Analysis of xx-top500-026-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 35.....2....41....9...........7..1.482.............6....16..2.......9.5.......... initial

Autosolve

position: 354..672167241...89182.746.539762184826.41.7.1475..6.27.16..24.4631298572.5.74.16 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # E6: 3 => CTR => E6: 8,9
* PRF # G2: 3,5 => SOL
* DIS # G2: 9 => CTR => G2: 3,5
* DIS # F7: 8 => CTR => F7: 3,5
* DIS # E7: 8 => CTR => E7: 3,5
* PRF # G2: 5 => SOL
* PRF # G2: 3,5 => SOL
* DIS # G2: 9 => CTR => G2: 3,5
* PRF # I5: 3,5 => SOL
* DIS # I5: 9 => CTR => I5: 3,5
* DIS # E6: 8 => CTR => E6: 3,9
* PRF # G5: 3,9 => SOL
* DIS # E6: 3,8 => CTR => E6: 9
* PRF # E6: 9 => SOL
* PRF # F7: 5 => SOL
* PRF # G5: 3,9 => SOL
* DIS # E6: 8 => CTR => E6: 3,9
* PRF # E7: 3,8 => SOL
* PRF # I5: 5 => SOL
* PRF # G5: 3,9 => SOL
* CNT  20 HDP CHAINS /  36 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 # E6: 3 => CTR => E6: 8,9
* PRF E6: 8,9 # G2: 3,5 => SOL
* STA E6: 8,9 + G2: 3,5
* CNT   2 HDP CHAINS /   3 HYP OPENED

