Analysis of xx-top500-348-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 4.....7..3..2.........1.....1..4..5...6..32..............6....1.4.....8.2....7... initial

Autosolve

position: 4.1...7..3..27.14.6..41.....1..4..5...6..3214..4..1......6.4..114....68.26.1.74.. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # E1: 5,9 => CTR => E1: 3,6
* DIS # E9: 3,9 => CTR => E9: 5,8
* DIS # H6: 3,9 => CTR => H6: 6,7
* CNT   3 HDP CHAINS /  17 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 # E1: 5,9 => CTR => E1: 3,6
* DIS E1: 3,6 # E9: 3,9 => CTR => E9: 5,8
* DIS E1: 3,6 + E9: 5,8 # H6: 3,9 => CTR => H6: 6,7
* DIS E1: 3,6 + E9: 5,8 + H6: 6,7 # H3: 2 => CTR => H3: 3,9
* DIS E1: 3,6 + E9: 5,8 + H6: 6,7 + H3: 3,9 # I6: 6,7 => CTR => I6: 3,8,9
* DIS E1: 3,6 + E9: 5,8 + H6: 6,7 + H3: 3,9 + I6: 3,8,9 # E7: 5,8 => CTR => E7: 2,3,9
* PRF E1: 3,6 + E9: 5,8 + H6: 6,7 + H3: 3,9 + I6: 3,8,9 + E7: 2,3,9 # I1: 2,6 => SOL
* STA E1: 3,6 + E9: 5,8 + H6: 6,7 + H3: 3,9 + I6: 3,8,9 + E7: 2,3,9 + I1: 2,6
* CNT   7 HDP CHAINS /  47 HYP OPENED

