Monday, October 31, 2016

11e Championnats du Monde de Sudoku et 25e Championnats du Monde de Jeux de Logique



À l'adresse des personnes peu familières de la langue anglaise, un compte-rendu en français agrémenté de nombreuses photos est disponible sur le site http://logic-club.wifeo.com/senec-2016.php

Le site étant en cours de construction, il est possible que l'adresse change au cours des prochaines semaines ; je remplacerai bien sûr le lien si tel est le cas. Bonne lecture !

Thursday, October 27, 2016

11th World Sudoku Championship and 25th World Puzzle Championship - Part 2



Then came the puzzles. There is not much to say here, at least regarding my performance; since I did not want to risk making my injury worse, and as I barely had the time to read the instruction booklet before the competition, my intention was to play even more casually than I usually do - and yes, as it turned out, it was possible. Contrary to sudoku, I could not solely focus on the hardest puzzles since there were many of them I would probably never have been able to solve. I picked puzzles somewhat randomly, made tons of mistakes despite my slow pace, and ended up with what was (I guess) my worst result at a WPC, but that was to be expected.
On the other hand, the team rounds went just fine; of course we did not do anything great in terms of score but we all had a really good time. I even got an occasion to shine with my one-man solving of the Double Block in round 16... on which we brilliantly managed to swap two "3" stickers, awarding us with 0 point.

Regarding the overall results, Endo Ken was first after the preliminary rounds with a solid lead on Ulrich Voigt and Palmer Mebane. And by "solid", I mean that he crushed the competition until this point; it was really impressive. Unfortunately for him the finals can bring their share of surprises, and the very first puzzle (Coded Nurikabe) got him stuck for more than enough time for Ulrich and Palmer to get past him. In the end, it was yet another crowning for Ulrich, followed by Palmer and Ken, with Philipp Weiß as a somewhat unexpected number 4. Congrats to the four of them.
Also, a special mention to our own Olivier Garçonnet who made it to the under 18 play-offs and got himself a bronze medal. Way to go!

Now for a few words about the championships from a broader perspective.

Organisation

To say things as they are, I am having a hard time finding something that did not go as smoothly as possible. Zuzana Hromcová did a terrific job as the head of the organising team. The army of volunteers were prompt and efficient, marking was done in a very reasonable amount of time and for the first time, online results were available as the competition was going. I know that was appreciated by people who followed the WSPC. Queries were treated efficiently by Peter Hudák and the group of judges and was there some urgent matter to discuss, it was fairly easy finding someone of the organizing team. Also, I should mention that each and every volunteer was not only efficient but friendly and doing their best to help when needed, which is to be saluted. Hats off!
 

Puzzles

For having solved quite an amount of slovak sudokus and puzzles (although not that many in the past two years), I thought I had a good idea of what to expect, i.e. a good variety of rather easy puzzles, nicely made and with quite a lot of original ideas but rarely striking in design. Well, I was completely caught off guard by what Matúš Demiger and his co-authors had done. I was absolutely not expecting a round such as the "Basics" one, and several sudokus had me surprised by the thought that had gone into making them. They were still mostly on the easy side but, regarding their quality, definitely on par with what had been done the previous years.

Additional thoughts

There were several innovations this year; one of them being that tons of additional awards/prizes were given during the ending ceremonies. There was one for guessing who would end at the 11th in sudoku and 25th place in puzzles, one for the worst writer (won by my teammate Olivier Garçonnet, who looks like he will be a great successor to Timothy Doyle in this category), and many more. All in all, it was funny and made the ceremonies more light-hearted than usual, which I enjoyed.
On the evening, some more events were organized such as a "Pyjama Sudoku Contest" and a Team Competition. I did not take part in many of them unfortunately, since I was trying to get all the rest I could to make my arm better; but the echoes I had were all positive.
Another thing the slovak team added was team play-offs. Well that was, in my opinion, the best part of the competition. It was really, really good and from a player perspective I dearly wish we will see some more of these. The puzzles were nice, the difficulty was spot-on, and there was just enough tactical planning involved to make things exciting while still consecrating the best sudoku-solving team. Also, it was much less stressful than the individual play-offs where you know you have only yourself to rely on and cannot afford a single mistake. I am glad I stayed in the A-team so that I could take part in this.

