Analysis of xx-top500-120-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 3...26.........4.15........2......6......5.3..4.1........41.7.....8.....6........ initial

Autosolve

position: 314526....623.84515...41623253..416.1..6.5234.46132..5.254137.643.86.5126.125.34. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # A6: 8 => SOL
* PRF # E4: 7,9 => SOL
* PRF # H1: 8,9 => SOL
* DIS # H1: 7 => CTR => H1: 8,9
* DIS # I1: 8,9 => CTR => I1: 7
* PRF # I1: 7 => SOL
* PRF # E4: 7,9 => SOL
* PRF # I4: 8 => SOL
* PRF # I4: 8,9 => SOL
* DIS # I4: 7 => CTR => I4: 8,9
* DIS # H6: 8,9 => CTR => H6: 7
* PRF # H6: 7 => SOL
* PRF # A6: 8,9 => SOL
* DIS # A6: 7 => CTR => A6: 8,9
* PRF # A6: 8,9 => SOL
* DIS # A6: 7 => CTR => A6: 8,9
* PRF # B9: 8 => SOL
* PRF # B9: 8 => SOL
* PRF # H1: 8,9 => SOL
* DIS # H1: 7 => CTR => H1: 8,9
* DIS # H6: 8,9 => CTR => H6: 7
* PRF # H6: 7 => SOL
* DIS # I1: 8,9 => CTR => I1: 7
* PRF # I1: 7 => SOL
* PRF # I4: 8,9 => SOL
* DIS # I4: 7 => CTR => I4: 8,9
* CNT  26 HDP CHAINS /  44 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 # A6: 8 => SOL
* STA A6: 8
* CNT   1 HDP CHAINS /   4 HYP OPENED