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

Details

Positions

4.....7..3..2.........1.....1..4..5...6..32..............6....1.4.....8.2....7... initial
4.1...7..3..27.14.6..41.....1..4..5...6..3214..4..1......6.4..114....68.26.1.74.. autosolve
491538762358276149672419835713842956986753214524961378837694521149325687265187493 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (8)
C4: 2,3
B6: 2,3
F4: 2,6
E5: 5,9
E6: 2,6
H7: 2,7
I8: 2,7
H9: 3,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
C4,B6: 2.. / C4 = 2  =>  0 pairs (X) / B6 = 2  =>  8 pairs (_)
F4,E6: 2.. / F4 = 2  =>  8 pairs (_) / E6 = 2  =>  0 pairs (X)
H7,I8: 2.. / H7 = 2  =>  8 pairs (_) / I8 = 2  =>  0 pairs (X)
C4,F4: 2.. / C4 = 2  =>  0 pairs (X) / F4 = 2  =>  8 pairs (_)
B6,E6: 2.. / B6 = 2  =>  8 pairs (_) / E6 = 2  =>  0 pairs (X)
E7,H7: 2.. / E7 = 2  =>  0 pairs (X) / H7 = 2  =>  8 pairs (_)
C3,C4: 2.. / C3 = 2  =>  8 pairs (_) / C4 = 2  =>  0 pairs (X)
F4,F8: 2.. / F4 = 2  =>  8 pairs (_) / F8 = 2  =>  0 pairs (X)
D1,E1: 3.. / D1 = 3  =>  9 pairs (_) / E1 = 3  =>  8 pairs (_)
C4,B6: 3.. / C4 = 3  =>  8 pairs (_) / B6 = 3  =>  0 pairs (X)
B6,B7: 3.. / B6 = 3  =>  0 pairs (X) / B7 = 3  =>  8 pairs (_)
D1,D8: 3.. / D1 = 3  =>  9 pairs (_) / D8 = 3  =>  8 pairs (_)
G7,I9: 5.. / G7 = 5  => 12 pairs (_) / I9 = 5  => 10 pairs (_)
A6,D6: 5.. / A6 = 5  =>  8 pairs (_) / D6 = 5  => 11 pairs (_)
G3,G7: 5.. / G3 = 5  => 10 pairs (_) / G7 = 5  => 12 pairs (_)
F4,E6: 6.. / F4 = 6  =>  0 pairs (X) / E6 = 6  =>  8 pairs (_)
F2,I2: 6.. / F2 = 6  =>  8 pairs (_) / I2 = 6  =>  0 pairs (X)
F4,I4: 6.. / F4 = 6  =>  0 pairs (X) / I4 = 6  =>  8 pairs (_)
E1,E6: 6.. / E1 = 6  =>  0 pairs (X) / E6 = 6  =>  8 pairs (_)
H1,H6: 6.. / H1 = 6  =>  8 pairs (_) / H6 = 6  =>  0 pairs (X)
B3,C3: 7.. / B3 = 7  =>  8 pairs (_) / C3 = 7  =>  0 pairs (X)
H7,I8: 7.. / H7 = 7  =>  0 pairs (X) / I8 = 7  =>  8 pairs (_)
C8,I8: 7.. / C8 = 7  =>  0 pairs (X) / I8 = 7  =>  8 pairs (_)
H6,H7: 7.. / H6 = 7  =>  8 pairs (_) / H7 = 7  =>  0 pairs (X)
E7,E9: 8.. / E7 = 8  => 14 pairs (_) / E9 = 8  =>  8 pairs (_)
C9,E9: 8.. / C9 = 8  => 14 pairs (_) / E9 = 8  =>  8 pairs (_)
* DURATION: 0:00:47.548912  START: 14:37:39.655859  END: 14:38:27.204771 2017-05-04
* CP COUNT: (26)
* CLUE FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B6,C4,E5,E6,F4,H7,H9,I8)
* 4.1...7..3..27.14.6..41.....1..4..5...6..3214..4..1......6.4..114....68.26.1.74..
* PAIR E5: 5,9 BLK 5
D5: 5,9,7,8                              # reduction candidate for 5,9
D5: 5,9                                  # 15 pairs
D6: 5,9,7,8                              # reduction candidate for 5,9
D6: 5,9                                  # 11 pairs
* PAIR E5: 5,9 ROW 5
A5: 5,9,7,8                              # reduction candidate for 5,9
A5: 5,9                                  # 12 pairs
B5: 5,9,7,8                              # reduction candidate for 5,9
B5: 5,9                                  # 12 pairs
* PAIR E5: 5,9 COL E
E1: 5,9,3,6                              # reduction candidate for 5,9
E1: 5,9 => CTR
* 4.13..76.3..27614.6..41.....1..42.56..6..3214.24.61....3.6.4..114..3.68226.1.74..
E1: 3,6                                  #  9 pairs
E7: 5,9,2,3,8                            # reduction candidate for 5,9
E7: 5,9                                  # 16 pairs
E8: 5,9,2,3                              # reduction candidate for 5,9
E8: 5,9                                  # 12 pairs
E9: 5,9,3,8                              # reduction candidate for 5,9
E9: 5,9                                  # 14 pairs
* PAIR H9: 3,9 BLK 9
G7: 3,9,5                                # reduction candidate for 3,9
G7: 3,9                                  # 10 pairs
I9: 3,9,5                                # reduction candidate for 3,9
I9: 3,9                                  # 12 pairs
* PAIR H9: 3,9 ROW 9
C9: 3,9,5,8                              # reduction candidate for 3,9
C9: 3,9                                  # 11 pairs
E9: 3,9,5,8                              # reduction candidate for 3,9
E9: 3,9 => CTR
* 4.1.3.7623.527614.6.241.593.13.42856.56..3214.24.61.7..3.684921149.25687268197435
E9: 5,8                                  #  9 pairs
* PAIR H9: 3,9 COL H
H3: 3,9,2                                # reduction candidate for 3,9
H3: 3,9                                  # 11 pairs
