Analysis of xx-top500-170-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 3.8..45.....61..7..........5...38....7.....6...........6.2.....4.....3.....7..... initial

Autosolve

position: 3.89745.6...61.8736.738....5.6.387..173529468.8..67.3576.2.3.8.4..8.63.783.7.16.. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # B3: 1,2 => SOL
* DIS # B3: 5 => CTR => B3: 1,2
* DIS # B2: 2,9 => CTR => B2: 4,5
* DIS # C2: 2,9 => CTR => C2: 4,5
* PRF # B2: 2,5 => SOL
* DIS # C2: 2,5 => CTR => C2: 4,9
* DIS # B3: 2,5 => CTR => B3: 1
* PRF # B3: 1 => SOL
* DIS # H3: 1,2 => CTR => H3: 4,9
* DIS # I3: 1,2 => CTR => I3: 4,9
* DIS # H4: 1,2 => CTR => H4: 9
* PRF # C6: 2,9 => SOL
* PRF # G6: 1 => SOL
* DIS # C8: 5,9 => CTR => C8: 1,2
* DIS # H8: 5,9 => CTR => H8: 1,2
* DIS # H8: 1,9 => CTR => H8: 2,5
* DIS # C7: 1,9 => CTR => C7: 5
* DIS # G3: 1,9 => CTR => G3: 2
* PRF # G3: 2 => SOL
* PRF # G6: 1,9 => SOL
* DIS # G6: 2 => CTR => G6: 1,9
* CNT  21 HDP CHAINS /  41 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 # B3: 1,2 => SOL
* STA B3: 1,2
* CNT   1 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

