEibLlRfeARjR4QxRDhvbKfn90ZpJ1rLqBe4y5JRzmqTD-HswavFZeJT-ZBtYf5CSS31r1vDLVaFn7Zike96p9o0Q_6EsBHiFKOy7DZ-gyp_EyVvr1l2F3bbG0zUuu9eoz8FOVjYmOFS7le_48Gvd0Nmc29E6ZiI_aCaEKo9uVExMVSRnjKLD7qG3h9NBA=s320" width="320" /></a></div><div><br /></div><div><b>Entry J - 7704</b></div><div><i>Rated 4 / 10 [Medium]</i></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/a/AVvXsEgrIbcUoPof-POs2_CI_cnmVIXAW0wqtCpcnuHQtSrLbZz1LM7dsNf6pHCNlWZDaz5dP5YdZ4xnG_FphGLn6f04I0lQreUHTjoRrz453U8BEarUfxQt8ZWjAkFgarQwz4HkvWfbl4II9z9Rf0zQJuj_DMbIK6iX2RSOLe9xdlDUVbvkX41wUasNC89aQQ=s435" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="435" data-original-width="435" height="320" src="https://blogger.googleusercontent.com/img/a/AVvXsEgrIbcUoPof-POs2_CI_cnmVIXAW0wqtCpcnuHQtSrLbZz1LM7dsNf6pHCNlWZDaz5dP5YdZ4xnG_FphGLn6f04I0lQreUHTjoRrz453U8BEarUfxQt8ZWjAkFgarQwz4HkvWfbl4II9z9Rf0zQJuj_DMbIK6iX2RSOLe9xdlDUVbvkX41wUasNC89aQQ=s320" width="320" /></a></div><div><br /></div><div><b>Entry K - 9133</b></div><div><i>Rated 4 / 10 [Medium]</i></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/a/AVvXsEhqLm-WCTy90rShVaf3YV34mKL2vip54rWcMwc1fHaYc-ONYqkRcryiJ3TsEGtCo9VXCnn5Q5QE1LRTD880EPVn26AgS9VCChfdRfzy6vEVL6UdJlRGiHEtFulN4HhgCh408Nt-JPtczu3rNZZgF_LEgJHzSVJRlAZI8NtLYM2CjUYwhsd5cq6t_w42Ww=s435" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="435" data-original-width="435" height="320" src="https://blogger.googleusercontent.com/img/a/AVvXsEhqLm-WCTy90rShVaf3YV34mKL2vip54rWcMwc1fHaYc-ONYqkRcryiJ3TsEGtCo9VXCnn5Q5QE1LRTD880EPVn26AgS9VCChfdRfzy6vEVL6UdJlRGiHEtFulN4HhgCh408Nt-JPtczu3rNZZgF_LEgJHzSVJRlAZI8NtLYM2CjUYwhsd5cq6t_w42Ww=s320" width="320" /></a></div><div><br /></div><div><b>Entry L - 9158</b></div><div><i>Rated 3 / 10 [Easy]</i></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/a/AVvXsEhJn8WUHRpq_jHYRu0wTTs0CZOc1wgFIYa-WNfD_fWK5PuKpNshwlKDSJ_FQNKpt9yQukwtRTyrCHe-XNnxryF8SaSVAyXxmY9SA1QmC9gt7vJC6Q5JfNYj2x-eNvb9KEN62q3SVir93vlrtH8U_JhazhaSgV_zC4RftjY8Ge97MqHoKEdvwFZ5btyUXA=s435" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="435" data-original-width="435" height="320" src="https://blogger.googleusercontent.com/img/a/AVvXsEhJn8WUHRpq_jHYRu0wTTs0CZOc1wgFIYa-WNfD_fWK5PuKpNshwlKDSJ_FQNKpt9yQukwtRTyrCHe-XNnxryF8SaSVAyXxmY9SA1QmC9gt7vJC6Q5JfNYj2x-eNvb9KEN62q3SVir93vlrtH8U_JhazhaSgV_zC4RftjY8Ge97MqHoKEdvwFZ5btyUXA=s320" width="320" /></a></div><br /><div><br /></div></div>Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-2031071943178978556.post-21014880952335620682022-01-22T13:27:00.003+00:002022-01-22T13:27:20.018+00:00Update - Puzzle Design CompetitionThis is a quick update on the previous post. I haven't really given much thought to how the public vote is going to work, so I've decided to keep it simple.<div><br /></div><div>All the entries will be anonymised and published after the closing date of 31st January, and I will set up a new google form for you to pick your own top 3. First preference will be awarded 5 points, second preference 3 points and third preference 1 point. I'll then tot everything up and the entry with the most points will be the public winner.</div><div><br /></div><div>I'll tentatively say that I'll keep the vote open for about a week after I publish the anonymised submissions. it really depends on the number of submissions as I'd like to give everyone a reasonable amount of time to solve the puzzles and come to an informed decision about their favourites.</div><div><br /></div><div>After the public vote I'll publish all the entries with full credit, and contact the winners for the best way to send across the prize money.</div><div><br /></div><div>That's all for now, I'm really looking forward to solving all these great entries. Thanks to everyone who has submitted so far.</div>Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-2031071943178978556.post-27316482249401818872022-01-05T18:54:00.007+00:002022-01-05T19:02:56.212+00:00New Year Puzzle Design CompetitionSomewhat on a whim, dearest reader, I have decided to try and revive one of the lesser known institutions of nikoli.com. The idea was to gather together as many authors as possible to see what they could collectively achieve when they are additionally constrained by a fixed layout of givens.