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Country : India |
Logic Masters India announces February Sudoku Test — Triplets & Triangles
Dates : 20 th - 22 nd Feb
Instruction Booklet & Submission : Link
Author : David McNeill
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Administrator
Country : India | |
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Para
Posts: 315
Country : The Netherlands | Para posted @ 2016-02-13 9:47 PM You'd have thought that this test would have been held in March. |
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margareta456
Posts: 30
Country : Poland | will the result of Triplets & Triangles consider in LMI Sudoku Ratings?
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Administrator
Country : India | margareta456 - 2016-02-16 7:37 PM
will the result of Triplets & Triangles consider in LMI Sudoku Ratings?
Yes. |
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kishy72
Posts: 419
Country : India | kishy72 posted @ 2016-02-17 7:46 PM Can someone tell me the logical start in Triangular sums example?I don't see much after putting in a few digits at the beginning.... |
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rakesh_rai
Posts: 774
Country : India | kishy72 - 2016-02-17 7:46 PM
Can someone tell me the logical start in Triangular sums example?I don't see much after putting in a few digits at the beginning.... not sure if logical or not. But I was able to find the triangle for R2C3, and therefore for R2C4 and R3C3 and R3C4 too. And the numbers too. Then I got the triangle for R3C6 which gives all triangles except the four at bottom right. After this it should be easier, though I did not solve completely. |
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kishy72
Posts: 419
Country : India | kishy72 posted @ 2016-02-18 12:14 AM rakesh_rai - 2016-02-17 8:37 PM
kishy72 - 2016-02-17 7:46 PM
Can someone tell me the logical start in Triangular sums example?I don't see much after putting in a few digits at the beginning.... not sure if logical or not. But I was able to find the triangle for R2C3, and therefore for R2C4 and R3C3 and R3C4 too. And the numbers too. Then I got the triangle for R3C6 which gives all triangles except the four at bottom right. After this it should be easier, though I did not solve completely.
Was your approach to randomly put a triangle in a cell and see if it works out or contradicts?If that's the approach,I am looking for something else because I did the same and it was very tiring. To elaborate ,how did you find which cell in R2C3 contains the triangle in the first place? |
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rakesh_rai
Posts: 774
Country : India | kishy72 - 2016-02-18 12:14 AM
...how did you find which cell in R2C3 contains the triangle in the first place? If there is a bottom/left triangle, it has 8 to the left. And the sum can be 15 or 21. In both cases R2C3 HAS to be 4. And then if you look at the triangle in R2C4 there is no way to make a perfect number. So the R2C3 has to have the upper/right triangle. |
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rajeshk
Posts: 542
Country : India | rajeshk posted @ 2016-02-19 4:09 PM |
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mihiryadav
Posts: 27
Country : India | Can anyone tell me.....how a black triangle act as a symmetrical arrowhead and which arrowhead is pointing to the two digits? |
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David McNeill
Posts: 63
Country : United Kingdom | It is the 90 degree corner of the triangle which acts as the point of the arrow (rather than either of the two 45 degree corners). Does this help? |
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Vishal
Posts: 22
Country : India | Vishal posted @ 2016-02-19 7:32 PM In Max/Min Triplet Sums, I have identified the outside clue-whether max or min- but I am unable to figure out how to use this information as help in solving the Sudoku (apart from Classic rules) ? Please help.. |
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mihiryadav
Posts: 27
Country : India | Not able to figure out the two digits which is pointed by corresponding arrowhead. |
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David McNeill
Posts: 63
Country : United Kingdom | Vishal,
Re: Max/Min Triplet Sums
I'm not very good at walkthroughs.
Try the following. Place two missing 8s by standard logic. Place 2s in boxes 6 and 7 by standard logic. Place 3 in box 8 by standard logic. Place 1 in box 3 by standard logic.
Now in row 4, the missing 1 cannot sit either side of the 3 and 2 (otherwise we would have a 6 sum in that row and we are told that 10 is the minimum sum) so it must go in column 2.
In the same row, the missing 5 must be either side of the 3 and 2 (otherwise we can't have a 10 sum). Therefore, column 3 in that row must have a 6.
In column 5, the 8 sum must be 1-3-4 in some order as the 2 is isolated. The 1 can't lie below the 3 as there would then be a 6 sum. So the 1 must go in row 5 and the 4 in row 6.
In box 4, the missing 3 can't go in bottom right corner as there would then be a 9 sum in row 6. So it goes immediately above that with the missing 4 to its left.
Then look at the 8 sum in column 3. etc.
Edited by David McNeill 2016-02-19 8:36 PM
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David McNeill
Posts: 63
Country : United Kingdom | Mihiryadav,
Re: Arrowhead
Consider the diagonally split cell in top right corner of box 5. The arrow cannot point to the south-east as the first digit in that direction is a 9 and the sum of the first two digits will therefore exceed the allowed value. So, the arrow must point to the north-west and the first two digits in this direction are 3 and 4, adding to 7. The top left triangle in our split cell is coloured black and a 7 is placed in the bottom right triangle.
