Analysis of xx-top500-128-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: ..4.....1.3..8.......3......7..2.6..1......4...2...........42........58.6..1..... initial

Autosolve

position: .642..831.31486.2.82.31.46.473.216.81.6.3..42..264.1.33..8.421621..635846481523.. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # A1: 5,9 => SOL
* DIS # A1: 7 => CTR => A1: 5,9
* DIS # A2: 5,9 => CTR => A2: 7
* PRF # A2: 7 => SOL
* PRF # F3: 5,9 => SOL
* DIS # F3: 7 => CTR => F3: 5,9
* DIS # I3: 5,9 => CTR => I3: 7
* PRF # I3: 7 => SOL
* DIS # C7: 5,9 => CTR => C7: 7
* PRF # C7: 7 => SOL
* DIS # F1: 7,9 => CTR => F1: 5
* DIS # A1: 5 => CTR => A1: 7,9
* DIS # I2: 7,9 => CTR => I2: 5
* DIS # A2: 5 => CTR => A2: 7,9
* DIS # B6: 5,9 => CTR => B6: 8
* PRF # H6: 5,9 => SOL
* DIS # H6: 7 => CTR => H6: 5,9
* PRF # A1: 5,9 => SOL
* DIS # A1: 7 => CTR => A1: 5,9
* DIS # A2: 5,9 => CTR => A2: 7
* PRF # A2: 7 => SOL
* PRF # D5: 5,9 => SOL
* DIS # D5: 7 => CTR => D5: 5,9
* PRF # H6: 5,9 => SOL
* DIS # H6: 7 => CTR => H6: 5,9
* PRF # H6: 7,9 => SOL
* DIS # H6: 5 => CTR => H6: 7,9
* DIS # D5: 7,9 => CTR => D5: 5
* PRF # D5: 5 => SOL
* DIS # F5: 7,9 => CTR => F5: 8
* DIS # C7: 5,9 => CTR => C7: 7
* PRF # C7: 7 => SOL
* DIS # B6: 5,9 => CTR => B6: 8
* PRF # C7: 7,9 => SOL
* DIS # C7: 5 => CTR => C7: 7,9
* PRF # C7: 7,9 => SOL
* DIS # C7: 5 => CTR => C7: 7,9
* DIS # D5: 7,9 => CTR => D5: 5
* PRF # D5: 5 => SOL
* PRF # H6: 7,9 => SOL
* DIS # H6: 5 => CTR => H6: 7,9
* DIS # I2: 7,9 => CTR => I2: 5
* CNT  42 HDP CHAINS /  55 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 # A1: 5,9 => SOL
* STA A1: 5,9
* CNT   1 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

