Analysis of xx-top500-106-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 7.....1.....3........6......38..........1.2....6....5..1....46.2...7.......5...3. initial

Autosolve

position: 76..5.1.38..3..6..3..6.....438265917975.132.61267..35.517.3.462243176...6895..731 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # F1: 2,4 => CTR => F1: 8,9
* PRF # F1: 8,9 => SOL
* DIS # H1: 2,4 => CTR => H1: 8,9
* PRF # H1: 8,9 => SOL
* PRF # I2: 5,9 => SOL
* DIS # I2: 4 => CTR => I2: 5,9
* DIS # I3: 5,9 => CTR => I3: 4,8
* PRF # I3: 4,8 => SOL
* DIS # I3: 5,8 => CTR => I3: 4,9
* DIS # E6: 4,8 => CTR => E6: 9
* PRF # E6: 9 => SOL
* PRF # F6: 4,8 => SOL
* DIS # F6: 9 => CTR => F6: 4,8
* DIS # D1: 9 => CTR => D1: 4,8
* PRF # H1: 4,8 => SOL
* DIS # H1: 2,9 => CTR => H1: 4,8
* DIS # H3: 4,8 => CTR => H3: 2,7,9
* DIS # E6: 4,8 => CTR => E6: 9
* PRF # E6: 9 => SOL
* PRF # F6: 4,8 => SOL
* DIS # F6: 9 => CTR => F6: 4,8
* PRF # I3: 4,8 => SOL
* DIS # I3: 5,9 => CTR => I3: 4,8
* DIS # D1: 8,9 => CTR => D1: 4
* PRF # D1: 4 => SOL
* PRF # F1: 8,9 => SOL
* DIS # F1: 2,4 => CTR => F1: 8,9
* DIS # F6: 8,9 => CTR => F6: 4
* PRF # F6: 4 => SOL
* PRF # E2: 2,4 => SOL
* DIS # E2: 9 => CTR => E2: 2,4
* DIS # E3: 2,4 => CTR => E3: 8,9
* PRF # E3: 8,9 => SOL
* DIS # F1: 2,4 => CTR => F1: 8,9
* PRF # F1: 8,9 => SOL
* PRF # I8: 5,8 => SOL
* DIS # I8: 9 => CTR => I8: 5,8
* DIS # I8: 8,9 => CTR => I8: 5
* PRF # I8: 5 => SOL
* PRF # H1: 8,9 => SOL
* DIS # H1: 2,4 => CTR => H1: 8,9
* DIS # H3: 8,9 => CTR => H3: 2,4,7
* CNT  42 HDP CHAINS /  48 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: 2,4 => CTR => F1: 8,9
* PRF F1: 8,9 => SOL
* STA F1: 8,9
* CNT   2 HDP CHAINS /   3 HYP OPENED

