Analysis of xx-top500-392-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 81..........5..3.....4....77.......5.....2.6.....1........6.12.5..7......4....... initial

Autosolve

position: 81.2.....4..5.63.1...4.12.77...4..151.4.5276.....17..2....651245.1724...24.1..57. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # B4: 8,9 => CTR => B4: 2,3,6
* DIS # C4: 8,9 => CTR => C4: 2,3,6
* DIS # D4: 8,9 => CTR => D4: 3,6
* PRF # C9: 3,9 => SOL
* PRF # C9: 3,9 => SOL
* CNT   5 HDP CHAINS /  47 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 # B4: 8,9 => CTR => B4: 2,3,6
* DIS B4: 2,3,6 # C4: 8,9 => CTR => C4: 2,3,6
* DIS B4: 2,3,6 + C4: 2,3,6 # D4: 8,9 => CTR => D4: 3,6
* PRF B4: 2,3,6 + C4: 2,3,6 + D4: 3,6 # F9: 8 => SOL
* STA B4: 2,3,6 + C4: 2,3,6 + D4: 3,6 + F9: 8
* CNT   4 HDP CHAINS /  31 HYP OPENED

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

Details

Positions

81..........5..3.....4....77.......5.....2.6.....1........6.12.5..7......4....... initial
81.2.....4..5.63.1...4.12.77...4..151.4.5276.....17..2....651245.1724...24.1..57. autosolve
815273649472596381936481257723649815194852763658317492387965124561724938249138576 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (7)
F1: 3,9
I1: 6,9
H2: 8,9
G4: 8,9
A7: 3,9
E9: 3,9
H8: 3,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
B2,C2: 2.. / B2 = 2  =>  8 pairs (_) / C2 = 2  =>  8 pairs (_)
B4,C4: 2.. / B4 = 2  =>  8 pairs (_) / C4 = 2  =>  8 pairs (_)
B2,B4: 2.. / B2 = 2  =>  8 pairs (_) / B4 = 2  =>  8 pairs (_)
C2,C4: 2.. / C2 = 2  =>  8 pairs (_) / C4 = 2  =>  8 pairs (_)
I5,H6: 3.. / I5 = 3  => 10 pairs (_) / H6 = 3  => 15 pairs (_)
H6,H8: 3.. / H6 = 3  => 15 pairs (_) / H8 = 3  => 10 pairs (_)
G1,H1: 4.. / G1 = 4  => 19 pairs (_) / H1 = 4  => 12 pairs (_)
G6,H6: 4.. / G6 = 4  => 12 pairs (_) / H6 = 4  => 19 pairs (_)
G1,G6: 4.. / G1 = 4  => 19 pairs (_) / G6 = 4  => 12 pairs (_)
H1,H6: 4.. / H1 = 4  => 12 pairs (_) / H6 = 4  => 19 pairs (_)
H1,H3: 5.. / H1 = 5  => 19 pairs (_) / H3 = 5  => 11 pairs (_)
B6,C6: 5.. / B6 = 5  =>  7 pairs (_) / C6 = 5  =>  0 pairs (X)
C1,H1: 5.. / C1 = 5  => 11 pairs (_) / H1 = 5  => 19 pairs (_)
B3,B6: 5.. / B3 = 5  =>  0 pairs (X) / B6 = 5  =>  7 pairs (_)
G1,I1: 6.. / G1 = 6  => 14 pairs (_) / I1 = 6  =>  8 pairs (_)
D4,D6: 6.. / D4 = 6  =>  7 pairs (_) / D6 = 6  => 11 pairs (_)
B8,C9: 6.. / B8 = 6  => 16 pairs (_) / C9 = 6  =>  7 pairs (_)
C9,I9: 6.. / C9 = 6  =>  7 pairs (_) / I9 = 6  => 16 pairs (_)
A3,A6: 6.. / A3 = 6  =>  8 pairs (_) / A6 = 6  =>  8 pairs (_)
G1,G8: 6.. / G1 = 6  => 14 pairs (_) / G8 = 6  =>  8 pairs (_)
E1,E2: 7.. / E1 = 7  => 10 pairs (_) / E2 = 7  => 19 pairs (_)
B7,C7: 7.. / B7 = 7  =>  8 pairs (_) / C7 = 7  =>  8 pairs (_)
C1,E1: 7.. / C1 = 7  => 19 pairs (_) / E1 = 7  => 10 pairs (_)
B2,B7: 7.. / B2 = 7  =>  8 pairs (_) / B7 = 7  =>  8 pairs (_)
E2,E3: 8.. / E2 = 8  => 20 pairs (_) / E3 = 8  =>  8 pairs (_)
H2,H3: 8.. / H2 = 8  =>  8 pairs (_) / H3 = 8  => 20 pairs (_)
D7,F9: 8.. / D7 = 8  => 18 pairs (_) / F9 = 8  => 11 pairs (_)
E2,H2: 8.. / E2 = 8  => 20 pairs (_) / H2 = 8  =>  8 pairs (_)
E3,H3: 8.. / E3 = 8  =>  8 pairs (_) / H3 = 8  => 20 pairs (_)
F4,F9: 8.. / F4 = 8  => 18 pairs (_) / F9 = 8  => 11 pairs (_)
* DURATION: 0:00:45.310084  START: 16:14:25.715122  END: 16:15:11.025206 2017-05-04
* CP COUNT: (30)
* CLUE FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A7,E9,F1,G4,H2,H8,I1)