..4.....1.3..8.......3......7..2.6..1......4...2...........42........58.6..1..... initial
.642..831.31486.2.82.31.46.473.216.81.6.3..42..264.1.33..8.421621..635846481523.. autosolve
964275831731486925825319467473921658196538742582647193357894216219763584648152379 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (13)
C3: 5,9
E1: 7,9
G2: 7,9
A6: 5,9
D4: 5,9
H4: 5,9
G5: 7,9
B7: 5,9
C8: 7,9
E7: 7,9
D8: 7,9
H9: 7,9
I9: 7,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
F1,F3: 5.. / F1 = 5  => 15 pairs (_) / F3 = 5  =>  0 pairs (X)
I2,I3: 5.. / I2 = 5  => 15 pairs (_) / I3 = 5  =>  0 pairs (X)
D4,D5: 5.. / D4 = 5  =>  0 pairs (X) / D5 = 5  =>  0 pairs (_)
H4,H6: 5.. / H4 = 5  =>  0 pairs (*) / H6 = 5  =>  0 pairs (X)
B7,C7: 5.. / B7 = 5  =>  0 pairs (*) / C7 = 5  =>  0 pairs (X)
A1,F1: 5.. / A1 = 5  =>  0 pairs (X) / F1 = 5  => 15 pairs (_)
A2,I2: 5.. / A2 = 5  =>  0 pairs (X) / I2 = 5  => 15 pairs (_)
D4,H4: 5.. / D4 = 5  =>  0 pairs (X) / H4 = 5  =>  0 pairs (_)
B5,D5: 5.. / B5 = 5  =>  0 pairs (X) / D5 = 5  =>  0 pairs (_)
C3,C7: 5.. / C3 = 5  =>  0 pairs (*) / C7 = 5  =>  0 pairs (X)
A1,A2: 7.. / A1 = 7  =>  0 pairs (X) / A2 = 7  =>  0 pairs (_)
G5,H6: 7.. / G5 = 7  =>  0 pairs (*) / H6 = 7  =>  0 pairs (X)
C7,C8: 7.. / C7 = 7  =>  0 pairs (*) / C8 = 7  =>  0 pairs (X)
E7,D8: 7.. / E7 = 7  =>  0 pairs (X) / D8 = 7  =>  0 pairs (_)
H9,I9: 7.. / H9 = 7  =>  0 pairs (*) / I9 = 7  =>  0 pairs (X)
F3,I3: 7.. / F3 = 7  =>  0 pairs (X) / I3 = 7  =>  0 pairs (_)
F6,H6: 7.. / F6 = 7  =>  0 pairs (*) / H6 = 7  =>  0 pairs (X)
C7,E7: 7.. / C7 = 7  =>  0 pairs (*) / E7 = 7  =>  0 pairs (X)
C8,D8: 7.. / C8 = 7  =>  0 pairs (X) / D8 = 7  =>  0 pairs (_)
D5,D8: 7.. / D5 = 7  =>  0 pairs (X) / D8 = 7  =>  0 pairs (_)
E1,E7: 7.. / E1 = 7  =>  0 pairs (*) / E7 = 7  =>  0 pairs (X)
G2,G5: 7.. / G2 = 7  =>  0 pairs (X) / G5 = 7  =>  0 pairs (_)
H6,H9: 7.. / H6 = 7  =>  0 pairs (X) / H9 = 7  =>  0 pairs (_)
B5,B6: 8.. / B5 = 8  =>  0 pairs (X) / B6 = 8  => 15 pairs (_)
F5,F6: 8.. / F5 = 8  => 15 pairs (_) / F6 = 8  =>  0 pairs (X)
B5,F5: 8.. / B5 = 8  =>  0 pairs (X) / F5 = 8  => 15 pairs (_)
B6,F6: 8.. / B6 = 8  => 15 pairs (_) / F6 = 8  =>  0 pairs (X)
E7,D8: 9.. / E7 = 9  =>  0 pairs (*) / D8 = 9  =>  0 pairs (X)
H9,I9: 9.. / H9 = 9  =>  0 pairs (X) / I9 = 9  =>  0 pairs (_)
D4,H4: 9.. / D4 = 9  =>  0 pairs (*) / H4 = 9  =>  0 pairs (X)
C8,D8: 9.. / C8 = 9  =>  0 pairs (*) / D8 = 9  =>  0 pairs (X)
E1,E7: 9.. / E1 = 9  =>  0 pairs (X) / E7 = 9  =>  0 pairs (_)
G2,G5: 9.. / G2 = 9  =>  0 pairs (*) / G5 = 9  =>  0 pairs (X)
* DURATION: 0:00:55.021984  START: 07:08:12.584752  END: 07:09:07.606736 2017-05-04
* CP COUNT: (33)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A6,B7,C3,C8,D4,D8,E1,E7,G2,G5,H4,H9,I9)
* .642..831.31486.2.82.31.46.473.216.81.6.3..42..264.1.33..8.421621..635846481523..
* PAIR C3: 5,9 BLK 1
A1: 5,9,7                                # reduction candidate for 5,9
A1: 5,9 => SOLVED
* 964275831731486925825319467473921658196538742582647193357894216219763584648152379
A1: 7 => CTR
* 764295831.31486.2.82.31746.473.216.81.673.942..26491.33..8.421621..635846481523..
A2: 5,9,7                                # reduction candidate for 5,9
A2: 5,9 => CTR
* 764295831.31486.2.82.31746.473.216.81.673.942..26491.33..8.421621..635846481523..
A2: 7 => SOLVED
* 964275831731486925825319467473921658196538742582647193357894216219763584648152379
* PAIR C3: 5,9 ROW 3
F3: 5,9,7                                # reduction candidate for 5,9
F3: 5,9 => SOLVED
* 964275831731486925825319467473921658196538742582647193357894216219763584648152379
F3: 7 => CTR
* .642.5831.31486.2.82.31746.473.216.81.673.942..26491.33..8.421621..635846481523..
I3: 5,9,7                                # reduction candidate for 5,9
I3: 5,9 => CTR
* .642..831.31486.2.82.31746.473.216.81.673.942..264.1733..8742162179635846481523..
I3: 7 => SOLVED
* 964275831731486925825319467473921658196538742582647193357894216219763584648152379
* PAIR C3: 5,9 COL C
C7: 5,9,7                                # reduction candidate for 5,9