I could go along but that's enough typing for today. I will complete this or post another message if I find some more matter to discuss tomorrow.

If not, see you next year in India!

Wednesday, October 26, 2016

11th World Sudoku Championship and 25th World Puzzle Championship - Part 1

 

A week. One full week of puzzle solving. And once again, it is as if it ended before it even started.

From the 16th to the 23rd of october, more than 300 puzzle and sudoku enthusiasts gathered in Senec, Slovakia, for the 11th World Sudoku Championship and the 25th World Puzzle Championship. Most of them I already knew, and most of them I had not seen in a year - same old recipe since 2011 and my first participation. But unlike the previous editions, there was a tiny difference this year: I had injured my right forearm just one day prior to my venue, and it looked quite bad as it was far from certain I would even be able to play.
After having done my best to use my arm as little as possible during sunday, I went to bed with very few expectations since my state hadn't changed a bit between morning and evening. On monday morning things were slightly better though, and I was able to hold a pen but at the condition that I would stop every couple minutes at most to let my arm rest, and so on. I did what I could, but after the first couple rounds it was clear that this was not the year Tiit and pals would have to worry about me.

That being said, I was still able to play. The situation being what it was, I decided to focus on harder sudokus to minimize the writing I had to do, and to use as little pencil marks as possible. My playstyle, if I may say so, has always consisted in making as little use of pencil marks as possible, so it wasn't really a big deal - and since I prefer harder sudokus... well, you get the idea. The difference was much more noticeable on the sprint rounds (of which there were quite a few, unfortunately) than on the longer ones where I managed to perform honorably. The second day went about the same way as the first one, not great but good enough that I would still be able to bring some points to the team, my primary focus.

I would not have bet a cent on it but as it appeared when the results were published, I had (barely) managed to make it into the top 10 and, more importantly, we were standing at the fourth place as a team - which meant I would soon have to take part in two play-offs.

The individual finals went as expected. Ahead of me were Qiu Yanzhe (China) and Hideaki Jo (Japan), and I was to start right before Jakub Hrazdira (Czech Republic). I knew I had very little chance to catch up with the first two in my current state, and indeed Hideaki was the one to make his way to the second round. Despite messing up royally on a Palindrome Sudoku, erasing it again and again (which my arm did not thank me for), I still managed to finish second from the round, hence ending at the 8th place. More than satisfying, since 48 hours ago I was considering resigning from my A-team spot!

In the end, and despite Jakub Ondroušek having been very impressive during the rounds, Tiit Vunk clinched victory and earned a long-time deserved world title. Jakub got Silver and, unsurprisingly, Kota Morinishi completed the podium.

Meanwhile, Qiu Yanzhe had had his revenge by taking the crown in the under 18 category, with Chen Shiyu earning Silver and Sun Cheran Bronze. The finals were extremely tensed and it was obvious that all five contestants were doing their absolute best, so I believe Hu Yuxuan (4th) and Dai Tantan (5th) deserve congratulations as well. The Chinese team did shine bright this year, as well in results as in their attitude.

The over 50 category saw Zoran Tanasic (Serbia) crush the finals despite starting in third place, and beating Mark Goodliffe (United Kingdom) who had been easily dominating the competition up to this point. Third was Taro Arimatsu from Japan.

Then came the time of the team play-offs. There was Japan, there was China, there was Czech Republic... and then there was us, France! There was no wonder we were overmatched (after the preliminary rounds we were standing at a modest 17k when the other teams were over 20k), but at least we had made it to the finals and we didn't have anything to lose. The format of the finals was a Weakest Link, meaning all four members of each team would have to solve two puzzles individually before they would be allowed to the team table and given a fifth of a Samurai Sudoku (the fifth - central - puzzle would be waiting for us on the table). There, our task was to reconstitute the Samurai and solve the whole puzzle. There was strategy involved, as it was necessary that the four players would reach the team table at some point in order to complete the Samurai; hence Timothy and I were given the - supposedly - hardest sets, which included a Little Killer Sudoku and a Fortress Sudoku, so that Yannick and Olivier would have an easier time going through their own sudokus and we would all meet at the table at around the same time.


