The New Sudoku Players' Forum

[shye]

Code: Select all

+-------+-------+-------+
| 5 . . | . . . | . . 3 |
| . 3 2 | . . . | 7 8 . |
| . . . | 1 2 3 | . . . |
+-------+-------+-------+
| 4 . . | . . . | . . 9 |
| . 1 . | . . . | . 5 . |
| . . 9 | 7 . 6 | 4 . . |
+-------+-------+-------+
| . . . | . 6 . | . . . |
| 6 . . | 9 . 1 | . . 8 |
| . 9 5 | . 3 . | 6 1 . |
+-------+-------+-------+
5.......3.32...78....123...4.......9.1.....5...97.64......6....6..9.1..8.95.3.61.

estimated rating: 8.3

[Cenoman]

Code: Select all

 +--------------------------+------------------------+------------------------+
 |  5      a46     a146     | b468   b4789  b4789    |  129    2469    3      |
 | a19      3       2       |  456    45-9   45-9    |  7      8       146    |
 |  789     4678    4678    |  1      2      3       |  59     469     456    |
 +--------------------------+------------------------+------------------------+
 |  4       25678   3678    |  2358   158    258     |  1238   67      9      |
 |  2378    1       3678    |  2348   489    2489    |  238    5       67     |
 |  238     258     9       |  7      158    6       |  4      23      12     |
 +--------------------------+------------------------+------------------------+
 |  12378   2478    13478   |  2458   6      24578   |  2359   23479   2457   |
 |  6       247     347     |  9      457    1       |  235    2347    8      |
 |  278     9       5       |  248    3      2478    |  6      1       247    |
 +--------------------------+------------------------+------------------------+

(9=146)b1p234 - (4|6=789)r1c456 => -9 r2c56; lclste (+45 r2c56 => -45 b2p1234, -4 r2c9; ste)

[P.O.]

basics:

Hidden Text: Show

Code: Select all

intersections:
((((8 0) (3 1 1) (7 8 9)) ((8 0) (3 2 1) (4 6 7 8)) ((8 0) (3 3 1) (4 6 7 8)))
 (((7 0) (3 1 1) (7 8 9)) ((7 0) (3 2 1) (4 6 7 8)) ((7 0) (3 3 1) (4 6 7 8)))
 (((5 0) (3 7 3) (5 9)) ((5 0) (3 9 3) (4 5 6))))

QUAD BOX: ((4 7 6) (1 2 3 8)) ((5 7 6) (2 3 8)) ((6 8 6) (2 3)) ((6 9 6) (1 2))
(((4 8 6) (2 3 6 7)) ((5 9 6) (2 6 7)))


Code: Select all

5      46     146    468    4789   4789   129    2469   3               
19     3      2      456    459    459    7      8      146             
789    4678   4678   1      2      3      59     469    456             
4      25678  3678   2358   158    258    1238   67     9               
2378   1      3678   2348   489    2489   238    5      67             
238    258    9      7      158    6      4      23     12             
12378  2478   13478  2458   6      24578  2359   23479  2457           
6      247    347    9      457    1      235    2347   8               
278    9      5      248    3      2478   6      1      247             

1r1c7 => r1c78 <> 2
 r1c7=1 - r2n1{c9 c1} - c1n9{r2 r3} - b3n9{r3c78 r1c8}
 
=> r1c7 <> 1
bte:


Hidden Text: Show

Code: Select all

( n1r4c7   n1r2c9   n1r1c3   n6r2c4   n8r5c7   n9r2c1   n2r6c9
  n3r6c8   n8r6c1   n5r6c2   n1r6c5   n7r3c1   n2r9c1   n3r5c1
  n1r7c1   n2r4c2   n3r4c4   n5r7c4   n2r7c6   n2r5c4   n5r3c9
  n5r8c7   n6r5c9   n7r4c8   n7r5c3   n9r3c7   n6r4c3   n3r7c7
  n2r1c7   n2r8c8   n3r8c3   n9r7c8 )

intersection:
((((4 0) (2 5 2) (4 5)) ((4 0) (2 6 2) (4 5)))

ste.


