Analysis of xx-top500-147-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: .9.83....6.....5.9.............2..3.5..9...........1...23....8......17.....5..... initial

Autosolve

position: .9583.21.63821.5.92.1.598.3...12593.5129.3..83.9..8152123.9..8595.38172....5.2391 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # F1: 4,7 => CTR => F1: 6
* DIS # H3: 4,7 => CTR => H3: 6
* DIS # B4: 4,7 => CTR => B4: 6,8
* DIS # B9: 4,7 => CTR => B9: 6,8
* DIS # F1: 4,7 => CTR => F1: 6
* DIS # F7: 6 => CTR => F7: 4,7
* DIS # H3: 4,7 => CTR => H3: 6
* DIS # H5: 6 => CTR => H5: 4,7
* DIS # E5: 4,6 => CTR => E5: 7
* DIS # B6: 4,6 => CTR => B6: 7
* PRF # D7: 4,6 => SOL
* DIS # I4: 4,6 => CTR => I4: 7
* DIS # E5: 4,6 => CTR => E5: 7
* DIS # C9: 4,6 => CTR => C9: 7
* DIS # C4: 7 => CTR => C4: 4,6
* PRF # D7: 4,6 => SOL
* DIS # C9: 4,6 => CTR => C9: 7
* DIS # E5: 4,6 => CTR => E5: 7
* PRF # D7: 4,6 => SOL
* DIS # I4: 4,6 => CTR => I4: 7
* CNT  20 HDP CHAINS /  56 HYP OPENED

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

Pair Reduction

Pair Reduction

The following important HDP chains were detected:

* DIS # F1: 4,7 => CTR => F1: 6
* DIS F1: 6 # B4: 4,7 => CTR => B4: 6,8
* PRF F1: 6 + B4: 6,8 # B6: 4,7 => SOL
* STA F1: 6 + B4: 6,8 + B6: 4,7
* CNT   3 HDP CHAINS /   7 HYP OPENED

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

Details

Positions

.9.83....6.....5.9.............2..3.5..9...........1...23....8......17.....5..... initial
.9583.21.63821.5.92.1.598.3...12593.5129.3..83.9..8152123.9..8595.38172....5.2391 autosolve
795836214638214579241759863486125937512973648379468152123697485954381726867542391 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (10)
A1: 4,7
B3: 4,7
F2: 4,7
H2: 4,7
D6: 4,6
G5: 4,6
C8: 4,6
E9: 4,6
G7: 4,6
I8: 4,6