3.8..45.....61..7..........5...38....7.....6...........6.2.....4.....3.....7..... initial
3.89745.6...61.8736.738....5.6.387..173529468.8..67.3576.2.3.8.4..8.63.783.7.16.. autosolve
328974516954612873617385249546138792173529468289467135765243981491856327832791654 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (10)
B1: 1,2
A2: 2,9
F2: 2,5
F3: 2,5
H1: 1,2
A6: 2,9
D4: 1,4
D6: 1,4
E8: 5,9
G7: 1,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
B1,B3: 1.. / B1 = 1  =>  0 pairs (X) / B3 = 1  =>  0 pairs (_)
D4,D6: 1.. / D4 = 1  =>  0 pairs (*) / D6 = 1  =>  0 pairs (X)
C7,C8: 1.. / C7 = 1  =>  0 pairs (X) / C8 = 1  => 11 pairs (_)
B1,H1: 1.. / B1 = 1  =>  0 pairs (X) / H1 = 1  =>  0 pairs (_)
D6,G6: 1.. / D6 = 1  => 10 pairs (_) / G6 = 1  =>  0 pairs (*)
C8,H8: 1.. / C8 = 1  => 11 pairs (_) / H8 = 1  =>  0 pairs (X)
F2,F3: 2.. / F2 = 2  =>  0 pairs (*) / F3 = 2  =>  0 pairs (X)
B1,H1: 2.. / B1 = 2  =>  0 pairs (*) / H1 = 2  =>  0 pairs (X)
A2,A6: 2.. / A2 = 2  =>  0 pairs (X) / A6 = 2  =>  0 pairs (_)
G3,G6: 2.. / G3 = 2  =>  0 pairs (*) / G6 = 2  =>  0 pairs (X)
B2,C2: 4.. / B2 = 4  => 10 pairs (_) / C2 = 4  =>  0 pairs (*)
H3,I3: 4.. / H3 = 4  => 10 pairs (_) / I3 = 4  =>  0 pairs (X)
B4,C6: 4.. / B4 = 4  =>  0 pairs (*) / C6 = 4  =>  0 pairs (X)
D4,D6: 4.. / D4 = 4  => 10 pairs (_) / D6 = 4  =>  0 pairs (*)
E7,E9: 4.. / E7 = 4  => 16 pairs (_) / E9 = 4  => 12 pairs (_)
B4,D4: 4.. / B4 = 4  =>  0 pairs (*) / D4 = 4  =>  0 pairs (X)
C6,D6: 4.. / C6 = 4  => 10 pairs (_) / D6 = 4  =>  0 pairs (*)
E7,I7: 4.. / E7 = 4  => 16 pairs (_) / I7 = 4  => 12 pairs (_)
B2,B4: 4.. / B2 = 4  => 10 pairs (_) / B4 = 4  =>  0 pairs (*)
C2,C6: 4.. / C2 = 4  =>  0 pairs (*) / C6 = 4  =>  0 pairs (X)
H3,H9: 4.. / H3 = 4  => 10 pairs (_) / H9 = 4  =>  0 pairs (X)
F2,F3: 5.. / F2 = 5  =>  0 pairs (X) / F3 = 5  =>  0 pairs (_)
H8,H9: 5.. / H8 = 5  =>  0 pairs (X) / H9 = 5  => 12 pairs (_)
B3,F3: 5.. / B3 = 5  =>  0 pairs (X) / F3 = 5  =>  0 pairs (_)
C7,E7: 5.. / C7 = 5  => 13 pairs (_) / E7 = 5  =>  0 pairs (X)
A2,A6: 9.. / A2 = 9  =>  0 pairs (*) / A6 = 9  =>  0 pairs (X)
* DURATION: 0:00:43.961425  START: 08:33:00.548166  END: 08:33:44.509591 2017-05-04
* CP COUNT: (26)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A2,A6,B1,D4,D6,E8,F2,F3,G7,H1)
* 3.89745.6...61.8736.738....5.6.387..173529468.8..67.3576.2.3.8.4..8.63.783.7.16..
* PAIR B1: 1,2 BLK 1
B3: 1,2,5                                # reduction candidate for 1,2
B3: 1,2 => SOLVED
* 328974516954612873617385249546138792173529468289467135765243981491856327832791654
B3: 5 => CTR
* 3189745262..615873657382...5264387..17352946898416723576.2.3.8.4928563178357.16.2
* PAIR A2: 2,9 BLK 1
B2: 2,9,4,5                              # reduction candidate for 2,9
B2: 2,9 => CTR
* 3.89745.6..4615873657382...5461387..173529468.8.467.3576.2.3.8.4..8.63.783.7.16..
B2: 4,5                                  # 11 pairs
C2: 2,9,4,5                              # reduction candidate for 2,9
C2: 2,9 => CTR
* 318974526249615873657382...5264387..17352946898416723576.2.3.8.4928563178357.16.2
C2: 4,5                                  # 11 pairs
* PAIR F2: 2,5 ROW 2
B2: 2,5,4,9                              # reduction candidate for 2,5
B2: 2,5 => SOLVED
* 328974516954612873617385249546138792173529468289467135765243981491856327832791654
B2: 4,9                                  # 11 pairs
C2: 2,5,4,9                              # reduction candidate for 2,5
C2: 2,5 => CTR
* 3289745169456128736173852..5964387211735294682841679357692531844518963.783.7.16..
C2: 4,9                                  # 12 pairs
* PAIR F3: 2,5 ROW 3
B3: 2,5,1                                # reduction candidate for 2,5
B3: 2,5 => CTR
* 3189745262..615873657382...5264387..17352946898416723576.2.3.8.4928563178357.16.2
B3: 1 => SOLVED
* 328974516954612873617385249546138792173529468289467135765243981491856327832791654
* PAIR H1: 1,2 BLK 3
G3: 1,2,9                                # reduction candidate for 1,2
G3: 1,2                                  # 13 pairs
H3: 1,2,4,9                              # reduction candidate for 1,2
H3: 1,2 => CTR
* 3.89745.62..6158736573829145264387911735294689841672357652431894918.635783.751642
H3: 4,9                                  # 11 pairs
I3: 1,2,4,9                              # reduction candidate for 1,2
I3: 1,2 => CTR
* 3.89745.62..61587365738294152643871917352946898416723576.2.318449185632783.7.16..
