Analysis of xx-top500-235-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 6.....1.....5.3......7......2.1.........2.6....7.....334..8..........27........5. initial

Autosolve

position: 67...21352..5.37.653.76...2.231765.9.5.32.617167.5..23345287961.16.3527.7.26..35. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # C2: 8,9 => CTR => C2: 1,4
* DIS # H2: 4 => CTR => H2: 8,9
* DIS # D1: 4,9 => CTR => D1: 8
* DIS # C1: 8 => CTR => C1: 4,9
* DIS # H3: 4,8 => CTR => H3: 9
* DIS # A5: 9 => CTR => A5: 4,8
* DIS # A5: 8,9 => CTR => A5: 4
* PRF # A5: 4 => SOL
* DIS # C2: 8,9 => CTR => C2: 1,4
* PRF # F6: 4,8 => SOL
* DIS # A5: 9 => CTR => A5: 4,8
* DIS # H3: 4,8 => CTR => H3: 9
* PRF # F6: 4,8 => SOL
* DIS # A5: 8,9 => CTR => A5: 4
* PRF # A5: 4 => SOL
* DIS # D1: 4,9 => CTR => D1: 8
* CNT  16 HDP CHAINS /  47 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 # C2: 8,9 => CTR => C2: 1,4
* DIS C2: 1,4 # H2: 4 => CTR => H2: 8,9
* DIS C2: 1,4 + H2: 8,9 # D1: 4,9 => CTR => D1: 8
* DIS C2: 1,4 + H2: 8,9 + D1: 8 # H3: 4,8 => CTR => H3: 9
* PRF C2: 1,4 + H2: 8,9 + D1: 8 + H3: 9 => SOL
* STA C2: 1,4 + H2: 8,9 + D1: 8 + H3: 9
* CNT   5 HDP CHAINS /   9 HYP OPENED

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

Details

Positions

6.....1.....5.3......7......2.1.........2.6....7.....334..8..........27........5. initial
67...21352..5.37.653.76...2.231765.9.5.32.617167.5..23345287961.16.3527.7.26..35. autosolve
674892135291543786538761492823176549459328617167954823345287961916435278782619354 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (13)
B2: 8,9
E1: 4,9
G3: 4,8
A4: 4,8
C5: 8,9
F5: 4,8
H4: 4,8
G6: 4,8
A8: 8,9
B9: 8,9
D8: 4,9
I8: 4,8
I9: 4,8