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

Details

Positions

7.....1.....3........6......38..........1.2....6....5..1....46.2...7.......5...3. initial
76..5.1.38..3..6..3..6.....438265917975.132.61267..35.517.3.462243176...6895..731 autosolve
762459183854321679391687524438265917975813246126794358517938462243176895689542731 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (15)
C1: 2,4
B2: 5,9
B3: 5,9
F2: 1,7
F3: 1,7
G3: 5,8
D5: 4,8
H5: 4,8
I6: 4,8
D7: 8,9
F7: 8,9
E9: 2,4
F9: 2,4
G8: 5,8
H8: 8,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
C2,C3: 1.. / C2 = 1  => 14 pairs (_) / C3 = 1  => 14 pairs (_)
F2,F3: 1.. / F2 = 1  => 14 pairs (_) / F3 = 1  => 14 pairs (_)
C2,F2: 1.. / C2 = 1  => 14 pairs (_) / F2 = 1  => 14 pairs (_)
C3,F3: 1.. / C3 = 1  => 14 pairs (_) / F3 = 1  => 14 pairs (_)
E9,F9: 2.. / E9 = 2  =>  0 pairs (X) / F9 = 2  =>  0 pairs (_)
F1,F9: 2.. / F1 = 2  =>  0 pairs (X) / F9 = 2  =>  0 pairs (_)
H5,I6: 4.. / H5 = 4  =>  0 pairs (*) / I6 = 4  =>  0 pairs (X)
E9,F9: 4.. / E9 = 4  =>  0 pairs (*) / F9 = 4  =>  0 pairs (X)
D5,H5: 4.. / D5 = 4  =>  0 pairs (X) / H5 = 4  =>  0 pairs (_)
D1,D5: 4.. / D1 = 4  =>  0 pairs (*) / D5 = 4  =>  0 pairs (X)
B2,B3: 5.. / B2 = 5  => 14 pairs (_) / B3 = 5  =>  0 pairs (X)
G8,I8: 5.. / G8 = 5  =>  0 pairs (X) / I8 = 5  =>  0 pairs (_)
B2,I2: 5.. / B2 = 5  => 14 pairs (_) / I2 = 5  =>  0 pairs (X)
G3,G8: 5.. / G3 = 5  =>  0 pairs (*) / G8 = 5  =>  0 pairs (X)
F2,F3: 7.. / F2 = 7  => 14 pairs (_) / F3 = 7  => 14 pairs (_)
H2,H3: 7.. / H2 = 7  => 14 pairs (_) / H3 = 7  => 14 pairs (_)
F2,H2: 7.. / F2 = 7  => 14 pairs (_) / H2 = 7  => 14 pairs (_)
F3,H3: 7.. / F3 = 7  => 14 pairs (_) / H3 = 7  => 14 pairs (_)
H5,I6: 8.. / H5 = 8  =>  0 pairs (X) / I6 = 8  =>  0 pairs (_)
D7,F7: 8.. / D7 = 8  =>  0 pairs (X) / F7 = 8  => 15 pairs (_)
D5,H5: 8.. / D5 = 8  =>  0 pairs (*) / H5 = 8  =>  0 pairs (X)
E3,E6: 8.. / E3 = 8  =>  0 pairs (*) / E6 = 8  =>  0 pairs (X)
G3,G8: 8.. / G3 = 8  =>  0 pairs (X) / G8 = 8  =>  0 pairs (_)
B2,B3: 9.. / B2 = 9  =>  0 pairs (X) / B3 = 9  => 14 pairs (_)
E6,F6: 9.. / E6 = 9  =>  0 pairs (*) / F6 = 9  =>  0 pairs (X)
D7,F7: 9.. / D7 = 9  => 15 pairs (_) / F7 = 9  =>  0 pairs (X)
H8,I8: 9.. / H8 = 9  =>  0 pairs (*) / I8 = 9  =>  0 pairs (X)
D1,D7: 9.. / D1 = 9  =>  0 pairs (X) / D7 = 9  => 15 pairs (_)
* DURATION: 0:00:46.924679  START: 06:23:21.441660  END: 06:24:08.366339 2017-05-04
* CP COUNT: (28)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B2,B3,C1,D5,D7,E9,F2,F3,F7,F9,G3,G8,H5,H8,I6)
* 76..5.1.38..3..6..3..6.....438265917975.132.61267..35.517.3.462243176...6895..731
* PAIR C1: 2,4 BLK 1
C2: 2,4,1                                # reduction candidate for 2,4
C2: 2,4                                  # 14 pairs
C3: 2,4,1                                # reduction candidate for 2,4
C3: 2,4                                  # 14 pairs
* PAIR C1: 2,4 ROW 1
F1: 2,4,8,9                              # reduction candidate for 2,4
F1: 2,4 => CTR
* 76..5.1.38..3..6..3..6.....438265917975.132.61267..35.517.3.462243176...6895..731
F1: 8,9 => SOLVED
* 762459183854321679391687524438265917975813246126794358517938462243176895689542731
H1: 2,4,8,9                              # reduction candidate for 2,4
H1: 2,4 => CTR
* 76..5.1.38..3..6..3..6.....438265917975.132.61267..35.517.3.462243176...6895..731
H1: 8,9 => SOLVED
* 762459183854321679391687524438265917975813246126794358517938462243176895689542731
* PAIR B2: 5,9 ROW 2
I2: 5,9,4                                # reduction candidate for 5,9
I2: 5,9 => SOLVED
* 762459183854321679391687524438265917975813246126794358517938462243176895689542731
I2: 4 => CTR
* 76.45.1.385.3..6.43946815..438265917975.132461267..358517.3.462243176..96895..731
* PAIR B3: 5,9 ROW 3
I3: 5,9,4,8                              # reduction candidate for 5,9
I3: 5,9 => CTR
