The New Sudoku Players' Forum

[ravel]

.....4..7.9..8..2.6..3.......4.....8.5..7..9.1.....6..8....6.......2..5...19..3..
.....9..6.3..2..4.7..8.......3.....5.6..1..2.1.....7..2....5.......6..3...92..8..

Thanks, the first one is a toughie (4 steps), i will add it to my list with Ocean's new puzzles.
The second one may be nice for pencil&paper (a turbot fish solves).

[maria45]

Hi Ronk,

Before e9=4, don't you need c8=9, a8=6, and g8=4?

not really. Before b7=4, e79=48, so its a naked pair, so if b7=4, e9 automatically is 4. For clearity's reason, I should perhaps have included e7=8 before e9=4. But your question led me to another observation, that the contradiction already occurs one step earlier, so the improved deduction should read like this now:

g5=7, (k1=7, g3=1, d1=1, f4=1, k9=1, c7=1, f3=3, f9=7, d7=3, g9=3, c6=7, d4=7, c2=3, h1=3, k6=3, a4=3, k5=9, e1=2, f2=6, c3=2, gh4=26, df8=2, k8=8, k2=2, d5=8, c5=6, a5=4, b6=9, e4=9, e3=5, a2=5, b9=5, b7=4, e7=8, e9=4, h2=4, column2!=8, contradiction >) g5!=7

And when you have naked pair steps like "gh4=26, df8=2", I assume you make exclusions without specific assignments. Is that correct?

right. My notation tries to be as short as possible, so the naked pair gh4=26 implies (trivially, I think) be4!=6, alternatively I could have written the hidden pair be4=89, but that would be perhaps even less obvious for some eyes.
And df8=2 implies (trivial step, too) pointing with gk8!=2.

[daj95376]

I find this
.....4..7.9..8..2.6..3.......4.....8.5..7..9.1.....6..8....6.......2..5...19..3..
.....9..6.3..2..4.7..8.......3.....5.6..1..2.1.....7..2....5.......6..3...92..8..

The first puzzle is interesting and difficult.

[ravel]

List updated, the BF step ratings of Ocean's list are:

# M21/D21:
17,8,9,6,9,7,9,12,10,8,12,8,11,14
# M22/D22:
14,6,8,4
# D21:
5,5,5,4,4
# D22:
5,8,6,7,8,7,4,7,4

So the list contains number 1,4,5,7 and 9 in my new hardest list.

[Ocean]

List updated, the BF step ratings of Ocean's list are:

# M21/D21:
17,8,9,6,9,7,9,12,10,8,12,8,11,14
# M22/D22:
14,6,8,4
# D21:
5,5,5,4,4
# D22:
5,8,6,7,8,7,4,7,4

So the list contains number 1,4,5,7 and 9 in my new hardest list.

Ravel,

Thanks for analyzing all the puzzles!

A bit weird that a new pattern suddenly became the most common for 12+ puzzles.

[Eioru]

A rookie question:
What is "step" represent for?
What main differences between a puzzle with 15 steps and 5 step?

[ravel]

I explained it roughly on top of this thread and more detailed here.

[Eioru]

I find 100 puzzles with
XOO
OXO
OOX
in boxes but center box is empty

this 25 puzzles are choosed by them

1..4..5...8..5..9...5..7..34.....2...6.....8...7.....98..2..3...1..7..6...6..9..4
1..4..7...7..2..3...6..9..59.....8...2.....4...5.....94..2..6...3..7..9...9..3..8
2..3..4...4..9..5...8..4..13.....7...9.....4...2.....61..5..2...5..8..6...7..6..9
2..4..5...8..9..7...7..6..37.....2...9.....3...1.....53..7..9...1..5..4...6..1..8
2..7..9...1..3..5...8..4..61.....8...5.....9...6.....57..9..2...6..1..7...3..7..8
3..7..6...8..4..1...7..2..81.....4...2.....9...6.....57..6..1...9..3..8...2..5..4
3..8..9...5..6..3...9..1..69.....7...3.....2...1.....45..6..8...7..2..4...2..3..9
3..9..5...7..2..3...8..4..99.....8...2.....7...4.....54..8..7...6..7..5...3..6..1
4..2..5...8..7..3...3..6..19.....4...3.....5...8.....61..6..2...9..4..1...2..8..7
4..2..9...6..3..1...8..5..21.....4...7.....3...5.....86..7..3...2..4..9...4..1..5
4..6..2...8..3..7...3..9..46.....7...1.....8...9.....17..4..8...2..1..5...8..5..6 ~ *
4..8..1...7..1..4...6..5..32.....8...4.....5...9.....73..2..5...2..4..3...1..6..9
5..7..4...9..4..5...3..1..92.....9...1.....7...7.....36..5..2...8..9..4...9..6..8
6..1..3...7..6..8...3..4..22.....7...6.....1...4.....59..7..2...2..9..4...5..3..8
6..3..9...5..6..8...1..7..22.....5...6.....3...9.....15..7..4...4..8..9...2..1..8
6..5..9...9..2..1...8..7..25.....3...7.....6...2.....83..2..1...1..4..5...4..8..3
7..1..5...5..2..4...8..5..34.....6...6.....2...1.....93..9..8...4..7..6...9..6..1
7..2..8...2..3..4...8..9..65.....1...1.....9...4.....31..9..5...6..7..8...3..6..4
7..5..3...8..2..6...6..9..12.....7...7.....8...1.....54..8..9...3..4..2...9..3..6
8..5..9...3..2..6...7..8..44.....7...5.....2...1.....61..7..4...9..1..5...3..2..1
8..7..9...3..2..5...4..6..32.....1...4.....9...7.....59..8..6...1..3..7...3..2..4
8..9..3...9..3..4...7..6..59.....2...4.....6...5.....14..8..1...3..5..2...1..7..8 ~ **
9..6..8...6..3..1...7..8..28.....9...3.....5...4.....76..3..7...1..5..2...5..4..1
9..7..8...3..1..5...2..4..68.....9...6.....4...4.....73..4..5...9..6..8...6..1..2
9..8..1...6..5..2...8..9..41.....2...5.....3...4.....68..9..5...9..6..7...3..4..1