<div><br /></div><div>I'd like to think this would work as an idea all by itself, but by means of encouragement I am willing to offer cash prizes of £25 to my three favourites. An additional prize of £25 is offered to the winner of a public vote. I will be accepting entries until the 31st January.</div><div><br /></div><div><b>The Puzzle and the Layout:</b></div><div>For this competition, I have chosen Sudoku, without any extra rules, constraints or other variations. The layout of givens I would like you to follow is this one:</div><div><br /></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/a/AVvXsEiPaBMcag1Ybxk2hIa4kl9dMdpCQIlDCVmB-DS9edgRVhQOH-J6TI3lF4QSv0l94baxLDrEEv79m3OwJchkdxEF8hEWuivYO0mqzjjzCLwiKOqrolyZO881C8MT29NUPV_HXuDMw741Q1cmKX65f8arO58iE13_Hh_2CH8LC180BcubwEQY3FEjXBuOsA=s408" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="408" data-original-width="408" height="320" src="https://blogger.googleusercontent.com/img/a/AVvXsEiPaBMcag1Ybxk2hIa4kl9dMdpCQIlDCVmB-DS9edgRVhQOH-J6TI3lF4QSv0l94baxLDrEEv79m3OwJchkdxEF8hEWuivYO0mqzjjzCLwiKOqrolyZO881C8MT29NUPV_HXuDMw741Q1cmKX65f8arO58iE13_Hh_2CH8LC180BcubwEQY3FEjXBuOsA=s320" width="320" /></a></div><div><br /></div><div>This layout is close to my heart, being very similar to the <a href="http://tcollyer.blogspot.co.uk/2009/05/tom-collyer-writes-some-logic-puzzles_1611.html" rel="nofollow" target="_blank">first ever puzzle I published on this blog back in 2009</a>. Back then I couldn't quite get this working without having to add an extra given digit at R5C5, but I'm sure my dearest readers will be able to manage without that. </div><div><br /></div><div>As an example, I made a small nod to this in one puzzle I made for the 2014 World Sudoku Championships. This puzzle was additionally designed so that there was no given 9 in the grid.</div><div><br /></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/a/AVvXsEjyJqFhYIzs_zbnjrBcWNDyXGoQLbawp3ADLf-v2ekqeZfTu8fMuOGGGQj0_EPw4NuduhcPL-RFpzl9nGgkrTDUKZqdg9M-RR44ANXnkpTzBLgvNokjloo3VnLNHPfP-E9TJW0K8nt3cufFi6ER6kWlE5Xot5zNyN5z67uw8PtyB-uiGYLvD4aPEbreyg=s433" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="433" data-original-width="433" height="320" src="https://blogger.googleusercontent.com/img/a/AVvXsEjyJqFhYIzs_zbnjrBcWNDyXGoQLbawp3ADLf-v2ekqeZfTu8fMuOGGGQj0_EPw4NuduhcPL-RFpzl9nGgkrTDUKZqdg9M-RR44ANXnkpTzBLgvNokjloo3VnLNHPfP-E9TJW0K8nt3cufFi6ER6kWlE5Xot5zNyN5z67uw8PtyB-uiGYLvD4aPEbreyg=s320" width="320" /></a></div><div><br /></div><div><b>Submitting your Entry:</b></div><div>This should work via the following google form: <a href="https://forms.gle/dZL7XN3GwJWGPEcS6" rel="nofollow" target="_blank">https://forms.gle/dZL7XN3GwJWGPEcS6</a></div><div><br /></div><div>Please let me know if this isn't working for you. I think it requires you to be signed in to Google to work, and you will need to attach your entry in a PDF or Image format.</div><div><br /></div><div>The form should additionally allow you to edit your entry after submitting if you think you can do better, although please note that it will only accept one submission.</div><div><br /></div><div><div><b>Rules:</b></div><div><ul style="text-align: left;"><li>No more than one entry per person.</li><li>Collaborations between two or more people are permitted (However you will have to determine how to share any prizes).</li><li>Each entry must be:</li><ul><li>A uniquely solvable puzzle under sudoku rules (no extra constraints or grid decorations permitted).</li><li>Have given digits as per the given layout.</li><li>Not totally computer generated (some computer assistance is fine).</li></ul><li>The last date I will accept entries is 23:59 GMT on Monday 31st January 2022.