Thanks for the puzzle Sleuth. Really liked the way you eliminated the possible magic square in box 6. I had to do that by case testing. I was able to eliminate the box 1 magic square by recognizing that whatever digit went into r2c3 would force r2c1 and r2c4 to be the same digit. Thanks for all the content on this channel!
i color as much as possible and label digits as low/high/5. i pair low green with low blue on v's and low pink with low orange. then x's are one color.
Nicely challenging! I started by finding the possible locations of the 5 in the magic square, narrowing it down to two of the same three you found, before even starting on in the coloring/lettering. (The one in box 1 was eliminated because of the X next to it, since r2c1 would have to be the same as r2c4 if it were the magic square.) Otherwise, my solve was more or less the same, minus a few things found in different orders. My time today was 30:32, solver number 485.
This one went surprisingly smooth for me even with my lack of sleep. My disambiguation for the placement of the magic box after putting in the digits was simply using low-high. 3 of the candidate 5s had different number of low and high neighbours, and the top left one had impossible 3-in-a-row clusters.
This is a very clever puzzle indeed! The two very useful insights are that in a magic square the digits neighboring the central 5 add to 10, and that V's & X's cannot occur in a magic square. (I found this Sudoku very hard until I realized the negative constraint on X's & V's (D'Oh!) 😞) A nice interplay indeed between magic squares & XV's!
From the offset the magic square was confined to exactly TWO choices (clearly the five cannot be in the perimeter OR flush with any X or V pair) and the XVs themselves can be systematically paired with their respective partners. A little colouring and everything falls into line. Completed in 17m12s.
@sudokusleuth This was definitely the hardest xv that I've solved to date using your patented method. Loved how column 2 was completely disambiguated from the very beginning (speaking algebraicly of course)
Just saw that you didn't resolve c2 until nearly the end but since c2 in box 1 is 5cg the 5 must separate the cg and c can't be adjacent to the b in box 4. QED
@SudokuSleuth - (I) A suggestion that may help you .... I see no point in the blue-green differentiation on these "All XVs are given" because ultimately you need to be using A through I and solve using alphabets. So may be just go for blues and reds , and go for a ABCD pencilmarking approach sooner. (II) Also, Box 1, C & G had to be chaperoned by the 5 in Col 2....And that was available from minute 1 of this solve. (III) Finally Box 1 could never have been the magic square because of the X in R2 between Box 1 and 2. For the 5 in the middle of Box 1 to be a magic square, the R2C4 had to also repeat in R2C1. Not possible!
Magic square in box 1 could be placed since the beginning, as it would neighbor with X in row 2, so what digit could possibly be placed in r2c1 to complete 15 sum?
Still so frustrating to make a mistake in these puzzles when doing the lettering / coloring. Happened to me again about 3/4 through my lettering and of course I have no idea where I made the mistake. It's pretty much start over.
Thank you! this one was fun to set and happy with how good a magic square works for xv disambiguation. At least 1 more comming soon
Excellent puzzle Nurglesgift, truly magical 🪄
Thanks for the puzzle Sleuth. Really liked the way you eliminated the possible magic square in box 6. I had to do that by case testing. I was able to eliminate the box 1 magic square by recognizing that whatever digit went into r2c3 would force r2c1 and r2c4 to be the same digit. Thanks for all the content on this channel!
You beat me to it. I saw that box one elimination and was about to comment.
My pleasure!
Nice tip on box 1, not sure how I missed it!
28:54!! Whoa!! Took me a long time to solve it (I paused this sudoku twice) and using you sometimes to get a hint... hehe thanks! 😀
i like this one, and i understood the magic square this time
my time 47:43
i color as much as possible and label digits as low/high/5. i pair low green with low blue on v's and low pink with low orange. then x's are one color.
1:05:28 - Got there in the end. Just over an hour to colour it all in and a couple of minutes to fill it in.
Lovely stuff , managed this one pretty quickly for a change , probably because I do a lot of nurglesgifts puzzles. 😊
Well done!
Nicely challenging! I started by finding the possible locations of the 5 in the magic square, narrowing it down to two of the same three you found, before even starting on in the coloring/lettering. (The one in box 1 was eliminated because of the X next to it, since r2c1 would have to be the same as r2c4 if it were the magic square.) Otherwise, my solve was more or less the same, minus a few things found in different orders. My time today was 30:32, solver number 485.
Nice work!
33:57 for me. Long time you missed in column 2 box 1 that candidates 5CG mean we know order thanks to negative constraint.
Of course!
Love this puzzle.
This one went surprisingly smooth for me even with my lack of sleep. My disambiguation for the placement of the magic box after putting in the digits was simply using low-high. 3 of the candidate 5s had different number of low and high neighbours, and the top left one had impossible 3-in-a-row clusters.
This is a very clever puzzle indeed! The two very useful insights are that in a magic square the digits neighboring the central 5 add to 10, and that V's & X's cannot occur in a magic square. (I found this Sudoku very hard until I realized the negative constraint on X's & V's (D'Oh!) 😞) A nice interplay indeed between magic squares & XV's!
Glad you enjoyed it!
From the offset the magic square was confined to exactly TWO choices (clearly the five cannot be in the perimeter OR flush with any X or V pair) and the XVs themselves can be systematically paired with their respective partners. A little colouring and everything falls into line.
Completed in 17m12s.
very nice puzzle and solve
@sudokusleuth This was definitely the hardest xv that I've solved to date using your patented method. Loved how column 2 was completely disambiguated from the very beginning (speaking algebraicly of course)
Just saw that you didn't resolve c2 until nearly the end but since c2 in box 1 is 5cg the 5 must separate the cg and c can't be adjacent to the b in box 4. QED
I know, I can’t believe I missed that for so long
@SudokuSleuth - (I) A suggestion that may help you .... I see no point in the blue-green differentiation on these "All XVs are given" because ultimately you need to be using A through I and solve using alphabets. So may be just go for blues and reds , and go for a ABCD pencilmarking approach sooner.
(II) Also, Box 1, C & G had to be chaperoned by the 5 in Col 2....And that was available from minute 1 of this solve.
(III) Finally Box 1 could never have been the magic square because of the X in R2 between Box 1 and 2. For the 5 in the middle of Box 1 to be a magic square, the R2C4 had to also repeat in R2C1. Not possible!
Magic square in box 1 could be placed since the beginning, as it would neighbor with X in row 2, so what digit could possibly be placed in r2c1 to complete 15 sum?
Still so frustrating to make a mistake in these puzzles when doing the lettering / coloring. Happened to me again about 3/4 through my lettering and of course I have no idea where I made the mistake. It's pretty much start over.