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