Analysis of xx-top500-233-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 725.6..........31...........4....8.....5.2......1.......1.....23..8.........3.4.. initial

Autosolve

position: 7253619488.4.2531..134..25.14...3825.3.5.21.425.14...3481.5..323.28145.95..23.481 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # B9: 6,9 => CTR => B9: 7
* PRF # B9: 7 => SOL
* DIS # D4: 7,9 => CTR => D4: 6
* DIS # C5: 6,9 => CTR => C5: 7,8
* DIS # H5: 7 => CTR => H5: 6,9
* DIS # D4: 7,9 => CTR => D4: 6
* DIS # C4: 6 => CTR => C4: 7,9
* DIS # H6: 6,7 => CTR => H6: 9
* DIS # B9: 9 => CTR => B9: 6,7
* DIS # B9: 6,9 => CTR => B9: 7
* PRF # B9: 7 => SOL
* DIS # C5: 6,9 => CTR => C5: 7,8
* PRF # F7: 6,7 => SOL
* DIS # B9: 9 => CTR => B9: 6,7
* PRF # F7: 6,7 => SOL
* DIS # H6: 6,7 => CTR => H6: 9
* CNT  16 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 # B9: 6,9 => CTR => B9: 7
* PRF B9: 7 => SOL
* STA B9: 7
* CNT   2 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

725.6..........31...........4....8.....5.2......1.......1.....23..8.........3.4.. initial
7253619488.4.2531..134..25.14...3825.3.5.21.425.14...3481.5..323.28145.95..23.481 autosolve
725361948894725316613489257147693825938572164256148793481957632362814579579236481 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (13)
B2: 6,9
A3: 6,9
D2: 7,9
I2: 6,7
I3: 6,7
A5: 6,9
E4: 7,9
G6: 6,7
B8: 6,7
C9: 6,9
F9: 6,7
G7: 6,7
H8: 6,7