H6: 3,9,6,7                              # reduction candidate for 3,9
H6: 3,9 => CTR
* 4.1...76.3..27614.6..41.....1..42.56..6..3214.24.61..7.3.6.4.71147...68226.1.74..
H6: 6,7                                  #  9 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-348-base-pr-000.dot
* REASONING
* DIS # E1: 5,9 => CTR => E1: 3,6
* DIS # E9: 3,9 => CTR => E9: 5,8
* DIS # H6: 3,9 => CTR => H6: 6,7
* CNT   3 HDP CHAINS /  17 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B6,C4,E5,E6,F4,H7,H9,I8)
* 4.1...7..3..27.14.6..41.....1..4..5...6..3214..4..1......6.4..114....68.26.1.74..
* PAIR E5: 5,9 BLK 5
D5: 5,9,7,8                              # reduction candidate for 5,9
D5: 5,9                                  # 15 pairs
D6: 5,9,7,8                              # reduction candidate for 5,9
D6: 5,9                                  # 11 pairs
* PAIR E5: 5,9 ROW 5
A5: 5,9,7,8                              # reduction candidate for 5,9
A5: 5,9                                  # 12 pairs
B5: 5,9,7,8                              # reduction candidate for 5,9
B5: 5,9                                  # 12 pairs
* PAIR E5: 5,9 COL E
E1: 5,9,3,6                              # reduction candidate for 5,9
E1: 5,9 => CTR
* 4.13..76.3..27614.6..41.....1..42.56..6..3214.24.61....3.6.4..114..3.68226.1.74..
E7: 5,9,2,3,8                            # reduction candidate for 5,9
E7: 5,9                                  # 16 pairs
E8: 5,9,2,3                              # reduction candidate for 5,9
E8: 5,9                                  # 12 pairs
E9: 5,9,3,8                              # reduction candidate for 5,9
E9: 5,9                                  # 14 pairs
* PAIR RESTART
* PAIR E5: 5,9 BLK 5
D5: 5,9,7,8                              # reduction candidate for 5,9
D5: 5,9                                  # 16 pairs
D6: 5,9,7,8                              # reduction candidate for 5,9
D6: 5,9                                  # 12 pairs
* PAIR E5: 5,9 ROW 5
A5: 5,9,7,8                              # reduction candidate for 5,9
A5: 5,9                                  # 13 pairs
B5: 5,9,7,8                              # reduction candidate for 5,9
B5: 5,9                                  # 13 pairs
* PAIR E5: 5,9 COL E
E7: 5,9,2,3,8                            # reduction candidate for 5,9
E7: 5,9                                  # 16 pairs
E8: 5,9,2,3                              # reduction candidate for 5,9
E8: 5,9                                  # 12 pairs
E9: 5,9,3,8                              # reduction candidate for 5,9
E9: 5,9                                  # 14 pairs
* PAIR H9: 3,9 BLK 9
G7: 3,9,5                                # reduction candidate for 3,9
G7: 3,9                                  # 11 pairs
I9: 3,9,5                                # reduction candidate for 3,9
I9: 3,9                                  # 13 pairs
* PAIR H9: 3,9 ROW 9
C9: 3,9,5,8                              # reduction candidate for 3,9
C9: 3,9                                  # 12 pairs
E9: 3,9,5,8                              # reduction candidate for 3,9
E9: 3,9 => CTR
* 4.153.7623.527614.6.241.593.13.42856.56..3214.24.61.7..3.684921149.25687268197435
* RESTART
* PAIR H9: 3,9 ROW 9
C9: 3,9,5,8                              # reduction candidate for 3,9
C9: 5,8                                  # 13 pairs
C9: 3,9                                  # 12 pairs
* PAIR H9: 3,9 COL H
H3: 3,9,2                                # reduction candidate for 3,9
H3: 3,9                                  # 13 pairs
H6: 3,9,6,7                              # reduction candidate for 3,9
H6: 3,9 => CTR
* 4.1...76.3..27614.6..41.....1..42.56..6..3214.24.61..7.3.6.4.71147...68226.1.74..
* RESTART
* PAIR H9: 3,9 COL H
H3: 3,9,2                                # reduction candidate for 3,9
H3: 2 => CTR
* 4.1...7..3..27.14.6..41..2..12.46.5...6..3214.34.21......6.4.71147..268.26.1.74..
* PAIR RESTART
* PAIR H9: 3,9 BLK 9
G7: 3,9,5                                # reduction candidate for 3,9
G7: 3,9                                  # 15 pairs
I9: 3,9,5                                # reduction candidate for 3,9
I9: 3,9                                  # 16 pairs
* PAIR H9: 3,9 ROW 9
C9: 3,9,5,8                              # reduction candidate for 3,9
C9: 5,8                                  # 16 pairs
C9: 3,9                                  # 15 pairs

