Analysis of xx-top95-061-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: .2......6....41.....78....1......7....37.....6..412....1..74..5..8.5..7......39.. initial

Autosolve

position: .2...7..6.35641..7.6782...1......7....37.....679412..831.974..5.98.56.7375..839.. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # A1: 1,4 => SOL
* DIS # A1: 8,9 => CTR => A1: 1,4
* DIS # A1: 8,9 => CTR => A1: 1,4
* PRF # A1: 1,4 => SOL
* DIS # H2: 2 => CTR => H2: 8,9
* DIS # A1: 4,9 => CTR => A1: 1,8
* PRF # H3: 4,9 => SOL
* PRF # E4: 3,9 => SOL
* DIS # E4: 6 => CTR => E4: 3,9
* DIS # H3: 5,9 => CTR => H3: 3,4
* DIS # H2: 2,8 => CTR => H2: 9
* DIS # G7: 2,8 => CTR => G7: 6
* PRF # G7: 6 => SOL
* DIS # A5: 1,2 => CTR => A5: 5
* DIS # H4: 1,2 => CTR => H4: 4,6
* DIS # E4: 6,9 => CTR => E4: 3
* PRF # E4: 3 => SOL
* DIS # G3: 4 => CTR => G3: 3,5
* PRF # H3: 4,9 => SOL
* PRF # C9: 2,6 => SOL
* DIS # C9: 4 => CTR => C9: 2,6
* DIS # H7: 2,6 => CTR => H7: 8
* DIS # C9: 2,4 => CTR => C9: 6
* PRF # C9: 6 => SOL
* DIS # G8: 2,4 => CTR => G8: 1
* PRF # G8: 1 => SOL
* PRF # G8: 1,2 => SOL
* DIS # G8: 4 => CTR => G8: 1,2
* PRF # H9: 1,2 => SOL
* DIS # H9: 4,6 => CTR => H9: 1,2
* DIS # G8: 2,4 => CTR => G8: 1
* PRF # G8: 1 => SOL
* PRF # H9: 2,4 => SOL
* DIS # C9: 2,4 => CTR => C9: 6
* PRF # C9: 6 => SOL
* DIS # I4: 2,4 => CTR => I4: 9
* CNT  36 HDP CHAINS /  53 HYP OPENED

See Appendix: Full HDP Chains for full list of HDP chains.

Pair Reduction

Pair Reduction

The following important HDP chains were detected:

* PRF # A1: 1,4 => SOL
* STA A1: 1,4
* CNT   1 HDP CHAINS /   1 HYP OPENED

See Appendix: Full HDP Chains for full list of HDP chains.

Details

Positions

.2......6....41.....78....1......7....37.....6..412....1..74..5..8.5..7......39.. initial
.2...7..6.35641..7.6782...1......7....37.....679412..831.974..5.98.56.7375..839.. autosolve
124397856835641297967825341241538769583769412679412538312974685498256173756183924 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (19)
C1: 1,4
A2: 8,9
A3: 4,9
D1: 3,5
E1: 3,9
F3: 5,9
G2: 2,8
B4: 4,8
C4: 1,2
B5: 4,8
D4: 3,5
E5: 6,9
G6: 3,5
H6: 3,5
C7: 2,6
A8: 2,4
D8: 1,2
D9: 1,2
I9: 2,4

