Analysis of xx-top500-232-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 4..58..........6.7.............1.84...7..3....3....1.....7.6.9.1...........2..... initial

Autosolve

position: 47658.31..981346.73.167..846..9178438174.3...9348.517..837.6.9114.3.87..76.2.1.38 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # G3: 9 => SOL
* PRF # G3: 2,9 => SOL
* DIS # G3: 5 => CTR => G3: 2,9
* PRF # G3: 2,9 => SOL
* DIS # G3: 5 => CTR => G3: 2,9
* PRF # I5: 2,9 => SOL
* PRF # G3: 9 => SOL
* DIS # C8: 9 => CTR => C8: 2,5
* DIS # I5: 2,6 => CTR => I5: 5,9
* DIS # I5: 2,6 => CTR => I5: 5,9
* PRF # I8: 5 => SOL
* DIS # C8: 9 => CTR => C8: 2,5
* DIS # G7: 4 => CTR => G7: 2,5
* DIS # C8: 5,9 => CTR => C8: 2
* PRF # C8: 2 => SOL
* DIS # E9: 4 => CTR => E9: 5,9
* DIS # E9: 9 => CTR => E9: 4,5
* DIS # G7: 4,5 => CTR => G7: 2
* PRF # G7: 2 => SOL
* DIS # E9: 4 => CTR => E9: 5,9
* DIS # C8: 5,9 => CTR => C8: 2
* PRF # C8: 2 => SOL
* DIS # G7: 4,5 => CTR => G7: 2
* PRF # G7: 2 => SOL
* DIS # E9: 9 => CTR => E9: 4,5
* CNT  25 HDP CHAINS /  42 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 # G3: 9 => SOL
* STA G3: 9
* CNT   1 HDP CHAINS /   2 HYP OPENED

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

Details

Positions

4..58..........6.7.............1.84...7..3....3....1.....7.6.9.1...........2..... initial
47658.31..981346.73.167..846..9178438174.3...9348.517..837.6.9114.3.87..76.2.1.38 autosolve
476589312298134657351672984625917843817463529934825176583746291142398765769251438 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (16)
A2: 2,5
B3: 2,5
F1: 2,9
F3: 2,9
I1: 2,9
H2: 2,5
B4: 2,5
C4: 2,5
E5: 2,6
E6: 2,6
I6: 2,6
A7: 2,5
C9: 5,9
E7: 4,5
E8: 5,9
G9: 4,5