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
A1,B3: 4.. / A1 = 4  =>  0 pairs (X) / B3 = 4  => 20 pairs (_)
G7,I8: 4.. / G7 = 4  =>  0 pairs (*) / I8 = 4  =>  0 pairs (X)
F2,H2: 4.. / F2 = 4  =>  0 pairs (*) / H2 = 4  =>  0 pairs (X)
C8,I8: 4.. / C8 = 4  =>  0 pairs (*) / I8 = 4  =>  0 pairs (X)
G5,G7: 4.. / G5 = 4  =>  0 pairs (X) / G7 = 4  =>  0 pairs (_)
F1,D3: 6.. / F1 = 6  => 14 pairs (_) / D3 = 6  =>  0 pairs (X)
I1,H3: 6.. / I1 = 6  =>  0 pairs (X) / H3 = 6  => 14 pairs (_)
G7,I8: 6.. / G7 = 6  =>  0 pairs (X) / I8 = 6  =>  0 pairs (_)
F1,I1: 6.. / F1 = 6  => 14 pairs (_) / I1 = 6  =>  0 pairs (X)
D3,H3: 6.. / D3 = 6  =>  0 pairs (X) / H3 = 6  => 14 pairs (_)
C8,I8: 6.. / C8 = 6  =>  0 pairs (X) / I8 = 6  =>  0 pairs (_)
F1,F7: 6.. / F1 = 6  => 14 pairs (_) / F7 = 6  =>  0 pairs (X)
G5,G7: 6.. / G5 = 6  =>  0 pairs (*) / G7 = 6  =>  0 pairs (X)
H3,H5: 6.. / H3 = 6  => 14 pairs (_) / H5 = 6  =>  0 pairs (X)
A1,B3: 7.. / A1 = 7  => 20 pairs (_) / B3 = 7  =>  0 pairs (X)
E5,E6: 7.. / E5 = 7  => 20 pairs (_) / E6 = 7  =>  0 pairs (X)
I4,H5: 7.. / I4 = 7  => 20 pairs (_) / H5 = 7  =>  0 pairs (X)
D7,F7: 7.. / D7 = 7  => 12 pairs (_) / F7 = 7  =>  0 pairs (*)
F2,H2: 7.. / F2 = 7  => 14 pairs (_) / H2 = 7  =>  0 pairs (*)
E5,H5: 7.. / E5 = 7  => 20 pairs (_) / H5 = 7  =>  0 pairs (X)
B6,E6: 7.. / B6 = 7  => 20 pairs (_) / E6 = 7  =>  0 pairs (X)
C4,C9: 7.. / C4 = 7  =>  0 pairs (X) / C9 = 7  => 12 pairs (_)
D3,D7: 7.. / D3 = 7  =>  0 pairs (*) / D7 = 7  =>  0 pairs (X)
I1,I4: 7.. / I1 = 7  =>  0 pairs (X) / I4 = 7  => 20 pairs (_)
A4,B4: 8.. / A4 = 8  => 12 pairs (_) / B4 = 8  => 11 pairs (_)
A9,B9: 8.. / A9 = 8  => 11 pairs (_) / B9 = 8  => 12 pairs (_)
A4,A9: 8.. / A4 = 8  => 12 pairs (_) / A9 = 8  => 11 pairs (_)
B4,B9: 8.. / B4 = 8  => 11 pairs (_) / B9 = 8  => 12 pairs (_)
* DURATION: 0:00:47.532143  START: 07:46:26.452977  END: 07:47:13.985120 2017-05-04
* CP COUNT: (28)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,B3,C8,D6,E9,F2,G5,G7,H2,I8)
* .9583.21.63821.5.92.1.598.3...12593.5129.3..83.9..8152123.9..8595.38172....5.2391
* PAIR A1: 4,7 ROW 1
F1: 4,7,6                                # reduction candidate for 4,7
F1: 4,7 => CTR
* .9583.21663821.5.92.16598.3...125937512973.6837946815212379648595.38172....5.2391
F1: 6                                    # 14 pairs
I1: 4,7,6                                # reduction candidate for 4,7
I1: 4,7                                  # 14 pairs
* PAIR A1: 4,7 COL A
A4: 4,7,8                                # reduction candidate for 4,7
A4: 4,7                                  # 11 pairs
A9: 4,7,8                                # reduction candidate for 4,7
A9: 4,7                                  # 12 pairs
* PAIR B3: 4,7 ROW 3
D3: 4,7,6                                # reduction candidate for 4,7
D3: 4,7                                  # 14 pairs
H3: 4,7,6                                # reduction candidate for 4,7
H3: 4,7 => CTR
* .9583.21663821.5.92.16598.3...125937512973.6837946815212379648595.38172....5.2391
H3: 6                                    # 14 pairs
* PAIR B3: 4,7 COL B
B4: 4,7,6,8                              # reduction candidate for 4,7
B4: 4,7 => CTR
* 49583.21.63821457927165984384.12593.5129.3..8369478152123.9..8595.38172..8.542391
B4: 6,8                                  # 11 pairs
B6: 4,7,6                                # reduction candidate for 4,7
B6: 4,7                                  # 15 pairs
B9: 4,7,6,8                              # reduction candidate for 4,7
B9: 4,7 => CTR
* .9583.21.63821.5.9241.598.34871259365129634.8369478152123.9..8595.38172.8..542391
B9: 6,8                                  # 11 pairs
* PAIR F2: 4,7 BLK 2
F1: 4,7,6                                # reduction candidate for 4,7
