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Administrator
   
Country : India | |
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Administrator
Country : India | |
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SKnight
Posts: 25
Country : United States | SKnight posted @ 2011-09-06 10:07 PM This looks like a lot of fun -- interesting variations on a common theme.
One thing that strikes me as worth clarification: The arrows in "Mirror Arrow Sudoku" aren't strictly mirror images of each other at all. The puzzle has the usual 180-degree rotational "crossword" symmetry, and the arrows follow that symmetry (assuming that the puzzle will follow its example in the booklet). That's the sort of thing that could be very confusing to somebody reading the instructions on the day of the test without carefully studying the instruction book. It may be better to call this one Symmetric Arrow Sudoku.
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vopani
Posts: 739
Country : India | vopani posted @ 2011-09-06 10:27 PM SKnight - 2011-09-06 10:07 PM
This looks like a lot of fun -- interesting variations on a common theme.
One thing that strikes me as worth clarification: The arrows in "Mirror Arrow Sudoku" aren't strictly mirror images of each other at all. The puzzle has the usual 180-degree rotational "crossword" symmetry, and the arrows follow that symmetry (assuming that the puzzle will follow its example in the booklet). That's the sort of thing that could be very confusing to somebody reading the instructions on the day of the test without carefully studying the instruction book. It may be better to call this one Symmetric Arrow Sudoku.
Yes, the circles and the arrows have the usual 180-degree rotational symmetry. And 'Symmetric' is a better name, I wonder why it didn't strike me earlier. |
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Administrator
Country : India | Updated IB with change in name uploaded. |
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deu
Posts: 69
Country : Japan | deu posted @ 2011-09-07 11:08 AM Lots of math puzzles! I'm really looking forward to this test.
I have some questions about Symmetric Arrow Sudoku.
What is the definition of "arrow"? More precisely,
1. Length: Can the length of arrows be 1?
2. Directions: Only 8 directions?
3. Only one arrow from each circle? |
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Gotroch
Posts: 83
Country : Czech Republic | Gotroch posted @ 2011-09-07 11:54 AM For Missing Arrow Sudoku:
Only one circle and one arrow tip should be placed for each line or we can place circle somewhere into the middle of the line (to create circle with two arrows)? |
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debmohanty
Country : India | Gotroch - 2011-09-07 11:54 AM
For Missing Arrow Sudoku:
Only one circle and one arrow tip should be placed for each line or we can place circle somewhere into the middle of the line (to create circle with two arrows)?
One end should be an arrow tip, and other end should be the circle.
Circle in the middle is not allowed. |
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Fred76
Posts: 337
Country : Switzerland | Fred76 posted @ 2011-09-07 4:36 PM deu - 2011-09-07 11:08 AM
1. Length: Can the length of arrows be 1?
I had the same question  . The example in the IB is not easy, considering you can have arrows of length 1 (but still have a unique solution ).
Fred |
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Fred76
Posts: 337
Country : Switzerland | Fred76 posted @ 2011-09-07 4:47 PM deu - 2011-09-07 11:08 AM
3. Only one arrow from each circle?
I think I can answer this question:
Consider a such grid where you have more than one arrow from each circle. Then, if you remove one arrow from that circle, it's also a valid grid, but perhaps it has more than one solution considering the starting configuration. If so, the entire problem will have more than one solution. Rohan cannot ask us to add some additional arrows to avoid the fact that the grid has more than one solution...
Therefore the grid must have a unique solution with a unique arrow from each circle .
I don't know if I'm clear, it's a bit hard to explain in English...
Fred |
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Nikola
Posts: 103
Country : Serbia | Nikola posted @ 2011-09-07 5:15 PM Nice explanation, Fred. I think you are right. Something else I noticed in this puzzle. In the example the middle circles may collect the numbers in two possible ways. I don't know is this counts as unique or double solution. The numbers are surely unchanged but maybe it's not bad to know does the same case can appear in real puzzle.