</li><li>By submitting an entry, you retain full author's copyright, but agree to let me redraw your entry and publish it (with credit to you) on my blog.</li><li>Entries must not be shared or discussed with other entrants before the winners have been declared.</li></ul><div>I reserve the right to disqualify entrants and entries not conforming to these rules. My decisions are final.</div></div><div><br /></div><div><b>Prizes:</b></div><div><ul style="text-align: left;"><li>This will kind of depend on how well I've chosen the layout, and the entries received.</li><li>The overall prize pool is £100. This will include £25 each for my three favourite entries, and a further £25 for the public vote.</li><li>I am happy to send prizes internationally using services such as <a href="https://wise.com" rel="nofollow" target="_blank">Wise</a> - although please note that prizes will also need to cover any associated charges and fees.</li><li>You do not have to claim the prize if you do not want to.</li></ul></div><div><br /></div><div><b>Voting:</b></div><div>After the closing date I will anonymously draw up the entries for your solving pleasure. I am not sure how many entries I will get so I won't commit to a publishing date. However, after the entries have been published there will be a 7 day voting period. I will have a think about exactly how I want the voting system to work, but it is likely to involve individuals picking their top 3, and me somehow aggregating this information all together!</div><div><br /></div><div>Any attempts to manipulate the voting will result in disqualification for the public vote prize.</div></div>Unknownnoreply@blogger.com6tag:blogger.com,1999:blog-2031071943178978556.post-13263223868661159322021-12-03T20:41:00.003+00:002021-12-03T20:41:45.552+00:00Puzzle 360: Killer SudokuI'm sure this sort of thing must have been tried before, dearest reader. Not my most elegant work, but the vast majority of the windows will need to be opened if you want to make it through to the end. Enjoy!<blockquote>
<b> #360 Killer Sudoku</b> – rated <b>6/10 [Hard]</b><div><div class="separator" style="clear: both;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgPvTMjetjbYmCzY_tzmi-6Qbx77tAJ1_ce3wOeNUR7bTIiaFv12g7wHc9Gys4JO6-6rDO7xDL7rZIvVOzBqrkZCcjFFsZPmodhLyToCqLonVoOtC2oOEvKiXmy3pV-Gc7hjrhBCDwWs9cP/s435/360ks.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="435" data-original-width="435" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgPvTMjetjbYmCzY_tzmi-6Qbx77tAJ1_ce3wOeNUR7bTIiaFv12g7wHc9Gys4JO6-6rDO7xDL7rZIvVOzBqrkZCcjFFsZPmodhLyToCqLonVoOtC2oOEvKiXmy3pV-Gc7hjrhBCDwWs9cP/s320/360ks.png" width="320" /></a></div>
</div></blockquote>
<a href="https://tcollyer.blogspot.com/p/copyright-statement.html" rel="nofollow" target="_blank">All puzzles © Tom Collyer 2009-21</a>.Unknownnoreply@blogger.com1tag:blogger.com,1999:blog-2031071943178978556.post-32218997569169966072021-09-02T21:30:00.002+01:002021-09-03T08:30:14.548+01:00Puzzle 359: HeyawakeIt's been a long time since I did Heyawake. As with the recent Masyu, it's not entirely Nikoli smooth, and there are bits I'd even go so far as describing as fiddly, but hopefully it makes for a decent challenge at least.<div><br /></div><div>As a bit of an aside, I came across semiexp.net recently, and lots of it basically seems like magic to me. For example:</div><div><ul style="text-align: left;"><li><a href="https://semiexp.net/games/infinite_numberlink/index.html" rel="nofollow" target="_blank">A Numberlink Generator</a></li><li><a href="https://semiexp.net/slitherlink/index.html" rel="nofollow" target="_blank">(Surprisingly good) Computer generated Slitherlink</a></li></ul><div>There's also something called <a href="https://semiexp.net/pzprrt/index.html" rel="nofollow" target="_blank">pzprRT</a>, which seems like an extraordinary setting tool. Basically, for a small number of types, including 4 of my favourites: Yajilin, Masyu, Slitherlink and indeed Heyawake, you are able to mark up your puzzle using the pzprjs project (i.e. as featured on puzz.link) and then you can press a button and it will give you the live deductions corresponding to the clues you've put in.