Things didn't go exactly as planned but eventually the four of us were standing around the table, struggling a bit to build the Samurai, until we finally figured the correct layout. We went on a rush to solve what was left of the puzzles... then got interrupted by applauses as team Japan had completed theirs and taken the third place. Czech Republic earned the gold, and China was a good second.
Fourth once again, but with nothing to be ashamed of. All three of our opponents had a fantastic team composition (all four players of China-A were in the top 12!), and considering we started with a 5 minutes handicap on team Japan and would have needed about 2 to 3 more minutes to finish the Samurai... well, between 20:30 and 21:30 on the 18th of october 2016, we were actually faster than team Japan. Well worth the trip to Slovakia!


And that's it for today. Soon, a few (probably short) words about the WPC, and an overall review of the week.

Pictures are courtesy of Théophane Garçonnet.

Wednesday, September 14, 2016

Grille de la semaine #174

The last variant from this series is a fairly easy Extra Regions Sudoku. This one should not give you too much trouble, unless maybe you have never seen such a puzzle. Good luck, and have fun playing.


Règles :
Chaque ligne, colonne et région, ainsi que chacune des régions grisées, doivent contenir les chiffres de 1 à 9.
°°°°°°°°°°°°°°°°°°°°
Each row, column and region, as well as each of the shaded areas, must contain the digits from 1 to 9.

#189 Extra Regions Sudoku

 

Wednesday, September 7, 2016

Grille de la semaine #173

The rules of Sudoku 6 Parmi 9 come from my fellow french player and author Sylvain Caudmont. They are a great twist to the original sudoku rules and allow the creation of really tough 6x6 puzzles. This one in particular isn't devilish but should still keep you busy for a little while, although there are ways to get around the intended path.


Règles :
La grille comporte 6 chiffres différents à déterminer entre 1 et 9.
Chaque ligne, colonne et région doivent contenir les chiffres en question.
De plus, le nombre en haut à gauche d'une zone délimitée correspond au produit des chiffres de cette zone.

°°°°°°°°°°°°°°°°°°°°
Use a set of 6 different digits amongst 1, 2, 3, 4, 5, 6, 7, 8 and 9.
Each row, column and region must contain the digits of the set.
The value on the top-left corner of a bounded area is equal to the product of this area's digits.

#188 Sudoku 6 Parmi 9 Product

 

Wednesday, August 31, 2016

Grille de la semaine #172

Medium-hard sudoku this week; again, this Pointing Evens Sudoku comes from the French Selections 2016. Considering it was the least solved sudoku variant on the whole event, it may have been a little underestimated. What do you think?


Règles :
Chaque ligne, colonne et région doivent contenir les chiffres de 1 à 9. Les indices à l'extérieur de la grille correspondent au nombre de chiffres pairs dans la diagonale indiquée par la flèche.

°°°°°°°°°°°°°°°°°°°°
Each row, column and region must contain the digits from 1 to 9. Clues outside the grid correspond to the number of even digits in the diagonal indicated by the arrow.

#187 Pointing Evens Sudoku

 

Wednesday, August 24, 2016

Grille de la semaine #171

One of the easiest variants of the competition, this sudoku was designed specifically to soften a round that was suffering from a severe difficulty overflow.


Règles :
Chaque ligne, colonne et région doivent contenir les chiffres de 1 à 9.
Les chiffres se trouvant au sein d'une même zone grisée doivent être tous différents ; de plus, au sein d'une même zone, deux chiffres ne peuvent jamais être consécutifs.
°°°°°°°°°°°°°°°°°°°°
Each row, column and region must contain the digits from 1 to 9.
Digits that belong to the same shaded area must all be different; also, within the same area, there can never be consecutive digits.

#186 Anti-Renban Sudoku

 

Wednesday, August 17, 2016

Grille de la semaine #170

Two puzzles this week, to make up for last wednesday's hiatus. The Diagonal Sudoku (round 1) is reasonably easy, the Sum Skyscraper (round 3)... not so much. This last one was the hardest puzzle I contributed to the French selections, only beaten by Timothy's Little Killer Sudoku. Both ended up being correctly solved by only three people, so good luck trying to make your way into it.