* 81.2.....4..5.63.1...4.12.77...4..151.4.5276.....17..2....651245.1724...24.1..57.
* PAIR F1: 3,9 BLK 2
E1: 3,9,7                                # reduction candidate for 3,9
E1: 3,9                                  # 19 pairs
E3: 3,9,8                                # reduction candidate for 3,9
E3: 3,9                                  # 20 pairs
* PAIR F1: 3,9 ROW 1
C1: 3,9,5,7                              # reduction candidate for 3,9
C1: 3,9                                  # 22 pairs
C1: 5,7                                  #  9 pairs
* PAIR F1: 3,9 COL F
F4: 3,9,8                                # reduction candidate for 3,9
F4: 3,9                                  # 11 pairs
F9: 3,9,8                                # reduction candidate for 3,9
F9: 3,9                                  # 18 pairs
* PAIR I1: 6,9 BLK 3
G1: 6,9,4                                # reduction candidate for 6,9
G1: 4                                    # 19 pairs
G1: 6,9                                  # 12 pairs
* PAIR I1: 6,9 COL I
I8: 6,9,3,8                              # reduction candidate for 6,9
I8: 6,9                                  # 13 pairs
I9: 6,9,3,8                              # reduction candidate for 6,9
I9: 6,9                                  # 11 pairs
* PAIR H2: 8,9 BLK 3
H3: 8,9,5                                # reduction candidate for 8,9
H3: 8,9                                  # 19 pairs
H3: 5                                    # 11 pairs
* PAIR H2: 8,9 ROW 2
E2: 8,9,7                                # reduction candidate for 8,9
E2: 7                                    # 19 pairs
E2: 8,9                                  # 10 pairs
* PAIR G4: 8,9 BLK 6
I5: 8,9,3                                # reduction candidate for 8,9
I5: 8,9                                  # 15 pairs
G6: 8,9,4                                # reduction candidate for 8,9
G6: 8,9                                  # 19 pairs
* PAIR G4: 8,9 ROW 4
B4: 8,9,2,3,6                            # reduction candidate for 8,9
B4: 8,9 => CTR
* 81.2.945642.5.63.1...4.12.77.2643.151.4.5276.....17..29783651245.17246.8246198573
B4: 2,3,6                                #  7 pairs
C4: 8,9,2,3,6                            # reduction candidate for 8,9
C4: 8,9 => CTR
* 81.2.94564.25.63.1...4.12.772.643.151.4.5276.....17..29..3651245.17246.8246198573
C4: 2,3,6                                #  7 pairs
D4: 8,9,3,6                              # reduction candidate for 8,9
D4: 8,9 => CTR
* 81.2.9..64..5.63.16..4.12.77...43.151.4.5276.3..617..29..3651245.172463.24.19857.
D4: 3,6                                  #  8 pairs
F4: 8,9,3                                # reduction candidate for 8,9
F4: 8,9                                  # 10 pairs
* PAIR G4: 8,9 COL G
G8: 8,9,6                                # reduction candidate for 8,9
G8: 8,9                                  # 14 pairs
G8: 6                                    #  8 pairs
* PAIR A7: 3,9 BLK 7
B7: 3,9,7,8                              # reduction candidate for 3,9
B7: 3,9                                  # 21 pairs
C7: 3,9,7,8                              # reduction candidate for 3,9
C7: 3,9                                  # 20 pairs
B8: 3,9,6,8                              # reduction candidate for 3,9
B8: 3,9                                  # 15 pairs
C9: 3,9,6,8                              # reduction candidate for 3,9
C9: 3,9 => SOLVED