* 76.85.1938..3..6..3..6..8..438265917975.132.61267893545179384622431765.86895..731
I3: 4,8 => SOLVED
* 762459183854321679391687524438265917975813246126794358517938462243176895689542731
* PAIR G3: 5,8 BLK 3
I3: 5,8,4,9                              # reduction candidate for 5,8
I3: 5,8 => CTR
* 76.85.19385.3..6..39.6.....438265917975.132.6126789354517938462243176...6895..731
I3: 4,9                                  # 16 pairs
* PAIR D5: 4,8 BLK 5
E6: 4,8,9                                # reduction candidate for 4,8
E6: 4,8 => CTR
* 76.85.1938..3..6..3..6..8..4382659179754132.61267.935.517938462243176.896895..731
E6: 9 => SOLVED
* 762459183854321679391687524438265917975813246126794358517938462243176895689542731
F6: 4,8,9                                # reduction candidate for 4,8
F6: 4,8 => SOLVED
* 762459183854321679391687524438265917975813246126794358517938462243176895689542731
F6: 9 => CTR
* 76.85.1938..3..6..3..6..8..4382659179754132.61267.935.517938462243176.896895..731
* PAIR D5: 4,8 COL D
D1: 4,8,9                                # reduction candidate for 4,8
D1: 9 => CTR
* 76.95.1.38..3..6..3..6.....438265917975413286126798354517839462243176.9.6895..731
D1: 4,8                                  # 15 pairs
* PAIR H5: 4,8 COL H
H1: 4,8,2,9                              # reduction candidate for 4,8
H1: 4,8 => SOLVED
* 762459183854321679391687524438265917975813246126794358517938462243176895689542731
H1: 2,9 => CTR
* 76..5.1.38..3..6..3..6.....438265917975413286126789354517938462243176.9.6895..731
H3: 4,8,2,7,9                            # reduction candidate for 4,8
H3: 4,8 => CTR
* 76..5.1238..3.167.3.1627...438265917975.132.6126789354517938462243176.9.689542731
H3: 2,7,9                                # 15 pairs
* PAIR I6: 4,8 ROW 6
E6: 4,8,9                                # reduction candidate for 4,8
E6: 4,8 => CTR
* 76.85.1938..3..6..3..6..8..4382659179754132.61267.935.517938462243176.896895..731
E6: 9 => SOLVED
* 762459183854321679391687524438265917975813246126794358517938462243176895689542731
F6: 4,8,9                                # reduction candidate for 4,8
F6: 4,8 => SOLVED
* 762459183854321679391687524438265917975813246126794358517938462243176895689542731
F6: 9 => CTR
* 76.85.1938..3..6..3..6..8..4382659179754132.61267.935.517938462243176.896895..731
* PAIR I6: 4,8 COL I
I3: 4,8,5,9                              # reduction candidate for 4,8
I3: 4,8 => SOLVED
* 762459183854321679391687524438265917975813246126794358517938462243176895689542731
I3: 5,9 => CTR
* 76.85.1938..3..6..3..6..8..438265917975.132.61267893545179384622431765.86895..731
* PAIR D7: 8,9 COL D
D1: 8,9,4                                # reduction candidate for 8,9
D1: 8,9 => CTR
* 76..5.1.38..3..6..3..6.....4382659179754132861267..354517.3.462243176.9.6895..731
D1: 4 => SOLVED
* 762459183854321679391687524438265917975813246126794358517938462243176895689542731
* PAIR F7: 8,9 COL F
F1: 8,9,2,4                              # reduction candidate for 8,9
F1: 8,9 => SOLVED
* 762459183854321679391687524438265917975813246126794358517938462243176895689542731
F1: 2,4 => CTR
* 76..5.1.38..3..6..3..6.....438265917975.132.61267..35.517.3.462243176...6895..731
F6: 8,9,4                                # reduction candidate for 8,9
F6: 8,9 => CTR
* 76..5.1.38..3..6..3..6.....438265917975.132.61267..35.517.3.462243176...6895..731
F6: 4 => SOLVED
* 762459183854321679391687524438265917975813246126794358517938462243176895689542731
* PAIR E9: 2,4 COL E
E2: 2,4,9                                # reduction candidate for 2,4
E2: 2,4 => SOLVED
* 762459183854321679391687524438265917975813246126794358517938462243176895689542731
E2: 9 => CTR
* 76..5.19385.39.6.439.6....5438265917975.13246126749358517938462243176589689524731
E3: 2,4,8,9                              # reduction candidate for 2,4
E3: 2,4 => CTR