F1: 4,7 => CTR
* .9583.21663821.5.92.16598.3...125937512973.6837946815212379648595.38172....5.2391
F1: 6                                    # 14 pairs
D3: 4,7,6                                # reduction candidate for 4,7
D3: 4,7                                  # 14 pairs
* PAIR F2: 4,7 COL F
F7: 4,7,6                                # reduction candidate for 4,7
F7: 6 => CTR
* .9583.21.63821.5.92.1.598.3...12593.5129.3..83.9..8152123796485954381726...542391
F7: 4,7                                  # 14 pairs
* PAIR H2: 4,7 BLK 3
I1: 4,7,6                                # reduction candidate for 4,7
I1: 4,7                                  # 14 pairs
H3: 4,7,6                                # reduction candidate for 4,7
H3: 4,7 => CTR
* .9583.21663821.5.92.16598.3...125937512973.6837946815212379648595.38172....5.2391
H3: 6                                    # 14 pairs
* PAIR H2: 4,7 COL H
H5: 4,7,6                                # reduction candidate for 4,7
H5: 6 => CTR
* 79583.21.63821.5.92.1.598.3...125937512973468379..8152123.9.685956381724..7562391
H5: 4,7                                  # 14 pairs
* PAIR D6: 4,6 BLK 5
E5: 4,6,7                                # reduction candidate for 4,6
E5: 4,6 => CTR
* .9583.217638217549271459863...12593.51294367834967815212379..8595.38172....5.2391
E5: 7                                    # 20 pairs
E6: 4,6,7                                # reduction candidate for 4,6
E6: 4,6                                  # 20 pairs
* PAIR D6: 4,6 ROW 6
B6: 4,6,7                                # reduction candidate for 4,6
B6: 4,6 => CTR
* .9583.217638217549271459863...12593.51294367834967815212379..8595.38172....5.2391
B6: 7                                    # 20 pairs
* PAIR D6: 4,6 COL D
D3: 4,6,7                                # reduction candidate for 4,6
D3: 4,6                                  # 12 pairs
D7: 4,6,7                                # reduction candidate for 4,6
D7: 4,6 => SOLVED
* 795836214638214579241759863486125937512973648379468152123697485954381726867542391
D7: 7                                    # 12 pairs
* PAIR G5: 4,6 BLK 6
I4: 4,6,7                                # reduction candidate for 4,6
I4: 4,6 => CTR
* .9583.217638217549271459863...12593.5129.3.783.967815212379468595.38172....5.2391
I4: 7                                    # 20 pairs
H5: 4,6,7                                # reduction candidate for 4,6
H5: 4,6                                  # 20 pairs
* PAIR G5: 4,6 ROW 5
E5: 4,6,7                                # reduction candidate for 4,6
E5: 4,6 => CTR
* .9583.217638217549271459863...12593.51294367834967815212379..8595.38172....5.2391
E5: 7                                    # 20 pairs
* PAIR C8: 4,6 BLK 7
B9: 4,6,7,8                              # reduction candidate for 4,6
B9: 4,6                                  # 13 pairs
C9: 4,6,7                                # reduction candidate for 4,6
C9: 4,6 => CTR
* .9583.217638217549271459863..712593.51294367834967815212379..8595.38172....5.2391
C9: 7                                    # 12 pairs
* PAIR C8: 4,6 COL C
C4: 4,6,7                                # reduction candidate for 4,6
C4: 7 => CTR
* .9583.217638217549271459863..712593.51294367834967815212379..8595.38172....5.2391
C4: 4,6                                  # 12 pairs
* PAIR E9: 4,6 BLK 8
D7: 4,6,7                                # reduction candidate for 4,6
D7: 4,6 => SOLVED
* 795836214638214579241759863486125937512973648379468152123697485954381726867542391
D7: 7                                    # 12 pairs
F7: 4,6,7                                # reduction candidate for 4,6
F7: 4,6                                  # 12 pairs
* PAIR E9: 4,6 ROW 9
B9: 4,6,7,8                              # reduction candidate for 4,6