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
B2,A3: 6.. / B2 = 6  =>  0 pairs (X) / A3 = 6  => 15 pairs (_)
I2,I3: 6.. / I2 = 6  => 15 pairs (_) / I3 = 6  =>  0 pairs (X)
D4,F6: 6.. / D4 = 6  => 15 pairs (_) / F6 = 6  =>  0 pairs (X)
G7,H8: 6.. / G7 = 6  =>  0 pairs (*) / H8 = 6  =>  0 pairs (X)
B2,I2: 6.. / B2 = 6  =>  0 pairs (X) / I2 = 6  => 15 pairs (_)
A3,I3: 6.. / A3 = 6  => 15 pairs (_) / I3 = 6  =>  0 pairs (X)
C4,D4: 6.. / C4 = 6  =>  0 pairs (X) / D4 = 6  => 15 pairs (_)
B8,H8: 6.. / B8 = 6  =>  0 pairs (*) / H8 = 6  =>  0 pairs (X)
A3,A5: 6.. / A3 = 6  => 15 pairs (_) / A5 = 6  =>  0 pairs (X)
D4,D7: 6.. / D4 = 6  => 15 pairs (_) / D7 = 6  =>  0 pairs (X)
G6,G7: 6.. / G6 = 6  =>  0 pairs (X) / G7 = 6  =>  0 pairs (_)
I2,I3: 7.. / I2 = 7  =>  0 pairs (X) / I3 = 7  => 15 pairs (_)
B8,B9: 7.. / B8 = 7  =>  0 pairs (X) / B9 = 7  =>  0 pairs (_)
G7,H8: 7.. / G7 = 7  =>  0 pairs (X) / H8 = 7  =>  0 pairs (_)
D2,I2: 7.. / D2 = 7  => 15 pairs (_) / I2 = 7  =>  0 pairs (X)
B8,H8: 7.. / B8 = 7  =>  0 pairs (X) / H8 = 7  =>  0 pairs (_)
B9,F9: 7.. / B9 = 7  =>  0 pairs (*) / F9 = 7  =>  0 pairs (X)
G6,G7: 7.. / G6 = 7  =>  0 pairs (*) / G7 = 7  =>  0 pairs (X)
E3,F3: 8.. / E3 = 8  => 17 pairs (_) / F3 = 8  => 14 pairs (_)
C5,C6: 8.. / C5 = 8  => 17 pairs (_) / C6 = 8  => 14 pairs (_)
E5,F6: 8.. / E5 = 8  => 14 pairs (_) / F6 = 8  => 17 pairs (_)
C5,E5: 8.. / C5 = 8  => 17 pairs (_) / E5 = 8  => 14 pairs (_)
C6,F6: 8.. / C6 = 8  => 14 pairs (_) / F6 = 8  => 17 pairs (_)
E3,E5: 8.. / E3 = 8  => 17 pairs (_) / E5 = 8  => 14 pairs (_)
F3,F6: 8.. / F3 = 8  => 14 pairs (_) / F6 = 8  => 17 pairs (_)
B2,A3: 9.. / B2 = 9  => 15 pairs (_) / A3 = 9  =>  0 pairs (X)
H5,H6: 9.. / H5 = 9  =>  0 pairs (X) / H6 = 9  => 14 pairs (_)
B9,C9: 9.. / B9 = 9  =>  0 pairs (X) / C9 = 9  => 15 pairs (_)
D7,F7: 9.. / D7 = 9  =>  0 pairs (*) / F7 = 9  =>  0 pairs (X)
B2,D2: 9.. / B2 = 9  => 15 pairs (_) / D2 = 9  =>  0 pairs (X)
A3,A5: 9.. / A3 = 9  =>  0 pairs (X) / A5 = 9  => 15 pairs (_)
B2,B9: 9.. / B2 = 9  => 15 pairs (_) / B9 = 9  =>  0 pairs (X)
* DURATION: 0:00:55.977160  START: 10:47:49.398838  END: 10:48:45.375998 2017-05-04
* CP COUNT: (32)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A3,A5,B2,B8,C9,D2,E4,F9,G6,G7,H8,I2,I3)
* 7253619488.4.2531..134..25.14...3825.3.5.21.425.14...3481.5..323.28145.95..23.481
* PAIR B2: 6,9 COL B
B9: 6,9,7                                # reduction candidate for 6,9
B9: 6,9 => CTR
* 7253619488947253166134..25714.6.382593658217425.14.6.34819567323728145695..237481
B9: 7 => SOLVED
* 725361948894725316613489257147693825938572164256148793481957632362814579579236481
* PAIR D2: 7,9 BLK 2
E3: 7,9,8                                # reduction candidate for 7,9
E3: 7,9                                  # 14 pairs
F3: 7,9,8                                # reduction candidate for 7,9
F3: 7,9                                  # 17 pairs
* PAIR D2: 7,9 COL D
D4: 7,9,6                                # reduction candidate for 7,9
D4: 7,9 => CTR
* 7253619488.4.2531..134..25.146..382593.5.216425.14679348165..323.28145.95..23.481
D4: 6                                    # 15 pairs
D7: 7,9,6                                # reduction candidate for 7,9
D7: 7,9                                  # 15 pairs
* PAIR A5: 6,9 BLK 4
C4: 6,9,7                                # reduction candidate for 6,9
C4: 6,9                                  # 17 pairs
C5: 6,9,7,8                              # reduction candidate for 6,9
C5: 6,9 => CTR
* 7253619488.4.2531..134..25.14...3825.3.58217425814769348175..323.28145.95..23.481
C5: 7,8                                  # 14 pairs
C6: 6,9,7,8                              # reduction candidate for 6,9
C6: 6,9                                  # 16 pairs
* PAIR A5: 6,9 ROW 5
H5: 6,9,7                                # reduction candidate for 6,9
H5: 7 => CTR
* 7253619488947253166134..25.14.673825.3.5921742571486934819567323728145695..237481
H5: 6,9                                  # 16 pairs
* PAIR E4: 7,9 BLK 5
D4: 7,9,6                                # reduction candidate for 7,9
D4: 7,9 => CTR
* 7253619488.4.2531..134..25.146..382593.5.216425.14679348165..323.28145.95..23.481
D4: 6                                    # 15 pairs
E5: 7,9,8                                # reduction candidate for 7,9
E5: 7,9                                  # 17 pairs
F6: 7,9,6,8                              # reduction candidate for 7,9
F6: 7,9                                  # 18 pairs
* PAIR E4: 7,9 ROW 4
C4: 7,9,6                                # reduction candidate for 7,9
C4: 6 => CTR
* 7253619488.4.2531..134..25.146..382593.5.216425.14679348165..323.28145.95..23.481
C4: 7,9                                  # 15 pairs