* 76.85.1938..39.6.53..6.....438265917975.132.6126789354517938462243176...6895..731
E3: 8,9 => SOLVED
* 762459183854321679391687524438265917975813246126794358517938462243176895689542731
* PAIR F9: 2,4 COL F
F1: 2,4,8,9                              # reduction candidate for 2,4
F1: 2,4 => CTR
* 76..5.1.38..3..6..3..6.....438265917975.132.61267..35.517.3.462243176...6895..731
F1: 8,9 => SOLVED
* 762459183854321679391687524438265917975813246126794358517938462243176895689542731
* PAIR G8: 5,8 BLK 9
I8: 5,8,9                                # reduction candidate for 5,8
I8: 5,8 => SOLVED
* 762459183854321679391687524438265917975813246126794358517938462243176895689542731
I8: 9 => CTR
* 76..5.1.38..3..6..3..6..8..4382659179758132461267..3585179384622431765896895..731
* PAIR H8: 8,9 BLK 9
I8: 8,9,5                                # reduction candidate for 8,9
I8: 8,9 => CTR
* 76.85.1938..3..6..3..6..8..438265917975.132.61267893545179384622431765.86895..731
I8: 5 => SOLVED
* 762459183854321679391687524438265917975813246126794358517938462243176895689542731
* PAIR H8: 8,9 COL H
H1: 8,9,2,4                              # reduction candidate for 8,9
H1: 8,9 => SOLVED
* 762459183854321679391687524438265917975813246126794358517938462243176895689542731
H1: 2,4 => CTR
* 76..5.1.38..3..6..3..6.....438265917975.132.61267..35.517.3.462243176...6895..731
H3: 8,9,2,4,7                            # reduction candidate for 8,9
H3: 8,9 => CTR
* 76..5.1238..3.167.3.1627..4438265917975.1324612678.35.517.3.462243176...6895..731
H3: 2,4,7                                # 15 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-106-base-pr-000.dot
* REASONING
* DIS # F1: 2,4 => CTR => F1: 8,9
* PRF # F1: 8,9 => SOL
* DIS # H1: 2,4 => CTR => H1: 8,9
* PRF # H1: 8,9 => SOL
* PRF # I2: 5,9 => SOL
* DIS # I2: 4 => CTR => I2: 5,9
* DIS # I3: 5,9 => CTR => I3: 4,8
* PRF # I3: 4,8 => SOL
* DIS # I3: 5,8 => CTR => I3: 4,9
* DIS # E6: 4,8 => CTR => E6: 9
* PRF # E6: 9 => SOL
* PRF # F6: 4,8 => SOL
* DIS # F6: 9 => CTR => F6: 4,8
* DIS # D1: 9 => CTR => D1: 4,8
* PRF # H1: 4,8 => SOL
* DIS # H1: 2,9 => CTR => H1: 4,8
* DIS # H3: 4,8 => CTR => H3: 2,7,9
* DIS # E6: 4,8 => CTR => E6: 9
* PRF # E6: 9 => SOL
* PRF # F6: 4,8 => SOL
* DIS # F6: 9 => CTR => F6: 4,8
* PRF # I3: 4,8 => SOL
* DIS # I3: 5,9 => CTR => I3: 4,8
* DIS # D1: 8,9 => CTR => D1: 4
* PRF # D1: 4 => SOL
* PRF # F1: 8,9 => SOL
* DIS # F1: 2,4 => CTR => F1: 8,9
* DIS # F6: 8,9 => CTR => F6: 4
* PRF # F6: 4 => SOL
* PRF # E2: 2,4 => SOL
* DIS # E2: 9 => CTR => E2: 2,4
* DIS # E3: 2,4 => CTR => E3: 8,9
* PRF # E3: 8,9 => SOL
* DIS # F1: 2,4 => CTR => F1: 8,9
* PRF # F1: 8,9 => SOL
* PRF # I8: 5,8 => SOL
* DIS # I8: 9 => CTR => I8: 5,8
* DIS # I8: 8,9 => CTR => I8: 5
* PRF # I8: 5 => SOL
* PRF # H1: 8,9 => SOL
* DIS # H1: 2,4 => CTR => H1: 8,9
* DIS # H3: 8,9 => CTR => H3: 2,4,7
* CNT  42 HDP CHAINS /  48 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B2,B3,C1,D5,D7,E9,F2,F3,F7,F9,G3,G8,H5,H8,I6)
* 76..5.1.38..3..6..3..6.....438265917975.132.61267..35.517.3.462243176...6895..731
* PAIR C1: 2,4 BLK 1
C2: 2,4,1                                # reduction candidate for 2,4
C2: 2,4                                  # 14 pairs
C3: 2,4,1                                # reduction candidate for 2,4
C3: 2,4                                  # 14 pairs
* PAIR C1: 2,4 ROW 1
F1: 2,4,8,9                              # reduction candidate for 2,4
F1: 2,4 => CTR
* 76..5.1.38..3..6..3..6.....438265917975.132.61267..35.517.3.462243176...6895..731
F1: 8,9 => SOLVED
* 762459183854321679391687524438265917975813246126794358517938462243176895689542731
* DURATION: 0:00:03.321474  START: 06:25:00.627548  END: 06:25:03.949022 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-106-base-pr-001.dot
* REASONING
* DIS # F1: 2,4 => CTR => F1: 8,9
* PRF F1: 8,9 => SOL
* STA F1: 8,9
* CNT   2 HDP CHAINS /   3 HYP OPENED