C7: 5,9 => CTR
* .6429.831.31486.2.82.31.46.47352169815673..42..264.1.33..8742162179635846481523..
C7: 7 => SOLVED
* 964275831731486925825319467473921658196538742582647193357894216219763584648152379
* PAIR E1: 7,9 BLK 2
F1: 7,9,5                                # reduction candidate for 7,9
F1: 7,9 => CTR
* 5642..831731486925829315467473.216.81.6.3.7429.264715339587421621..635846481523..
F1: 5                                    # 15 pairs
F3: 7,9,5                                # reduction candidate for 7,9
F3: 7,9                                  # 15 pairs
* PAIR E1: 7,9 ROW 1
A1: 7,9,5                                # reduction candidate for 7,9
A1: 5 => CTR
* 5642..831731486925829315467473.216.81.6.3.7429.264715339587421621..635846481523..
A1: 7,9                                  # 15 pairs
* PAIR G2: 7,9 BLK 3
I2: 7,9,5                                # reduction candidate for 7,9
I2: 7,9 => CTR
* 764295831531486.2.8293174654735216981.6.3..429.264.1.33958742162179635846481523..
I2: 5                                    # 15 pairs
I3: 7,9,5                                # reduction candidate for 7,9
I3: 7,9                                  # 15 pairs
* PAIR G2: 7,9 ROW 2
A2: 7,9,5                                # reduction candidate for 7,9
A2: 5 => CTR
* 764295831531486.2.829317465473.216.81.673.9429.26481.33..8.421621..635846481523..
A2: 7,9                                  # 15 pairs
* PAIR A6: 5,9 BLK 4
B5: 5,9,8                                # reduction candidate for 5,9
B5: 5,9                                  # 15 pairs
B6: 5,9,8                                # reduction candidate for 5,9
B6: 5,9 => CTR
* .6427.83173148692.82.31.46.473.216.818653..42..26481733..8.421621.763584648152397
B6: 8                                    # 15 pairs
* PAIR A6: 5,9 ROW 6
H6: 5,9,7                                # reduction candidate for 5,9
H6: 5,9 => SOLVED
* 964275831731486925825319467473921658196538742582647193357894216219763584648152379
H6: 7 => CTR
* .6427.831731486.2.82.31.46.473.216581.653.942..264.1733..8.421621.763584648152397
* PAIR A6: 5,9 COL A
A1: 5,9,7                                # reduction candidate for 5,9
A1: 5,9 => SOLVED
* 964275831731486925825319467473921658196538742582647193357894216219763584648152379
A1: 7 => CTR
* 764295831.31486.2.82.31746.473.216.81.673.942..26491.33..8.421621..635846481523..
A2: 5,9,7                                # reduction candidate for 5,9
A2: 5,9 => CTR
* 764295831.31486.2.82.31746.473.216.81.673.942..26491.33..8.421621..635846481523..
A2: 7 => SOLVED
* 964275831731486925825319467473921658196538742582647193357894216219763584648152379
* PAIR D4: 5,9 BLK 5
D5: 5,9,7                                # reduction candidate for 5,9
D5: 5,9 => SOLVED
* 964275831731486925825319467473921658196538742582647193357894216219763584648152379
D5: 7 => CTR
* .642..831.31486.2.82.31.46.47352169815673..42..264.1.33..8.421621..635846481523..
* PAIR H4: 5,9 BLK 6
H6: 5,9,7                                # reduction candidate for 5,9
H6: 5,9 => SOLVED
* 964275831731486925825319467473921658196538742582647193357894216219763584648152379
H6: 7 => CTR
* .6427.831731486.2.82.31.46.473.216581.653.942..264.1733..8.421621.763584648152397
* PAIR G5: 7,9 BLK 6
H6: 7,9,5                                # reduction candidate for 7,9
H6: 7,9 => SOLVED
* 964275831731486925825319467473921658196538742582647193357894216219763584648152379
H6: 5 => CTR
* .6427.83173148692582.31.46747352169815693874298264715339.8.421621.763584648152379
* PAIR G5: 7,9 ROW 5
D5: 7,9,5                                # reduction candidate for 7,9
D5: 7,9 => CTR
* .642..831.31486.2.82.31.46.473521698156.3874298264715339587421621..635846481523..
D5: 5 => SOLVED
* 964275831731486925825319467473921658196538742582647193357894216219763584648152379
F5: 7,9,8                                # reduction candidate for 7,9
F5: 7,9 => CTR
* .6427.83173148692.82.31.46.473.216.818653..42..26481733..8.421621.763584648152397
F5: 8                                    # 15 pairs
* PAIR B7: 5,9 BLK 7