* LEVEL 0 PASS 1 ROUND 2 (AUTO SOLVE) (B6,C4,E1,E5,E6,E9,F4,H1,H3,H6,H7,H9,I8)
* 4.1...7..3..27.14.6..41.....1..4..5...6..3214..4..1......6.4..114....68.26.1.74..
* PAIR H1: 2,6 BLK 3
I1: 2,6,5,8,9                            # reduction candidate for 2,6
I1: 5,8,9                                # 13 pairs
I1: 2,6                                  #  9 pairs
* PAIR H3: 3,9 BLK 3
G3: 3,9,5,8                              # reduction candidate for 3,9
G3: 3,9                                  # 18 pairs
I3: 3,9,2,5,8                            # reduction candidate for 3,9
I3: 3,9                                  # 18 pairs
* PAIR E5: 5,9 BLK 5
D5: 5,9,7,8                              # reduction candidate for 5,9
D5: 5,9                                  # 20 pairs
D6: 5,9,7,8                              # reduction candidate for 5,9
D6: 5,9                                  # 16 pairs
* PAIR E5: 5,9 ROW 5
A5: 5,9,7,8                              # reduction candidate for 5,9
A5: 5,9                                  # 17 pairs
B5: 5,9,7,8                              # reduction candidate for 5,9
B5: 5,9                                  # 17 pairs
* PAIR E5: 5,9 COL E
E7: 5,9,2,3,8                            # reduction candidate for 5,9
E7: 5,9                                  # 16 pairs
E8: 5,9,2,3                              # reduction candidate for 5,9
E8: 5,9                                  # 15 pairs
* PAIR H6: 6,7 BLK 6
I4: 6,7,3,8,9                            # reduction candidate for 6,7
I4: 6,7                                  # 14 pairs
I6: 6,7,3,8,9                            # reduction candidate for 6,7
I6: 6,7 => CTR
* 4.1.6.72.3..27.1466..41.....1..46.5...6..3214.34.21.67...6.4.71147..268.26.1.74..
* RESTART
* PAIR E9: 5,8 BLK 8
E7: 5,8,2,3,9                            # reduction candidate for 5,8
E7: 5,8 => CTR
* 4.193.762398276145672415....13.42.56.86.93214.24.61.7.837654.2114532968726.1.74..
* PAIR H9: 3,9 BLK 9
G7: 3,9,5                                # reduction candidate for 3,9
G7: 3,9                                  # 17 pairs
I9: 3,9,5                                # reduction candidate for 3,9
I9: 3,9                                  # 15 pairs
* PAIR H9: 3,9 ROW 9
C9: 3,9,5                                # reduction candidate for 3,9
C9: 3,9                                  # 17 pairs
C9: 5                                    # 15 pairs

