Analysis of xx-top95-029-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: .47.8...1............6..7..6....357......5....1..6....28..4.....9.1...4.....2.69. initial

Autosolve

position: .47.8..61.6..........6..7..62..1357......5..6.1..6....28..4.....9.1...4.....2.69. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # C2: 3,5 => SOL
* DIS # A3: 3,5 => CTR => A3: 1,8,9
* DIS # C3: 3,5 => CTR => C3: 1,2,8,9
* DIS # H3: 3,5 => CTR => H3: 2,8
* DIS # I3: 3,5 => CTR => I3: 2,4,8,9
* PRF # B9: 7 => SOL
* DIS # D1: 2,9 => CTR => D1: 3,5
* PRF # B9: 3,7 => SOL
* DIS # B9: 5 => CTR => B9: 3,7
* DIS # D5: 7,9 => CTR => D5: 2,4,8
* PRF # A5: 7,9 => SOL
* CNT  11 HDP CHAINS /  46 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 # C2: 3,5 => SOL
* STA C2: 3,5
* CNT   1 HDP CHAINS /   3 HYP OPENED

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

Details

Positions

.47.8...1............6..7..6....357......5....1..6....28..4.....9.1...4.....2.69. initial
.47.8..61.6..........6..7..62..1357......5..6.1..6....28..4.....9.1...4.....2.69. autosolve
947582361863471952152639784624813579738295416519764823285946137396157248471328695 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (8)
B3: 3,5
F1: 2,9
B5: 3,7
E5: 7,9
A9: 1,4
C9: 1,4
F9: 7,8
G7: 1,3