Hope this gets you going. |
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margareta456
Posts: 30
Country : Poland | | How well did you like the theme of the contest? | I really liked the theme | | | What was your opinion of the distribution of easy/hard puzzles? | Too many hard puzzles | | | What did you think about the puzzle quality of the test? | Very nice | | | Your 3 most favorite puzzles of the contest. | 12. Renban Squeeze | | | Your 3 most favorite puzzles of the contest. | 10. Tight Fit | | | Your 3 most favorite puzzles of the contest. | 11. Non-Consecutive Squeeze | |
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Plucky
Posts: 8
Country : United Kingdom | Plucky posted @ 2016-02-20 2:33 AM | How well did you like the theme of the contest? | I somewhat liked the theme | | | What was your opinion of the distribution of easy/hard puzzles? | Just right | | | What did you think about the puzzle quality of the test? | Very nice | | | Your 3 most favorite puzzles of the contest. | 7. Max/Min Triplet Sums | | | Your 3 most favorite puzzles of the contest. | 13. Triangular Sums | | | Your 3 most favorite puzzles of the contest. | 4. Trio | |
This was a good test : ) would have given it 3-stars if online solving was available - I don't have a printer so for puzzles without online solving I have to write all my answers in MSPaint with my mouse, which makes it take quite a bit longer and makes it difficult to write pencil marks. |
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Vishal
Posts: 22
Country : India | Vishal posted @ 2016-02-20 2:53 PM Thanks David for your help and guiding me through the solving technique.. By the way, I failed to understand the rule - it was for all the combinations of consecutive numbers along a row and column; not only for the first 3...Thanks for your explanation.. |
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deu
Posts: 69
Country : Japan | deu posted @ 2016-02-20 4:30 PM | How well did you like the theme of the contest? | I really liked the theme | | | What was your opinion of the distribution of easy/hard puzzles? | Just right | | | What did you think about the puzzle quality of the test? | Very nice | | | Your 3 most favorite puzzles of the contest. | 6. Outside Sums | | | Your 3 most favorite puzzles of the contest. | 7. Max/Min Triplet Sums | | | Your 3 most favorite puzzles of the contest. | 12. Renban Squeeze | |
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gaurav.kjain
Posts: 52
Country : India | | How well did you like the theme of the contest? | I somewhat liked the theme | | | What was your opinion of the distribution of easy/hard puzzles? | Just right | | | What did you think about the puzzle quality of the test? | Fairly Nice | | | Your 3 most favorite puzzles of the contest. | 9. Thropki | | | Your 3 most favorite puzzles of the contest. | 14. Arrowhead | | | Your 3 most favorite puzzles of the contest. | 10. Tight Fit | |
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kishy72
Posts: 419
Country : India | kishy72 posted @ 2016-02-20 8:02 PM | How well did you like the theme of the contest? | I somewhat liked the theme | | | What was your opinion of the distribution of easy/hard puzzles? | Just right | | | What did you think about the puzzle quality of the test? | Very nice | | | Your 3 most favorite puzzles of the contest. | 6. Outside Sums | | | Your 3 most favorite puzzles of the contest. | 13. Triangular Sums | | | Your 3 most favorite puzzles of the contest. | 9. Thropki | |
I really liked this test.Normally,I hate Math based variants in sudoku but this test was different.I remember thinking before the test that I would be happy with a score somewhere around 400.I didn't expect 470 in 90 mins (74?! ).In the last 16 mins of the test,I really had a go at Thropki (100 ) but it seemed beyond my reach despite multiple guesses. I greatly enjoyed solving Outside and Triangular sums both of which had a very systematic solve and I also loved the squeeze variants. Thanks a lot to David for this wonderful test and to all test solvers. The set was delightful and I had great fun! |
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bskbri
Posts: 34
Country : Turkey | bskbri posted @ 2016-02-20 8:14 PM I have two questions on triangular sums:
1. Are we sure that we won't split any more cells? I am confused because the rule says triangles cannot touch grid boundary. These already placed ones are far enough not to touch :)
2. May the three numbers around a triangle be same? |
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David McNeill
Posts: 63
Country : United Kingdom | Bskbri,
Re: Triangular Sums
All split cells will be indicated before solving.