Nikola
Edited by Nikola 2011-09-07 5:22 PM
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deu
Posts: 69
Country : Japan | deu posted @ 2011-09-07 5:28 PM Thanks, Fred. Everything is clear. And I noticed the same point as Nikola. |
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vopani
Posts: 739
Country : India | vopani posted @ 2011-09-07 5:48 PM Nikola - 2011-09-07 5:15 PM
Nice explanation, Fred. I think you are right. Something else I noticed in this puzzle. In the example the middle circles may collect the numbers in two possible ways. I don't know is this counts as unique or double solution. The numbers are surely unchanged but maybe it's not bad to know does the same case can appear in real puzzle.
Nikola
Regarding Symmetric Arrow Sudoku:
1. There is one unique arrow from each circle. This arrow must have a 180-degree symmetric arrow from the opposite circle. Fred's earlier post is absolutely correct.
2. There CAN be arrows of length one.
3. In the example, the middle circles can collect its numbers in two ways. The '9' can collect 4-5 and 5-4 (Similarly, the 1-3 and 3-1 for the '4' ). But, the solution does not change and both ways is considered to be the SAME SOLUTION. As long as you collect the numbers from the same cells, the arrows are the same, irrespective of the order/direction.
4. No part of an arrow can go outside the grid. It can travel only through centres of neighbouring cells (in standard format ), i.e. it can go in any of the 8 directions, but it cannot touch/cross the grid border.
5. I should've put a better example in the IB :- )
(I will create one more example of Symmetric Arrow Sudoku and post it by tomorrow, it should be clearer then ) Edited by Rohan Rao 2011-09-07 6:24 PM
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Para
Posts: 315
Country : The Netherlands | Para posted @ 2011-09-07 10:03 PM For 0-9 Arrow Sudoku:
1. Can a circle have more than one arrow?
2. If so, can the sum change over the different arrows? Say, a circle has the digits 1 and 2 in it, can one arrow sum to 12 and the other sum to 21?
I was wondering this because the instructions says both orientations would be considered correct. And I would assume if the sum of each circle is unique, it would be more logical to just accept only the correct sum for the circle as an answer. My other idea for the reasoning would be that some circles have their digits given, but not necessarily in the right order and people might forget to change it when putting in the answer key. |
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debmohanty
Country : India | 0-9 Arrow Sudoku
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Each circle will have exactly one arrow.
Circles won't have givens, if that helps.
I think Rohan wanted to clarify that while entering the answer, one can enter the 2 digits in the circle in any order. |
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vopani
Posts: 739
Country : India | vopani posted @ 2011-09-07 11:04 PM Para - 2011-09-07 10:03 PM
For 0-9 Arrow Sudoku:
1. Can a circle have more than one arrow?
2. If so, can the sum change over the different arrows? Say, a circle has the digits 1 and 2 in it, can one arrow sum to 12 and the other sum to 21?
I was wondering this because the instructions says both orientations would be considered correct. And I would assume if the sum of each circle is unique, it would be more logical to just accept only the correct sum for the circle as an answer. My other idea for the reasoning would be that some circles have their digits given, but not necessarily in the right order and people might forget to change it when putting in the answer key.
Each circle has exactly one arrow. That should solve the problem now. Of course, you will get a unique order of the two digits inside a circle while solving.
Both orientations are accepted as correct 'answers' just for convenience of players. As long as you get the two correct digits in the circle, it is ok for me. For example, an arrow over two cells may have 0 and 8 in its circle. The sum is obviously not 80. So, even if a player types '80' instead of '08' (maybe due to quickly typing it from the paper ), it is as good as correct. |
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vopani
Posts: 739
Country : India | vopani posted @ 2011-09-08 11:05 AM Here is a fairly easy Symmetric Arrow Sudoku that you can try out:  Solution: |
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rakesh_rai
Posts: 774
Country : India | If X submits 11 correct sudokus and 13 digits correct in the last sudoku, and one of the five wrong digits is a given clue. Does X get the time bonus ?