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
A2,B3: 2.. / A2 = 2  =>  0 pairs (*) / B3 = 2  =>  0 pairs (X)
F1,F3: 2.. / F1 = 2  => 14 pairs (_) / F3 = 2  =>  0 pairs (*)
B4,C4: 2.. / B4 = 2  =>  0 pairs (*) / C4 = 2  =>  0 pairs (X)
E5,E6: 2.. / E5 = 2  => 14 pairs (_) / E6 = 2  => 15 pairs (_)
A7,C8: 2.. / A7 = 2  =>  0 pairs (X) / C8 = 2  =>  0 pairs (_)
F1,I1: 2.. / F1 = 2  => 14 pairs (_) / I1 = 2  =>  0 pairs (*)
A2,H2: 2.. / A2 = 2  =>  0 pairs (*) / H2 = 2  =>  0 pairs (X)
E6,I6: 2.. / E6 = 2  => 15 pairs (_) / I6 = 2  => 14 pairs (_)
A7,G7: 2.. / A7 = 2  =>  0 pairs (X) / G7 = 2  =>  0 pairs (_)
A2,A7: 2.. / A2 = 2  =>  0 pairs (*) / A7 = 2  =>  0 pairs (X)
B3,B4: 2.. / B3 = 2  =>  0 pairs (X) / B4 = 2  =>  0 pairs (_)
C4,C8: 2.. / C4 = 2  =>  0 pairs (X) / C8 = 2  =>  0 pairs (_)
E7,E9: 4.. / E7 = 4  => 16 pairs (_) / E9 = 4  =>  0 pairs (X)
G7,G9: 4.. / G7 = 4  =>  0 pairs (X) / G9 = 4  => 16 pairs (_)
E7,G7: 4.. / E7 = 4  => 16 pairs (_) / G7 = 4  =>  0 pairs (X)
E9,G9: 4.. / E9 = 4  =>  0 pairs (X) / G9 = 4  => 16 pairs (_)
A2,B3: 5.. / A2 = 5  =>  0 pairs (X) / B3 = 5  =>  0 pairs (_)
H2,G3: 5.. / H2 = 5  =>  0 pairs (*) / G3 = 5  =>  0 pairs (X)
B4,C4: 5.. / B4 = 5  =>  0 pairs (X) / C4 = 5  =>  0 pairs (_)
A2,H2: 5.. / A2 = 5  =>  0 pairs (X) / H2 = 5  =>  0 pairs (_)
B3,G3: 5.. / B3 = 5  =>  0 pairs (*) / G3 = 5  =>  0 pairs (X)
A2,A7: 5.. / A2 = 5  =>  0 pairs (X) / A7 = 5  =>  0 pairs (_)
B3,B4: 5.. / B3 = 5  =>  0 pairs (*) / B4 = 5  =>  0 pairs (X)
I5,I8: 5.. / I5 = 5  => 16 pairs (_) / I8 = 5  =>  0 pairs (*)
E5,E6: 6.. / E5 = 6  => 15 pairs (_) / E6 = 6  => 14 pairs (_)
H8,I8: 6.. / H8 = 6  => 18 pairs (_) / I8 = 6  => 12 pairs (_)
E6,I6: 6.. / E6 = 6  => 14 pairs (_) / I6 = 6  => 15 pairs (_)
H5,H8: 6.. / H5 = 6  => 12 pairs (_) / H8 = 6  => 18 pairs (_)
F1,F3: 9.. / F1 = 9  =>  0 pairs (*) / F3 = 9  =>  0 pairs (X)
I1,G3: 9.. / I1 = 9  => 14 pairs (_) / G3 = 9  =>  0 pairs (*)
G5,I5: 9.. / G5 = 9  => 14 pairs (_) / I5 = 9  =>  0 pairs (*)
C8,C9: 9.. / C8 = 9  =>  0 pairs (X) / C9 = 9  => 16 pairs (_)
E8,E9: 9.. / E8 = 9  => 16 pairs (_) / E9 = 9  =>  0 pairs (X)
F1,I1: 9.. / F1 = 9  =>  0 pairs (*) / I1 = 9  =>  0 pairs (X)
F3,G3: 9.. / F3 = 9  => 14 pairs (_) / G3 = 9  =>  0 pairs (*)
C8,E8: 9.. / C8 = 9  =>  0 pairs (X) / E8 = 9  => 16 pairs (_)
C9,E9: 9.. / C9 = 9  => 16 pairs (_) / E9 = 9  =>  0 pairs (X)
G3,G5: 9.. / G3 = 9  =>  0 pairs (*) / G5 = 9  =>  0 pairs (X)
I1,I5: 9.. / I1 = 9  => 14 pairs (_) / I5 = 9  =>  0 pairs (*)
* DURATION: 0:01:05.598324  START: 10:45:44.922601  END: 10:46:50.520925 2017-05-04
* CP COUNT: (39)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A2,A7,B3,B4,C4,C9,E5,E6,E7,E8,F1,F3,G9,H2,I1,I6)
* 47658.31..981346.73.167..846..9178438174.3...9348.517..837.6.9114.3.87..76.2.1.38
* PAIR B3: 2,5 ROW 3
G3: 2,5,9                                # reduction candidate for 2,5
G3: 9 => SOLVED
* 476589312298134657351672984625917843817463529934825176583746291142398765769251438
G3: 2,5                                  # 14 pairs
* PAIR F3: 2,9 ROW 3
G3: 2,9,5                                # reduction candidate for 2,9
G3: 2,9 => SOLVED
* 476589312298134657351672984625917843817463529934825176583746291142398765769251438
G3: 5 => CTR
* 47658.319.981346273216795846529178438174.39..9348.517.28375649114.3.87..76.2.1.38
* PAIR I1: 2,9 BLK 3
G3: 2,9,5                                # reduction candidate for 2,9
G3: 2,9 => SOLVED
* 476589312298134657351672984625917843817463529934825176583746291142398765769251438
G3: 5 => CTR
* 47658.319.981346273216795846529178438174.39..9348.517.28375649114.3.87..76.2.1.38
* PAIR I1: 2,9 COL I
I5: 2,9,5,6                              # reduction candidate for 2,9
I5: 2,9 => SOLVED
* 476589312298134657351672984625917843817463529934825176583746291142398765769251438
I5: 5,6                                  # 15 pairs
* PAIR H2: 2,5 BLK 3
G3: 2,5,9                                # reduction candidate for 2,5
G3: 9 => SOLVED
* 476589312298134657351672984625917843817463529934825176583746291142398765769251438
G3: 2,5                                  # 14 pairs
* PAIR H2: 2,5 COL H
H5: 2,5,6                                # reduction candidate for 2,5
H5: 2,5                                  # 18 pairs
H8: 2,5,6                                # reduction candidate for 2,5
H8: 2,5                                  # 12 pairs
* PAIR C4: 2,5 COL C
C8: 2,5,9                                # reduction candidate for 2,5
C8: 9 => CTR
* 47658.31.5981346273216795846.29178438174.3...9348.517.2837.6.911493587..765291438
C8: 2,5                                  # 16 pairs
* PAIR E5: 2,6 ROW 5
H5: 2,6,5                                # reduction candidate for 2,6
H5: 2,6                                  # 19 pairs
I5: 2,6,5,9                              # reduction candidate for 2,6