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
A1,C1: 1.. / A1 = 1  =>  0 pairs (*) / C1 = 1  =>  0 pairs (X)
D8,D9: 1.. / D8 = 1  =>  0 pairs (X) / D9 = 1  =>  0 pairs (_)
G8,H9: 1.. / G8 = 1  =>  0 pairs (*) / H9 = 1  =>  0 pairs (X)
D8,G8: 1.. / D8 = 1  =>  0 pairs (X) / G8 = 1  =>  0 pairs (_)
D9,H9: 1.. / D9 = 1  =>  0 pairs (*) / H9 = 1  =>  0 pairs (X)
C1,C4: 1.. / C1 = 1  =>  0 pairs (X) / C4 = 1  =>  0 pairs (_)
G5,G8: 1.. / G5 = 1  =>  0 pairs (X) / G8 = 1  =>  0 pairs (_)
G2,H2: 2.. / G2 = 2  => 21 pairs (_) / H2 = 2  =>  0 pairs (X)
D8,D9: 2.. / D8 = 2  =>  0 pairs (*) / D9 = 2  =>  0 pairs (X)
D1,E1: 3.. / D1 = 3  =>  0 pairs (*) / E1 = 3  =>  0 pairs (X)
G3,H3: 3.. / G3 = 3  => 18 pairs (_) / H3 = 3  => 18 pairs (_)
D4,E4: 3.. / D4 = 3  =>  0 pairs (X) / E4 = 3  =>  0 pairs (_)
G6,H6: 3.. / G6 = 3  => 18 pairs (_) / H6 = 3  => 18 pairs (_)
D1,D4: 3.. / D1 = 3  =>  0 pairs (*) / D4 = 3  =>  0 pairs (X)
E1,E4: 3.. / E1 = 3  =>  0 pairs (X) / E4 = 3  =>  0 pairs (_)
G3,G6: 3.. / G3 = 3  => 18 pairs (_) / G6 = 3  => 18 pairs (_)
H3,H6: 3.. / H3 = 3  => 18 pairs (_) / H6 = 3  => 18 pairs (_)
B4,B5: 4.. / B4 = 4  => 19 pairs (_) / B5 = 4  => 22 pairs (_)
A8,C9: 4.. / A8 = 4  =>  0 pairs (*) / C9 = 4  =>  0 pairs (X)
A8,G8: 4.. / A8 = 4  =>  0 pairs (*) / G8 = 4  =>  0 pairs (X)
C1,C9: 4.. / C1 = 4  =>  0 pairs (*) / C9 = 4  =>  0 pairs (X)
D1,F3: 5.. / D1 = 5  =>  0 pairs (X) / F3 = 5  =>  0 pairs (_)
A4,A5: 5.. / A4 = 5  =>  0 pairs (X) / A5 = 5  => 23 pairs (_)
G6,H6: 5.. / G6 = 5  => 18 pairs (_) / H6 = 5  => 18 pairs (_)
A5,F5: 5.. / A5 = 5  => 23 pairs (_) / F5 = 5  =>  0 pairs (X)
D1,D4: 5.. / D1 = 5  =>  0 pairs (X) / D4 = 5  =>  0 pairs (_)
E4,E5: 6.. / E4 = 6  =>  0 pairs (X) / E5 = 6  =>  0 pairs (_)
C7,C9: 6.. / C7 = 6  =>  0 pairs (X) / C9 = 6  =>  0 pairs (_)
E4,H4: 6.. / E4 = 6  =>  0 pairs (X) / H4 = 6  =>  0 pairs (_)
C9,H9: 6.. / C9 = 6  =>  0 pairs (*) / H9 = 6  =>  0 pairs (X)
G5,G7: 6.. / G5 = 6  =>  0 pairs (X) / G7 = 6  =>  0 pairs (_)
A1,A2: 8.. / A1 = 8  =>  0 pairs (X) / A2 = 8  => 19 pairs (_)
B4,B5: 8.. / B4 = 8  => 22 pairs (_) / B5 = 8  => 19 pairs (_)
F4,F5: 8.. / F4 = 8  => 19 pairs (_) / F5 = 8  => 22 pairs (_)
G7,H7: 8.. / G7 = 8  =>  0 pairs (X) / H7 = 8  => 21 pairs (_)
B4,F4: 8.. / B4 = 8  => 22 pairs (_) / F4 = 8  => 19 pairs (_)
B5,F5: 8.. / B5 = 8  => 19 pairs (_) / F5 = 8  => 22 pairs (_)
E1,F3: 9.. / E1 = 9  =>  0 pairs (*) / F3 = 9  =>  0 pairs (X)
I4,I5: 9.. / I4 = 9  => 22 pairs (_) / I5 = 9  =>  0 pairs (X)
A2,H2: 9.. / A2 = 9  =>  0 pairs (X) / H2 = 9  => 19 pairs (_)
* DURATION: 0:01:14.995051  START: 00:10:36.440725  END: 00:11:51.435776 2017-05-04
* CP COUNT: (40)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A2,A3,A8,B4,B5,C1,C4,C7,D1,D4,D8,D9,E1,E5,F3,G2,G6,H6,I9)
* .2...7..6.35641..7.6782...1......7....37.....679412..831.974..5.98.56.7375..839..
* PAIR C1: 1,4 BLK 1
A1: 1,4,8,9                              # reduction candidate for 1,4
A1: 1,4 => SOLVED
* 124397856835641297967825341241538769583769412679412538312974685498256173756183924
A1: 8,9 => CTR
* .21..7..6.35641..746782...1..2...7....37.....679412..8316974..529815647375..839..
* PAIR A2: 8,9 BLK 1
A1: 8,9,1,4                              # reduction candidate for 8,9
A1: 8,9 => CTR
* .21..7..6.35641..746782...1..2...7....37.....679412..8316974..529815647375..839..
A1: 1,4 => SOLVED
* 124397856835641297967825341241538769583769412679412538312974685498256173756183924
* PAIR A2: 8,9 ROW 2
H2: 8,9,2                                # reduction candidate for 8,9
H2: 2 => CTR
* .2...7..693564182746782...1......7....37.....679412..831.974.852981564737542839..
H2: 8,9                                  # 21 pairs
* PAIR A3: 4,9 BLK 1
A1: 4,9,1,8                              # reduction candidate for 4,9
A1: 4,9 => CTR
* .21..7..6835641297.6782...1..2...7....37.....679412..831697482529815647375..839..