</div><div><br /></div><div>I am still generally avoiding marking up my puzzles using puzz.link, as the interaction between the puzzle player and the hidden database (which stores the metadata of logged in solvers) is still not entirely clear to me. I think I saw that this metadata is indexed by hashed versions of the puzzle URLs rather than the URLs themselves - this would kind of be fine by me I think as it means the database would be genuinely only metadata, rather than actual puzzle data making up some kind of secret dystopian mega master puzzle database. But in any case pzprRT generated me a puzz.link, so I think it means this puzzle is now on the database, hashed or otherwise, and now what’s done is done.</div><div><br /></div><div>I suppose what it does mean for you, dearest reader, is that you can also <a href="https://puzz.link/p?heyawake/24/14/a9109944154gh54gi4ki28iki94mi94iq94ib94i9a8i299289548954114kg44ig00v003g1vjovs0000007vsfv007000000007007vhvv0000001voufs0e007o002212g344452324g15g45g4g4424534031h411" rel="nofollow" target="_blank">play along online</a>! I may even start making a habit of it. Enjoy!</div>
<blockquote><b> #359 Heyawake</b> – rated <b>8/10 [Very Hard]</b><div><div class="separator" style="clear: both;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgzfkgLiAR3pt86AzEuYig8NV6c-s7S4TosBk8kweFGSIow6VIdrHqAxUPV4VCijsb1_jZ3-swRU3_zeqMH4MdhLuX08axpq0OqElQz4_7v5v0qWo4XUXwO8Ekl-Kakpjuz6LSQ5erXjY8i/s867/359he.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="507" data-original-width="867" height="187" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgzfkgLiAR3pt86AzEuYig8NV6c-s7S4TosBk8kweFGSIow6VIdrHqAxUPV4VCijsb1_jZ3-swRU3_zeqMH4MdhLuX08axpq0OqElQz4_7v5v0qWo4XUXwO8Ekl-Kakpjuz6LSQ5erXjY8i/s320/359he.png" width="320" /></a></div></div></blockquote>
<a href="https://tcollyer.blogspot.com/p/copyright-statement.html" rel="nofollow" target="_blank">All puzzles © Tom Collyer 2009-21</a>.</div>Unknownnoreply@blogger.com7tag:blogger.com,1999:blog-2031071943178978556.post-40809456130599814742021-08-22T19:49:00.005+01:002021-08-22T19:49:41.117+01:00Puzzle 358: MasyuSo I don't think this is really as smooth and polished so as to live up to Nikoli standards, but there are a couple of flashes of something here and there to keep you interested, dearest reader. Enjoy!<br />
<blockquote><b> #358 Masyu</b> – rated <b>6/10 [hard]</b><div class="separator" style="clear: both;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgzfdXBQMCydx7SeR5F7CqwpNHI4Zwpx-tIE2V847RI-XV5tHkhRmbGXiaGXDlFxGZteZRF4MhPSmdThxcjetLDreFracNj7cZ_gpOkxuGjxlX9alda5_pz6_J0K3Lbbkatc_DV2X-GxL9x/s813/358ma.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="475" data-original-width="813" height="187" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgzfdXBQMCydx7SeR5F7CqwpNHI4Zwpx-tIE2V847RI-XV5tHkhRmbGXiaGXDlFxGZteZRF4MhPSmdThxcjetLDreFracNj7cZ_gpOkxuGjxlX9alda5_pz6_J0K3Lbbkatc_DV2X-GxL9x/s320/358ma.png" width="320" /></a></div></blockquote>
<a href="https://tcollyer.blogspot.com/p/copyright-statement.html" rel="nofollow" target="_blank">All puzzles © Tom Collyer 2009-21</a>.Unknownnoreply@blogger.com2tag:blogger.com,1999:blog-2031071943178978556.post-39533206361111263892021-08-21T15:02:00.000+01:002021-08-21T15:02:36.382+01:00Puzzle 357: SudokuI'm going to be posting a few Nikoli style puzzles over the next few days. I was about to say that there probably won't be any Sudoku, but that's not entirely true. As a bit of a preview, there will probably be a few Renban Groups that I'll post, mainly because I've seen too many examples where the groups are presented as lines, rather than shaded regions, and it's annoyed me past a critical point.<div><br /></div><div>Anyhow, puzzles like these I guess aren't as common as they used to be. Nothing too flash here. Enjoy!