I5: 2,6 => CTR
* 4765823195981346273216795846529178438174.395.9348.517.2837.6.9114.3.876576.2.1438
I5: 5,9                                  # 17 pairs
* PAIR I6: 2,6 BLK 6
H5: 2,6,5                                # reduction candidate for 2,6
H5: 2,6                                  # 19 pairs
I5: 2,6,5,9                              # reduction candidate for 2,6
I5: 2,6 => CTR
* 4765823195981346273216795846529178438174.395.9348.517.2837.6.9114.3.876576.2.1438
I5: 5,9                                  # 17 pairs
* PAIR I6: 2,6 COL I
I8: 2,6,5                                # reduction candidate for 2,6
I8: 5 => SOLVED
* 476589312298134657351672984625917843817463529934825176583746291142398765769251438
I8: 2,6                                  # 16 pairs
* PAIR A7: 2,5 BLK 7
C8: 2,5,9                                # reduction candidate for 2,5
C8: 9 => CTR
* 47658.31.5981346273216795846.29178438174.3...9348.517.2837.6.911493587..765291438
C8: 2,5                                  # 16 pairs
* PAIR A7: 2,5 ROW 7
G7: 2,5,4                                # reduction candidate for 2,5
G7: 4 => CTR
* 47658.31..981346.73.167..846..9178438174.3...9348.517.28375649114.3987..769241538
G7: 2,5                                  # 16 pairs
* PAIR C9: 5,9 BLK 7
C8: 5,9,2                                # reduction candidate for 5,9
C8: 5,9 => CTR
* 47658.31.5981346273216795846.29178438174.3...9348.517.2837.6.9114.3.87..76.2.1.38
C8: 2 => SOLVED
* 476589312298134657351672984625917843817463529934825176583746291142398765769251438
* PAIR C9: 5,9 ROW 9
E9: 5,9,4                                # reduction candidate for 5,9
E9: 4 => CTR
* 47658.31..9813465735167..846259178438174.3...9348.517..837.6.9114.3987..769241538
E9: 5,9                                  # 16 pairs
* PAIR E7: 4,5 BLK 8
E9: 4,5,9                                # reduction candidate for 4,5
E9: 9 => CTR
* 47658.3195981346273.167..846..9178438174.3..59348.517..837465911493587..765291438
E9: 4,5                                  # 16 pairs
* PAIR E7: 4,5 ROW 7
G7: 4,5,2                                # reduction candidate for 4,5
G7: 4,5 => CTR
* 47658.31.5981346273216795846..9178438174.3...9348.517.2837.6.9114.3.87..76.2.1.38
G7: 2 => SOLVED
* 476589312298134657351672984625917843817463529934825176583746291142398765769251438
* PAIR E8: 5,9 BLK 8
E9: 5,9,4                                # reduction candidate for 5,9
E9: 4 => CTR
* 47658.31..9813465735167..846259178438174.3...9348.517..837.6.9114.3987..769241538
E9: 5,9                                  # 16 pairs
* PAIR E8: 5,9 ROW 8
C8: 5,9,2                                # reduction candidate for 5,9
C8: 5,9 => CTR
* 47658.31.5981346273216795846.29178438174.3...9348.517.2837.6.9114.3.87..76.2.1.38
C8: 2 => SOLVED
* 476589312298134657351672984625917843817463529934825176583746291142398765769251438
* PAIR G9: 4,5 BLK 9
G7: 4,5,2                                # reduction candidate for 4,5
G7: 4,5 => CTR
* 47658.31.5981346273216795846..9178438174.3...9348.517.2837.6.9114.3.87..76.2.1.38
G7: 2 => SOLVED
* 476589312298134657351672984625917843817463529934825176583746291142398765769251438
* PAIR G9: 4,5 ROW 9
E9: 4,5,9                                # reduction candidate for 4,5
E9: 9 => CTR
* 47658.3195981346273.167..846..9178438174.3..59348.517..837465911493587..765291438
E9: 4,5                                  # 16 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-232-base-pr-000.dot
* REASONING
* PRF # G3: 9 => SOL
* PRF # G3: 2,9 => SOL
* DIS # G3: 5 => CTR => G3: 2,9
* PRF # G3: 2,9 => SOL
* DIS # G3: 5 => CTR => G3: 2,9
* PRF # I5: 2,9 => SOL
* PRF # G3: 9 => SOL
* DIS # C8: 9 => CTR => C8: 2,5
* DIS # I5: 2,6 => CTR => I5: 5,9
* DIS # I5: 2,6 => CTR => I5: 5,9
* PRF # I8: 5 => SOL
* DIS # C8: 9 => CTR => C8: 2,5
* DIS # G7: 4 => CTR => G7: 2,5
* DIS # C8: 5,9 => CTR => C8: 2
* PRF # C8: 2 => SOL
* DIS # E9: 4 => CTR => E9: 5,9
* DIS # E9: 9 => CTR => E9: 4,5
* DIS # G7: 4,5 => CTR => G7: 2
* PRF # G7: 2 => SOL
* DIS # E9: 4 => CTR => E9: 5,9
* DIS # C8: 5,9 => CTR => C8: 2
* PRF # C8: 2 => SOL
* DIS # G7: 4,5 => CTR => G7: 2
* PRF # G7: 2 => SOL
* DIS # E9: 9 => CTR => E9: 4,5
* CNT  25 HDP CHAINS /  42 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A2,A7,B3,B4,C4,C9,E5,E6,E7,E8,F1,F3,G9,H2,I1,I6)
* 47658.31..981346.73.167..846..9178438174.3...9348.517..837.6.9114.3.87..76.2.1.38
* PAIR B3: 2,5 ROW 3
G3: 2,5,9                                # reduction candidate for 2,5
G3: 9 => SOLVED
* 476589312298134657351672984625917843817463529934825176583746291142398765769251438
* DURATION: 0:00:02.833934  START: 10:47:32.106301  END: 10:47:34.940235 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-232-base-pr-001.dot
* REASONING
* PRF # G3: 9 => SOL
* STA G3: 9
* CNT   1 HDP CHAINS /   2 HYP OPENED