* PAIR E4: 7,9 COL E
E3: 7,9,8                                # reduction candidate for 7,9
E3: 8                                    # 17 pairs
E3: 7,9                                  # 14 pairs
* PAIR G6: 6,7 BLK 6
H5: 6,7,9                                # reduction candidate for 6,7
H5: 6,7                                  # 14 pairs
H6: 6,7,9                                # reduction candidate for 6,7
H6: 6,7 => CTR
* 7253619488.4.2531.9134..25614..9382563.5.2194259148..3481.59.323.28145.959623.481
H6: 9                                    # 14 pairs
* PAIR G6: 6,7 ROW 6
C6: 6,7,8,9                              # reduction candidate for 6,7
C6: 6,7                                  # 19 pairs
F6: 6,7,8,9                              # reduction candidate for 6,7
F6: 6,7                                  # 18 pairs
* PAIR B8: 6,7 BLK 7
B9: 6,7,9                                # reduction candidate for 6,7
B9: 9 => CTR
* 72536194886492531791347825614...3825.3.5.21.425.14...3481.5..32372814569596237481
B9: 6,7                                  # 15 pairs
* PAIR C9: 6,9 BLK 7
B9: 6,9,7                                # reduction candidate for 6,9
B9: 6,9 => CTR
* 7253619488947253166134..25714.6.382593658217425.14.6.34819567323728145695..237481
B9: 7 => SOLVED
* 725361948894725316613489257147693825938572164256148793481957632362814579579236481
* PAIR C9: 6,9 COL C
C4: 6,9,7                                # reduction candidate for 6,9
C4: 6,9                                  # 17 pairs
C5: 6,9,7,8                              # reduction candidate for 6,9
C5: 6,9 => CTR
* 7253619488.4.2531..134..25.14...3825.3.58217425814769348175..323.28145.95..23.481
C5: 7,8                                  # 14 pairs
C6: 6,9,7,8                              # reduction candidate for 6,9
C6: 6,9                                  # 16 pairs
* PAIR F9: 6,7 BLK 8
D7: 6,7,9                                # reduction candidate for 6,7
D7: 6,7                                  # 15 pairs
F7: 6,7,9                                # reduction candidate for 6,7
F7: 6,7 => SOLVED
* 725361948894725316613489257147693825938572164256148793481957632362814579579236481
F7: 9                                    # 15 pairs
* PAIR F9: 6,7 ROW 9
B9: 6,7,9                                # reduction candidate for 6,7
B9: 9 => CTR
* 72536194886492531791347825614...3825.3.5.21.425.14...3481.5..32372814569596237481
B9: 6,7                                  # 15 pairs
* PAIR F9: 6,7 COL F
F6: 6,7,8,9                              # reduction candidate for 6,7
F6: 6,7                                  # 18 pairs
F6: 8,9                                  # 17 pairs
* PAIR G7: 6,7 ROW 7
D7: 6,7,9                                # reduction candidate for 6,7
D7: 6,7                                  # 15 pairs
F7: 6,7,9                                # reduction candidate for 6,7
F7: 6,7 => SOLVED
* 725361948894725316613489257147693825938572164256148793481957632362814579579236481
F7: 9                                    # 15 pairs
* PAIR H8: 6,7 COL H
H5: 6,7,9                                # reduction candidate for 6,7
H5: 6,7                                  # 14 pairs
H6: 6,7,9                                # reduction candidate for 6,7
H6: 6,7 => CTR
* 7253619488.4.2531.9134..25614..9382563.5.2194259148..3481.59.323.28145.959623.481
H6: 9                                    # 14 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-233-base-pr-000.dot
* REASONING
* DIS # B9: 6,9 => CTR => B9: 7
* PRF # B9: 7 => SOL
* DIS # D4: 7,9 => CTR => D4: 6
* DIS # C5: 6,9 => CTR => C5: 7,8
* DIS # H5: 7 => CTR => H5: 6,9
* DIS # D4: 7,9 => CTR => D4: 6
* DIS # C4: 6 => CTR => C4: 7,9
* DIS # H6: 6,7 => CTR => H6: 9
* DIS # B9: 9 => CTR => B9: 6,7
* DIS # B9: 6,9 => CTR => B9: 7
* PRF # B9: 7 => SOL
* DIS # C5: 6,9 => CTR => C5: 7,8
* PRF # F7: 6,7 => SOL
* DIS # B9: 9 => CTR => B9: 6,7
* PRF # F7: 6,7 => SOL
* DIS # H6: 6,7 => CTR => H6: 9
* CNT  16 HDP CHAINS /  47 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A3,A5,B2,B8,C9,D2,E4,F9,G6,G7,H8,I2,I3)
* 7253619488.4.2531..134..25.14...3825.3.5.21.425.14...3481.5..323.28145.95..23.481
* PAIR B2: 6,9 COL B
B9: 6,9,7                                # reduction candidate for 6,9
B9: 6,9 => CTR
* 7253619488947253166134..25714.6.382593658217425.14.6.34819567323728145695..237481
B9: 7 => SOLVED
* 725361948894725316613489257147693825938572164256148793481957632362814579579236481
* DURATION: 0:00:03.026159  START: 10:49:30.116277  END: 10:49:33.142436 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-233-base-pr-001.dot
* REASONING
* DIS # B9: 6,9 => CTR => B9: 7
* PRF B9: 7 => SOL
* STA B9: 7
* CNT   2 HDP CHAINS /   1 HYP OPENED