<blockquote><b> #357 Sudoku</b> – rated <b>3/10 [Easy]</b><div><div class="separator" style="clear: both;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj0RlESMDnBZAPk1xUWL2_jSHWRRdb_8DW1n2fnjl___2qKXWQ1NP4NsDFGtyOA_QhJtYrRbXElay-4JtwI_drOE5kZoYv3FdEjJQVumV_dHVR-7Y69QWlFU8SKWc1wahIQpff1B89HkMXm/s435/357su.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="435" data-original-width="435" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj0RlESMDnBZAPk1xUWL2_jSHWRRdb_8DW1n2fnjl___2qKXWQ1NP4NsDFGtyOA_QhJtYrRbXElay-4JtwI_drOE5kZoYv3FdEjJQVumV_dHVR-7Y69QWlFU8SKWc1wahIQpff1B89HkMXm/s320/357su.png" width="320" /></a></blockquote></div><a href="https://tcollyer.blogspot.com/p/copyright-statement.html" rel="nofollow" target="_blank">All puzzles © Tom Collyer 2009-21</a>.</div></div>Unknownnoreply@blogger.com1tag:blogger.com,1999:blog-2031071943178978556.post-38615894893108664222021-08-17T09:00:00.003+01:002021-08-17T09:00:38.831+01:00Maki KajiI saw in the news today that Nikoli president Maki Kaji has passed away at the age of 69.<div><br /></div><div>I had the chance to meet him at the 2010 world sudoku championships, hosted that year in Philadelphia, USA. Always fond of games and gambling - Nikoli the puzzle company takes its name from <a href="https://youtube.com/watch?v=4QAL3nXoQao" rel="nofollow" target="_blank">Nikoli the racehorse </a>- he hosted a couple of rounds of the Nikoli derby in which I was lucky enough to finish to second, winning a tenugui which I still have with me today. </div><div><div><br /></div><div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjkNm3r9w872ZgwGaT2RQI9GjPeCNXUEqw885RD1li3pMaGJimjoEI-EXHJ4j_35pURNGLaYWeXQlLgQ8TDHEFirLrq-OB6fQI8hvjb5BI6ydTfruM6LcklDCEfdqZ1LYTWcs8T5C_sIJKm/s719/DA8BA5CA-55C9-46F4-8488-1D9AB783F7BF.jpeg" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="478" data-original-width="719" height="213" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjkNm3r9w872ZgwGaT2RQI9GjPeCNXUEqw885RD1li3pMaGJimjoEI-EXHJ4j_35pURNGLaYWeXQlLgQ8TDHEFirLrq-OB6fQI8hvjb5BI6ydTfruM6LcklDCEfdqZ1LYTWcs8T5C_sIJKm/s320/DA8BA5CA-55C9-46F4-8488-1D9AB783F7BF.jpeg" width="320" /></a></div><div class="separator" style="clear: both; text-align: center;"><span style="text-align: left;"><br /></span></div><div class="separator" style="clear: both; text-align: center;"><span style="text-align: left;">(Thanks - in advance! - to Przemysław Dębiak for the photo)</span></div><div><br /></div></div></div><div>Kaji was known as the “godfather of sudoku,” following his role in the worldwide explosion of its popularity in 2004. </div><div><br /></div><div>I am tickled to see an example of a Masyu puzzle included on the <a href="http://news.bbc.co.uk/1/hi/world/asia-pacific/6745433.stm" rel="nofollow" target="_blank">BBC website</a> (and also how much better designed it used to be!). But I come under the category of a puzzle fanatic. I think part of his puzzling greatness is reflected in this quote:</div><div><div style="text-align: left;"></div><blockquote><div style="text-align: left;">"The secret to inventing a good puzzle," he said, "is to make the rules simple and easy for everyone, including beginners. </div><div style="text-align: left;"><br /></div><div style="text-align: left;">"You have to be able to make both easy and difficult puzzles using the same rules.</div><div style="text-align: left;"><br /></div><div style="text-align: left;">"Between 200 and 300 people help to complete a new puzzle. It has to be something that children, old people and everyone in between can enjoy, to be really good."</div><div style="text-align: left;"></div><div></div></blockquote>
<div>Rest in peace. </div></div>Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-2031071943178978556.post-69896431099877197742021-07-28T17:52:00.001+01:002021-07-28T22:34:13.767+01:00Puzzle ProjectsFirst a quick update: I haven't written here for a little while, which feels a bit personally disappointing. I suppose part of it reflects my continuing malaise within the puzzle community. As I've previously said, it used to be a place where I thought I fit in, and increasingly I am made to feel as if I do not. The best way I can describe this is that any enthusiasm I have for the puzzle community has been blunted by expediency, apathy and lethargy.