Règles :
Chaque ligne, colonne et région, ainsi que chacune des deux grandes diagonales, doivent contenir les chiffres de 1 à 9.
°°°°°°°°°°°°°°°°°°°°
Each row, column and region, as well as each of the two main diagonals, must contain the digits from 1 to 9.

#184 Diagonal Sudoku


 


Chaque ligne, colonne et région doivent contenir les chiffres de 1 à 9.
Chaque chiffre de la grille correspond à un gratte-ciel dont la hauteur est égale a ce chiffre.
Les indices extérieurs correspondent à la somme des tailles des immeubles visibles, sachant qu'un gratte-ciel dont la hauteur est supérieure à un autre masque celui-ci.
°°°°°°°°°°°°°°°°°°°°
Each row, column and region must contain the digits from 1 to 9.
Moreover, each digit inside the grid is a skyscraper of the corresponding height. An outside clue corresponds to the sum of the heights of all skyscrapers which are visible in its row or column, starting from this point, knowing that a skyscraper which height is superior to another masks this last one.

#185 Sum Skyscraper Sudoku



Wednesday, August 3, 2016

Grille de la semaine #169

Again, this one is not too easy; just as last week's puzzle, it appeared in the third and last round of the competition, which featured unusual - and mostly harder - variants.


Règles :
Chaque ligne, colonne et région doivent contenir les chiffres de 1 à 9.
La somme de deux chiffres orthogonalement adjacents est toujours strictement inférieure à 15.
°°°°°°°°°°°°°°°°°°°°
Each row, column and region must contain the digits from 1 to 9.
No two orthogonally adjacent digits can have a sum of 15 or more.

#183 Lesser Than 15 Sudoku

 

Wednesday, July 27, 2016

Grille de la semaine #168

Time for a quite harder puzzle; this one I will not challenge you to solve in five minutes. Do your best, and enjoy.


Règles :
Chaque ligne, colonne et région doivent contenir les chiffres de 1 à 9.
Les indices cerclés signalent que les chiffres en question doivent nécessairement se trouver au sein des
quatre cases chevauchées par le cercle. Tous les chiffres ne sont pas donnés.
°°°°°°°°°°°°°°°°°°°°
Each row, column and region must contain the digits from 1 to 9
 Circled clues mean that the corresponding digits must be found in the four cells overlapped by said circle. All digits are not given.

#182 Sudoku Incomplete Quadruple

 

Wednesday, July 20, 2016

Grille de la semaine #167

Here comes the second sudoku in this series from the French Selections 2016. Today's puzzle is a medium Sudokube; nothing too hard, and the rules themselves are quite simple, but there are still a few things to notice. Can you find them all in five minutes or less?


Règles :
Chaque rangée, ainsi que chaque région, doivent contenir les chiffres de 1 à 8. Une rangée est
constituée de huit cases parcourues en traversant les côtés opposés de chacune des cases.
°°°°°°°°°°°°°°°°°°°°
Each "row" and bold region must contain the digits from 1 to 8. A "row" follows the opposite, parallel sides of each cell.

#181 Sudokube

 

Wednesday, July 13, 2016

Grille de la semaine #166

Hello there. I know it has been a while, but the break I took since last december was much needed. I can't get back to publishing a weekly puzzle yet, but I will try to post something once in a while; and despite what I just said, I am actually going to publish a puzzle a week for a few weeks since the French Selections for the WSC happened just two weeks ago and I have some brand new puzzles to share.
I hope you will enjoy them. Have fun playing, and good luck.


Règles :
Chaque ligne, colonne et région doivent contenir les chiffres de 1 à 9.
Au sein d'une flèche, le chiffre situé dans le rond est égal à la somme des chiffres situés sur le reste de la flèche.
°°°°°°°°°°°°°°°°°°°°
Each row, column and region must contain the digits from 1 to 9.
Within an arrow, the digit in the circled cell is equal to the sum of the digits on the rest of the arrow.

#180 Thermo Sudoku