Header Info

Top 500 Minimum 17 106

solution: 762459183854321679391687524438265917975813246126794358517938462243176895689542731
info: 1624     FNBHW    S8.f     36343

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

Solution

position: 762459183854321679391687524438265917975813246126794358517938462243176895689542731 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 # C2: 2,4 => UNS
* INC # C3: 2,4 => UNS
* DIS # F1: 2,4 => CTR => F1: 8,9
* PRF # F1: 8,9 => SOL
* DIS # H1: 2,4 => CTR => H1: 8,9
* PRF # H1: 8,9 => SOL
* PRF # I2: 5,9 => SOL
* DIS # I2: 4 => CTR => I2: 5,9
* DIS # I3: 5,9 => CTR => I3: 4,8
* PRF # I3: 4,8 => SOL
* DIS # I3: 5,8 => CTR => I3: 4,9
* INC # I3: 4,9 => UNS
* DIS # E6: 4,8 => CTR => E6: 9
* PRF # E6: 9 => SOL
* PRF # F6: 4,8 => SOL
* DIS # F6: 9 => CTR => F6: 4,8
* INC # D1: 4,8 => UNS
* DIS # D1: 9 => CTR => D1: 4,8
* PRF # H1: 4,8 => SOL
* DIS # H1: 2,9 => CTR => H1: 4,8
* DIS # H3: 4,8 => CTR => H3: 2,7,9
* INC # H3: 2,7,9 => UNS
* DIS # E6: 4,8 => CTR => E6: 9
* PRF # E6: 9 => SOL
* PRF # F6: 4,8 => SOL
* DIS # F6: 9 => CTR => F6: 4,8
* PRF # I3: 4,8 => SOL
* DIS # I3: 5,9 => CTR => I3: 4,8
* DIS # D1: 8,9 => CTR => D1: 4
* PRF # D1: 4 => SOL
* PRF # F1: 8,9 => SOL
* DIS # F1: 2,4 => CTR => F1: 8,9
* DIS # F6: 8,9 => CTR => F6: 4
* PRF # F6: 4 => SOL
* PRF # E2: 2,4 => SOL
* DIS # E2: 9 => CTR => E2: 2,4
* DIS # E3: 2,4 => CTR => E3: 8,9
* PRF # E3: 8,9 => SOL
* DIS # F1: 2,4 => CTR => F1: 8,9
* PRF # F1: 8,9 => SOL
* PRF # I8: 5,8 => SOL
* DIS # I8: 9 => CTR => I8: 5,8
* DIS # I8: 8,9 => CTR => I8: 5
* PRF # I8: 5 => SOL
* PRF # H1: 8,9 => SOL
* DIS # H1: 2,4 => CTR => H1: 8,9
* DIS # H3: 8,9 => CTR => H3: 2,4,7
* INC # H3: 2,4,7 => UNS
* CNT  48 HDP CHAINS /  48 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # C2: 2,4 => UNS
* INC # C3: 2,4 => UNS
* DIS # F1: 2,4 => CTR => F1: 8,9
* PRF F1: 8,9 => SOL
* STA F1: 8,9
* CNT   4 HDP CHAINS /   3 HYP OPENED