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
C2,C3: 1.. / C2 = 1  => 17 pairs (_) / C3 = 1  => 14 pairs (_)
E2,F3: 1.. / E2 = 1  => 14 pairs (_) / F3 = 1  => 17 pairs (_)
E9,F9: 1.. / E9 = 1  => 17 pairs (_) / F9 = 1  => 14 pairs (_)
C2,E2: 1.. / C2 = 1  => 17 pairs (_) / E2 = 1  => 14 pairs (_)
C3,F3: 1.. / C3 = 1  => 14 pairs (_) / F3 = 1  => 17 pairs (_)
E2,E9: 1.. / E2 = 1  => 14 pairs (_) / E9 = 1  => 17 pairs (_)
F3,F9: 1.. / F3 = 1  => 17 pairs (_) / F9 = 1  => 14 pairs (_)
A4,A5: 4.. / A4 = 4  =>  0 pairs (X) / A5 = 4  =>  0 pairs (_)
H4,G6: 4.. / H4 = 4  =>  0 pairs (*) / G6 = 4  =>  0 pairs (X)
I8,I9: 4.. / I8 = 4  =>  0 pairs (X) / I9 = 4  => 15 pairs (_)
A4,H4: 4.. / A4 = 4  =>  0 pairs (X) / H4 = 4  =>  0 pairs (_)
A5,F5: 4.. / A5 = 4  =>  0 pairs (*) / F5 = 4  =>  0 pairs (X)
D8,I8: 4.. / D8 = 4  => 15 pairs (_) / I8 = 4  =>  0 pairs (X)
G3,G6: 4.. / G3 = 4  =>  0 pairs (*) / G6 = 4  =>  0 pairs (X)
D1,F3: 8.. / D1 = 8  => 15 pairs (_) / F3 = 8  =>  0 pairs (X)
H4,G6: 8.. / H4 = 8  =>  0 pairs (X) / G6 = 8  =>  0 pairs (_)
A8,B9: 8.. / A8 = 8  =>  0 pairs (X) / B9 = 8  => 15 pairs (_)
I8,I9: 8.. / I8 = 8  => 15 pairs (_) / I9 = 8  =>  0 pairs (X)
C1,D1: 8.. / C1 = 8  =>  0 pairs (X) / D1 = 8  => 15 pairs (_)
A4,H4: 8.. / A4 = 8  =>  0 pairs (*) / H4 = 8  =>  0 pairs (X)
A8,I8: 8.. / A8 = 8  =>  0 pairs (X) / I8 = 8  => 15 pairs (_)
B9,I9: 8.. / B9 = 8  => 15 pairs (_) / I9 = 8  =>  0 pairs (X)
B2,B9: 8.. / B2 = 8  =>  0 pairs (X) / B9 = 8  => 15 pairs (_)
D1,D6: 8.. / D1 = 8  => 15 pairs (_) / D6 = 8  =>  0 pairs (X)
G3,G6: 8.. / G3 = 8  =>  0 pairs (X) / G6 = 8  =>  0 pairs (_)
H2,H3: 9.. / H2 = 9  =>  0 pairs (X) / H3 = 9  => 14 pairs (_)
A5,C5: 9.. / A5 = 9  =>  0 pairs (X) / C5 = 9  => 15 pairs (_)
D6,F6: 9.. / D6 = 9  =>  0 pairs (*) / F6 = 9  =>  0 pairs (X)
A8,B9: 9.. / A8 = 9  => 15 pairs (_) / B9 = 9  =>  0 pairs (X)
A8,D8: 9.. / A8 = 9  => 15 pairs (_) / D8 = 9  =>  0 pairs (X)
A5,A8: 9.. / A5 = 9  =>  0 pairs (X) / A8 = 9  => 15 pairs (_)
B2,B9: 9.. / B2 = 9  => 15 pairs (_) / B9 = 9  =>  0 pairs (X)
* DURATION: 0:00:55.617899  START: 10:51:29.150857  END: 10:52:24.768756 2017-05-04
* CP COUNT: (32)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A4,A8,B2,B9,C5,D8,E1,F5,G3,G6,H4,I8,I9)
* 67...21352..5.37.653.76...2.231765.9.5.32.617167.5..23345287961.16.3527.7.26..35.
* PAIR B2: 8,9 BLK 1
C1: 8,9,4                                # reduction candidate for 8,9
C1: 8,9                                  # 17 pairs
C2: 8,9,1,4                              # reduction candidate for 8,9
C2: 8,9 => CTR
* 67...21352..513746531764892423176589.5.32861716745..23345287961.16.3527.7.26..35.
C2: 1,4                                  # 14 pairs
C3: 8,9,1,4                              # reduction candidate for 8,9
C3: 8,9                                  # 16 pairs
* PAIR B2: 8,9 ROW 2
H2: 8,9,4                                # reduction candidate for 8,9
H2: 4 => CTR
* 67.84213529.5.374653.76.892423176589.5.324617167.58423345287961.16.3527.7.26.935.
H2: 8,9                                  # 16 pairs
* PAIR E1: 4,9 BLK 2
D1: 4,9,8                                # reduction candidate for 4,9
D1: 4,9 => CTR
* 678..213529.5.378653.76849282317654945.32.617167.5..23345287961.16.3527.7.26..35.
D1: 8                                    # 15 pairs
E2: 4,9,1                                # reduction candidate for 4,9
E2: 4,9                                  # 17 pairs
F3: 4,9,1,8                              # reduction candidate for 4,9
F3: 4,9                                  # 18 pairs
* PAIR E1: 4,9 ROW 1