* ~ this is specil and has 3 X-Wing 2 XYZ-Wing 3 XY-Wing
** ~ this is rare and has 2 Aligned Triplet Exclusions

[ravel]

Thanks,

number 14 and 18 needed 4 steps.

[Eioru]

These are choosed from another 100 puzzle and be ordered,
and their difficulty are rated 9.0 and 9.1 by Sudoku Explainer
1..2..3...3..4..5...4..6..24.....7...7.....3...1.....58..1..9...6..5..8...9..7..6
1..2..3...4..5..1...6..7..53.....8...2.....4...7.....97..1..6...5..4..7...8..9..3
1..2..3...4..5..1...6..7..83.....5...8.....7...9.....67..6..9...9..1..4...2..3..5
1..2..3...4..5..1...6..7..88.....9...5.....7...9.....32..3..7...7..6..4...8..2..5
1..2..3...4..5..6...3..7..58.....9...9.....7...1.....62..1..6...1..4..9...4..5..7
1..2..3...4..5..6...5..7..89.....7...1.....2...8.....33..5..4...6..2..1...1..8..9
1..2..3...4..5..6...7..6..84.....2...9.....8...1.....73..9..8...6..2..5...4..8..1
1..2..3...4..5..6...7..8..28.....7...3.....4...6.....59..3..4...5..7..2...1..9..8
1..2..3...4..5..6...7..8..99.....2...3.....4...6.....18..6..7...5..4..1...3..2..8

PS...I did't find a puzzle with this parttern rated grater than 9.1 by S.E.

[ravel]

Thanks again,
3 more with 4 steps: lines 5, 6 and 8.

[ronk]

3 more with 4 steps: lines 5, 6 and 8.

I understand your solver to find a solution path with the smallest number of steps, disregarding the complexity of the steps. I would like to examine the step complexity for the relatively simple 4-steppers above, so ...

... would you please post the exc.usion(s) for the 4 steps for each of the above puzzles? Just the rMcN<>D for each step should be sufficient. [edit: OTOH, the technique names might be helpful too.]

TIA, Ron

[ravel]

All following exclusions were done with BF steps.
line 5:
r2c9<>1, r3c7<>4, r7c6<>3, r2c3<>8
r3c5<>1, r3c7<>4, r7c6<>3, r2c3<>8
r4c2<>6, r2c9<>1, r1c6<>4, r1c5<>6
r8c3<>6, r2c9<>1, r1c6<>4, r1c5<>6
r8c4<>8, r2c3<>8, r8c6<>2, r1c2<>5
r8c7<>8, r2c9<>1, r8c6<>2, r4c5<>1
r9c2<>8, r2c9<>1, r1c6<>4, r1c5<>6
r9c5<>6, r2c9<>1, r7c2<>7, r2c3<>8
line 6:
r1c3<>7, r3c2<>9, r2c9<>1, r1c2<>9
r2c3<>2, r1c9<>4, r2c9<>1, r8c3<>9
r3c2<>9, r1c3<>7, r2c9<>1, r1c2<>9
r3c7<>2, r1c9<>4, r2c7<>2, r8c3<>9
r4c4<>3, r1c9<>4, r2c9<>1, r1c3<>9
r7c2<>7, r1c9<>4, r2c9<>1, r8c3<>9
line 8:
r1c8<>5, r1c8<>8, r2c3<>9, r2c4<>7
r1c8<>8, r2c3<>9, r1c8<>5, r2c4<>7
r2c3<>8, r2c3<>9, r1c8<>5, r2c4<>7
r2c3<>9, r1c8<>8, r1c8<>5, r2c4<>7
r3c1<>5, r1c8<>8, r2c3<>9, r2c4<>7
r3c4<>1, r2c6<>3, r1c8<>5, r2c4<>7
r5c1<>7, r7c2<>8, r3c2<>6, r2c4<>7
r5c4<>8, r1c8<>8, r2c3<>9, r1c5<>6
r6c7<>8, r2c6<>3, r1c8<>5, r2c4<>7
r7c5<>8, r1c8<>8, r2c3<>9, r1c5<>6
r8c3<>8, r1c8<>8, r2c3<>9, r1c5<>6

Sorry, i have no trace, which techniques were used for the eliminations.

[ronk]

All following exclusions were done with BF steps.
[size=9]line 5:
r2c9<>1, r3c7<>4, r7c6<>3, r2c3<>8

Sorry I didn't think to ask this in the previous post. Obviously both naked single and hidden single placements are not counted as steps. Is anything else not "counted"?

Perhaps you can point me to another thread where your solver has already been discussed. Thanks again, Ron

[ravel]

Obviously both naked single and hidden single placements are not counted as steps. Is anything else not "counted"?

Tuples (pairs to quads), box interactions, x-wings and UR type 1. If you disable all other methods in a solver, you always should get to the grids, where the BF steps are made.

Perhaps you can point me to another thread where your solver has already been discussed.

Have you read this post ?