I3: 4,9                                  # 11 pairs
* PAIR H1: 1,2 COL H
H4: 1,2,9                                # reduction candidate for 1,2
H4: 1,2 => CTR
* 318974526...61.8736.738....5.6.387..173529468.8..67.3576.2.3.8.4218.63.783.7.16.2
H4: 9                                    # 13 pairs
H8: 1,2,5,9                              # reduction candidate for 1,2
H8: 1,2                                  # 16 pairs
* PAIR A6: 2,9 BLK 4
B4: 2,9,4                                # reduction candidate for 2,9
B4: 2,9                                  # 10 pairs
C6: 2,9,4                                # reduction candidate for 2,9
C6: 2,9 => SOLVED
* 328974516954612873617385249546138792173529468289467135765243981491856327832791654
C6: 4                                    # 10 pairs
* PAIR A6: 2,9 ROW 6
G6: 2,9,1                                # reduction candidate for 2,9
G6: 1 => SOLVED
* 328974516954612873617385249546138792173529468289467135765243981491856327832791654
G6: 2,9                                  # 10 pairs
* PAIR E8: 5,9 BLK 8
E7: 5,9,4                                # reduction candidate for 5,9
E7: 5,9                                  # 12 pairs
E9: 5,9,4                                # reduction candidate for 5,9
E9: 5,9                                  # 16 pairs
* PAIR E8: 5,9 ROW 8
B8: 5,9,2                                # reduction candidate for 5,9
B8: 5,9                                  # 19 pairs
C8: 5,9,1,2                              # reduction candidate for 5,9
C8: 5,9 => CTR
* 318974526...61.8736.738.14952643879117352946898416723576125398445.896317839741652
C8: 1,2                                  # 11 pairs
H8: 5,9,1,2                              # reduction candidate for 5,9
H8: 5,9 => CTR
* 318974526...61.873657382...5.6.387.2173529468.8..67.3576.2.3.8.4218.63.783.7.16..
H8: 1,2                                  # 16 pairs
* PAIR G7: 1,9 BLK 9
I7: 1,9,4                                # reduction candidate for 1,9
I7: 1,9                                  # 16 pairs
H8: 1,9,2,5                              # reduction candidate for 1,9
H8: 1,9 => CTR
* 32897451694561.8736.738..4.5.6.3872.173529468.8..67.3576.2.3.844..8.6397839741652
H8: 2,5                                  # 12 pairs
* PAIR G7: 1,9 ROW 7
C7: 1,9,5                                # reduction candidate for 1,9
C7: 1,9 => CTR
* 32897451694561287361738524959643872.173529468.8..67.3576.253.844..8963.783.7416..
C7: 5                                    # 13 pairs
* PAIR G7: 1,9 COL G
G3: 1,9,2                                # reduction candidate for 1,9
G3: 1,9 => CTR
* 3.89745.62..615873657382...5264387..17352946898416723576.2.3.8.49.8563.783.7.1652
G3: 2 => SOLVED
* 328974516954612873617385249546138792173529468289467135765243981491856327832791654
G6: 1,9,2                                # reduction candidate for 1,9
G6: 1,9 => SOLVED
* 328974516954612873617385249546138792173529468289467135765243981491856327832791654
G6: 2 => CTR
* 3.89745.62..615873657382...5264387..17352946898416723576.2.3.8.49.8563.783.7.1652
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-170-base-pr-000.dot
* REASONING
* PRF # B3: 1,2 => SOL
* DIS # B3: 5 => CTR => B3: 1,2
* DIS # B2: 2,9 => CTR => B2: 4,5
* DIS # C2: 2,9 => CTR => C2: 4,5
* PRF # B2: 2,5 => SOL
* DIS # C2: 2,5 => CTR => C2: 4,9
* DIS # B3: 2,5 => CTR => B3: 1
* PRF # B3: 1 => SOL
* DIS # H3: 1,2 => CTR => H3: 4,9
* DIS # I3: 1,2 => CTR => I3: 4,9
* DIS # H4: 1,2 => CTR => H4: 9
* PRF # C6: 2,9 => SOL
* PRF # G6: 1 => SOL
* DIS # C8: 5,9 => CTR => C8: 1,2
* DIS # H8: 5,9 => CTR => H8: 1,2
* DIS # H8: 1,9 => CTR => H8: 2,5
* DIS # C7: 1,9 => CTR => C7: 5
* DIS # G3: 1,9 => CTR => G3: 2
* PRF # G3: 2 => SOL
* PRF # G6: 1,9 => SOL
* DIS # G6: 2 => CTR => G6: 1,9
* CNT  21 HDP CHAINS /  41 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A2,A6,B1,D4,D6,E8,F2,F3,G7,H1)
* 3.89745.6...61.8736.738....5.6.387..173529468.8..67.3576.2.3.8.4..8.63.783.7.16..
* PAIR B1: 1,2 BLK 1
B3: 1,2,5                                # reduction candidate for 1,2
B3: 1,2 => SOLVED
* 328974516954612873617385249546138792173529468289467135765243981491856327832791654
* DURATION: 0:00:02.081533  START: 08:34:24.158211  END: 08:34:26.239744 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-170-base-pr-001.dot
* REASONING
* PRF # B3: 1,2 => SOL
* STA B3: 1,2
* CNT   1 HDP CHAINS /   1 HYP OPENED