C1: 4,9,8                                # reduction candidate for 4,9
C1: 8 => CTR
* 678..213529.5.378653.76849282317654945.32.617167.5..23345287961.16.3527.7.26..35.
C1: 4,9                                  # 15 pairs
* PAIR E1: 4,9 COL E
E9: 4,9,1                                # reduction candidate for 4,9
E9: 1                                    # 17 pairs
E9: 4,9                                  # 14 pairs
* PAIR G3: 4,8 BLK 3
H2: 4,8,9                                # reduction candidate for 4,8
H2: 4,8                                  # 14 pairs
H3: 4,8,9                                # reduction candidate for 4,8
H3: 4,8 => CTR
* 67..9213528.5.3796539761..2.231765.9958324617167.5..23345287961.16.3527.7926..358
H3: 9                                    # 14 pairs
* PAIR G3: 4,8 ROW 3
C3: 4,8,1,9                              # reduction candidate for 4,8
C3: 4,8                                  # 19 pairs
F3: 4,8,1,9                              # reduction candidate for 4,8
F3: 4,8                                  # 18 pairs
* PAIR A4: 4,8 BLK 4
A5: 4,8,9                                # reduction candidate for 4,8
A5: 9 => CTR
* 67...21352..5.37.653.76...2423176589958324617167.5.423345287961816935274792641358
A5: 4,8                                  # 15 pairs
* PAIR C5: 8,9 BLK 4
A5: 8,9,4                                # reduction candidate for 8,9
A5: 8,9 => CTR
* 67.8.213529851374653.76.8.2423176589.5.3246171679584233452879619164352787826..354
A5: 4 => SOLVED
* 674892135291543786538761492823176549459328617167954823345287961916435278782619354
* PAIR C5: 8,9 COL C
C1: 8,9,4                                # reduction candidate for 8,9
C1: 8,9                                  # 17 pairs
C2: 8,9,1,4                              # reduction candidate for 8,9
C2: 8,9 => CTR
* 67...21352..513746531764892423176589.5.32861716745..23345287961.16.3527.7.26..35.
C2: 1,4                                  # 14 pairs
C3: 8,9,1,4                              # reduction candidate for 8,9
C3: 8,9                                  # 16 pairs
* PAIR F5: 4,8 BLK 5
D6: 4,8,9                                # reduction candidate for 4,8
D6: 4,8                                  # 15 pairs
F6: 4,8,9                                # reduction candidate for 4,8
F6: 4,8 => SOLVED
* 674892135291543786538761492823176549459328617167954823345287961916435278782619354
F6: 9                                    # 15 pairs
* PAIR F5: 4,8 ROW 5
A5: 4,8,9                                # reduction candidate for 4,8
A5: 9 => CTR
* 67...21352..5.37.653.76...2423176589958324617167.5.423345287961816935274792641358
A5: 4,8                                  # 15 pairs
* PAIR F5: 4,8 COL F
F3: 4,8,1,9                              # reduction candidate for 4,8
F3: 4,8                                  # 18 pairs
F3: 1,9                                  # 17 pairs
* PAIR H4: 4,8 COL H
H2: 4,8,9                                # reduction candidate for 4,8
H2: 4,8                                  # 14 pairs
H3: 4,8,9                                # reduction candidate for 4,8
H3: 4,8 => CTR
* 67..9213528.5.3796539761..2.231765.9958324617167.5..23345287961.16.3527.7926..358
H3: 9                                    # 14 pairs
* PAIR G6: 4,8 ROW 6
D6: 4,8,9                                # reduction candidate for 4,8
D6: 4,8                                  # 15 pairs
F6: 4,8,9                                # reduction candidate for 4,8
F6: 4,8 => SOLVED
* 674892135291543786538761492823176549459328617167954823345287961916435278782619354