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

Details

Positions

3...26.........4.15........2......6......5.3..4.1........41.7.....8.....6........ initial
314526....623.84515...41623253..416.1..6.5234.46132..5.254137.643.86.5126.125.34. autosolve
314526897762398451598741623253974168179685234846132975925413786437869512681257349 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (12)
A2: 7,9
E2: 7,9
D3: 7,9
G1: 8,9
D4: 7,9
G6: 8,9
A7: 8,9
C8: 7,9
F8: 7,9
F9: 7,9
H7: 8,9
I9: 8,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
E2,D3: 7.. / E2 = 7  =>  0 pairs (X) / D3 = 7  =>  0 pairs (_)
H1,I1: 7.. / H1 = 7  =>  0 pairs (X) / I1 = 7  =>  0 pairs (_)
I4,H6: 7.. / I4 = 7  =>  0 pairs (X) / H6 = 7  =>  0 pairs (_)
C8,B9: 7.. / C8 = 7  => 12 pairs (_) / B9 = 7  => 16 pairs (_)
F8,F9: 7.. / F8 = 7  => 16 pairs (_) / F9 = 7  => 12 pairs (_)
A2,E2: 7.. / A2 = 7  =>  0 pairs (*) / E2 = 7  =>  0 pairs (X)
A6,H6: 7.. / A6 = 7  =>  0 pairs (X) / H6 = 7  =>  0 pairs (_)
C8,F8: 7.. / C8 = 7  => 12 pairs (_) / F8 = 7  => 16 pairs (_)
B9,F9: 7.. / B9 = 7  => 16 pairs (_) / F9 = 7  => 12 pairs (_)
A2,A6: 7.. / A2 = 7  =>  0 pairs (*) / A6 = 7  =>  0 pairs (X)
D3,D4: 7.. / D3 = 7  =>  0 pairs (*) / D4 = 7  =>  0 pairs (X)
H1,H6: 7.. / H1 = 7  =>  0 pairs (X) / H6 = 7  =>  0 pairs (_)
I1,I4: 7.. / I1 = 7  =>  0 pairs (*) / I4 = 7  =>  0 pairs (X)
B3,C3: 8.. / B3 = 8  => 18 pairs (_) / C3 = 8  => 14 pairs (_)
E4,E5: 8.. / E4 = 8  => 16 pairs (_) / E5 = 8  =>  0 pairs (*)
A7,B9: 8.. / A7 = 8  => 16 pairs (_) / B9 = 8  =>  0 pairs (*)
H7,I9: 8.. / H7 = 8  =>  0 pairs (*) / I9 = 8  =>  0 pairs (X)
E4,I4: 8.. / E4 = 8  => 16 pairs (_) / I4 = 8  =>  0 pairs (*)
A7,H7: 8.. / A7 = 8  => 16 pairs (_) / H7 = 8  =>  0 pairs (*)
B9,I9: 8.. / B9 = 8  =>  0 pairs (*) / I9 = 8  =>  0 pairs (X)
A6,A7: 8.. / A6 = 8  =>  0 pairs (*) / A7 = 8  =>  0 pairs (X)
C3,C5: 8.. / C3 = 8  => 14 pairs (_) / C5 = 8  => 18 pairs (_)
G1,G6: 8.. / G1 = 8  => 16 pairs (_) / G6 = 8  =>  0 pairs (X)
E2,D3: 9.. / E2 = 9  =>  0 pairs (*) / D3 = 9  =>  0 pairs (X)
F8,F9: 9.. / F8 = 9  => 12 pairs (_) / F9 = 9  => 16 pairs (_)
H7,I9: 9.. / H7 = 9  => 16 pairs (_) / I9 = 9  =>  0 pairs (*)
A2,E2: 9.. / A2 = 9  =>  0 pairs (X) / E2 = 9  =>  0 pairs (_)
A7,H7: 9.. / A7 = 9  =>  0 pairs (*) / H7 = 9  =>  0 pairs (X)
C8,F8: 9.. / C8 = 9  => 16 pairs (_) / F8 = 9  => 12 pairs (_)
D3,D4: 9.. / D3 = 9  =>  0 pairs (X) / D4 = 9  =>  0 pairs (_)
G1,G6: 9.. / G1 = 9  =>  0 pairs (X) / G6 = 9  => 16 pairs (_)
* DURATION: 0:00:51.556454  START: 06:53:05.069792  END: 06:53:56.626246 2017-05-04
* CP COUNT: (31)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A2,A7,C8,D3,D4,E2,F8,F9,G1,G6,H7,I9)
* 314526....623.84515...41623253..416.1..6.5234.46132..5.254137.643.86.5126.125.34.
* PAIR A2: 7,9 BLK 1
B3: 7,9,8                                # reduction candidate for 7,9
B3: 7,9                                  # 14 pairs
C3: 7,9,8                                # reduction candidate for 7,9
C3: 7,9                                  # 18 pairs
* PAIR A2: 7,9 COL A
A6: 7,9,8                                # reduction candidate for 7,9
A6: 8 => SOLVED
* 314526897762398451598741623253974168179685234846132975925413786437869512681257349
A6: 7,9                                  # 16 pairs
* PAIR E2: 7,9 COL E
E4: 7,9,8                                # reduction candidate for 7,9
E4: 7,9 => SOLVED
* 314526897762398451598741623253974168179685234846132975925413786437869512681257349
E4: 8                                    # 16 pairs
E5: 7,9,8                                # reduction candidate for 7,9
E5: 7,9                                  # 16 pairs
* PAIR D3: 7,9 ROW 3
B3: 7,9,8                                # reduction candidate for 7,9
B3: 7,9                                  # 14 pairs
C3: 7,9,8                                # reduction candidate for 7,9
C3: 7,9                                  # 18 pairs
* PAIR G1: 8,9 BLK 3
H1: 8,9,7                                # reduction candidate for 8,9
H1: 8,9 => SOLVED
* 314526897762398451598741623253974168179685234846132975925413786437869512681257349
H1: 7 => CTR
* 314526.7..623.84515...41623253..41671..675234746132..582541379643.86.5126.125.348
I1: 8,9,7                                # reduction candidate for 8,9
I1: 8,9 => CTR
* 314526.7..623.84515...41623253..41671..675234746132..582541379643.86.5126.125.348
I1: 7 => SOLVED
* 314526897762398451598741623253974168179685234846132975925413786437869512681257349
* PAIR D4: 7,9 BLK 5
E4: 7,9,8                                # reduction candidate for 7,9
E4: 7,9 => SOLVED
* 314526897762398451598741623253974168179685234846132975925413786437869512681257349
E4: 8                                    # 16 pairs
E5: 7,9,8                                # reduction candidate for 7,9
E5: 7,9                                  # 16 pairs
* PAIR D4: 7,9 ROW 4
I4: 7,9,8                                # reduction candidate for 7,9
I4: 8 => SOLVED
* 314526897762398451598741623253974168179685234846132975925413786437869512681257349
I4: 7,9                                  # 16 pairs