Header Info

Top 500 Minimum 17 170

solution: 328974516954612873617385249546138792173529468289467135765243981491856327832791654
info: 1825     FNBTWY   S8.f     29857

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

Solution

position: 328974516954612873617385249546138792173529468289467135765243981491856327832791654 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 # B3: 1,2 => SOL
* DIS # B3: 5 => CTR => B3: 1,2
* DIS # B2: 2,9 => CTR => B2: 4,5
* INC # B2: 4,5 => UNS
* DIS # C2: 2,9 => CTR => C2: 4,5
* INC # C2: 4,5 => UNS
* PRF # B2: 2,5 => SOL
* INC # B2: 4,9 => UNS
* DIS # C2: 2,5 => CTR => C2: 4,9
* INC # C2: 4,9 => UNS
* DIS # B3: 2,5 => CTR => B3: 1
* PRF # B3: 1 => SOL
* INC # G3: 1,2 => UNS
* DIS # H3: 1,2 => CTR => H3: 4,9
* INC # H3: 4,9 => UNS
* DIS # I3: 1,2 => CTR => I3: 4,9
* INC # I3: 4,9 => UNS
* DIS # H4: 1,2 => CTR => H4: 9
* INC # H4: 9 => UNS
* INC # H8: 1,2 => UNS
* INC # B4: 2,9 => UNS
* PRF # C6: 2,9 => SOL
* INC # C6: 4 => UNS
* INC # G6: 2,9 => UNS
* PRF # G6: 1 => SOL
* INC # E7: 5,9 => UNS
* INC # E9: 5,9 => UNS
* INC # B8: 5,9 => UNS
* DIS # C8: 5,9 => CTR => C8: 1,2
* INC # C8: 1,2 => UNS
* DIS # H8: 5,9 => CTR => H8: 1,2
* INC # H8: 1,2 => UNS
* INC # I7: 1,9 => UNS
* DIS # H8: 1,9 => CTR => H8: 2,5
* INC # H8: 2,5 => UNS
* DIS # C7: 1,9 => CTR => C7: 5
* INC # C7: 5 => UNS
* DIS # G3: 1,9 => CTR => G3: 2
* PRF # G3: 2 => SOL
* PRF # G6: 1,9 => SOL
* DIS # G6: 2 => CTR => G6: 1,9
* CNT  41 HDP CHAINS /  41 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* PRF # B3: 1,2 => SOL
* STA B3: 1,2
* CNT   1 HDP CHAINS /   1 HYP OPENED