There is no special rule prohibiting more than one edge of a triangle having the same digit. |
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An LMI player
| An LMI player posted @ 2016-02-20 9:00 PM | How well did you like the theme of the contest? | I really liked the theme | | | What was your opinion of the distribution of easy/hard puzzles? | Too many hard puzzles | | | What did you think about the puzzle quality of the test? | Very nice | | | Your 3 most favorite puzzles of the contest. | 10. Tight Fit | | | Your 3 most favorite puzzles of the contest. | 3. Classic | | | Your 3 most favorite puzzles of the contest. | 6. Outside Sums | |
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misko
Posts: 11
Country : Germany | misko posted @ 2016-02-20 9:01 PM | How well did you like the theme of the contest? | I somewhat liked the theme | | | What was your opinion of the distribution of easy/hard puzzles? | Just right | | | What did you think about the puzzle quality of the test? | Very nice | | | Your 3 most favorite puzzles of the contest. | 14. Arrowhead | | | Your 3 most favorite puzzles of the contest. | 8. Thropki | | | Your 3 most favorite puzzles of the contest. | 9. Thropki | |
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aashay
Posts: 46
Country : India | aashay posted @ 2016-02-20 10:09 PM I am unable to submit Classic-3 solution. The answer key is A - 249516837 and B - 847925316
Sorry, was typing the wrong answer I guess. The key was not allowing me to submit.
Edited by aashay 2016-02-20 10:27 PM
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An LMI player
| An LMI player posted @ 2016-02-20 10:11 PM | How well did you like the theme of the contest? | I really liked the theme | | | What was your opinion of the distribution of easy/hard puzzles? | Too many hard puzzles | | | What did you think about the puzzle quality of the test? | Very nice | | | Your 3 most favorite puzzles of the contest. | 5. Anti-Diagonal | | | Your 3 most favorite puzzles of the contest. | 6. Outside Sums | | | Your 3 most favorite puzzles of the contest. | 11. Non-Consecutive Squeeze | |
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An LMI player
| An LMI player posted @ 2016-02-20 11:37 PM | How well did you like the theme of the contest? | I really liked the theme | | | What was your opinion of the distribution of easy/hard puzzles? | Just right | | | What did you think about the puzzle quality of the test? | Fairly Nice | | | Your 3 most favorite puzzles of the contest. | 9. Thropki | |
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rakesh_rai
Posts: 774
Country : India | | How well did you like the theme of the contest? | I somewhat liked the theme | | | What was your opinion of the distribution of easy/hard puzzles? | Just right | | | What did you think about the puzzle quality of the test? | Very nice | | | Your 3 most favorite puzzles of the contest. | 13. Triangular Sums | | | Your 3 most favorite puzzles of the contest. | 9. Thropki | | | Your 3 most favorite puzzles of the contest. | 14. Arrowhead | |
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Swagatam
Posts: 45
Country : India | | What was your opinion of the distribution of easy/hard puzzles? | Just right | | | What did you think about the puzzle quality of the test? | Very nice | | | Your 3 most favorite puzzles of the contest. | 5. Anti-Diagonal | | | Your 3 most favorite puzzles of the contest. | 6. Outside Sums | | | Your 3 most favorite puzzles of the contest. | 4. Trio | |
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An LMI player
| An LMI player posted @ 2016-02-21 1:25 AM | How well did you like the theme of the contest? | I really liked the theme | | | What was your opinion of the distribution of easy/hard puzzles? | Just right | | | What did you think about the puzzle quality of the test? | Very nice | | | Your 3 most favorite puzzles of the contest. | 8. Thropki | | | Your 3 most favorite puzzles of the contest. | 7. Max/Min Triplet Sums | | | Your 3 most favorite puzzles of the contest. | 6. Outside Sums | |
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tiphan
Posts: 4
Country : France | tiphan posted @ 2016-02-21 12:22 PM | How well did you like the theme of the contest? | I really liked the theme | | | What was your opinion of the distribution of easy/hard puzzles? | Just right | | | What did you think about the puzzle quality of the test? | Very nice | | | Your 3 most favorite puzzles of the contest. | 5. Anti-Diagonal | | | Your 3 most favorite puzzles of the contest. | 4. Trio | | | Your 3 most favorite puzzles of the contest. | 1. Classic | |
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TiiT
Posts: 139
Country : Estonia | TiiT posted @ 2016-02-21 6:47 PM | How well did you like the theme of the contest? | I really liked the theme | | | What was your opinion of the distribution of easy/hard puzzles? | Just right | | | What did you think about the puzzle quality of the test? | Fairly Nice | | | Your 3 most favorite puzzles of the contest. | 11. Non-Consecutive Squeeze | | | Your 3 most favorite puzzles of the contest. | 12. Renban Squeeze | | | Your 3 most favorite puzzles of the contest. | 14. Arrowhead | |
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Vishal
Posts: 22
Country : India | Vishal posted @ 2016-02-21 7:38 PM | How well did you like the theme of the contest? | I really liked the theme | | | What was your opinion of the distribution of easy/hard puzzles? | Just right | | | What did you think about the puzzle quality of the test? | Very nice | | | Your 3 most favorite puzzles of the contest. | 14. Arrowhead | | | Your 3 most favorite puzzles of the contest. | 6. Outside Sums | |