<div><br /></div><div>About this time last year I outlined that I'd like to try and work on a bunch of different puzzle projects as a way of trying to get back into the swing of things. In some ways it was going to be part of my own recovery, but for a number of reasons none of them really happened. The main thing to say is that I haven't forgotten about them, and I would like to try and make them happen.</div><div><br /></div><div>Recently I have been thinking about what a week-long online global festival of puzzles might look like. And yes, I have been corresponding privately with some relevant people before you ask, dearest reader. But I'd also like to share the sorts of things I would hypothetically like to see.</div><span><a name='more'></a></span><div><br /></div><div>As such an event is global, such a festival needs to be a collection of individual smaller events happening around the clock, perhaps with repeats. This is partly because of the issue with time zones, but also because participants may have other commitments such as work or school at various times during the day. </div><div><br /></div><div>The events need to be interactive because, bluntly, everyone is pretty fed up with sitting in on large video calls they aren't participating in. I also think the sense of interactivity is increased when you know you are doing something at the same time as everyone else. Some of the most fun I have had puzzling this year has been as a result of the contests on puzzle duel where everyone has to show up to start solving at the same time. The USPC (at least when it was happening) also retains a greater excitement because it remains a competition everyone participates in simultaneously.</div><div><br /></div><div>I'd also suggest that if such a festival of puzzles is to appeal to a wide audience, then you need to start moving away from the (by now mature) format of the WPF's grand prix series. I no longer believe that that format holds widespread appeal for people who haven't done a puzzle competition before.</div><div><br /></div><div>That spiel sketches out a vision for such a global festival of puzzles. All that needs to be done is to take a timetable view of the week, and to fill it up with the events themselves. Some ideas for these events include:</div><div><ul style="text-align: left;"><li>Shorter (1 hour max) competitive puzzle rounds, grouped around single puzzle types with perhaps some gentle variation (Frequency: every 8/12 hours)</li><li>Longer (perhaps 2 hours) competitive puzzle rounds full of more "creative" variations, combinations and novelties. (Frequency: maybe 1-2 of these in the week)</li><li>The return of the nikoli time trial! Single puzzles to solve with the first person to register a solution being the winner (Frequency: every 6 hours)</li><li>Non-competitive puzzle club: at the start of a 24h period, a harder puzzle is released and the aim is to return an answer within the 24 hours. At the end of the week there's an award for everyone who returned correct answers for all of the puzzles</li><li>Puzzle authors club: at the start of a 24h period, a puzzle assignment on some kind of a theme is published, and then authors go away and submit their creations. Puzzles are judged by an expert panel, with the results published later for everyone to have a go at.</li><li>Team competition: the return of the croco-liga! Teams of 4 are formed, with 4 puzzles for each round and teams allocating a puzzle to each team member who then face off 1v1 vs. another team. The timings for a competition bracket begin to get a little tight, but if you have a straight knock-out then 4 rounds accommodates 16 teams, 5 rounds gives you 32, 6 rounds 64 and so on.</li><ul><li>This could either have free-for-all teams, or else also be organised around national teams.</li><li>Even better if you could somehow observe the puzzles as they are being solved</li></ul><li>Non-competitive collaborative solving: those interested can join some kind of a lobby, and from there share a link to get involved with a collaborative solve. Perhaps some of the functionality as developed by Rob Vollmert for puzz.link might work here?</li><li>You also want some kind of chat room after each event has finished, so that people can gather together and discussed what just happened.</li></ul><div>I'll finish by stop by dropping my pretences and coyness. I am well aware that the WPF is trying to plan such an event. Having previously declared I couldn't give a flying focaccia about whatever it is that the WPF is doing, I attended a meeting back in April where the idea of such an event was mooted, with a committee formed and the promise of ideas being brought back for further discussion a month later. As far as I can tell (I might be wrong!) planning for this event had only really begun in earnest as of July.