* PAIR G6: 8,9 BLK 6
I4: 8,9,7                                # reduction candidate for 8,9
I4: 8,9 => SOLVED
* 314526897762398451598741623253974168179685234846132975925413786437869512681257349
I4: 7 => CTR
* 314526....623.84515...41623253.841671..675234746132..582541379643.86.5126.125.348
H6: 8,9,7                                # reduction candidate for 8,9
H6: 8,9 => CTR
* 314526.7..623.84515...41623253..41671..675234746132..582541379643.86.5126.125.348
H6: 7 => SOLVED
* 314526897762398451598741623253974168179685234846132975925413786437869512681257349
* PAIR G6: 8,9 ROW 6
A6: 8,9,7                                # reduction candidate for 8,9
A6: 8,9 => SOLVED
* 314526897762398451598741623253974168179685234846132975925413786437869512681257349
A6: 7 => CTR
* 314526.799623784515..9416232537.416.1..6.5234746132..582541379643.86.5126.125.348
* PAIR A7: 8,9 BLK 7
B9: 8,9,7                                # reduction candidate for 8,9
B9: 7                                    # 16 pairs
B9: 8,9                                  # 12 pairs
* PAIR A7: 8,9 COL A
A6: 8,9,7                                # reduction candidate for 8,9
A6: 8,9 => SOLVED
* 314526897762398451598741623253974168179685234846132975925413786437869512681257349
A6: 7 => CTR
* 314526.799623784515..9416232537.416.1..6.5234746132..582541379643.86.5126.125.348
* PAIR C8: 7,9 BLK 7
B9: 7,9,8                                # reduction candidate for 7,9
B9: 8 => SOLVED
* 314526897762398451598741623253974168179685234846132975925413786437869512681257349
B9: 7,9                                  # 16 pairs
* PAIR C8: 7,9 COL C
C3: 7,9,8                                # reduction candidate for 7,9
C3: 7,9                                  # 18 pairs
C5: 7,9,8                                # reduction candidate for 7,9
C5: 7,9                                  # 14 pairs
* PAIR F9: 7,9 ROW 9
B9: 7,9,8                                # reduction candidate for 7,9
B9: 8 => SOLVED
* 314526897762398451598741623253974168179685234846132975925413786437869512681257349
B9: 7,9                                  # 16 pairs
* PAIR H7: 8,9 COL H
H1: 8,9,7                                # reduction candidate for 8,9
H1: 8,9 => SOLVED
* 314526897762398451598741623253974168179685234846132975925413786437869512681257349
H1: 7 => CTR
* 314526.7..623.84515...41623253..41671..675234746132..582541379643.86.5126.125.348
H6: 8,9,7                                # reduction candidate for 8,9
H6: 8,9 => CTR
* 314526.7..623.84515...41623253..41671..675234746132..582541379643.86.5126.125.348
H6: 7 => SOLVED
* 314526897762398451598741623253974168179685234846132975925413786437869512681257349
* PAIR I9: 8,9 ROW 9
B9: 8,9,7                                # reduction candidate for 8,9
B9: 7                                    # 16 pairs
B9: 8,9                                  # 12 pairs
* PAIR I9: 8,9 COL I
I1: 8,9,7                                # reduction candidate for 8,9
I1: 8,9 => CTR
* 314526.7..623.84515...41623253..41671..675234746132..582541379643.86.5126.125.348
I1: 7 => SOLVED
* 314526897762398451598741623253974168179685234846132975925413786437869512681257349
I4: 8,9,7                                # reduction candidate for 8,9
I4: 8,9 => SOLVED
* 314526897762398451598741623253974168179685234846132975925413786437869512681257349
I4: 7 => CTR
* 314526....623.84515...41623253.841671..675234746132..582541379643.86.5126.125.348
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-120-base-pr-000.dot
* REASONING
* PRF # A6: 8 => SOL
* PRF # E4: 7,9 => SOL
* PRF # H1: 8,9 => SOL
* DIS # H1: 7 => CTR => H1: 8,9
* DIS # I1: 8,9 => CTR => I1: 7
* PRF # I1: 7 => SOL
* PRF # E4: 7,9 => SOL
* PRF # I4: 8 => SOL
* PRF # I4: 8,9 => SOL
* DIS # I4: 7 => CTR => I4: 8,9
* DIS # H6: 8,9 => CTR => H6: 7
* PRF # H6: 7 => SOL
* PRF # A6: 8,9 => SOL
* DIS # A6: 7 => CTR => A6: 8,9
* PRF # A6: 8,9 => SOL
* DIS # A6: 7 => CTR => A6: 8,9
* PRF # B9: 8 => SOL
* PRF # B9: 8 => SOL
* PRF # H1: 8,9 => SOL
* DIS # H1: 7 => CTR => H1: 8,9
* DIS # H6: 8,9 => CTR => H6: 7
* PRF # H6: 7 => SOL
* DIS # I1: 8,9 => CTR => I1: 7
* PRF # I1: 7 => SOL
* PRF # I4: 8,9 => SOL
* DIS # I4: 7 => CTR => I4: 8,9
* CNT  26 HDP CHAINS /  44 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A2,A7,C8,D3,D4,E2,F8,F9,G1,G6,H7,I9)
* 314526....623.84515...41623253..416.1..6.5234.46132..5.254137.643.86.5126.125.34.
* PAIR A2: 7,9 BLK 1
B3: 7,9,8                                # reduction candidate for 7,9
B3: 7,9                                  # 14 pairs
C3: 7,9,8                                # reduction candidate for 7,9
C3: 7,9                                  # 18 pairs
* PAIR A2: 7,9 COL A
A6: 7,9,8                                # reduction candidate for 7,9
A6: 8 => SOLVED
* 314526897762398451598741623253974168179685234846132975925413786437869512681257349
* DURATION: 0:00:04.556573  START: 06:54:41.513627  END: 06:54:46.070200 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-120-base-pr-001.dot
* REASONING
* PRF # A6: 8 => SOL
* STA A6: 8
* CNT   1 HDP CHAINS /   4 HYP OPENED