C7: 5,9,7                                # reduction candidate for 5,9
C7: 5,9 => CTR
* .6429.831.31486.2.82.31.46.47352169815673..42..264.1.33..8742162179635846481523..
C7: 7 => SOLVED
* 964275831731486925825319467473921658196538742582647193357894216219763584648152379
* PAIR B7: 5,9 COL B
B5: 5,9,8                                # reduction candidate for 5,9
B5: 5,9                                  # 15 pairs
B6: 5,9,8                                # reduction candidate for 5,9
B6: 5,9 => CTR
* .6427.83173148692.82.31.46.473.216.818653..42..26481733..8.421621.763584648152397
B6: 8                                    # 15 pairs
* PAIR C8: 7,9 BLK 7
C7: 7,9,5                                # reduction candidate for 7,9
C7: 7,9 => SOLVED
* 964275831731486925825319467473921658196538742582647193357894216219763584648152379
C7: 5 => CTR
* .6429.831.31486.2.82931.46.47352169815673..42..264.1.33.58742162179635846481523..
* PAIR E7: 7,9 ROW 7
C7: 7,9,5                                # reduction candidate for 7,9
C7: 7,9 => SOLVED
* 964275831731486925825319467473921658196538742582647193357894216219763584648152379
C7: 5 => CTR
* .6429.831.31486.2.82931.46.47352169815673..42..264.1.33.58742162179635846481523..
* PAIR D8: 7,9 COL D
D5: 7,9,5                                # reduction candidate for 7,9
D5: 7,9 => CTR
* .642..831.31486.2.82.31.46.473521698156.3874298264715339587421621..635846481523..
D5: 5 => SOLVED
* 964275831731486925825319467473921658196538742582647193357894216219763584648152379
* PAIR H9: 7,9 COL H
H6: 7,9,5                                # reduction candidate for 7,9
H6: 7,9 => SOLVED
* 964275831731486925825319467473921658196538742582647193357894216219763584648152379
H6: 5 => CTR
* .6427.83173148692582.31.46747352169815693874298264715339.8.421621.763584648152379
* PAIR I9: 7,9 COL I
I2: 7,9,5                                # reduction candidate for 7,9
I2: 7,9 => CTR
* 764295831531486.2.8293174654735216981.6.3..429.264.1.33958742162179635846481523..
I2: 5                                    # 15 pairs
I3: 7,9,5                                # reduction candidate for 7,9
I3: 7,9                                  # 15 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-128-base-pr-000.dot
* REASONING
* PRF # A1: 5,9 => SOL
* DIS # A1: 7 => CTR => A1: 5,9
* DIS # A2: 5,9 => CTR => A2: 7
* PRF # A2: 7 => SOL
* PRF # F3: 5,9 => SOL
* DIS # F3: 7 => CTR => F3: 5,9
* DIS # I3: 5,9 => CTR => I3: 7
* PRF # I3: 7 => SOL
* DIS # C7: 5,9 => CTR => C7: 7
* PRF # C7: 7 => SOL
* DIS # F1: 7,9 => CTR => F1: 5
* DIS # A1: 5 => CTR => A1: 7,9
* DIS # I2: 7,9 => CTR => I2: 5
* DIS # A2: 5 => CTR => A2: 7,9
* DIS # B6: 5,9 => CTR => B6: 8
* PRF # H6: 5,9 => SOL
* DIS # H6: 7 => CTR => H6: 5,9
* PRF # A1: 5,9 => SOL
* DIS # A1: 7 => CTR => A1: 5,9
* DIS # A2: 5,9 => CTR => A2: 7
* PRF # A2: 7 => SOL
* PRF # D5: 5,9 => SOL
* DIS # D5: 7 => CTR => D5: 5,9
* PRF # H6: 5,9 => SOL
* DIS # H6: 7 => CTR => H6: 5,9
* PRF # H6: 7,9 => SOL
* DIS # H6: 5 => CTR => H6: 7,9
* DIS # D5: 7,9 => CTR => D5: 5
* PRF # D5: 5 => SOL
* DIS # F5: 7,9 => CTR => F5: 8
* DIS # C7: 5,9 => CTR => C7: 7
* PRF # C7: 7 => SOL
* DIS # B6: 5,9 => CTR => B6: 8
* PRF # C7: 7,9 => SOL
* DIS # C7: 5 => CTR => C7: 7,9
* PRF # C7: 7,9 => SOL
* DIS # C7: 5 => CTR => C7: 7,9
* DIS # D5: 7,9 => CTR => D5: 5
* PRF # D5: 5 => SOL
* PRF # H6: 7,9 => SOL
* DIS # H6: 5 => CTR => H6: 7,9
* DIS # I2: 7,9 => CTR => I2: 5
* CNT  42 HDP CHAINS /  55 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A6,B7,C3,C8,D4,D8,E1,E7,G2,G5,H4,H9,I9)
* .642..831.31486.2.82.31.46.473.216.81.6.3..42..264.1.33..8.421621..635846481523..
* PAIR C3: 5,9 BLK 1
A1: 5,9,7                                # reduction candidate for 5,9
A1: 5,9 => SOLVED
* 964275831731486925825319467473921658196538742582647193357894216219763584648152379
* DURATION: 0:00:02.028244  START: 07:10:04.643989  END: 07:10:06.672233 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-128-base-pr-001.dot
* REASONING
* PRF # A1: 5,9 => SOL
* STA A1: 5,9
* CNT   1 HDP CHAINS /   1 HYP OPENED