Edited by rakesh_rai 2011-09-09 4:22 PM
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vopani
Posts: 739
Country : India | vopani posted @ 2011-09-09 4:25 PM rakesh_rai - 2011-09-09 4:21 PM
If X submits 11 correct sudokus and 13 digits correct in the last sudoku, and one of the five wrong digits is a given clue. Does X get the time bonus ?
Yes, of course. |
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Administrator
Country : India | Password protected booklet uploaded. It has 12 pages, each page one Sudoku. There is no cover page. |
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swaroop2011
Posts: 668
Country : India | nice set of SUDOS!!! (it was really CRAZY)
I dont know what happens to me while having sudoku test..
kinda find difficult to solve any sudoku..
Just missed submitting my sum1 sudoku answer.
but anyways it was nice experience
surely i need lots of practise to get command on sudoku. |
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flk
Posts: 23
Country : Australia | flk posted @ 2011-09-10 6:13 PM Thanks for the puzzles Rohan |
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neerajmehrotra
Posts: 328
Country : India | awesome puzzles Rohan......the arrows have really made me crazy!!!! |
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vopani
Posts: 739
Country : India | vopani posted @ 2011-09-11 10:43 AM Thanks Swaroop, flk and Neeraj. A lot of people have gone crazy due to different reasons :-) |
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prasanna16391
Posts: 1775
Country : India | Excellent test, really had fun solving :) Unfortunately I made the awesomely horrible mistake of forgetting to click "submit answers" after half time :P But really enjoyed it. especially missing arrow Sudoku, which was quite confusing.. :P |
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Richard
Posts: 191
Country : The Netherlands | Richard posted @ 2011-09-11 3:14 PM Thanks a lot for a nice set of puzzles! :-)
I had a good time solving (a few) of them this morning. It was my first time.
During the test I had a few more solved, and was busy with another one when I noticed my time was almost over. Then I submitted already one answer and tried to finish the other one quickly, assuming I could submit (with penalty) after the time was over. I really only needed 10 more seconds. But I wasn't able to do so after the 110 minutes have passed.
Question: can you submit part of your answers first and later some more, when the time is not over yet?
Normally I am on the other side of the process; I do prepare sudokus for the Dutch and the German championships, and I am not very used to solving in a race against time. But I will participate more often in the future. Liked it a lot!
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debmohanty
Country : India | Richard - 2011-09-11 3:14 PM
Question: can you submit part of your answers first and later some more, when the time is not over yet?
Yes, that is allowed and that is advisable.
It is always better to solve 2-3 puzzles, submit them and solve more.
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rakesh_rai
Posts: 774
Country : India | Nice test Rohan. The intuitions I had by just looking at the grid ultimately proved to be true in some grids. Enjoyed all the sudokus (that I could solve). Already looking forward to "Crazier Arrows."
Edited by rakesh_rai 2011-09-11 3:58 PM
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vopani
Posts: 739
Country : India | vopani posted @ 2011-09-11 9:37 PM Thanks Prasanna, Richard, Rakesh. |
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forcolin
Posts: 172
Country : ITALY | It was an excellent set of puzzles. Thank you so much Rohan + admnistrators. Pity I wasted a lot of time to no avail on one of them (found the correct solution later).
Just a remark. I noticed the CLAIM BONUS button is dangerously close to the SUBMIT ANSWERS one, a couple of times I nearly hit it by mistake, better to move it a bit out of the way, at the end of the day it has to be used only once..... |
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debmohanty
Country : India | With no one participating in Crazy Arrows now, the test is over. 3 players managed to solve more than 9 Sudokus and they take the podium - motris (11), Nikola(10), Kota(10). Congratulations to them and thank you everyone for participating.