* 815273649472596381936481257723649815194852763658317492387965124561724938249138576
C9: 6,8                                  #  8 pairs
* PAIR A7: 3,9 ROW 7
D7: 3,9,8                                # reduction candidate for 3,9
D7: 8                                    # 18 pairs
D7: 3,9                                  # 11 pairs
* PAIR A7: 3,9 COL A
A3: 3,9,6                                # reduction candidate for 3,9
A3: 3,9                                  #  8 pairs
A6: 3,9,6                                # reduction candidate for 3,9
A6: 3,9                                  #  8 pairs
* PAIR E9: 3,9 BLK 8
D7: 3,9,8                                # reduction candidate for 3,9
D7: 3,9                                  # 11 pairs
F9: 3,9,8                                # reduction candidate for 3,9
F9: 3,9                                  # 18 pairs
* PAIR E9: 3,9 ROW 9
C9: 3,9,6,8                              # reduction candidate for 3,9
C9: 3,9 => SOLVED
* 815273649472596381936481257723649815194852763658317492387965124561724938249138576
C9: 6,8                                  #  8 pairs
I9: 3,9,6,8                              # reduction candidate for 3,9
I9: 3,9                                  # 15 pairs
* PAIR E9: 3,9 COL E
E1: 3,9,7                                # reduction candidate for 3,9
E1: 3,9                                  # 19 pairs
E3: 3,9,8                                # reduction candidate for 3,9
E3: 3,9                                  # 20 pairs
* PAIR H8: 3,9 BLK 9
I8: 3,9,6,8                              # reduction candidate for 3,9
I8: 3,9                                  # 11 pairs
I9: 3,9,6,8                              # reduction candidate for 3,9
I9: 3,9                                  # 15 pairs
* PAIR H8: 3,9 ROW 8
B8: 3,9,6,8                              # reduction candidate for 3,9
B8: 3,9                                  # 15 pairs
B8: 6,8                                  #  9 pairs
* PAIR H8: 3,9 COL H
H6: 3,9,4                                # reduction candidate for 3,9
H6: 4                                    # 19 pairs
H6: 3,9                                  # 12 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-392-base-pr-000.dot
* REASONING
* DIS # B4: 8,9 => CTR => B4: 2,3,6
* DIS # C4: 8,9 => CTR => C4: 2,3,6
* DIS # D4: 8,9 => CTR => D4: 3,6
* PRF # C9: 3,9 => SOL
* PRF # C9: 3,9 => SOL
* CNT   5 HDP CHAINS /  47 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A7,E9,F1,G4,H2,H8,I1)
* 81.2.....4..5.63.1...4.12.77...4..151.4.5276.....17..2....651245.1724...24.1..57.
* PAIR F1: 3,9 BLK 2
E1: 3,9,7                                # reduction candidate for 3,9
E1: 3,9                                  # 19 pairs
E3: 3,9,8                                # reduction candidate for 3,9
E3: 3,9                                  # 20 pairs
* PAIR F1: 3,9 ROW 1
C1: 3,9,5,7                              # reduction candidate for 3,9
C1: 3,9                                  # 22 pairs
C1: 5,7                                  #  9 pairs
* PAIR F1: 3,9 COL F
F4: 3,9,8                                # reduction candidate for 3,9
F4: 3,9                                  # 11 pairs
F9: 3,9,8                                # reduction candidate for 3,9
F9: 3,9                                  # 18 pairs
* PAIR I1: 6,9 BLK 3
G1: 6,9,4                                # reduction candidate for 6,9