F6: 9                                    # 15 pairs
* PAIR A8: 8,9 COL A
A5: 8,9,4                                # reduction candidate for 8,9
A5: 8,9 => CTR
* 67.8.213529851374653.76.8.2423176589.5.3246171679584233452879619164352787826..354
A5: 4 => SOLVED
* 674892135291543786538761492823176549459328617167954823345287961916435278782619354
* PAIR D8: 4,9 BLK 8
E9: 4,9,1                                # reduction candidate for 4,9
E9: 4,9                                  # 14 pairs
F9: 4,9,1                                # reduction candidate for 4,9
F9: 4,9                                  # 17 pairs
* PAIR D8: 4,9 COL D
D1: 4,9,8                                # reduction candidate for 4,9
D1: 4,9 => CTR
* 678..213529.5.378653.76849282317654945.32.617167.5..23345287961.16.3527.7.26..35.
D1: 8                                    # 15 pairs
D6: 4,9,8                                # reduction candidate for 4,9
D6: 4,9                                  # 15 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-235-base-pr-000.dot
* REASONING
* DIS # C2: 8,9 => CTR => C2: 1,4
* DIS # H2: 4 => CTR => H2: 8,9
* DIS # D1: 4,9 => CTR => D1: 8
* DIS # C1: 8 => CTR => C1: 4,9
* DIS # H3: 4,8 => CTR => H3: 9
* DIS # A5: 9 => CTR => A5: 4,8
* DIS # A5: 8,9 => CTR => A5: 4
* PRF # A5: 4 => SOL
* DIS # C2: 8,9 => CTR => C2: 1,4
* PRF # F6: 4,8 => SOL
* DIS # A5: 9 => CTR => A5: 4,8
* DIS # H3: 4,8 => CTR => H3: 9
* PRF # F6: 4,8 => SOL
* DIS # A5: 8,9 => CTR => A5: 4
* PRF # A5: 4 => SOL
* DIS # D1: 4,9 => CTR => D1: 8
* CNT  16 HDP CHAINS /  47 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A4,A8,B2,B9,C5,D8,E1,F5,G3,G6,H4,I8,I9)
* 67...21352..5.37.653.76...2.231765.9.5.32.617167.5..23345287961.16.3527.7.26..35.
* PAIR B2: 8,9 BLK 1
C1: 8,9,4                                # reduction candidate for 8,9
C1: 8,9                                  # 17 pairs
C2: 8,9,1,4                              # reduction candidate for 8,9
C2: 8,9 => CTR
* 67...21352..513746531764892423176589.5.32861716745..23345287961.16.3527.7.26..35.
C3: 8,9,1,4                              # reduction candidate for 8,9
C3: 8,9                                  # 16 pairs
* PAIR B2: 8,9 ROW 2
H2: 8,9,4                                # reduction candidate for 8,9
H2: 4 => CTR
* 67...213528.59374653.761892423176589.58324617167.5842334528796181693527.7.26..35.
* PAIR RESTART
* PAIR B2: 8,9 BLK 1
C1: 8,9,4                                # reduction candidate for 8,9
C1: 8,9                                  # 18 pairs
C3: 8,9,1                                # reduction candidate for 8,9
C3: 8,9                                  # 16 pairs
* PAIR E1: 4,9 BLK 2
D1: 4,9,8                                # reduction candidate for 4,9
D1: 4,9 => CTR
* 678..213529451378653176849282317654945.32.617167.5..23345287961.16.3527.7.26..35.
* PAIR G3: 4,8 BLK 3
H3: 4,8,9                                # reduction candidate for 4,8
H3: 4,8 => CTR
* 67.8.21352..5.379653.76...2.231765.9.5.32.617167.5..23345287961.16.3527.792614358
H3: 9 => SOLVED
* 674892135291543786538761492823176549459328617167954823345287961916435278782619354
* DURATION: 0:00:12.613780  START: 10:53:10.711873  END: 10:53:23.325653 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-235-base-pr-001.dot
* REASONING
* DIS # C2: 8,9 => CTR => C2: 1,4
* DIS C2: 1,4 # H2: 4 => CTR => H2: 8,9
* DIS C2: 1,4 + H2: 8,9 # D1: 4,9 => CTR => D1: 8
* DIS C2: 1,4 + H2: 8,9 + D1: 8 # H3: 4,8 => CTR => H3: 9
* PRF C2: 1,4 + H2: 8,9 + D1: 8 + H3: 9 => SOL
* STA C2: 1,4 + H2: 8,9 + D1: 8 + H3: 9
* CNT   5 HDP CHAINS /   9 HYP OPENED