Indian results : Rakesh, Amit and Jaipal take the top 3 spots.
Overall 184 players participated, and 134 got non-zero scores.
A tough test indeed with so many zero scores and many players not submitting anything towards the end. Although there were many easy puzzles, I thought SYMMETRIC was highly undervalued, thus trapping many solvers. It was only 75 points, but is solved by only 10 players. Having correct points for that puzzle would have been a huge step forward for a perfect test. |
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motris
Posts: 199
Country : United States | motris posted @ 2011-09-12 6:06 AM forcolin - 2011-09-11 3:45 PM
It was an excellent set of puzzles. Thank you so much Rohan + admnistrators. Pity I wasted a lot of time to no avail on one of them (found the correct solution later).
Just a remark. I noticed the CLAIM BONUS button is dangerously close to the SUBMIT ANSWERS one, a couple of times I nearly hit it by mistake, better to move it a bit out of the way, at the end of the day it has to be used only once.....
I can't comment on this test since I didn't finish, but on the last few tests I've caught that this button is not "active" until you have enough correctly formatted answers in the system. In other words, while it is there to click on, it cannot end your test until you could possible have a bonus to have. It also has a "are you sure" dialog afterwards which always costs me another minute of bonus as I keep forgetting it exists and losing 3 seconds to go over a quanta of minute. |
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motris
Posts: 199
Country : United States | motris posted @ 2011-09-12 6:08 AM I didn't post any comments during the test for a few reasons - first I was rushing off to help run a puzzle event and didn't have time and also I had some mixed feelings because the puzzles were great in places and hard in places and it really paid to switch to new puzzles. Some of it may be that puzzles like Symmetric Arrow were simply unfamiliar, but I also felt a puzzle like that had a lot of necessary steps at least under time pressure that felt more like guesses than deductions. So I put Symmetric quickly on my do not do pile until after I ran out of time. I ended up getting back to Sum 1 and Missing Arrow (worth more) before running out of time on Symmetric. Outside of those three puzzles, I think I really liked everything on the test. Thanks Rohan for a really creative set of arrow variations. I'm sure I'll be playing with some of these again in the future. |
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debmohanty
Country : India | motris - 2011-09-12 6:06 AM
forcolin - 2011-09-11 3:45 PM
It was an excellent set of puzzles. Thank you so much Rohan + admnistrators. Pity I wasted a lot of time to no avail on one of them (found the correct solution later).
Just a remark. I noticed the CLAIM BONUS button is dangerously close to the SUBMIT ANSWERS one, a couple of times I nearly hit it by mistake, better to move it a bit out of the way, at the end of the day it has to be used only once.....
I can't comment on this test since I didn't finish, but on the last few tests I've caught that this button is not "active" until you have enough correctly formatted answers in the system. In other words, while it is there to click on, it cannot end your test until you could possible have a bonus to have. It also has a "are you sure" dialog afterwards which always costs me another minute of bonus as I keep forgetting it exists and losing 3 seconds to go over a quanta of minute.
1 ) In a puzzle test, we deactivate the button until all puzzles are "filled in". But in Sudoku test, we don't do that because players could be solving/submitting online. ( Of course, this test didn't have online mode, but ... )
In Sudoku test, it remains enabled all the time, and it works like "Submit". Once all your sudokus are submitted (either paper mode or online mode ), it pops up the "Are you sure" dialog.
If you have entered only half of the sudokus, and you click on "Claim Bonus", the sudokus will be submitted, and nothing else will happen. So it is close to the "Submit" button, but not dangerous.
motris - 2011-09-12 6:06 AM
It also has a "are you sure" dialog afterwards which always costs me another minute of bonus as I keep forgetting it exists and losing 3 seconds to go over a quanta of minute.
2 ) After you finish typing all puzzles/sudokus, you can directly click on "Claim Bonus". As I've noted in some earlier thread, "Claim Bonus" button also submits all puzzles. So, if you are anyway planning to claim bonus immediately after submitting, you may directly click on "Claim Bonus".