G1: 4                                    # 19 pairs
G1: 6,9                                  # 12 pairs
* PAIR I1: 6,9 COL I
I8: 6,9,3,8                              # reduction candidate for 6,9
I8: 6,9                                  # 13 pairs
I9: 6,9,3,8                              # reduction candidate for 6,9
I9: 6,9                                  # 11 pairs
* PAIR H2: 8,9 BLK 3
H3: 8,9,5                                # reduction candidate for 8,9
H3: 8,9                                  # 19 pairs
H3: 5                                    # 11 pairs
* PAIR H2: 8,9 ROW 2
E2: 8,9,7                                # reduction candidate for 8,9
E2: 7                                    # 19 pairs
E2: 8,9                                  # 10 pairs
* PAIR G4: 8,9 BLK 6
I5: 8,9,3                                # reduction candidate for 8,9
I5: 8,9                                  # 15 pairs
G6: 8,9,4                                # reduction candidate for 8,9
G6: 8,9                                  # 19 pairs
* PAIR G4: 8,9 ROW 4
B4: 8,9,2,3,6                            # reduction candidate for 8,9
B4: 8,9 => CTR
* 81.2.945642.5.63.1...4.12.77.2643.151.4.5276.....17..29783651245.17246.8246198573
C4: 8,9,2,3,6                            # reduction candidate for 8,9
C4: 8,9 => CTR
* 81.2.94564.25.63.1...4.12.772.643.151.4.5276.....17..29..3651245.17246.8246198573
D4: 8,9,3,6                              # reduction candidate for 8,9
D4: 8,9 => CTR
* 81.2.9..64..5.63.16..4.12.77...43.151.4.5276.3..617..29..3651245.172463.24.19857.
* RESTART
* PAIR G4: 8,9 COL G
G8: 8,9,6                                # reduction candidate for 8,9
G8: 8,9                                  # 14 pairs
G8: 6                                    # 14 pairs
* PAIR RESTART
* PAIR G4: 8,9 BLK 6
I5: 8,9,3                                # reduction candidate for 8,9
I5: 8,9                                  # 15 pairs
G6: 8,9,4                                # reduction candidate for 8,9
G6: 8,9                                  # 19 pairs
* PAIR G4: 8,9 COL G
G8: 8,9,6                                # reduction candidate for 8,9
G8: 8,9                                  # 14 pairs
G8: 6                                    # 14 pairs
* PAIR A7: 3,9 BLK 7
B7: 3,9,7,8                              # reduction candidate for 3,9
B7: 3,9                                  # 21 pairs
C7: 3,9,7,8                              # reduction candidate for 3,9
C7: 3,9                                  # 20 pairs
* PAIR A7: 3,9 COL A
A3: 3,9,6                                # reduction candidate for 3,9
A3: 3,9                                  # 13 pairs
A6: 3,9,6                                # reduction candidate for 3,9
A6: 3,9                                  # 11 pairs
* PAIR E9: 3,9 BLK 8
F9: 3,9,8                                # reduction candidate for 3,9
F9: 8 => SOLVED
* 815273649472596381936481257723649815194852763658317492387965124561724938249138576
* DURATION: 0:00:29.381229  START: 16:15:50.722664  END: 16:16:20.103893 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-392-base-pr-001.dot
* REASONING
* DIS # B4: 8,9 => CTR => B4: 2,3,6
* DIS B4: 2,3,6 # C4: 8,9 => CTR => C4: 2,3,6
* DIS B4: 2,3,6 + C4: 2,3,6 # D4: 8,9 => CTR => D4: 3,6
* PRF B4: 2,3,6 + C4: 2,3,6 + D4: 3,6 # F9: 8 => SOL
* STA B4: 2,3,6 + C4: 2,3,6 + D4: 3,6 + F9: 8
* CNT   4 HDP CHAINS /  31 HYP OPENED