A1: 1,8                                  # 20 pairs
* PAIR A3: 4,9 ROW 3
H3: 4,9,3,5                              # reduction candidate for 4,9
H3: 4,9 => SOLVED
* 124397856835641297967825341241538769583769412679412538312974685498256173756183924
H3: 3,5                                  # 20 pairs
* PAIR E1: 3,9 COL E
E4: 3,9,6                                # reduction candidate for 3,9
E4: 3,9 => SOLVED
* 124397856835641297967825341241538769583769412679412538312974685498256173756183924
E4: 6 => CTR
* .2.537..6.35641..7467829..1...36.7.9..379....679412..831.974..52981564737542839..
* PAIR F3: 5,9 ROW 3
H3: 5,9,3,4                              # reduction candidate for 5,9
H3: 5,9 => CTR
* .2...7..6.35641..746782.3.1......7....37.....67941253831.974..52981564737542839..
H3: 3,4                                  # 20 pairs
* PAIR F3: 5,9 COL F
F4: 5,9,8                                # reduction candidate for 5,9
F4: 5,9                                  # 22 pairs
F5: 5,9,8                                # reduction candidate for 5,9
F5: 5,9                                  # 19 pairs
* PAIR G2: 2,8 BLK 3
H2: 2,8,9                                # reduction candidate for 2,8
H2: 2,8 => CTR
* .2...7..6935641..746782...1......7....37.....679412..831.974..52981564737542839..
H2: 9                                    # 19 pairs
* PAIR G2: 2,8 COL G
G7: 2,8,6                                # reduction candidate for 2,8
G7: 2,8 => CTR
* .24.37..6.35641..7967825..1....6.7....379.6..679412..831.974..549825617375.1839..
G7: 6 => SOLVED
* 124397856835641297967825341241538769583769412679412538312974685498256173756183924
* PAIR C4: 1,2 BLK 4
A4: 1,2,5                                # reduction candidate for 1,2
A4: 1,2                                  # 23 pairs
A5: 1,2,5                                # reduction candidate for 1,2
A5: 1,2 => CTR
* .2.537..6.35641..7467829..154.3.87...837.5...679412..831.974..52981564737542839..
A5: 5                                    # 23 pairs
* PAIR C4: 1,2 ROW 4
H4: 1,2,4,6                              # reduction candidate for 1,2
H4: 1,2 => CTR
* .2.537..6.35641..7467829..1.4.3687.9.83795...679412..831.974..52981564737542839..
H4: 4,6                                  # 21 pairs
* PAIR E5: 6,9 BLK 5
E4: 6,9,3                                # reduction candidate for 6,9
E4: 6,9 => CTR
* .2.537..6.35641..7467829..1...3..7....37.....679412..831.974..52981564737542839..
E4: 3 => SOLVED
* 124397856835641297967825341241538769583769412679412538312974685498256173756183924
* PAIR G6: 3,5 COL G
G3: 3,5,4                                # reduction candidate for 3,5
G3: 4 => CTR
* .24..75.6.35641..7967825431..153.76.5.376....67941235831.974685498.56.73756.839..
G3: 3,5                                  # 21 pairs
* PAIR H6: 3,5 COL H
H3: 3,5,4,9                              # reduction candidate for 3,5
H3: 4,9 => SOLVED
* 124397856835641297967825341241538769583769412679412538312974685498256173756183924
H3: 3,5                                  # 20 pairs
* PAIR C7: 2,6 BLK 7
C9: 2,6,4                                # reduction candidate for 2,6
C9: 2,6 => SOLVED
* 124397856835641297967825341241538769583769412679412538312974685498256173756183924
C9: 4 => CTR
* .2...7..6.35641..7.6782...1......7....37.....679412..8316974..529815647375..839..
* PAIR C7: 2,6 ROW 7
G7: 2,6,8                                # reduction candidate for 2,6
G7: 2,6                                  # 21 pairs
H7: 2,6,8                                # reduction candidate for 2,6
H7: 2,6 => CTR
* .24.375.6.356412.7.6782...1....6.7....379.6..679412..831.9748.549825617375.1839..
H7: 8                                    # 21 pairs
* PAIR A8: 2,4 BLK 7
C9: 2,4,6                                # reduction candidate for 2,4
C9: 2,4 => CTR
* .24.37..6.35641..7967825..1....6.7....379.6..679412..8316974..5.98.5617375.183964
C9: 6 => SOLVED