I think the "are you sure" dialog is necessary to avert any unwanted claims (especially that submission is not allowed after that ). It is easy to remove the dialog box if players don't think it is any useful.
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motris
Posts: 199
Country : United States | motris posted @ 2011-09-12 6:48 AM Don't get me wrong, I like the concept of the "are you sure" box preventing mistaken clicks. And it is very good as you describe that the actual functionality is just "submit" not "end test" as Stefano was worried. This system seems ideal to get the correct functionality for all solvers. The exact functionality has not been described though until this response so now we can remove the potential stress some solvers might get from it.
And my nitpicky-ness is probably due to having played the typical WPC game of clock watching to "stop checking the last puzzle before the next minute" on the last two tests and gotten small point drops. My last submission was exactly on the minute I think for JPL and ST (95:00 and 41:00 I think) which is when I hit submit and claim. I should obviously have given myself 3 more seconds each time, as I just rolled over to the next minute with the second click in the other window.
Edited by motris 2011-09-12 6:49 AM
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debmohanty
Country : India | I misunderstood and thought you wanted to remove the "are you sure" dialog.
Yes, I agree that some of these features are not documented anywhere. We need a FAQ kinda thingy for the tests. With LMI attracting new players every week, players are unlikely to browse through old posts to know how certain things behave. With (at least) 3 weeks gap between now and next LMI test, we'll try to make a FAQ. |
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MellowMelon
Country : United States | Given that I felt like all 9 of the puzzles I solved were at a fairly sluggish pace (possible exception of sum 1, but even that had a wrong guess) and yet I still got that rank, this was evidently a very tough set. I personally enjoyed Count, Sum 2, and Product the most. My solve of Parted was rife with bifurcations, so I'll have to go back and see if I missed something. I didn't even touch Symmetric because the example in the IB destroyed me; there's too many ways to draw those arrows... |
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vopani
Posts: 739
Country : India | vopani posted @ 2011-09-12 10:33 AM Thanks Stefano, Thomas and Palmer.
Firstly, congrats to the top three, Thomas, Nikola and Kota and thanks to all participants. I hope you enjoyed.
This was certainly a tough set. I thought Missing was the toughest and required some guesswork and luck.
I apologize for Symmetric. It was worth 75 points and that was clearly misleading. We missed something during testing. When I saw very few people solving Symmetric, we checked the puzzle again and thats when we found out it was much tougher than earlier thought. This is completely my lack of completion and Symmetric was worth much more (probably more than 120), only I am at fault.
Regarding the other sudokus, most of the players liked Sum2 the best. My favourite three were Sum2, Wrong and Product.
I'm glad I could conduct this event since I got the idea of Crazy Arrows over a year back.
Hope to see you in 'Crazier Arrows' :-)
Edited by Rohan Rao 2011-09-12 11:13 AM
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Ziti
Posts: 42
Country : United States | Ziti posted @ 2011-09-12 10:46 AM Rohan, there were some exceptional puzzles in here and you deserve many congratulations for putting together such a clever set! Rarely does a sudoku really get the mind working so hard for so long, and for the designs to be so nifty is a nice touch as well. Thank you for the set.
Having said this, I found the Missing Arrow EXTREMELY difficult/impossible/guess-y (as did nearly everyone else) and the Parted Arrow felt similar to me (although 25 people solved it so I must have missed something, as usual). Until today, I had never ever torn up the page in a fit of absolute rage upon finding an error, so that must mean something! :) It is uncommon for a LMI sudoku test to have what feels like many necessary bifurcation steps, and in that sense I guess I am surprised. Of course it's very possible I just don't see the logic-based steps...