Header Info

Top 500 Minimum 17 392

solution: 815273649472596381936481257723649815194852763658317492387965124561724938249138576
info: 51242    FNBTXYK  S8.f     38623

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

Solution

position: 815273649472596381936481257723649815194852763658317492387965124561724938249138576 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 # E1: 3,9 => UNS
* INC # E3: 3,9 => UNS
* INC # C1: 3,9 => UNS
* INC # C1: 5,7 => UNS
* INC # F4: 3,9 => UNS
* INC # F9: 3,9 => UNS
* INC # G1: 6,9 => UNS
* INC # G1: 4 => UNS
* INC # I8: 6,9 => UNS
* INC # I9: 6,9 => UNS
* INC # H3: 8,9 => UNS
* INC # H3: 5 => UNS
* INC # E2: 8,9 => UNS
* INC # E2: 7 => UNS
* INC # I5: 8,9 => UNS
* INC # G6: 8,9 => UNS
* DIS # B4: 8,9 => CTR => B4: 2,3,6
* INC # B4: 2,3,6 => UNS
* DIS # C4: 8,9 => CTR => C4: 2,3,6
* INC # C4: 2,3,6 => UNS
* DIS # D4: 8,9 => CTR => D4: 3,6
* INC # D4: 3,6 => UNS
* INC # F4: 8,9 => UNS
* INC # G8: 8,9 => UNS
* INC # G8: 6 => UNS
* INC # B7: 3,9 => UNS
* INC # C7: 3,9 => UNS
* INC # B8: 3,9 => UNS
* PRF # C9: 3,9 => SOL
* INC # C9: 6,8 => UNS
* INC # D7: 3,9 => UNS
* INC # D7: 8 => UNS
* INC # A3: 3,9 => UNS
* INC # A6: 3,9 => UNS
* INC # D7: 3,9 => UNS
* INC # F9: 3,9 => UNS
* PRF # C9: 3,9 => SOL
* INC # C9: 6,8 => UNS
* INC # I9: 3,9 => UNS
* INC # E1: 3,9 => UNS
* INC # E3: 3,9 => UNS
* INC # I8: 3,9 => UNS
* INC # I9: 3,9 => UNS
* INC # B8: 3,9 => UNS
* INC # B8: 6,8 => UNS
* INC # H6: 3,9 => UNS
* INC # H6: 4 => UNS
* CNT  47 HDP CHAINS /  47 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # E1: 3,9 => UNS
* INC # E3: 3,9 => UNS
* INC # C1: 3,9 => UNS
* INC # C1: 5,7 => UNS
* INC # F4: 3,9 => UNS
* INC # F9: 3,9 => UNS
* INC # G1: 6,9 => UNS
* INC # G1: 4 => UNS
* INC # I8: 6,9 => UNS
* INC # I9: 6,9 => UNS
* INC # H3: 8,9 => UNS
* INC # H3: 5 => UNS
* INC # E2: 8,9 => UNS
* INC # E2: 7 => UNS
* INC # I5: 8,9 => UNS
* INC # G6: 8,9 => UNS
* DIS # B4: 8,9 => CTR => B4: 2,3,6
* DIS B4: 2,3,6 # C4: 8,9 => CTR => C4: 2,3,6
* DIS B4: 2,3,6 + C4: 2,3,6 # D4: 8,9 => CTR => D4: 3,6
* INC B4: 2,3,6 + C4: 2,3,6 + D4: 3,6 # G8: 8,9 => UNS
* INC B4: 2,3,6 + C4: 2,3,6 + D4: 3,6 # G8: 6 => UNS
* INC B4: 2,3,6 + C4: 2,3,6 + D4: 3,6 # I5: 8,9 => UNS
* INC B4: 2,3,6 + C4: 2,3,6 + D4: 3,6 # G6: 8,9 => UNS
* INC B4: 2,3,6 + C4: 2,3,6 + D4: 3,6 # G8: 8,9 => UNS
* INC B4: 2,3,6 + C4: 2,3,6 + D4: 3,6 # G8: 6 => UNS
* INC B4: 2,3,6 + C4: 2,3,6 + D4: 3,6 # B7: 3,9 => UNS
* INC B4: 2,3,6 + C4: 2,3,6 + D4: 3,6 # C7: 3,9 => UNS
* INC B4: 2,3,6 + C4: 2,3,6 + D4: 3,6 # A3: 3,9 => UNS
* INC B4: 2,3,6 + C4: 2,3,6 + D4: 3,6 # A6: 3,9 => UNS
* INC B4: 2,3,6 + C4: 2,3,6 + D4: 3,6 # F9: 3,9 => UNS
* PRF B4: 2,3,6 + C4: 2,3,6 + D4: 3,6 # F9: 8 => SOL
* STA B4: 2,3,6 + C4: 2,3,6 + D4: 3,6 + F9: 8
* CNT  31 HDP CHAINS /  31 HYP OPENED