Analysis of xx-top500-357-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: ......2.1.8.4........7........54..8.3.2......1........5...326...7.....4.......... initial

Autosolve

position: 4.53.827178142..3..2371.4.8..75413823.2.87.1.1.82.37..51483269727.15.84383..74125 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # F3: 6,9 => SOL
* DIS # F3: 5 => CTR => F3: 6,9
* PRF # F3: 6,9 => SOL
* DIS # F3: 5 => CTR => F3: 6,9
* DIS # F3: 5,6 => CTR => F3: 9
* PRF # F3: 9 => SOL
* PRF # I5: 6,9 => SOL
* DIS # I5: 4 => CTR => I5: 6,9
* DIS # I6: 6,9 => CTR => I6: 4
* PRF # I6: 4 => SOL
* DIS # F3: 5,6 => CTR => F3: 9
* PRF # F3: 9 => SOL
* PRF # I5: 6,9 => SOL
* DIS # I5: 4 => CTR => I5: 6,9
* DIS # I6: 6,9 => CTR => I6: 4
* PRF # I6: 4 => SOL
* PRF # F3: 6,9 => SOL
* DIS # F3: 5 => CTR => F3: 6,9
* CNT  18 HDP CHAINS /  18 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 # F3: 6,9 => SOL
* STA F3: 6,9
* CNT   1 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