* LEVEL 0 PASS 1 ROUND 3 (AUTO SOLVE) (B6,C4,E1,E5,E6,F4,H1,H3,H6,H7,H9,I4,I8)
* 4.1...7..3..27.14.6..41.....1..4..5...6..3214..4..1......6.4..114....68.26.1874..
* PAIR H1: 2,6 BLK 3
I1: 2,6,5,8,9                            # reduction candidate for 2,6
I1: 2,6 => SOLVED
* 491538762358276149672419835713842956986753214524961378837694521149325687265187493
* DURATION: 0:00:49.559741  START: 14:38:43.867026  END: 14:39:33.426767 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-348-base-pr-001.dot
* REASONING
* DIS # E1: 5,9 => CTR => E1: 3,6
* DIS E1: 3,6 # E9: 3,9 => CTR => E9: 5,8
* DIS E1: 3,6 + E9: 5,8 # H6: 3,9 => CTR => H6: 6,7
* DIS E1: 3,6 + E9: 5,8 + H6: 6,7 # H3: 2 => CTR => H3: 3,9
* DIS E1: 3,6 + E9: 5,8 + H6: 6,7 + H3: 3,9 # I6: 6,7 => CTR => I6: 3,8,9
* DIS E1: 3,6 + E9: 5,8 + H6: 6,7 + H3: 3,9 + I6: 3,8,9 # E7: 5,8 => CTR => E7: 2,3,9
* PRF E1: 3,6 + E9: 5,8 + H6: 6,7 + H3: 3,9 + I6: 3,8,9 + E7: 2,3,9 # I1: 2,6 => SOL
* STA E1: 3,6 + E9: 5,8 + H6: 6,7 + H3: 3,9 + I6: 3,8,9 + E7: 2,3,9 + I1: 2,6
* CNT   7 HDP CHAINS /  47 HYP OPENED