* 124397856835641297967825341241538769583769412679412538312974685498256173756183924
* PAIR A8: 2,4 ROW 8
G8: 2,4,1                                # reduction candidate for 2,4
G8: 2,4 => CTR
* .24..7..6.35641..7967825431..153.76.5.376.14267941235831.974685.98156.73756283914
G8: 1 => SOLVED
* 124397856835641297967825341241538769583769412679412538312974685498256173756183924
* PAIR D8: 1,2 ROW 8
G8: 1,2,4                                # reduction candidate for 1,2
G8: 1,2 => SOLVED
* 124397856835641297967825341241538769583769412679412538312974685498256173756183924
G8: 4 => CTR
* .2...7..6.35641..7.6782...1......7....37..1..679412..831.974685.9815647375..839..
* PAIR D9: 1,2 ROW 9
H9: 1,2,4,6                              # reduction candidate for 1,2
H9: 1,2 => SOLVED
* 124397856835641297967825341241538769583769412679412538312974685498256173756183924
H9: 4,6 => CTR
* .24..7..6.35641..7967825..1..153.76.5.376..1.679412..831.97468549825617375618394.
* PAIR I9: 2,4 BLK 9
G8: 2,4,1                                # reduction candidate for 2,4
G8: 2,4 => CTR
* .24..7..6.35641..7967825431..153.76.5.376.14267941235831.974685.98156.73756283914
G8: 1 => SOLVED
* 124397856835641297967825341241538769583769412679412538312974685498256173756183924
H9: 2,4,1,6                              # reduction candidate for 2,4
H9: 2,4 => SOLVED
* 124397856835641297967825341241538769583769412679412538312974685498256173756183924
H9: 1,6                                  # 20 pairs
* PAIR I9: 2,4 ROW 9
C9: 2,4,6                                # reduction candidate for 2,4
C9: 2,4 => CTR
* .24.37..6.35641..7967825..1....6.7....379.6..679412..8316974..5.98.5617375.183964
C9: 6 => SOLVED
* 124397856835641297967825341241538769583769412679412538312974685498256173756183924
* PAIR I9: 2,4 COL I
I4: 2,4,9                                # reduction candidate for 2,4
I4: 2,4 => CTR
* 124397856835641297967825..12815397645437681.9679412..8312974685498.56.73756.839..
I4: 9                                    # 22 pairs
I5: 2,4,9                                # reduction candidate for 2,4
I5: 2,4                                  # 22 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top95-061-base-pr-000.dot
* REASONING
* PRF # A1: 1,4 => SOL
* DIS # A1: 8,9 => CTR => A1: 1,4
* DIS # A1: 8,9 => CTR => A1: 1,4
* PRF # A1: 1,4 => SOL
* DIS # H2: 2 => CTR => H2: 8,9
* DIS # A1: 4,9 => CTR => A1: 1,8
* PRF # H3: 4,9 => SOL
* PRF # E4: 3,9 => SOL
* DIS # E4: 6 => CTR => E4: 3,9
* DIS # H3: 5,9 => CTR => H3: 3,4
* DIS # H2: 2,8 => CTR => H2: 9
* DIS # G7: 2,8 => CTR => G7: 6
* PRF # G7: 6 => SOL
* DIS # A5: 1,2 => CTR => A5: 5
* DIS # H4: 1,2 => CTR => H4: 4,6
* DIS # E4: 6,9 => CTR => E4: 3
* PRF # E4: 3 => SOL
* DIS # G3: 4 => CTR => G3: 3,5
* PRF # H3: 4,9 => SOL
* PRF # C9: 2,6 => SOL
* DIS # C9: 4 => CTR => C9: 2,6
* DIS # H7: 2,6 => CTR => H7: 8
* DIS # C9: 2,4 => CTR => C9: 6
* PRF # C9: 6 => SOL
* DIS # G8: 2,4 => CTR => G8: 1
* PRF # G8: 1 => SOL
* PRF # G8: 1,2 => SOL
* DIS # G8: 4 => CTR => G8: 1,2
* PRF # H9: 1,2 => SOL
* DIS # H9: 4,6 => CTR => H9: 1,2
* DIS # G8: 2,4 => CTR => G8: 1
* PRF # G8: 1 => SOL
* PRF # H9: 2,4 => SOL
* DIS # C9: 2,4 => CTR => C9: 6
* PRF # C9: 6 => SOL
* DIS # I4: 2,4 => CTR => I4: 9
* CNT  36 HDP CHAINS /  53 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A2,A3,A8,B4,B5,C1,C4,C7,D1,D4,D8,D9,E1,E5,F3,G2,G6,H6,I9)
* .2...7..6.35641..7.6782...1......7....37.....679412..831.974..5.98.56.7375..839..
* PAIR C1: 1,4 BLK 1
A1: 1,4,8,9                              # reduction candidate for 1,4
A1: 1,4 => SOLVED
* 124397856835641297967825341241538769583769412679412538312974685498256173756183924
* DURATION: 0:00:02.383817  START: 00:12:51.229682  END: 00:12:53.613499 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top95-061-base-pr-001.dot
* REASONING
* PRF # A1: 1,4 => SOL
* STA A1: 1,4
* CNT   1 HDP CHAINS /   1 HYP OPENED