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

Details

Positions

35.....2....41....9...........7..1.482.............6....16..2.......9.5.......... initial
354..672167241...89182.746.539762184826.41.7.1475..6.27.16..24.4631298572.5.74.16 autosolve
354986721672413598918257463539762184826341975147598632781635249463129857295874316 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (14)
D1: 8,9
E1: 8,9
F2: 3,5
E3: 3,5
H2: 3,9
I3: 3,5
D5: 3,9
F6: 3,8
H6: 3,9
B7: 8,9
B9: 8,9
D9: 3,8
I7: 3,9
G9: 3,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
F2,E3: 3.. / F2 = 3  =>  0 pairs (*) / E3 = 3  =>  0 pairs (X)
I7,G9: 3.. / I7 = 3  =>  0 pairs (X) / G9 = 3  =>  0 pairs (_)
E3,I3: 3.. / E3 = 3  => 15 pairs (_) / I3 = 3  =>  0 pairs (*)
D9,G9: 3.. / D9 = 3  =>  0 pairs (X) / G9 = 3  =>  0 pairs (_)
D5,D9: 3.. / D5 = 3  =>  0 pairs (*) / D9 = 3  =>  0 pairs (X)
H2,H6: 3.. / H2 = 3  =>  0 pairs (X) / H6 = 3  =>  0 pairs (_)
F2,E3: 5.. / F2 = 5  => 15 pairs (_) / E3 = 5  =>  0 pairs (*)
G2,I3: 5.. / G2 = 5  =>  0 pairs (*) / I3 = 5  =>  0 pairs (X)
G5,I5: 5.. / G5 = 5  => 15 pairs (_) / I5 = 5  =>  0 pairs (*)
E7,F7: 5.. / E7 = 5  => 15 pairs (_) / F7 = 5  =>  0 pairs (*)
F2,G2: 5.. / F2 = 5  => 15 pairs (_) / G2 = 5  =>  0 pairs (*)
E3,I3: 5.. / E3 = 5  =>  0 pairs (*) / I3 = 5  =>  0 pairs (X)
E3,E7: 5.. / E3 = 5  =>  0 pairs (*) / E7 = 5  =>  0 pairs (X)
F2,F7: 5.. / F2 = 5  => 15 pairs (_) / F7 = 5  =>  0 pairs (*)
G2,G5: 5.. / G2 = 5  =>  0 pairs (*) / G5 = 5  =>  0 pairs (X)
I3,I5: 5.. / I3 = 5  => 15 pairs (_) / I5 = 5  =>  0 pairs (*)
D1,E1: 8.. / D1 = 8  =>  0 pairs (X) / E1 = 8  =>  0 pairs (_)
E6,F6: 8.. / E6 = 8  =>  0 pairs (X) / F6 = 8  => 15 pairs (_)
B7,B9: 8.. / B7 = 8  =>  0 pairs (*) / B9 = 8  =>  0 pairs (X)
B9,D9: 8.. / B9 = 8  =>  0 pairs (X) / D9 = 8  =>  0 pairs (_)
D1,D9: 8.. / D1 = 8  =>  0 pairs (X) / D9 = 8  =>  0 pairs (_)
F6,F7: 8.. / F6 = 8  => 15 pairs (_) / F7 = 8  =>  0 pairs (X)
D1,E1: 9.. / D1 = 9  =>  0 pairs (*) / E1 = 9  =>  0 pairs (X)
G2,H2: 9.. / G2 = 9  =>  0 pairs (X) / H2 = 9  =>  0 pairs (_)
D5,E6: 9.. / D5 = 9  =>  0 pairs (X) / E6 = 9  =>  0 pairs (_)
B7,B9: 9.. / B7 = 9  =>  0 pairs (X) / B9 = 9  =>  0 pairs (_)
I7,G9: 9.. / I7 = 9  =>  0 pairs (*) / G9 = 9  =>  0 pairs (X)
E6,H6: 9.. / E6 = 9  =>  0 pairs (*) / H6 = 9  =>  0 pairs (X)
B7,I7: 9.. / B7 = 9  =>  0 pairs (X) / I7 = 9  =>  0 pairs (_)
B9,G9: 9.. / B9 = 9  =>  0 pairs (*) / G9 = 9  =>  0 pairs (X)
D1,D5: 9.. / D1 = 9  =>  0 pairs (*) / D5 = 9  =>  0 pairs (X)
E1,E6: 9.. / E1 = 9  =>  0 pairs (X) / E6 = 9  =>  0 pairs (_)
H2,H6: 9.. / H2 = 9  =>  0 pairs (*) / H6 = 9  =>  0 pairs (X)
I5,I7: 9.. / I5 = 9  =>  0 pairs (X) / I7 = 9  =>  0 pairs (_)
* DURATION: 0:01:13.076118  START: 03:29:34.520035  END: 03:30:47.596153 2017-05-04
* CP COUNT: (34)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B7,B9,D1,D5,D9,E1,E3,F2,F6,G9,H2,H6,I3,I7)
* 354..672167241...89182.746.539762184826.41.7.1475..6.27.16..24.4631298572.5.74.16
* PAIR E1: 8,9 COL E
E6: 8,9,3                                # reduction candidate for 8,9
E6: 3 => CTR
* 354.9672167241...89182.746.539762184826941.7.1475386927.168524.4631298572.5.74.16
E6: 8,9                                  # 16 pairs
* PAIR F2: 3,5 ROW 2
G2: 3,5,9                                # reduction candidate for 3,5
G2: 3,5 => SOLVED
* 354986721672413598918257463539762184826341975147598632781635249463129857295874316
G2: 9 => CTR
* 354..6721672415938918237465539762184826.415731475.36927.16582494631298572.5.74.16
* PAIR F2: 3,5 COL F
F7: 3,5,8                                # reduction candidate for 3,5
F7: 8 => CTR
* 354..6721672415..8918237465539762184826.4157.1475.36927.165.24.4631298572.5.74.16
F7: 3,5                                  # 15 pairs
* PAIR E3: 3,5 COL E
E7: 3,5,8                                # reduction candidate for 3,5
E7: 8 => CTR
* 354..672167241...8918257463539762184826.41.751475386.27.16..24.4631298572.5.74.16
E7: 3,5                                  # 16 pairs
* PAIR H2: 3,9 BLK 3
G2: 3,9,5                                # reduction candidate for 3,9
G2: 5 => SOLVED
* 354986721672413598918257463539762184826341975147598632781635249463129857295874316
G2: 3,9                                  # 15 pairs
* PAIR I3: 3,5 BLK 3
G2: 3,5,9                                # reduction candidate for 3,5
G2: 3,5 => SOLVED
* 354986721672413598918257463539762184826341975147598632781635249463129857295874316
G2: 9 => CTR
* 354..6721672415938918237465539762184826.415731475.36927.16582494631298572.5.74.16