Header Info

Top 500 Minimum 17 348

solution: 491538762358276149672419835713842956986753214524961378837694521149325687265187493
info: 4834     FNBTHWXY S8.f     45069

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

Solution

position: 491538762358276149672419835713842956986753214524961378837694521149325687265187493 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 # D5: 5,9 => UNS
* INC # D6: 5,9 => UNS
* INC # A5: 5,9 => UNS
* INC # B5: 5,9 => UNS
* DIS # E1: 5,9 => CTR => E1: 3,6
* INC # E1: 3,6 => UNS
* INC # E7: 5,9 => UNS
* INC # E8: 5,9 => UNS
* INC # E9: 5,9 => UNS
* INC # G7: 3,9 => UNS
* INC # I9: 3,9 => UNS
* INC # C9: 3,9 => UNS
* DIS # E9: 3,9 => CTR => E9: 5,8
* INC # E9: 5,8 => UNS
* INC # H3: 3,9 => UNS
* DIS # H6: 3,9 => CTR => H6: 6,7
* INC # H6: 6,7 => UNS
* CNT  17 HDP CHAINS /  17 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # D5: 5,9 => UNS
* INC # D6: 5,9 => UNS
* INC # A5: 5,9 => UNS
* INC # B5: 5,9 => UNS
* DIS # E1: 5,9 => CTR => E1: 3,6
* INC E1: 3,6 # E7: 5,9 => UNS
* INC E1: 3,6 # E8: 5,9 => UNS
* INC E1: 3,6 # E9: 5,9 => UNS
* INC E1: 3,6 # D5: 5,9 => UNS
* INC E1: 3,6 # D6: 5,9 => UNS
* INC E1: 3,6 # A5: 5,9 => UNS
* INC E1: 3,6 # B5: 5,9 => UNS
* INC E1: 3,6 # E7: 5,9 => UNS
* INC E1: 3,6 # E8: 5,9 => UNS
* INC E1: 3,6 # E9: 5,9 => UNS
* INC E1: 3,6 # G7: 3,9 => UNS
* INC E1: 3,6 # I9: 3,9 => UNS
* INC E1: 3,6 # C9: 3,9 => UNS
* DIS E1: 3,6 # E9: 3,9 => CTR => E9: 5,8
* INC E1: 3,6 + E9: 5,8 # C9: 3,9 => UNS
* INC E1: 3,6 + E9: 5,8 # C9: 5,8 => UNS
* INC E1: 3,6 + E9: 5,8 # H3: 3,9 => UNS
* DIS E1: 3,6 + E9: 5,8 # H6: 3,9 => CTR => H6: 6,7
* INC E1: 3,6 + E9: 5,8 + H6: 6,7 # H3: 3,9 => UNS
* DIS E1: 3,6 + E9: 5,8 + H6: 6,7 # H3: 2 => CTR => H3: 3,9
* INC E1: 3,6 + E9: 5,8 + H6: 6,7 + H3: 3,9 # G7: 3,9 => UNS
* INC E1: 3,6 + E9: 5,8 + H6: 6,7 + H3: 3,9 # I9: 3,9 => UNS
* INC E1: 3,6 + E9: 5,8 + H6: 6,7 + H3: 3,9 # C9: 3,9 => UNS
* INC E1: 3,6 + E9: 5,8 + H6: 6,7 + H3: 3,9 # C9: 5,8 => UNS
* INC E1: 3,6 + E9: 5,8 + H6: 6,7 + H3: 3,9 # I1: 2,6 => UNS
* INC E1: 3,6 + E9: 5,8 + H6: 6,7 + H3: 3,9 # I1: 5,8,9 => UNS
* INC E1: 3,6 + E9: 5,8 + H6: 6,7 + H3: 3,9 # G3: 3,9 => UNS
* INC E1: 3,6 + E9: 5,8 + H6: 6,7 + H3: 3,9 # I3: 3,9 => UNS
* INC E1: 3,6 + E9: 5,8 + H6: 6,7 + H3: 3,9 # D5: 5,9 => UNS
* INC E1: 3,6 + E9: 5,8 + H6: 6,7 + H3: 3,9 # D6: 5,9 => UNS
* INC E1: 3,6 + E9: 5,8 + H6: 6,7 + H3: 3,9 # A5: 5,9 => UNS
* INC E1: 3,6 + E9: 5,8 + H6: 6,7 + H3: 3,9 # B5: 5,9 => UNS
* INC E1: 3,6 + E9: 5,8 + H6: 6,7 + H3: 3,9 # E7: 5,9 => UNS
* INC E1: 3,6 + E9: 5,8 + H6: 6,7 + H3: 3,9 # E8: 5,9 => UNS
* INC E1: 3,6 + E9: 5,8 + H6: 6,7 + H3: 3,9 # I4: 6,7 => UNS
* DIS E1: 3,6 + E9: 5,8 + H6: 6,7 + H3: 3,9 # I6: 6,7 => CTR => I6: 3,8,9
* DIS E1: 3,6 + E9: 5,8 + H6: 6,7 + H3: 3,9 + I6: 3,8,9 # E7: 5,8 => CTR => E7: 2,3,9
* INC E1: 3,6 + E9: 5,8 + H6: 6,7 + H3: 3,9 + I6: 3,8,9 + E7: 2,3,9 # G7: 3,9 => UNS
* INC E1: 3,6 + E9: 5,8 + H6: 6,7 + H3: 3,9 + I6: 3,8,9 + E7: 2,3,9 # I9: 3,9 => UNS
* INC E1: 3,6 + E9: 5,8 + H6: 6,7 + H3: 3,9 + I6: 3,8,9 + E7: 2,3,9 # C9: 3,9 => UNS
* INC E1: 3,6 + E9: 5,8 + H6: 6,7 + H3: 3,9 + I6: 3,8,9 + E7: 2,3,9 # C9: 5 => UNS
* PRF E1: 3,6 + E9: 5,8 + H6: 6,7 + H3: 3,9 + I6: 3,8,9 + E7: 2,3,9 # I1: 2,6 => SOL
* STA E1: 3,6 + E9: 5,8 + H6: 6,7 + H3: 3,9 + I6: 3,8,9 + E7: 2,3,9 + I1: 2,6
* CNT  47 HDP CHAINS /  47 HYP OPENED