</div></div><div><br /></div><div>I have been very badly burned by volunteering for the WPF before, so I have absolutely no intention in getting involved this time round. On the other hand, if an event like the one I sketched out above could ever come to fruition, then I think it would be an amazing event with the potential to transform the puzzle community. If the WPF - or indeed anyone else - picks up on any of the ideas above, then I am very happy for them to run with them and to try to make something like this happen.</div>Unknownnoreply@blogger.com6tag:blogger.com,1999:blog-2031071943178978556.post-19857172347214097862021-05-15T23:41:00.004+01:002021-07-28T16:59:48.699+01:00Portrait of a flying fishIf, like me dearest reader, you are interested in sudoku solving techniques, then perhaps this is an interesting link to a youtube video.<div><ul style="text-align: left;"><li><a href="https://www.youtube.com/watch?v=n2No8hU2OwI" rel="nofollow" target="_blank">https://www.youtube.com/watch?v=n2No8hU2OwI</a></li></ul><div>If you found that video interesting, then perhaps this is an interesting picture. [Someone going by the pseudonym shye is responsible for this puzzle, and it even has a name. Imagine that, dearest reader: a sudoku with a name! Rather grandly, this one is called "Valtari"]</div></div><div><br /></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhLrMx3ppq4rYBErN2ci9N8H9v3moB4BB4TAZtwotAJt2XSIa1-wwtmPvwXA9ya-K00X4LG12y3NaNb3QZDaNmazQW5OFGEPBtAnSp78q2K6yHn83Nd87cUo7YGDWG98WJ_pV92kIz0dvOp/s856/Screen+Shot+2021-05-15+at+22.41.58.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="856" data-original-width="852" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhLrMx3ppq4rYBErN2ci9N8H9v3moB4BB4TAZtwotAJt2XSIa1-wwtmPvwXA9ya-K00X4LG12y3NaNb3QZDaNmazQW5OFGEPBtAnSp78q2K6yHn83Nd87cUo7YGDWG98WJ_pV92kIz0dvOp/s320/Screen+Shot+2021-05-15+at+22.41.58.png" /></a></div><div><br /></div><div>If you found that picture interesting, then perhaps these are some interesting words.</div><div><ul style="text-align: left;"><li>Add rows 1, 3, 5, 7, 9 together with box 5 (in blue, with double weights in R5C4 and R5C6).</li><li>Subtract Columns 3, 5, 7 (in red).</li><li>The blue cells, considered with multiplicity, have the same contents as the red cells plus 3 extra copies of the digits 1-9.</li><li>In the double-weighted blue cells, the only possibilities are 2, 3 and 4.</li><li>There are already exactly two each of 2, 3 and 4 appearing as given digits in the single-weighted blue cells.</li><li>This means that whichever two of the three digits ends up in the double-weighted blue cells will end up bring the multiplicity of both of those digits up to 4 within the blue cells.</li><li>This means that the two empty red cells have the same contents as the two empty double-weighted blue cells.</li><li>It also means that those two digits cannot appear again in any other blue cell.</li><li>More on this to come I'm sure, following this good work by Philip Newman: <a href="https://docs.google.com/document/d/1Y7m2tTUDmUTj3BZ0w5viNuQlaiBVv9kmYksSLrm_XLE/edit" rel="nofollow" target="_blank">https://docs.google.com/document/d/1Y7m2tTUDmUTj3BZ0w5viNuQlaiBVv9kmYksSLrm_XLE/edit</a></li></ul><div><b>UPDATE:</b> as far as I can tell, there is no need to add Box 5 to the equation here - this makes the intersections slightly simpler (no need for double-weights any more) - but it does make it harder to identify where you are supposed to be looking.</div></div><div><br /></div><div>If you didn't find that interesting, then I'll leave you with some whimsical musings. I always thought that an obscure and difficult sudoku solving technique going by the name Exocet was named for a powerful missile that could bust open the hardest of puzzles. Cela a plus de sens en français.</div>Unknownnoreply@blogger.com2tag:blogger.com,1999:blog-2031071943178978556.post-62755573224270379992021-05-15T15:30:00.000+01:002021-05-15T15:30:56.912+01:00Concord and Discord<div>I was pleased to receive a couple of messages on discord yesterday by virtue of sharing a server - namely the cracking the cryptic server. Unfortunately I can't reply to any messages any more as I've decided it's for the best for me to leave that server, perhaps permanently.