I will say that both Sum puzzles were terrific. The first one had a neat killer feel to it, and I felt that a necessary step was one I had never seen before in an Arrow puzzle. The second one had such a clean path to its solution that it will be remembered. A pity I spent 30-some minutes hitting my head against the desk on the three puzzles that stumped me midway through the test, else I might've gotten some points on #2! |
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akash.doulani
Posts: 157
Country : India | i wish i had not attempted the symmetric arrow which ate up my valuable 25 minutes in which i could have solved atleast 2 more . but the puzzles were really good. thanks a lot rohan for such nice set of sudokus. |
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vopani
Posts: 739
Country : India | vopani posted @ 2011-09-12 11:32 AM Ziti - 2011-09-12 10:46 AM
Rohan, there were some exceptional puzzles in here and you deserve many congratulations for putting together such a clever set! Rarely does a sudoku really get the mind working so hard for so long, and for the designs to be so nifty is a nice touch as well. Thank you for the set.
Having said this, I found the Missing Arrow EXTREMELY difficult/impossible/guess-y (as did nearly everyone else) and the Parted Arrow felt similar to me (although 25 people solved it so I must have missed something, as usual). Until today, I had never ever torn up the page in a fit of absolute rage upon finding an error, so that must mean something! :) It is uncommon for a LMI sudoku test to have what feels like many necessary bifurcation steps, and in that sense I guess I am surprised. Of course it's very possible I just don't see the logic-based steps...
Missing Arrow was tough and guesswork was obligatory. An interesting fact: Missing Arrow Sudoku is the least solved individual sudoku in any LMI sudoku test so far. So, kudos to Hideaki, Minfang, Murat, Thomas and Zafer.
I will say that both Sum puzzles were terrific. The first one had a neat killer feel to it, and I felt that a necessary step was one I had never seen before in an Arrow puzzle. The second one had such a clean path to its solution that it will be remembered. A pity I spent 30-some minutes hitting my head against the desk on the three puzzles that stumped me midway through the test, else I might've gotten some points on #2!
I had created 5 Arrow Sums Sudokus for this test and I had to include two of them. I think I chose wisely :- )
Thanks a lot, and I'm glad you enjoyed. |
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vopani
Posts: 739
Country : India | vopani posted @ 2011-09-12 11:39 AM akash.doulani - 2011-09-12 10:49 AM
i wish i had not attempted the symmetric arrow which ate up my valuable 25 minutes in which i could have solved atleast 2 more . but the puzzles were really good. thanks a lot rohan for such nice set of sudokus.
Thats unfortunate, I'm sorry. Thanks :- ) |
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harmeet
Posts: 85
Country : India | harmeet posted @ 2011-09-12 6:18 PM Beautiful puzzles Rohan. All of them were gems. Congratulations!
I look forward to equally crazy arrows, not crazier, please!  |
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vopani
Posts: 739
Country : India | vopani posted @ 2011-09-12 9:28 PM harmeet - 2011-09-12 6:18 PM
Beautiful puzzles Rohan. All of them were gems. Congratulations!
I look forward to equally crazy arrows, not crazier, please!
Thanks Harmeet. |
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Fred76
Posts: 337
Country : Switzerland | Fred76 posted @ 2011-09-13 3:56 AM Thanks for the fun tournament ! Very nice variations. Missing arrow and parted arrow made me completely crazy ! I lost a lot of time on these both grids and at the end I had some mistakes...
I've to solve these grids again and the symetric, which I have not yet began. Others were very beautiful and nice grids.
Fred |
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vopani
Posts: 739
Country : India | vopani posted @ 2011-09-13 10:27 AM Fred76 - 2011-09-13 3:56 AM
Thanks for the fun tournament ! Very nice variations. Missing arrow and parted arrow made me completely crazy ! I lost a lot of time on these both grids and at the end I had some mistakes...
I've to solve these grids again and the symetric, which I have not yet began. Others were very beautiful and nice grids.
Fred
Thanks Fred. |
Crazy Arrows — LMI Sep Sudoku Test — 10th and 11th September