B9: 4,6                                  # 13 pairs
C9: 4,6,7                                # reduction candidate for 4,6
C9: 4,6 => CTR
* .9583.217638217549271459863..712593.51294367834967815212379..8595.38172....5.2391
C9: 7                                    # 12 pairs
* PAIR E9: 4,6 COL E
E5: 4,6,7                                # reduction candidate for 4,6
E5: 4,6 => CTR
* .9583.217638217549271459863...12593.51294367834967815212379..8595.38172....5.2391
E5: 7                                    # 20 pairs
E6: 4,6,7                                # reduction candidate for 4,6
E6: 4,6                                  # 20 pairs
* PAIR G7: 4,6 ROW 7
D7: 4,6,7                                # reduction candidate for 4,6
D7: 4,6 => SOLVED
* 795836214638214579241759863486125937512973648379468152123697485954381726867542391
D7: 7                                    # 12 pairs
F7: 4,6,7                                # reduction candidate for 4,6
F7: 4,6                                  # 12 pairs
* PAIR I8: 4,6 COL I
I1: 4,6,7                                # reduction candidate for 4,6
I1: 4,6                                  # 20 pairs
I4: 4,6,7                                # reduction candidate for 4,6
I4: 4,6 => CTR
* .9583.217638217549271459863...12593.5129.3.783.967815212379468595.38172....5.2391
I4: 7                                    # 20 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-147-base-pr-000.dot
* REASONING
* DIS # F1: 4,7 => CTR => F1: 6
* DIS # H3: 4,7 => CTR => H3: 6
* DIS # B4: 4,7 => CTR => B4: 6,8
* DIS # B9: 4,7 => CTR => B9: 6,8
* DIS # F1: 4,7 => CTR => F1: 6
* DIS # F7: 6 => CTR => F7: 4,7
* DIS # H3: 4,7 => CTR => H3: 6
* DIS # H5: 6 => CTR => H5: 4,7
* DIS # E5: 4,6 => CTR => E5: 7
* DIS # B6: 4,6 => CTR => B6: 7
* PRF # D7: 4,6 => SOL
* DIS # I4: 4,6 => CTR => I4: 7
* DIS # E5: 4,6 => CTR => E5: 7
* DIS # C9: 4,6 => CTR => C9: 7
* DIS # C4: 7 => CTR => C4: 4,6
* PRF # D7: 4,6 => SOL
* DIS # C9: 4,6 => CTR => C9: 7
* DIS # E5: 4,6 => CTR => E5: 7
* PRF # D7: 4,6 => SOL
* DIS # I4: 4,6 => CTR => I4: 7
* CNT  20 HDP CHAINS /  56 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,B3,C8,D6,E9,F2,G5,G7,H2,I8)
* .9583.21.63821.5.92.1.598.3...12593.5129.3..83.9..8152123.9..8595.38172....5.2391
* PAIR A1: 4,7 ROW 1
F1: 4,7,6                                # reduction candidate for 4,7
F1: 4,7 => CTR
* .9583.21663821.5.92.16598.3...125937512973.6837946815212379648595.38172....5.2391
* RESTART
* PAIR A1: 4,7 COL A
A4: 4,7,8                                # reduction candidate for 4,7
A4: 4,7                                  # 15 pairs
A9: 4,7,8                                # reduction candidate for 4,7
A9: 4,7                                  # 16 pairs
* PAIR RESTART
* PAIR A1: 4,7 COL A
A4: 4,7,8                                # reduction candidate for 4,7
A4: 4,7                                  # 15 pairs
A9: 4,7,8                                # reduction candidate for 4,7
A9: 4,7                                  # 16 pairs
* PAIR B3: 4,7 COL B
B4: 4,7,6,8                              # reduction candidate for 4,7
B4: 4,7 => CTR
* .9583621.63821.5.92.1.598638..12593.5129.3..8369478152123697485954381726786542391
B6: 4,7,6                                # reduction candidate for 4,7
B6: 4,7 => SOLVED
* 795836214638214579241759863486125937512973648379468152123697485954381726867542391
* DURATION: 0:00:07.885201  START: 07:48:06.017771  END: 07:48:13.902972 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-147-base-pr-001.dot
* REASONING
* DIS # F1: 4,7 => CTR => F1: 6
* DIS F1: 6 # B4: 4,7 => CTR => B4: 6,8
* PRF F1: 6 + B4: 6,8 # B6: 4,7 => SOL
* STA F1: 6 + B4: 6,8 + B6: 4,7
* CNT   3 HDP CHAINS /   7 HYP OPENED