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
F2,F3: 1.. / F2 = 1  =>  8 pairs (_) / F3 = 1  =>  9 pairs (_)
G5,H5: 1.. / G5 = 1  => 13 pairs (_) / H5 = 1  =>  8 pairs (_)
A9,C9: 1.. / A9 = 1  =>  9 pairs (_) / C9 = 1  =>  6 pairs (_)
G7,H7: 1.. / G7 = 1  =>  8 pairs (_) / H7 = 1  => 13 pairs (_)
G5,G7: 1.. / G5 = 1  => 13 pairs (_) / G7 = 1  =>  8 pairs (_)
H5,H7: 1.. / H5 = 1  =>  8 pairs (_) / H7 = 1  => 13 pairs (_)
C2,C3: 2.. / C2 = 2  =>  8 pairs (_) / C3 = 2  =>  8 pairs (_)
G8,I8: 2.. / G8 = 2  => 10 pairs (_) / I8 = 2  =>  9 pairs (_)
A9,C9: 4.. / A9 = 4  =>  6 pairs (_) / C9 = 4  =>  9 pairs (_)
F3,I3: 4.. / F3 = 4  =>  8 pairs (_) / I3 = 4  =>  9 pairs (_)
A6,C6: 5.. / A6 = 5  =>  0 pairs (*) / C6 = 5  =>  0 pairs (X)
A1,D1: 5.. / A1 = 5  =>  0 pairs (X) / D1 = 5  => 12 pairs (_)
B3,B9: 5.. / B3 = 5  =>  0 pairs (*) / B9 = 5  =>  0 pairs (X)
C7,C8: 6.. / C7 = 6  => 12 pairs (_) / C8 = 6  => 13 pairs (_)
F7,F8: 6.. / F7 = 6  => 13 pairs (_) / F8 = 6  => 12 pairs (_)
C7,F7: 6.. / C7 = 6  => 12 pairs (_) / F7 = 6  => 13 pairs (_)
C8,F8: 6.. / C8 = 6  => 13 pairs (_) / F8 = 6  => 12 pairs (_)
A8,B9: 7.. / A8 = 7  => 12 pairs (_) / B9 = 7  =>  0 pairs (*)
B5,B9: 7.. / B5 = 7  => 12 pairs (_) / B9 = 7  =>  0 pairs (*)
D7,F7: 9.. / D7 = 9  => 12 pairs (_) / F7 = 9  => 12 pairs (_)
* DURATION: 0:00:24.108877  START: 23:25:27.935821  END: 23:25:52.044698 2017-05-03
* CP COUNT: (20)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A9,B3,B5,C9,E5,F1,F9,G7)
* .47.8..61.6..........6..7..62..1357......5..6.1..6....28..4.....9.1...4.....2.69.
* PAIR B3: 3,5 BLK 1
A1: 3,5,9                                # reduction candidate for 3,5
A1: 3,5                                  #  9 pairs
A2: 3,5,1,8,9                            # reduction candidate for 3,5
A2: 3,5                                  # 13 pairs
C2: 3,5,1,2,8,9                          # reduction candidate for 3,5
C2: 3,5 => SOLVED
* 947582361863471952152639784624813579738295416519764823285946137396157248471328695
C2: 1,2,8,9                              #  8 pairs
A3: 3,5,1,8,9                            # reduction candidate for 3,5
A3: 3,5 => CTR
* 947582361.6..3.......69.7..62..1357.....75..6715.6....28..4.1...9.15..4.....2.69.
A3: 1,8,9                                #  8 pairs
C3: 3,5,1,2,8,9                          # reduction candidate for 3,5
C3: 3,5 => CTR
* .47.8..61.62.........6..7..62..1357......5..6.1..6....28..4.....9.1...4.4.1.2.69.
C3: 1,2,8,9                              #  8 pairs
* PAIR B3: 3,5 ROW 3
E3: 3,5,9                                # reduction candidate for 3,5
E3: 3,5                                  # 10 pairs
H3: 3,5,2,8                              # reduction candidate for 3,5
H3: 3,5 => CTR
* .47.82.61.6........5.69.73.62..1357..3..75..6715.6....28..4....59.13..4..7.528693
H3: 2,8                                  #  9 pairs
I3: 3,5,2,4,8,9                          # reduction candidate for 3,5
I3: 3,5 => CTR
* .47.82.61.6.7.1....5.6947.362..1357..3..75..6715.69...28.94....59.13..4..7..2869.
I3: 2,4,8,9                              #  8 pairs
* PAIR B3: 3,5 COL B
B9: 3,5,7                                # reduction candidate for 3,5
B9: 7 => SOLVED
* 947582361863471952152639784624813579738295416519764823285946137396157248471328695
B9: 3,5                                  # 12 pairs
* PAIR F1: 2,9 BLK 2
D1: 2,9,3,5                              # reduction candidate for 2,9
D1: 2,9 => CTR
* 547.8.361.6..7.....3.65.7..62..1357..7..95.16.15.6....28.5491377931...4..5..2.69.
D1: 3,5                                  #  9 pairs
D2: 2,9,3,4,5,7                          # reduction candidate for 2,9
D2: 2,9                                  # 15 pairs
F2: 2,9,1,4,7                            # reduction candidate for 2,9
F2: 2,9                                  # 19 pairs
F3: 2,9,1,4                              # reduction candidate for 2,9
F3: 2,9                                  # 15 pairs
* PAIR F1: 2,9 ROW 1
G1: 2,9,3                                # reduction candidate for 2,9
G1: 2,9                                  # 11 pairs
G1: 3                                    # 10 pairs
* PAIR F1: 2,9 COL F
F6: 2,9,4,7,8                            # reduction candidate for 2,9
F6: 2,9                                  # 15 pairs
F6: 4,7,8                                #  8 pairs
* PAIR B5: 3,7 BLK 4
A5: 3,7,4,8,9                            # reduction candidate for 3,7
A5: 3,7                                  # 13 pairs
A6: 3,7,4,5,8,9                          # reduction candidate for 3,7
A6: 3,7                                  # 13 pairs
* PAIR B5: 3,7 COL B
B9: 3,7,5                                # reduction candidate for 3,7
B9: 3,7 => SOLVED
* 947582361863471952152639784624813579738295416519764823285946137396157248471328695
B9: 5 => CTR
* .47.8..61.6..7.....3.65.7..62..1357..7..95..6.1..6....28.549..779.136.4..5..2.69.
* PAIR E5: 7,9 BLK 5
D5: 7,9,2,4,8                            # reduction candidate for 7,9
D5: 7,9 => CTR
* .4758..61.6........5.6..7..629.1357..3...5..6715.6....28..4....59.1...4..7.328695
D5: 2,4,8                                #  8 pairs
D6: 7,9,2,4,8                            # reduction candidate for 7,9
D6: 7,9                                  # 10 pairs
F6: 7,9,2,4,8                            # reduction candidate for 7,9
F6: 7,9                                  # 12 pairs
* PAIR E5: 7,9 ROW 5
A5: 7,9,3,4,8                            # reduction candidate for 7,9
A5: 7,9 => SOLVED
* 947582361863471952152639784624813579738295416519764823285946137396157248471328695
A5: 3,4,8                                #  8 pairs
* PAIR E5: 7,9 COL E
E2: 7,9,3,5                              # reduction candidate for 7,9
E2: 7,9                                  # 12 pairs
E2: 3,5                                  # 12 pairs
* PAIR F9: 7,8 BLK 8
F8: 7,8,6                                # reduction candidate for 7,8
F8: 7,8                                  # 13 pairs
D9: 7,8,3,5                              # reduction candidate for 7,8
D9: 7,8                                  # 21 pairs
* PAIR F9: 7,8 ROW 9
I9: 7,8,3,5                              # reduction candidate for 7,8
I9: 7,8                                  # 15 pairs
I9: 3,5                                  # 13 pairs
* PAIR F9: 7,8 COL F
F6: 7,8,2,4,9                            # reduction candidate for 7,8
F6: 7,8                                  # 14 pairs
F6: 2,4,9                                #  8 pairs
* PAIR G7: 1,3 BLK 9
H7: 1,3,5                                # reduction candidate for 1,3
H7: 1,3                                  # 12 pairs
H7: 5                                    #  9 pairs
* PAIR G7: 1,3 COL G
G5: 1,3,2,4,8,9                          # reduction candidate for 1,3
G5: 1,3                                  # 13 pairs
G5: 2,4,8,9                              #  8 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top95-029-base-pr-000.dot
* REASONING
* PRF # C2: 3,5 => SOL
* DIS # A3: 3,5 => CTR => A3: 1,8,9
* DIS # C3: 3,5 => CTR => C3: 1,2,8,9
* DIS # H3: 3,5 => CTR => H3: 2,8
* DIS # I3: 3,5 => CTR => I3: 2,4,8,9
* PRF # B9: 7 => SOL
* DIS # D1: 2,9 => CTR => D1: 3,5
* PRF # B9: 3,7 => SOL
* DIS # B9: 5 => CTR => B9: 3,7
* DIS # D5: 7,9 => CTR => D5: 2,4,8
* PRF # A5: 7,9 => SOL
* CNT  11 HDP CHAINS /  46 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A9,B3,B5,C9,E5,F1,F9,G7)
* .47.8..61.6..........6..7..62..1357......5..6.1..6....28..4.....9.1...4.....2.69.
* PAIR B3: 3,5 BLK 1
A1: 3,5,9                                # reduction candidate for 3,5
A1: 3,5                                  #  9 pairs
A2: 3,5,1,8,9                            # reduction candidate for 3,5
A2: 3,5                                  # 13 pairs
C2: 3,5,1,2,8,9                          # reduction candidate for 3,5
C2: 3,5 => SOLVED
* 947582361863471952152639784624813579738295416519764823285946137396157248471328695
* DURATION: 0:00:03.942484  START: 23:26:24.374668  END: 23:26:28.317152 2017-05-03
* SOLUTION FOUND
* SAVE PR GRAPH xx-top95-029-base-pr-001.dot
* REASONING
* PRF # C2: 3,5 => SOL
* STA C2: 3,5
* CNT   1 HDP CHAINS /   3 HYP OPENED