Header Info

Top 500 Minimum 17 120

solution: 314526897762398451598741623253974168179685234846132975925413786437869512681257349
info: 1802     FNWX     S8.f     29127

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

Solution

position: 314526897762398451598741623253974168179685234846132975925413786437869512681257349 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 # B3: 7,9 => UNS
* INC # C3: 7,9 => UNS
* INC # A6: 7,9 => UNS
* PRF # A6: 8 => SOL
* PRF # E4: 7,9 => SOL
* INC # E4: 8 => UNS
* INC # E5: 7,9 => UNS
* INC # B3: 7,9 => UNS
* INC # C3: 7,9 => UNS
* PRF # H1: 8,9 => SOL
* DIS # H1: 7 => CTR => H1: 8,9
* DIS # I1: 8,9 => CTR => I1: 7
* PRF # I1: 7 => SOL
* PRF # E4: 7,9 => SOL
* INC # E4: 8 => UNS
* INC # E5: 7,9 => UNS
* INC # I4: 7,9 => UNS
* PRF # I4: 8 => SOL
* PRF # I4: 8,9 => SOL
* DIS # I4: 7 => CTR => I4: 8,9
* DIS # H6: 8,9 => CTR => H6: 7
* PRF # H6: 7 => SOL
* PRF # A6: 8,9 => SOL
* DIS # A6: 7 => CTR => A6: 8,9
* INC # B9: 8,9 => UNS
* INC # B9: 7 => UNS
* PRF # A6: 8,9 => SOL
* DIS # A6: 7 => CTR => A6: 8,9
* INC # B9: 7,9 => UNS
* PRF # B9: 8 => SOL
* INC # C3: 7,9 => UNS
* INC # C5: 7,9 => UNS
* INC # B9: 7,9 => UNS
* PRF # B9: 8 => SOL
* PRF # H1: 8,9 => SOL
* DIS # H1: 7 => CTR => H1: 8,9
* DIS # H6: 8,9 => CTR => H6: 7
* PRF # H6: 7 => SOL
* INC # B9: 8,9 => UNS
* INC # B9: 7 => UNS
* DIS # I1: 8,9 => CTR => I1: 7
* PRF # I1: 7 => SOL
* PRF # I4: 8,9 => SOL
* DIS # I4: 7 => CTR => I4: 8,9
* CNT  44 HDP CHAINS /  44 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # B3: 7,9 => UNS
* INC # C3: 7,9 => UNS
* INC # A6: 7,9 => UNS
* PRF # A6: 8 => SOL
* STA A6: 8
* CNT   4 HDP CHAINS /   4 HYP OPENED