The New Sudoku Players' Forum

[Hajime]

A nice puzzle I could not solve manually.
I got stuck within various gen.intersections.
And also never spotted the XY-wings at the end.

Code: Select all

...........1234......5.....4.26...7..5.....4..7...18.5.....5......4186..........

has 80 chars, is missing a last dot.

A possible solution path:

Hidden Text: Show

Code: Select all

[1,1] r4c5=5 Hidden Single in row 4
[1,2] r4c2=8 Hidden Single in row 4
[1,3] r6c5=4 Hidden Single in row 6
[1,4] r1c4=1 Hidden Single in col 4
[1,5] r5c4=8 Hidden Single in col 4
[1,6] r5c1=1 Hidden Single in box 4
[1,7] r3c7=1 Hidden Single in sudokuX/
[2,8] r2c2=9 Naked Single
[3,9] r4c9=1 Hidden Single in row 4
[3,10] r6c8=2 Hidden Single in row 6
[3,11] r5c9=6 Hidden Single in box 6
[4,11] Naked/Hidden Pairs,Triplets,Quads  | NPair (39)r5c37 => (-39)r5c6 | NPair (39)c7r45 => (-39)r1c7 (-3)r7c7 (-39)r9c7 | NQuad (2379)/4568 => (-2379)r1c9 (-379)r7c3 (-2379)r9c1 | NPair (39)/46 => (-3)r8c2 | NTriple (239)/468 => (-2)r5c5
[5,12] r5c5=7 Naked Single
[5,13] r5c6=2 Naked Single
[5,14] r8c2=2 Naked Single
[6,14] Pointing, Claiming  | (7)c4,b8 => (-7)r9c6
[6,14] Generalized Intersection  | (4)/,r1,c3 => (-4)r1c3 | (2)r1,c7,\ => (-2)r7c7 | (5)\,r1,c8 => (-5)r1c8 | (6)r2,c1,/ => (-6)r9c1 | (5)/,r2,c1 => (-5)r2c1 | (5)r2,c7,b3 => (-5)r1c7 | (4)/,r7,c9 => (-4)r7c9 | (5)\,r8,c1 => (-5)r8c1 | (5)/,r9,c8 => (-5)r9c8
[7,15] r7c7=4 Naked Single
[8,16] r9c3=4 Hidden Single in col 3
[8,17] r1c9=4 Hidden Single in sudokuX/
[9,18] r3c2=4 Hidden Single in row 3
[10,18] Naked/Hidden Pairs,Triplets,Quads  | NQuad (3689)c3r3567 [HPair (57)c3r18] => (-368)r1c3 (-39)r8c3
[11,18] Pointing, Claiming  | (9)b7,c1 => (-9)r6c1
[10,18] XY-Wing  |
XY-wing [3 cells] (6=3)r1c2-(3=8)r3c3-(8=6)r7c3 => (-6)r7c2 (-6)r9c2
[11,19] r1c2=6 Hidden Single in col 2
[12,20] r2c8=6 Hidden Single in row 2
[12,21] r6c3=6 Hidden Single in col 3
[12,22] r5c3=9 Hidden Single in col 3
[12,23] r4c7=9 Hidden Single in col 7
[12,24] r8c8=5 Hidden Single in col 8
[12,25] r1c3=5 Hidden Single in box 1
[12,26] r2c7=5 Hidden Single in box 3
[12,27] r6c1=3 Hidden Single in box 4
[12,28] r4c6=3 Hidden Single in box 5
[12,29] r6c4=9 Hidden Single in box 5
[12,30] r5c7=3 Hidden Single in box 6
[12,31] r9c1=5 Hidden Single in box 7
[12,32] r7c1=6 Hidden Single in box 7
[12,33] r7c3=8 Hidden Single in box 7
[12,34] r8c1=9 Hidden Single in box 7
[13,35] r3c3=3 Naked Single
[13,36] r8c3=7 Naked Single
[13,37] r8c9=3 Naked Single
[14,38] r1c8=3 Hidden Single in row 1
[15,38] Pointing, Claiming  | (9)r1,b2 => (-9)r3c5 (-9)r3c6
[16,38] XY-Wing  |
XY-wing [3 cells] (8=2)r1c1-(2=7)r1c7-(7=8)r2c9 => (-8)r2c1 (-8)r9c9
[17,39] r2c1=7 Naked Single
[17,40] r2c9=8 Naked Single
[17,41] r3c8=9 Naked Single
[17,42] r7c8=1 Naked Single
[17,43] r9c8=8 Naked Single
[17,44] r9c9=2 Naked Single
[18,45] r1c1=8 Naked Single
[18,46] r1c5=9 Naked Single
[18,47] r1c6=7 Naked Single
[18,48] r1c7=2 Naked Single
[18,49] r3c1=2 Naked Single
[18,50] r3c6=6 Naked Single
[18,51] r3c9=7 Naked Single
[18,52] r7c2=3 Naked Single
[18,53] r7c4=7 Naked Single
[18,54] r7c5=2 Naked Single
[18,55] r7c9=9 Naked Single
[18,56] r9c2=1 Naked Single
[18,57] r9c4=3 Naked Single
[18,58] r9c5=6 Naked Single
[18,59] r9c6=9 Naked Single
[18,60] r9c7=7 Naked Single
[19,61] r3c5=8 Naked Single