Header Info

Top 95 Sudokus 029
[sudoku:top95] “95 Hard Puzzles”, http://magictour.free.fr/top95, or http://norvig.com/top95.txt

Solution

position: 947582361863471952152639784624813579738295416519764823285946137396157248471328695 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 # A1: 3,5 => UNS
* INC # A2: 3,5 => UNS
* PRF # C2: 3,5 => SOL
* INC # C2: 1,2,8,9 => UNS
* DIS # A3: 3,5 => CTR => A3: 1,8,9
* INC # A3: 1,8,9 => UNS
* DIS # C3: 3,5 => CTR => C3: 1,2,8,9
* INC # C3: 1,2,8,9 => UNS
* INC # E3: 3,5 => UNS
* DIS # H3: 3,5 => CTR => H3: 2,8
* INC # H3: 2,8 => UNS
* DIS # I3: 3,5 => CTR => I3: 2,4,8,9
* INC # I3: 2,4,8,9 => UNS
* INC # B9: 3,5 => UNS
* PRF # B9: 7 => SOL
* DIS # D1: 2,9 => CTR => D1: 3,5
* INC # D1: 3,5 => UNS
* INC # D2: 2,9 => UNS
* INC # F2: 2,9 => UNS
* INC # F3: 2,9 => UNS
* INC # G1: 2,9 => UNS
* INC # G1: 3 => UNS
* INC # F6: 2,9 => UNS
* INC # F6: 4,7,8 => UNS
* INC # A5: 3,7 => UNS
* INC # A6: 3,7 => UNS
* PRF # B9: 3,7 => SOL
* DIS # B9: 5 => CTR => B9: 3,7
* DIS # D5: 7,9 => CTR => D5: 2,4,8
* INC # D5: 2,4,8 => UNS
* INC # D6: 7,9 => UNS
* INC # F6: 7,9 => UNS
* PRF # A5: 7,9 => SOL
* INC # A5: 3,4,8 => UNS
* INC # E2: 7,9 => UNS
* INC # E2: 3,5 => UNS
* INC # F8: 7,8 => UNS
* INC # D9: 7,8 => UNS
* INC # I9: 7,8 => UNS
* INC # I9: 3,5 => UNS
* INC # F6: 7,8 => UNS
* INC # F6: 2,4,9 => UNS
* INC # H7: 1,3 => UNS
* INC # H7: 5 => UNS
* INC # G5: 1,3 => UNS
* INC # G5: 2,4,8,9 => UNS
* CNT  46 HDP CHAINS /  46 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # A1: 3,5 => UNS
* INC # A2: 3,5 => UNS
* PRF # C2: 3,5 => SOL
* STA C2: 3,5
* CNT   3 HDP CHAINS /   3 HYP OPENED