Header Info

Top 500 Minimum 17 147

solution: 795836214638214579241759863486125937512973648379468152123697485954381726867542391
info: 1815     FNBWX    S8.f     24613

http://www.sfsudoku.com/su17ExtremeDiff500.txt from http://www.minimumsudoku.com/

Solution

position: 795836214638214579241759863486125937512973648379468152123697485954381726867542391 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:

* DIS # F1: 4,7 => CTR => F1: 6
* INC # F1: 6 => UNS
* INC # I1: 4,7 => UNS
* INC # A4: 4,7 => UNS
* INC # A9: 4,7 => UNS
* INC # D3: 4,7 => UNS
* DIS # H3: 4,7 => CTR => H3: 6
* INC # H3: 6 => UNS
* DIS # B4: 4,7 => CTR => B4: 6,8
* INC # B4: 6,8 => UNS
* INC # B6: 4,7 => UNS
* DIS # B9: 4,7 => CTR => B9: 6,8
* INC # B9: 6,8 => UNS
* DIS # F1: 4,7 => CTR => F1: 6
* INC # F1: 6 => UNS
* INC # D3: 4,7 => UNS
* INC # F7: 4,7 => UNS
* DIS # F7: 6 => CTR => F7: 4,7
* INC # I1: 4,7 => UNS
* DIS # H3: 4,7 => CTR => H3: 6
* INC # H3: 6 => UNS
* INC # H5: 4,7 => UNS
* DIS # H5: 6 => CTR => H5: 4,7
* DIS # E5: 4,6 => CTR => E5: 7
* INC # E5: 7 => UNS
* INC # E6: 4,6 => UNS
* DIS # B6: 4,6 => CTR => B6: 7
* INC # B6: 7 => UNS
* INC # D3: 4,6 => UNS
* PRF # D7: 4,6 => SOL
* INC # D7: 7 => UNS
* DIS # I4: 4,6 => CTR => I4: 7
* INC # I4: 7 => UNS
* INC # H5: 4,6 => UNS
* DIS # E5: 4,6 => CTR => E5: 7
* INC # E5: 7 => UNS
* INC # B9: 4,6 => UNS
* DIS # C9: 4,6 => CTR => C9: 7
* INC # C9: 7 => UNS
* INC # C4: 4,6 => UNS
* DIS # C4: 7 => CTR => C4: 4,6
* PRF # D7: 4,6 => SOL
* INC # D7: 7 => UNS
* INC # F7: 4,6 => UNS
* INC # B9: 4,6 => UNS
* DIS # C9: 4,6 => CTR => C9: 7
* INC # C9: 7 => UNS
* DIS # E5: 4,6 => CTR => E5: 7
* INC # E5: 7 => UNS
* INC # E6: 4,6 => UNS
* PRF # D7: 4,6 => SOL
* INC # D7: 7 => UNS
* INC # F7: 4,6 => UNS
* INC # I1: 4,6 => UNS
* DIS # I4: 4,6 => CTR => I4: 7
* INC # I4: 7 => UNS
* CNT  56 HDP CHAINS /  56 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # F1: 4,7 => CTR => F1: 6
* INC F1: 6 # A4: 4,7 => UNS
* INC F1: 6 # A9: 4,7 => UNS
* INC F1: 6 # A4: 4,7 => UNS
* INC F1: 6 # A9: 4,7 => UNS
* DIS F1: 6 # B4: 4,7 => CTR => B4: 6,8
* PRF F1: 6 + B4: 6,8 # B6: 4,7 => SOL
* STA F1: 6 + B4: 6,8 + B6: 4,7
* CNT   7 HDP CHAINS /   7 HYP OPENED