Header Info

Top 500 Minimum 17 233

solution: 725361948894725316613489257147693825938572164256148793481957632362814579579236481
info: 2067     FNBWXY   S8.f     37570

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

Solution

position: 725361948894725316613489257147693825938572164256148793481957632362814579579236481 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 # B9: 6,9 => CTR => B9: 7
* PRF # B9: 7 => SOL
* INC # E3: 7,9 => UNS
* INC # F3: 7,9 => UNS
* DIS # D4: 7,9 => CTR => D4: 6
* INC # D4: 6 => UNS
* INC # D7: 7,9 => UNS
* INC # C4: 6,9 => UNS
* DIS # C5: 6,9 => CTR => C5: 7,8
* INC # C5: 7,8 => UNS
* INC # C6: 6,9 => UNS
* INC # H5: 6,9 => UNS
* DIS # H5: 7 => CTR => H5: 6,9
* DIS # D4: 7,9 => CTR => D4: 6
* INC # D4: 6 => UNS
* INC # E5: 7,9 => UNS
* INC # F6: 7,9 => UNS
* INC # C4: 7,9 => UNS
* DIS # C4: 6 => CTR => C4: 7,9
* INC # E3: 7,9 => UNS
* INC # E3: 8 => UNS
* INC # H5: 6,7 => UNS
* DIS # H6: 6,7 => CTR => H6: 9
* INC # H6: 9 => UNS
* INC # C6: 6,7 => UNS
* INC # F6: 6,7 => UNS
* INC # B9: 6,7 => UNS
* DIS # B9: 9 => CTR => B9: 6,7
* DIS # B9: 6,9 => CTR => B9: 7
* PRF # B9: 7 => SOL
* INC # C4: 6,9 => UNS
* DIS # C5: 6,9 => CTR => C5: 7,8
* INC # C5: 7,8 => UNS
* INC # C6: 6,9 => UNS
* INC # D7: 6,7 => UNS
* PRF # F7: 6,7 => SOL
* INC # F7: 9 => UNS
* INC # B9: 6,7 => UNS
* DIS # B9: 9 => CTR => B9: 6,7
* INC # F6: 6,7 => UNS
* INC # F6: 8,9 => UNS
* INC # D7: 6,7 => UNS
* PRF # F7: 6,7 => SOL
* INC # F7: 9 => UNS
* INC # H5: 6,7 => UNS
* DIS # H6: 6,7 => CTR => H6: 9
* INC # H6: 9 => UNS
* CNT  47 HDP CHAINS /  47 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # B9: 6,9 => CTR => B9: 7
* PRF B9: 7 => SOL
* STA B9: 7
* CNT   2 HDP CHAINS /   1 HYP OPENED