......2.1.8.4........7........54..8.3.2......1........5...326...7.....4.......... initial
4.53.827178142..3..2371.4.8..75413823.2.87.1.1.82.37..51483269727.15.84383..74125 autosolve
495368271781425936623719458967541382342687519158293764514832697279156843836974125 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (19)
B1: 6,9
A3: 6,9
E1: 6,9
F2: 5,6
G2: 5,9
I2: 6,9
H3: 5,6
A4: 6,9
B4: 6,9
B5: 4,5
B6: 4,5
D5: 6,9
E6: 6,9
G5: 5,9
H6: 5,6
C8: 6,9
C9: 6,9
F8: 6,9
D9: 6,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
B5,B6: 4.. / B5 = 4  =>  0 pairs (*) / B6 = 4  =>  0 pairs (X)
I5,I6: 4.. / I5 = 4  =>  0 pairs (X) / I6 = 4  =>  0 pairs (_)
B5,I5: 4.. / B5 = 4  =>  0 pairs (*) / I5 = 4  =>  0 pairs (X)
B6,I6: 4.. / B6 = 4  =>  0 pairs (X) / I6 = 4  =>  0 pairs (_)
F2,F3: 5.. / F2 = 5  =>  0 pairs (*) / F3 = 5  =>  0 pairs (X)
G2,H3: 5.. / G2 = 5  =>  0 pairs (X) / H3 = 5  =>  0 pairs (_)
B5,B6: 5.. / B5 = 5  =>  0 pairs (X) / B6 = 5  =>  0 pairs (_)
G5,H6: 5.. / G5 = 5  =>  0 pairs (*) / H6 = 5  =>  0 pairs (X)
F2,G2: 5.. / F2 = 5  =>  0 pairs (*) / G2 = 5  =>  0 pairs (X)
F3,H3: 5.. / F3 = 5  =>  0 pairs (X) / H3 = 5  =>  0 pairs (_)
B5,G5: 5.. / B5 = 5  =>  0 pairs (X) / G5 = 5  =>  0 pairs (_)
B6,H6: 5.. / B6 = 5  =>  0 pairs (*) / H6 = 5  =>  0 pairs (X)
G2,G5: 5.. / G2 = 5  =>  0 pairs (X) / G5 = 5  =>  0 pairs (_)
H3,H6: 5.. / H3 = 5  =>  0 pairs (*) / H6 = 5  =>  0 pairs (X)
B1,A3: 6.. / B1 = 6  =>  0 pairs (X) / A3 = 6  =>  0 pairs (_)
I2,H3: 6.. / I2 = 6  =>  0 pairs (*) / H3 = 6  =>  0 pairs (X)
A4,B4: 6.. / A4 = 6  =>  0 pairs (X) / B4 = 6  =>  0 pairs (_)
D5,E6: 6.. / D5 = 6  =>  0 pairs (*) / E6 = 6  =>  0 pairs (X)
C8,C9: 6.. / C8 = 6  =>  0 pairs (X) / C9 = 6  =>  0 pairs (_)
F8,D9: 6.. / F8 = 6  =>  0 pairs (*) / D9 = 6  =>  0 pairs (X)
B1,E1: 6.. / B1 = 6  =>  0 pairs (X) / E1 = 6  =>  0 pairs (_)
F2,I2: 6.. / F2 = 6  =>  0 pairs (X) / I2 = 6  =>  0 pairs (_)
D5,I5: 6.. / D5 = 6  =>  0 pairs (*) / I5 = 6  =>  0 pairs (X)
C8,F8: 6.. / C8 = 6  =>  0 pairs (X) / F8 = 6  =>  0 pairs (_)
C9,D9: 6.. / C9 = 6  =>  0 pairs (*) / D9 = 6  =>  0 pairs (X)
A3,A4: 6.. / A3 = 6  =>  0 pairs (*) / A4 = 6  =>  0 pairs (X)
B1,B4: 6.. / B1 = 6  =>  0 pairs (X) / B4 = 6  =>  0 pairs (_)
D5,D9: 6.. / D5 = 6  =>  0 pairs (*) / D9 = 6  =>  0 pairs (X)
E1,E6: 6.. / E1 = 6  =>  0 pairs (*) / E6 = 6  =>  0 pairs (X)
H3,H6: 6.. / H3 = 6  =>  0 pairs (X) / H6 = 6  =>  0 pairs (_)
B1,A3: 9.. / B1 = 9  =>  0 pairs (*) / A3 = 9  =>  0 pairs (X)
E1,F3: 9.. / E1 = 9  =>  0 pairs (X) / F3 = 9  =>  0 pairs (_)
G2,I2: 9.. / G2 = 9  =>  0 pairs (*) / I2 = 9  =>  0 pairs (X)
A4,B4: 9.. / A4 = 9  =>  0 pairs (*) / B4 = 9  =>  0 pairs (X)
D5,E6: 9.. / D5 = 9  =>  0 pairs (X) / E6 = 9  =>  0 pairs (_)
C8,C9: 9.. / C8 = 9  =>  0 pairs (*) / C9 = 9  =>  0 pairs (X)
F8,D9: 9.. / F8 = 9  =>  0 pairs (X) / D9 = 9  =>  0 pairs (_)
B1,E1: 9.. / B1 = 9  =>  0 pairs (*) / E1 = 9  =>  0 pairs (X)
A3,F3: 9.. / A3 = 9  =>  0 pairs (X) / F3 = 9  =>  0 pairs (_)
E6,I6: 9.. / E6 = 9  =>  0 pairs (*) / I6 = 9  =>  0 pairs (X)
C8,F8: 9.. / C8 = 9  =>  0 pairs (*) / F8 = 9  =>  0 pairs (X)
C9,D9: 9.. / C9 = 9  =>  0 pairs (X) / D9 = 9  =>  0 pairs (_)
A3,A4: 9.. / A3 = 9  =>  0 pairs (X) / A4 = 9  =>  0 pairs (_)
B1,B4: 9.. / B1 = 9  =>  0 pairs (*) / B4 = 9  =>  0 pairs (X)
D5,D9: 9.. / D5 = 9  =>  0 pairs (X) / D9 = 9  =>  0 pairs (_)
E1,E6: 9.. / E1 = 9  =>  0 pairs (X) / E6 = 9  =>  0 pairs (_)
F3,F8: 9.. / F3 = 9  =>  0 pairs (*) / F8 = 9  =>  0 pairs (X)
G2,G5: 9.. / G2 = 9  =>  0 pairs (*) / G5 = 9  =>  0 pairs (X)
* DURATION: 0:01:27.164943  START: 14:57:10.123048  END: 14:58:37.287991 2017-05-04
* CP COUNT: (48)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A3,A4,B1,B4,B5,B6,C8,C9,D5,D9,E1,E6,F2,F8,G2,G5,H3,H6,I2)
* 4.53.827178142..3..2371.4.8..75413823.2.87.1.1.82.37..51483269727.15.84383..74125
* PAIR A3: 6,9 ROW 3
F3: 6,9,5                                # reduction candidate for 6,9
F3: 6,9 => SOLVED
* 495368271781425936623719458967541382342687519158293764514832697279156843836974125
F3: 5 => CTR
* 4.5398271781426539923715468697541382352987.1.1.82.37..51483269727.15.84383..74125
* PAIR E1: 6,9 BLK 2
F3: 6,9,5                                # reduction candidate for 6,9
F3: 6,9 => SOLVED
* 495368271781425936623719458967541382342687519158293764514832697279156843836974125
F3: 5 => CTR
* 4.5398271781426539923715468697541382352987.1.1.82.37..51483269727.15.84383..74125
* PAIR F2: 5,6 BLK 2
F3: 5,6,9                                # reduction candidate for 5,6
F3: 5,6 => CTR
* 4.539827178142..3.92371.4.86975413823.29875161.82.37..51483269727.15.84383..74125
F3: 9 => SOLVED
* 495368271781425936623719458967541382342687519158293764514832697279156843836974125
* PAIR I2: 6,9 COL I
I5: 6,9,4                                # reduction candidate for 6,9
I5: 6,9 => SOLVED
* 495368271781425936623719458967541382342687519158293764514832697279156843836974125
I5: 4 => CTR
* 4.53.827178142..3..2371.4.8..75413823.268791414829375651483269727.15684383..74125
I6: 6,9,4                                # reduction candidate for 6,9
I6: 6,9 => CTR
* 4.5368271781425.3..2371.4.8..75413823.2.87.141482.375651483269727.15.84383..74125
I6: 4 => SOLVED
* 495368271781425936623719458967541382342687519158293764514832697279156843836974125
* PAIR H3: 5,6 ROW 3
F3: 5,6,9                                # reduction candidate for 5,6
F3: 5,6 => CTR
* 4.539827178142..3.92371.4.86975413823.29875161.82.37..51483269727.15.84383..74125
F3: 9 => SOLVED
* 495368271781425936623719458967541382342687519158293764514832697279156843836974125
* PAIR D5: 6,9 ROW 5
I5: 6,9,4                                # reduction candidate for 6,9
I5: 6,9 => SOLVED
* 495368271781425936623719458967541382342687519158293764514832697279156843836974125
I5: 4 => CTR
* 4.53.827178142..3..2371.4.8..75413823.268791414829375651483269727.15684383..74125
* PAIR E6: 6,9 ROW 6
I6: 6,9,4                                # reduction candidate for 6,9
I6: 6,9 => CTR
* 4.5368271781425.3..2371.4.8..75413823.2.87.141482.375651483269727.15.84383..74125
I6: 4 => SOLVED
* 495368271781425936623719458967541382342687519158293764514832697279156843836974125
* PAIR F8: 6,9 COL F
F3: 6,9,5                                # reduction candidate for 6,9
F3: 6,9 => SOLVED
* 495368271781425936623719458967541382342687519158293764514832697279156843836974125
F3: 5 => CTR
* 4.5398271781426539923715468697541382352987.1.1.82.37..51483269727.15.84383..74125
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-357-base-pr-000.dot
* REASONING
* PRF # F3: 6,9 => SOL
* DIS # F3: 5 => CTR => F3: 6,9
* PRF # F3: 6,9 => SOL
* DIS # F3: 5 => CTR => F3: 6,9
* DIS # F3: 5,6 => CTR => F3: 9
* PRF # F3: 9 => SOL
* PRF # I5: 6,9 => SOL
* DIS # I5: 4 => CTR => I5: 6,9
* DIS # I6: 6,9 => CTR => I6: 4
* PRF # I6: 4 => SOL
* DIS # F3: 5,6 => CTR => F3: 9
* PRF # F3: 9 => SOL
* PRF # I5: 6,9 => SOL
* DIS # I5: 4 => CTR => I5: 6,9
* DIS # I6: 6,9 => CTR => I6: 4
* PRF # I6: 4 => SOL
* PRF # F3: 6,9 => SOL
* DIS # F3: 5 => CTR => F3: 6,9
* CNT  18 HDP CHAINS /  18 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A3,A4,B1,B4,B5,B6,C8,C9,D5,D9,E1,E6,F2,F8,G2,G5,H3,H6,I2)
* 4.53.827178142..3..2371.4.8..75413823.2.87.1.1.82.37..51483269727.15.84383..74125
* PAIR A3: 6,9 ROW 3
F3: 6,9,5                                # reduction candidate for 6,9
F3: 6,9 => SOLVED
* 495368271781425936623719458967541382342687519158293764514832697279156843836974125
* DURATION: 0:00:02.024625  START: 14:59:00.570499  END: 14:59:02.595124 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-357-base-pr-001.dot
* REASONING
* PRF # F3: 6,9 => SOL
* STA F3: 6,9
* CNT   1 HDP CHAINS /   1 HYP OPENED