Header Info

Top 500 Minimum 17 232

solution: 476589312298134657351672984625917843817463529934825176583746291142398765769251438
info: 2065     FNWXY    S8.f     31085

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

Solution

position: 476589312298134657351672984625917843817463529934825176583746291142398765769251438 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:

* INC # G3: 2,5 => UNS
* PRF # G3: 9 => SOL
* PRF # G3: 2,9 => SOL
* DIS # G3: 5 => CTR => G3: 2,9
* PRF # G3: 2,9 => SOL
* DIS # G3: 5 => CTR => G3: 2,9
* PRF # I5: 2,9 => SOL
* INC # I5: 5,6 => UNS
* INC # G3: 2,5 => UNS
* PRF # G3: 9 => SOL
* INC # H5: 2,5 => UNS
* INC # H8: 2,5 => UNS
* INC # C8: 2,5 => UNS
* DIS # C8: 9 => CTR => C8: 2,5
* INC # H5: 2,6 => UNS
* DIS # I5: 2,6 => CTR => I5: 5,9
* INC # I5: 5,9 => UNS
* INC # H5: 2,6 => UNS
* DIS # I5: 2,6 => CTR => I5: 5,9
* INC # I5: 5,9 => UNS
* INC # I8: 2,6 => UNS
* PRF # I8: 5 => SOL
* INC # C8: 2,5 => UNS
* DIS # C8: 9 => CTR => C8: 2,5
* INC # G7: 2,5 => UNS
* DIS # G7: 4 => CTR => G7: 2,5
* DIS # C8: 5,9 => CTR => C8: 2
* PRF # C8: 2 => SOL
* INC # E9: 5,9 => UNS
* DIS # E9: 4 => CTR => E9: 5,9
* INC # E9: 4,5 => UNS
* DIS # E9: 9 => CTR => E9: 4,5
* DIS # G7: 4,5 => CTR => G7: 2
* PRF # G7: 2 => SOL
* INC # E9: 5,9 => UNS
* DIS # E9: 4 => CTR => E9: 5,9
* DIS # C8: 5,9 => CTR => C8: 2
* PRF # C8: 2 => SOL
* DIS # G7: 4,5 => CTR => G7: 2
* PRF # G7: 2 => SOL
* INC # E9: 4,5 => UNS
* DIS # E9: 9 => CTR => E9: 4,5
* CNT  42 HDP CHAINS /  42 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # G3: 2,5 => UNS
* PRF # G3: 9 => SOL
* STA G3: 9
* CNT   2 HDP CHAINS /   2 HYP OPENED