</div><div><br /></div><div>The first message was from Philip Newman, letting me know about a document he's been working on.</div><div><br /></div><div><a href="https://docs.google.com/document/d/1Y7m2tTUDmUTj3BZ0w5viNuQlaiBVv9kmYksSLrm_XLE/edit">https://docs.google.com/document/d/1Y7m2tTUDmUTj3BZ0w5viNuQlaiBVv9kmYksSLrm_XLE/edit</a></div><div><br /></div><div>This is, in fairness, an acquired taste. It takes what was to me an impenetrable concept of sudoku solving techniques (Exocets), and relates them to a slightly less impenetrable concept of sudoku solving technique, namely "SET". </div><div><br /></div><div>As an aside, I don't think endless jargon, neologisms, portmanteaus, puns and acronyms is always very helpful when it comes to the dispersal of knowledge and understanding. I should say that SET stands for "set equivalence theory", which is what has emerged following some of the discussions and posts on this blog (I still don't like that word even after all these years!) in autumn 2020. I'd previously referred to it vaguely as intersection theory and will probably continue to do so in the future as well, in case that causes any confusion.</div><div><br /></div><div>Anyhow, whilst I might not love the words, I do find the underlying conepts fascinating. if you enjoyed said posts and discussions from last autumn then I think you'll enjoy Philip's document. In particular, it seems to move the discussion on to more complicated and extended equivalent sets/intersections, and in particular more complicated interactions inside individual instances of them. The way in which seemingly unrelated cells become strongly related turns out to be far more subtle than we really touched on previously.</div><div><br /></div><div>Hopefully the last section implies this isn't going to be the final word on the matter either! Maybe I'll take the time to add my own musings on Philip's work if I can muster up time and/or motivation.</div><div><br /></div><div><br /></div><div>The second message I received was from someone who had read one of my earlier blog (ugh) posts where I had previously mentioned that I wasn't having a great time on either the Puzzler's Club or the Cracking the Cryptic discord servers. </div><div><br /></div><a href="https://tcollyer.blogspot.com/2020/09/348-doppelblock.html " rel="nofollow" target="_blank">https://tcollyer.blogspot.com/2020/09/348-doppelblock.html </a><div><br /></div><div><div>I tried to reply privately to that message, but it turns out that having left the server I can't send the message. So on the off chance that person is also reading this, let me reply in slightly less specific terms: thank you for your message, it was very kind of you to think of me and there was certainly no need to apologise on anyone's behalf. Plenty of people have a better time of it there than I do - I can only relate my own experience. At times (not all the time) it can feel very cliquey, hierarchical and beset by an unpleasant group-think of what is and isn't the best way to think about things. </div><div><br /></div><div>I particularly appreciate that is by no means reflective of all the members of the server, but it is reflective of enough it for me to conclude that it doesn't really work for me right now.</div></div><div><br /></div>Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-2031071943178978556.post-56942491026024383822021-02-14T23:20:00.006+00:002021-02-14T23:23:14.467+00:00Puzzle 356: Arrow Sudoku<div>Well, I don't see why everyone else should be having fun with arrow sudoku and leave me feeling left out. Who knows? Maybe I'll make a few more. </div><div><br /></div><div>A.K.A. you need a spare arrow somewhere to break the symmetry. Enjoy!</div>
<blockquote><b> #356 Arrow Sudoku</b> – rated <b>6/10 [Hard]</b><div class="separator" style="clear: both;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEijXSOkpmfKfaQnPlsYhW_hyjDdU8hCqnb0dLZ94rVHG9QM7EB6vYfZjVcgYHSF9rVL_b4NPKx5E7wt0-TXl0J71grlxNIx-pSvgeA4TKxPTihQyFsVE4ES7DELHyCm2qBmPKGlmm0fxZMU/s435/366arr-su.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="435" data-original-width="435" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEijXSOkpmfKfaQnPlsYhW_hyjDdU8hCqnb0dLZ94rVHG9QM7EB6vYfZjVcgYHSF9rVL_b4NPKx5E7wt0-TXl0J71grlxNIx-pSvgeA4TKxPTihQyFsVE4ES7DELHyCm2qBmPKGlmm0fxZMU/s320/366arr-su.png" /></a></div></blockquote>
<a href="https://tcollyer.blogspot.com/p/copyright-statement.html" rel="nofollow" target="_blank">All puzzles © Tom Collyer 2009-20</a>.Unknownnoreply@blogger.com8