* PAIR I3: 3,5 COL I
I5: 3,5,9                                # reduction candidate for 3,5
I5: 3,5 => SOLVED
* 354986721672413598918257463539762184826341975147598632781635249463129857295874316
I5: 9 => CTR
* 354..672167241...89182.7465539762184826.415791475986327916..24.4631298572.5.74.16
* PAIR D5: 3,9 BLK 5
E6: 3,9,8                                # reduction candidate for 3,9
E6: 8 => CTR
* 354.9672167241...89182.746.539762184826941.7.1475836927.16.82494631298572.5.74.16
E6: 3,9                                  # 15 pairs
* PAIR D5: 3,9 ROW 5
G5: 3,9,5                                # reduction candidate for 3,9
G5: 3,9 => SOLVED
* 354986721672413598918257463539762184826341975147598632781635249463129857295874316
G5: 5                                    # 15 pairs
I5: 3,9,5                                # reduction candidate for 3,9
I5: 3,9                                  # 15 pairs
* PAIR F6: 3,8 BLK 5
E6: 3,8,9                                # reduction candidate for 3,8
E6: 3,8 => CTR
* 354.9672167241...89182.746.539762184826941.7.1475..6927.16..249463129857295.74.16
E6: 9 => SOLVED
* 354986721672413598918257463539762184826341975147598632781635249463129857295874316
* PAIR F6: 3,8 COL F
F7: 3,8,5                                # reduction candidate for 3,8
F7: 5 => SOLVED
* 354986721672413598918257463539762184826341975147598632781635249463129857295874316
F7: 3,8                                  # 15 pairs
* PAIR H6: 3,9 BLK 6
G5: 3,9,5                                # reduction candidate for 3,9
G5: 3,9 => SOLVED
* 354986721672413598918257463539762184826341975147598632781635249463129857295874316
G5: 5                                    # 15 pairs
I5: 3,9,5                                # reduction candidate for 3,9
I5: 3,9                                  # 15 pairs
* PAIR H6: 3,9 ROW 6
E6: 3,9,8                                # reduction candidate for 3,9
E6: 8 => CTR
* 354.9672167241...89182.746.539762184826941.7.1475836927.16.82494631298572.5.74.16
E6: 3,9                                  # 15 pairs
* PAIR D9: 3,8 BLK 8
E7: 3,8,5                                # reduction candidate for 3,8
E7: 3,8 => SOLVED
* 354986721672413598918257463539762184826341975147598632781635249463129857295874316
E7: 5                                    # 15 pairs
F7: 3,8,5                                # reduction candidate for 3,8
F7: 3,8                                  # 15 pairs
* PAIR I7: 3,9 COL I
I5: 3,9,5                                # reduction candidate for 3,9
I5: 5 => SOLVED
* 354986721672413598918257463539762184826341975147598632781635249463129857295874316
I5: 3,9                                  # 15 pairs
* PAIR G9: 3,9 COL G
G2: 3,9,5                                # reduction candidate for 3,9
G2: 3,9                                  # 15 pairs
G5: 3,9,5                                # reduction candidate for 3,9
G5: 3,9 => SOLVED
* 354986721672413598918257463539762184826341975147598632781635249463129857295874316
G5: 5                                    # 15 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-026-base-pr-000.dot
* REASONING
* DIS # E6: 3 => CTR => E6: 8,9
* PRF # G2: 3,5 => SOL
* DIS # G2: 9 => CTR => G2: 3,5
* DIS # F7: 8 => CTR => F7: 3,5
* DIS # E7: 8 => CTR => E7: 3,5
* PRF # G2: 5 => SOL
* PRF # G2: 3,5 => SOL
* DIS # G2: 9 => CTR => G2: 3,5
* PRF # I5: 3,5 => SOL
* DIS # I5: 9 => CTR => I5: 3,5
* DIS # E6: 8 => CTR => E6: 3,9
* PRF # G5: 3,9 => SOL
* DIS # E6: 3,8 => CTR => E6: 9
* PRF # E6: 9 => SOL
* PRF # F7: 5 => SOL
* PRF # G5: 3,9 => SOL
* DIS # E6: 8 => CTR => E6: 3,9
* PRF # E7: 3,8 => SOL
* PRF # I5: 5 => SOL
* PRF # G5: 3,9 => SOL
* CNT  20 HDP CHAINS /  36 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B7,B9,D1,D5,D9,E1,E3,F2,F6,G9,H2,H6,I3,I7)
* 354..672167241...89182.746.539762184826.41.7.1475..6.27.16..24.4631298572.5.74.16
* PAIR E1: 8,9 COL E
E6: 8,9,3                                # reduction candidate for 8,9
E6: 3 => CTR
* 354.9672167241...89182.746.539762184826941.7.1475386927.168524.4631298572.5.74.16
* PAIR RESTART
* PAIR F2: 3,5 ROW 2
G2: 3,5,9                                # reduction candidate for 3,5
G2: 3,5 => SOLVED
* 354986721672413598918257463539762184826341975147598632781635249463129857295874316
* DURATION: 0:00:04.721507  START: 03:31:35.744980  END: 03:31:40.466487 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-026-base-pr-001.dot
* REASONING
* DIS # E6: 3 => CTR => E6: 8,9
* PRF E6: 8,9 # G2: 3,5 => SOL
* STA E6: 8,9 + G2: 3,5
* CNT   2 HDP CHAINS /   3 HYP OPENED