Header Info

Top 95 Sudokus 061
[sudoku:top95] “95 Hard Puzzles”, http://magictour.free.fr/top95, or http://norvig.com/top95.txt

Solution

position: 124397856835641297967825341241538769583769412679412538312974685498256173756183924 solved
Solution

See section Pair Reduction for the HDP chains leading to this result.

Appendix: Full HDP Chains

A1. Pair Reduction Analysis

Full list of HDP chains traversed:

* PRF # A1: 1,4 => SOL
* DIS # A1: 8,9 => CTR => A1: 1,4
* DIS # A1: 8,9 => CTR => A1: 1,4
* PRF # A1: 1,4 => SOL
* INC # H2: 8,9 => UNS
* DIS # H2: 2 => CTR => H2: 8,9
* DIS # A1: 4,9 => CTR => A1: 1,8
* INC # A1: 1,8 => UNS
* PRF # H3: 4,9 => SOL
* INC # H3: 3,5 => UNS
* PRF # E4: 3,9 => SOL
* DIS # E4: 6 => CTR => E4: 3,9
* DIS # H3: 5,9 => CTR => H3: 3,4
* INC # H3: 3,4 => UNS
* INC # F4: 5,9 => UNS
* INC # F5: 5,9 => UNS
* DIS # H2: 2,8 => CTR => H2: 9
* INC # H2: 9 => UNS
* DIS # G7: 2,8 => CTR => G7: 6
* PRF # G7: 6 => SOL
* INC # A4: 1,2 => UNS
* DIS # A5: 1,2 => CTR => A5: 5
* INC # A5: 5 => UNS
* DIS # H4: 1,2 => CTR => H4: 4,6
* INC # H4: 4,6 => UNS
* DIS # E4: 6,9 => CTR => E4: 3
* PRF # E4: 3 => SOL
* INC # G3: 3,5 => UNS
* DIS # G3: 4 => CTR => G3: 3,5
* INC # H3: 3,5 => UNS
* PRF # H3: 4,9 => SOL
* PRF # C9: 2,6 => SOL
* DIS # C9: 4 => CTR => C9: 2,6
* INC # G7: 2,6 => UNS
* DIS # H7: 2,6 => CTR => H7: 8
* INC # H7: 8 => UNS
* DIS # C9: 2,4 => CTR => C9: 6
* PRF # C9: 6 => SOL
* DIS # G8: 2,4 => CTR => G8: 1
* PRF # G8: 1 => SOL
* PRF # G8: 1,2 => SOL
* DIS # G8: 4 => CTR => G8: 1,2
* PRF # H9: 1,2 => SOL
* DIS # H9: 4,6 => CTR => H9: 1,2
* DIS # G8: 2,4 => CTR => G8: 1
* PRF # G8: 1 => SOL
* PRF # H9: 2,4 => SOL
* INC # H9: 1,6 => UNS
* DIS # C9: 2,4 => CTR => C9: 6
* PRF # C9: 6 => SOL
* DIS # I4: 2,4 => CTR => I4: 9
* INC # I4: 9 => UNS
* INC # I5: 2,4 => UNS
* CNT  53 HDP CHAINS /  53 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* PRF # A1: 1,4 => SOL
* STA A1: 1,4
* CNT   1 HDP CHAINS /   1 HYP OPENED