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rajeshk
Posts: 542
Country : India | rajeshk posted @ 2016-02-22 11:47 AM | How well did you like the theme of the contest? | I really liked the theme | | | What was your opinion of the distribution of easy/hard puzzles? | Too many medium difficult puzzles | | | What did you think about the puzzle quality of the test? | Very nice | | | Your 3 most favorite puzzles of the contest. | 12. Renban Squeeze | | | Your 3 most favorite puzzles of the contest. | 5. Anti-Diagonal | | | Your 3 most favorite puzzles of the contest. | 11. Non-Consecutive Squeeze | |
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An LMI player
| An LMI player posted @ 2016-02-22 12:12 PM | How well did you like the theme of the contest? | I really liked the theme | | | What was your opinion of the distribution of easy/hard puzzles? | Too many medium difficult puzzles | | | What did you think about the puzzle quality of the test? | Very nice | | | Your 3 most favorite puzzles of the contest. | 4. Trio | | | Your 3 most favorite puzzles of the contest. | 5. Anti-Diagonal | | | Your 3 most favorite puzzles of the contest. | 10. Tight Fit | |
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rvarun
Posts: 268
Country : India | rvarun posted @ 2016-02-22 10:40 PM | How well did you like the theme of the contest? | I really liked the theme | | | What was your opinion of the distribution of easy/hard puzzles? | Just right | | | What did you think about the puzzle quality of the test? | Very nice | | | Your 3 most favorite puzzles of the contest. | 6. Outside Sums | | | Your 3 most favorite puzzles of the contest. | 5. Anti-Diagonal | |
Thanks for the great set of puzzles David. The solving path was seamless in the puzzles I attempted. Personally, back to solving puzzles after a brief period of 2-3 months and it was a great experience for me attempting the puzzles. Hope to be active in the upcoming contests. |
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tamz29
Posts: 225
Country : Thailand | tamz29 posted @ 2016-02-23 12:40 AM That was fun :)
Thanks David, some very interesting new variants here. |
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An LMI player
| An LMI player posted @ 2016-02-23 1:55 AM | How well did you like the theme of the contest? | I really liked the theme | | | What was your opinion of the distribution of easy/hard puzzles? | Just right | | | What did you think about the puzzle quality of the test? | Fairly Nice | | | Your 3 most favorite puzzles of the contest. | 6. Outside Sums | | | Your 3 most favorite puzzles of the contest. | 11. Non-Consecutive Squeeze | | | Your 3 most favorite puzzles of the contest. | 14. Arrowhead | |
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RameshLMI
Posts: 51
Country : India | | How well did you like the theme of the contest? | I really liked the theme | | | What was your opinion of the distribution of easy/hard puzzles? | Too many hard puzzles | | | What did you think about the puzzle quality of the test? | Fairly Nice | | | Your 3 most favorite puzzles of the contest. | 10. Tight Fit | | | Your 3 most favorite puzzles of the contest. | 5. Anti-Diagonal | |
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sena
Posts: 21
Country : India | sena posted @ 2016-02-23 5:41 PM 10 minutes witin the time I finished classic-2 sudoku and tried to submit, but the submit button was not enabled.
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David McNeill
Posts: 63
Country : United Kingdom | Deb has invited me to make some comments on the contest. I think it is appropriate to thank Deb for being so willing to host this and the variety of other competitions that LMI encourages. I'd also like to thank my test solvers - Tom Collyer, Robert Vollmert and Yuhei Kusui. They helped me to improve the classic puzzles and keep the difficulty of some of the later puzzles in check.
Thank you to the LMI puzzle community for turning up (especially after my last contest proved so long and difficult). There were difficult puzzles in this set as well but I was delighted to see so many different puzzles receive your accolades for favourite puzzle. Hopefully, not just the best of a bad bunch! My personal favourite was the second Thropki, so I couldn't resist including two of those. I was surprised to find that the Outside Sums was so popular. I know that it didn't require too many pencil marks, so maybe that was the reason.
Congratulations to the intrepid 10 who finished the lot and particularly Hideaki, Tiit and Kota for making the podium places.
Now I can get back to solving for a while. |
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riccared
Posts: 7
Country : ITALY | Hello! Please, I'd like to print this contest in order to have a look at these puzzles and trying to solve, but the .pdf file is still password protected.... Can anyone help? Thanks in advance for your help, regards! |
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debmohanty
Country : India | riccared - 2016-03-15 11:25 PM
Hello! Please, I'd like to print this contest in order to have a look at these puzzles and trying to solve, but the .pdf file is still password protected.... Can anyone help? Thanks in advance for your help, regards! Password - sT9AxgYm |
Triplets & Triangles — LMI February Sudoku Test — 20th to 22nd Feb