Header Info

Top 500 Minimum 17 026

solution: 354986721672413598918257463539762184826341975147598632781635249463129857295874316
info: 1323     FNBTWXY  S8.f     30025

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

Solution

position: 354986721672413598918257463539762184826341975147598632781635249463129857295874316 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 # E6: 8,9 => UNS
* DIS # E6: 3 => CTR => E6: 8,9
* PRF # G2: 3,5 => SOL
* DIS # G2: 9 => CTR => G2: 3,5
* INC # F7: 3,5 => UNS
* DIS # F7: 8 => CTR => F7: 3,5
* INC # E7: 3,5 => UNS
* DIS # E7: 8 => CTR => E7: 3,5
* INC # G2: 3,9 => UNS
* PRF # G2: 5 => SOL
* PRF # G2: 3,5 => SOL
* DIS # G2: 9 => CTR => G2: 3,5
* PRF # I5: 3,5 => SOL
* DIS # I5: 9 => CTR => I5: 3,5
* INC # E6: 3,9 => UNS
* DIS # E6: 8 => CTR => E6: 3,9
* PRF # G5: 3,9 => SOL
* INC # G5: 5 => UNS
* INC # I5: 3,9 => UNS
* DIS # E6: 3,8 => CTR => E6: 9
* PRF # E6: 9 => SOL
* INC # F7: 3,8 => UNS
* PRF # F7: 5 => SOL
* PRF # G5: 3,9 => SOL
* INC # G5: 5 => UNS
* INC # I5: 3,9 => UNS
* INC # E6: 3,9 => UNS
* DIS # E6: 8 => CTR => E6: 3,9
* PRF # E7: 3,8 => SOL
* INC # E7: 5 => UNS
* INC # F7: 3,8 => UNS
* INC # I5: 3,9 => UNS
* PRF # I5: 5 => SOL
* INC # G2: 3,9 => UNS
* PRF # G5: 3,9 => SOL
* INC # G5: 5 => UNS
* CNT  36 HDP CHAINS /  36 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # E6: 8,9 => UNS
* DIS # E6: 3 => CTR => E6: 8,9
* PRF E6: 8,9 # G2: 3,5 => SOL
* STA E6: 8,9 + G2: 3,5
* CNT   3 HDP CHAINS /   3 HYP OPENED