[Leren]

Code: Select all

*---------------------------------------------------------*
| 5     46    146   | 468  4789 4789  | 129   2469   3    |
|a19    3     2     | 456  459  459   | 7     8     b146  |
| 78-9  4678  4678  | 1    2    3     |b59   b469   b456  |
|-------------------+-----------------+-------------------|
| 4     25678 3678  | 2358 158  258   | 1238  67     9    |
| 2378  1     3678  | 2348 489  2489  | 238   5      67   |
| 238   258   9     | 7    158  6     | 4     23     12   |
|-------------------+-----------------+-------------------|
| 12378 2478  13478 | 2458 6    24578 | 2359  23479  2457 |
| 6     247   347   | 9    457  1     | 235   2347   8    |
| 278   9     5     | 248  3    2478  | 6     1      247  |
*---------------------------------------------------------*

(9=1) r2c1 - (1=9) r2c9, r3c789 => - 9 r3c1; lclste

Leren

[RSW]

Code: Select all

 +-------------------+------------------+-----------------+
 | 5    a46   a146   |a468 a4789 a4789  | 129  2469  3    |
 |b19    3     2     | 456   45-9 45-9  | 7    8     146  |
 | 789   4678  4678  | 1     2    3     | 59   469   456  |
 +-------------------+------------------+-----------------+
 | 4     25678 3678  | 2358  158  258   | 1238 67    9    |
 | 2378  1     3678  | 2348  489  2489  | 238  5     67   |
 | 238   258   9     | 7     158  6     | 4    23    12   |
 +-------------------+------------------+-----------------+
 | 12378 2478  13478 | 2458  6    24578 | 2359 23479 2457 |
 | 6     247   347   | 9     457  1     | 235  2347  8    |
 | 278   9     5     | 248   3    2478  | 6    1     247  |
 +-------------------+------------------+-----------------+


(9=46781)r1c23456 - (1=9)r2c1 => -9r2c56; stte

Thanks for the puzzle.

[yzfwsf]

Almost Locked Set XY-Wing: A=r2c156{1459}, B=r2c56{459}, C=r1c23456{146789}, X,Y=1, 9, Z=45 => r1c456,r2c49<>4 r2c49<>5; stte

[shye]

thank you everyone for solving! I did something (perhaps needlessly?) fancy for this one using "roping". i had a quick search in the forum to see how often this concept has been discussed but didn't see much, so i should probably provide an explanation of it too:

Code: Select all

+-------+-------+-------+      +-------+-------+-------+
| . . . | A A A | . . . |      | b b b | A A A | c c c |
| A A A | . . . | . . . |  ->  | A A A | c c c | b b b |
| . . . | . . . | . . . |      | c c c | b b b | a a a |
+-------+-------+-------+      +-------+-------+-------+

+-------+-------+-------+      +-------+-------+-------+
| . . . | B B B | . . . |      | c c c | B B B | a a a |
| A A A | . . . | . . . |  ->  | A A A | c c c | b b b |
| . . . | . . . | . . . |      | b b b | a a a | c c c |
+-------+-------+-------+      +-------+-------+-------+

when looking at a band or stack, if two minilines contain triples with either entirely the same, or entirely different clues, the whole band/stack will become "roped", meaning that every miniline within the tier will contain predictable triples

Code: Select all

+-------+-------+-------+      +-------+-------+-------+      +-------+-------+-------+
| 5 . . | . . . | . . 3 |      | b b b | c c c | a a a |      | . . . | . 9 9 | 9 9 . |
| . 3 2 | . . . | 7 8 . |      | a a a | b b b | c c c |      | 9 . . | . 9 9 | . . . |
| . . . | 1 2 3 | . . . |      | c c c | a a a | b b b |      | 9 . . | . . . | 9 9 . |
+-------+-------+-------+      +-------+-------+-------+      +-------+-------+-------+

in this puzzle r123 are nearly roped, but the positions for 9 in these rows could not be placed in the same letter group
after determining roping isnt possible here, there is an easy elimination:
-1r2c1 lcstte

might be an idea worth further exploration, but this is all i could come up with for now

[eleven]

Interesting point of view. Here probably a quicker way than to find the ALS's for the same elimination(s) (which always will be there).

[coloin]

to shye for info
https://www.sudopedia.org/wiki/Braid_Analysis
follow-the-numbers-t768-15.html
and a stormy
chat-room-t32828-30.html

gives some history to ropes/braids and travelling pairs ....

[eleven]

chat-room-t32828-30.html

Hm, i had a look at StrmCkr's example, but it only shows, that if r2c7 is 1 (not 2), then r5c8 can't be 8, which is obvious.