Header Info

Top 500 Minimum 17 128

solution: 964275831731486925825319467473921658196538742582647193357894216219763584648152379
info: 1810     FNBWY    S8.f     49074

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

Solution

position: 964275831731486925825319467473921658196538742582647193357894216219763584648152379 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 # A1: 5,9 => SOL
* DIS # A1: 7 => CTR => A1: 5,9
* DIS # A2: 5,9 => CTR => A2: 7
* PRF # A2: 7 => SOL
* PRF # F3: 5,9 => SOL
* DIS # F3: 7 => CTR => F3: 5,9
* DIS # I3: 5,9 => CTR => I3: 7
* PRF # I3: 7 => SOL
* DIS # C7: 5,9 => CTR => C7: 7
* PRF # C7: 7 => SOL
* DIS # F1: 7,9 => CTR => F1: 5
* INC # F1: 5 => UNS
* INC # F3: 7,9 => UNS
* INC # A1: 7,9 => UNS
* DIS # A1: 5 => CTR => A1: 7,9
* DIS # I2: 7,9 => CTR => I2: 5
* INC # I2: 5 => UNS
* INC # I3: 7,9 => UNS
* INC # A2: 7,9 => UNS
* DIS # A2: 5 => CTR => A2: 7,9
* INC # B5: 5,9 => UNS
* DIS # B6: 5,9 => CTR => B6: 8
* INC # B6: 8 => UNS
* PRF # H6: 5,9 => SOL
* DIS # H6: 7 => CTR => H6: 5,9
* PRF # A1: 5,9 => SOL
* DIS # A1: 7 => CTR => A1: 5,9
* DIS # A2: 5,9 => CTR => A2: 7
* PRF # A2: 7 => SOL
* PRF # D5: 5,9 => SOL
* DIS # D5: 7 => CTR => D5: 5,9
* PRF # H6: 5,9 => SOL
* DIS # H6: 7 => CTR => H6: 5,9
* PRF # H6: 7,9 => SOL
* DIS # H6: 5 => CTR => H6: 7,9
* DIS # D5: 7,9 => CTR => D5: 5
* PRF # D5: 5 => SOL
* DIS # F5: 7,9 => CTR => F5: 8
* INC # F5: 8 => UNS
* DIS # C7: 5,9 => CTR => C7: 7
* PRF # C7: 7 => SOL
* INC # B5: 5,9 => UNS
* DIS # B6: 5,9 => CTR => B6: 8
* INC # B6: 8 => UNS
* PRF # C7: 7,9 => SOL
* DIS # C7: 5 => CTR => C7: 7,9
* PRF # C7: 7,9 => SOL
* DIS # C7: 5 => CTR => C7: 7,9
* DIS # D5: 7,9 => CTR => D5: 5
* PRF # D5: 5 => SOL
* PRF # H6: 7,9 => SOL
* DIS # H6: 5 => CTR => H6: 7,9
* DIS # I2: 7,9 => CTR => I2: 5
* INC # I2: 5 => UNS
* INC # I3: 7,9 => UNS
* CNT  55 HDP CHAINS /  55 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* PRF # A1: 5,9 => SOL
* STA A1: 5,9
* CNT   1 HDP CHAINS /   1 HYP OPENED