Header Info

Top 500 Minimum 17 235

solution: 674892135291543786538761492823176549459328617167954823345287961916435278782619354
info: 2068     FNBWXY   S8.f     34170

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

Solution

position: 674892135291543786538761492823176549459328617167954823345287961916435278782619354 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 # C1: 8,9 => UNS
* DIS # C2: 8,9 => CTR => C2: 1,4
* INC # C2: 1,4 => UNS
* INC # C3: 8,9 => UNS
* INC # H2: 8,9 => UNS
* DIS # H2: 4 => CTR => H2: 8,9
* DIS # D1: 4,9 => CTR => D1: 8
* INC # D1: 8 => UNS
* INC # E2: 4,9 => UNS
* INC # F3: 4,9 => UNS
* INC # C1: 4,9 => UNS
* DIS # C1: 8 => CTR => C1: 4,9
* INC # E9: 4,9 => UNS
* INC # E9: 1 => UNS
* INC # H2: 4,8 => UNS
* DIS # H3: 4,8 => CTR => H3: 9
* INC # H3: 9 => UNS
* INC # C3: 4,8 => UNS
* INC # F3: 4,8 => UNS
* INC # A5: 4,8 => UNS
* DIS # A5: 9 => CTR => A5: 4,8
* DIS # A5: 8,9 => CTR => A5: 4
* PRF # A5: 4 => SOL
* INC # C1: 8,9 => UNS
* DIS # C2: 8,9 => CTR => C2: 1,4
* INC # C2: 1,4 => UNS
* INC # C3: 8,9 => UNS
* INC # D6: 4,8 => UNS
* PRF # F6: 4,8 => SOL
* INC # F6: 9 => UNS
* INC # A5: 4,8 => UNS
* DIS # A5: 9 => CTR => A5: 4,8
* INC # F3: 4,8 => UNS
* INC # F3: 1,9 => UNS
* INC # H2: 4,8 => UNS
* DIS # H3: 4,8 => CTR => H3: 9
* INC # H3: 9 => UNS
* INC # D6: 4,8 => UNS
* PRF # F6: 4,8 => SOL
* INC # F6: 9 => UNS
* DIS # A5: 8,9 => CTR => A5: 4
* PRF # A5: 4 => SOL
* INC # E9: 4,9 => UNS
* INC # F9: 4,9 => UNS
* DIS # D1: 4,9 => CTR => D1: 8
* INC # D1: 8 => UNS
* INC # D6: 4,9 => UNS
* CNT  47 HDP CHAINS /  47 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # C1: 8,9 => UNS
* DIS # C2: 8,9 => CTR => C2: 1,4
* INC C2: 1,4 # C3: 8,9 => UNS
* INC C2: 1,4 # H2: 8,9 => UNS
* DIS C2: 1,4 # H2: 4 => CTR => H2: 8,9
* INC C2: 1,4 + H2: 8,9 # C1: 8,9 => UNS
* INC C2: 1,4 + H2: 8,9 # C3: 8,9 => UNS
* DIS C2: 1,4 + H2: 8,9 # D1: 4,9 => CTR => D1: 8
* DIS C2: 1,4 + H2: 8,9 + D1: 8 # H3: 4,8 => CTR => H3: 9
* PRF C2: 1,4 + H2: 8,9 + D1: 8 + H3: 9 => SOL
* STA C2: 1,4 + H2: 8,9 + D1: 8 + H3: 9
* CNT  10 HDP CHAINS /   9 HYP OPENED