[m_b_metcalf]

Code: Select all

...........1234......5.....4.26...7..5.....4..7...18.5.....5......4186..........

has 80 chars, is missing a last dot.

Whoops, sorry. Corrected.

[m_b_metcalf]

Interesting puzzle (for dogged human solvers) :

Code: Select all

 . . 1 . . 2 . 3 .
 . . . 4 . 5 . . .
 . 4 . . . . . . 6
 . . . . . 6 7 1 .
 . . . . . . . . .
 . 1 5 8 . . . . .
 2 . . . . . . 7 .
 . . . 5 . 9 . . .
 . 9 . 6 . . 3 . .

..1..2.3....4.5....4......6.....671...........158.....2......7....5.9....9.6..3..

Mike

[m_b_metcalf]

Another:

Code: Select all

 . . . . 1 2 . . .
 . . . 3 . . . . 4
 2 . . . . . 1 5 3
 . . . . . . 5 4 .
 . . . . . . . . .
 . 5 2 . . . . . .
 6 4 3 . . . . . 7
 8 . . . . 1 . . .
 . . . 8 7 . . . .

....12......3....42.....153......54...........52......643.....78....1......87....


[philvo]

Another X-sudoku (for human solvers ?) :

Code: Select all

 . . . . . . . . .
 . . . . 1 . . . .
 . 2 . 3 . 4 . 5 .
 . . 6 . . . 2 . .
 . . 3 . . . 5 . .
 . 7 2 . 6 . 1 3 .
 . 3 . 4 . 2 . 7 .
 . . . . 8 . . . .
 . . . . . . . . .

.............1.....2.3.4.5...6...2....3...5...72.6.13..3.4.2.7.....8.............


phil

[m_b_metcalf]

Another X-sudoku (for human solvers ?) :

phil

I think that's much too hard! How about this:

Code: Select all

 . . . . . . . . .
 . . . . 1 . . . .
 . 2 . 3 . 4 . 5 .
 . . 6 . . . 5 . .
 . . 1 . . . 7 . .
 . 7 2 . 6 . 1 8 .
 . 4 . 6 . 3 . 2 .
 . . . . 5 . . . .
 . . . . . . . . .

.............1.....2.3.4.5...6...5....1...7...72.6.18..4.6.3.2.....5.............

?

Mike

[philvo]

The both puzzles have the same pattern. The 2nd puzzle is indeed easier, as seen from my solver (I haven't tried to solve it manually).
phil

[m_b_metcalf]

The both puzzles have the same pattern. The 2nd puzzle is indeed easier, as seen from my solver (I haven't tried to solve it manually).
phil

Yes, it's a lovely pattern, but your puzzle is rated at over SE 9, much too hard for humans. Here's a selection of other puzzles with that pattern:

Code: Select all

.............1.....2.3.4.5...5...2....3...5...62.5.73..3.4.2.6.....8.............   ED=2.9/2.9/2.9 
 
.............1.....2.3.4.5...6...4....7...8...32.5.17..8.9.2.3.....8.............   ED=4.3/2.9/2.9
 
.............1.....2.3.4.5...6...2....3...4...78.6.13..3.4.2.7.....9.............   ED=5.5/1.2/1.2
 
.............1.....2.3.4.5...5...2....3...5...64.5.73..3.4.2.6.....8.............   ED=6.3/2.9/2.9
 
.............1.....2.3.4.5...6...2....1...7...82.6.13..3.4.2.8.....7.............   ED=7.1/2.9/2.9   
.............1.....2.3.4.5...6...4....3...7...82.5.13..7.9.1.8.....7.............   ED=7.2/2.9/2.9     
.............1.....2.3.4.5...6...2....4...5...72.5.83..3.6.2.7.....9.............   ED=7.7/2.9/2.9     
.............1.....2.3.4.5...3...2....6...5...72.5.63..3.4.2.7.....8.............   ED=7.8/2.9/2.9   
.............1.....2.3.4.5...5...6....3...5...72.5.83..3.4.2.7.....6.............   ED=7.9/2.9/2.9 
 
.............1.....2.3.4.5...6...2....3...5...17.6.83..3.4.2.1.....7.............   ED=8.0/2.9/2.9   
.............1.....2.3.4.5...6...4....3...5...72.5.83..8.4.2.7.....8.............   ED=8.2/1.2/1.2   
.............1.....2.3.4.5...6...4....7...8...32.5.17..9.8.2.3.....9.............   ED=8.3/8.3/2.9   
.............1.....2.3.4.5...6...4....3...5...72.5.18..9.8.2.7.....4.............   ED=8.4/4.3/2.9   
.............1.....2.3.4.5...6...4....3...7...82.7.13..5.9.2.8.....8.............   ED=8.5/2.9/2.9   
.............1.....1.2.3.4...5...6....2...7...86.5.12..2.3.6.8.....7.............   ED=8.6/2.9/2.9   
.............1.....1.2.3.4...5...6....2...4...76.5.12..2.3.4.7.....8.............   ED=8.8/2.9/2.9   
.............1.....2.3.4.5...6...2....1...5...72.5.83..3.4.8.7.....9.............   ED=8.9/2.9/2.9 
 
.............1.....2.3.4.5...6...4....3...7...85.7.13..9.2.5.8.....9.............   ED=9.0/9.0/2.9   
.............1.....2.3.4.5...6...7....3...5...82.7.13..9.4.2.8.....9.............   ED=9.1/9.1/2.9   
.............1.....2.3.4.5...6...4....3...7...82.5.13..7.9.2.8.....6.............   ED=9.2/9.2/2.9   
.............1.....2.3.4.5...6...4....3...7...82.5.13..1.7.2.8.....9.............   ED=9.3/9.3/2.9     
.............1.....2.3.4.5...6...4....3...6...72.5.13..8.9.2.7.....6.............   ED=9.4/9.4/2.9   
.............1.....2.3.4.5...6...4....3...7...82.7.63..9.5.2.8.....9.............   ED=9.5/9.5/2.9   
.............1.....2.3.4.5...6...4....3...7...72.6.13..1.8.2.7.....9.............   ED=9.6/9.6/2.9   
.............1.....2.3.4.5...6...4....7...5...82.6.19..3.9.2.8.....7.............   ED=9.7/9.7/2.9   
.............1.....2.3.4.5...6...2....3...5...72.5.18..9.8.2.7.....9.............   ED=9.8/4.3/2.9   
.............1.....2.3.4.5...6...7....3...5...82.5.13..4.9.2.8.....8.............   ED=9.9/4.3/2.9 
 
.............1.....2.3.4.5...6...4....3...5...72.5.13..8.9.2.7.....8.............   ED=10.0/4.3/2.9


Mike

[philvo]

The last 6 puzzles are very impressive !
phil

[m_b_metcalf]

So, I gave it one last fling, and found:

Code: Select all

.............1.....2.3.4.5...1...4....3...6...72.5.83..9.6.2.4.....9.............   ED=9.8/9.8/2.9   
.............1.....2.3.4.1...5...4....3...6...12.6.73..8.9.2.4.....8.............   ED=9.9/9.9/2.9   
.............1.....2.3.4.1...3...4....5...6...12.3.75..8.9.2.4.....8.............   ED=10.0/10.0/2.9
.............1.....2.3.4.5...1...6....3...7...82.5.93..6.7.2.4.....8.............   ED=10.1/10.1/2.9


Mike