Header Info

Top 500 Minimum 17 357

solution: 495368271781425936623719458967541382342687519158293764514832697279156843836974125
info: 4893     FNBWY    S8.f     982

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

Solution

position: 495368271781425936623719458967541382342687519158293764514832697279156843836974125 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 # F3: 6,9 => SOL
* DIS # F3: 5 => CTR => F3: 6,9
* PRF # F3: 6,9 => SOL
* DIS # F3: 5 => CTR => F3: 6,9
* DIS # F3: 5,6 => CTR => F3: 9
* PRF # F3: 9 => SOL
* PRF # I5: 6,9 => SOL
* DIS # I5: 4 => CTR => I5: 6,9
* DIS # I6: 6,9 => CTR => I6: 4
* PRF # I6: 4 => SOL
* DIS # F3: 5,6 => CTR => F3: 9
* PRF # F3: 9 => SOL
* PRF # I5: 6,9 => SOL
* DIS # I5: 4 => CTR => I5: 6,9
* DIS # I6: 6,9 => CTR => I6: 4
* PRF # I6: 4 => SOL
* PRF # F3: 6,9 => SOL
* DIS # F3: 5 => CTR => F3: 6,9
* CNT  18 HDP CHAINS /  18 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* PRF # F3: 6,9 => SOL
* STA F3: 6,9
* CNT   1 HDP CHAINS /   1 HYP OPENED