Analysis of xx-top500-371-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 17.....4.2..8........6......38.....6....1..3...4......5.....2.8...3...........7.. initial

Autosolve

position: 17653.84.24.8..36.38.6......384..1.6652.1843..14.63.8.5631..2988.73..6144.1.86753 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # I2: 5,9 => SOL
* DIS # I2: 1,7 => CTR => I2: 5,9
* DIS # I2: 7,9 => CTR => I2: 1,5
* DIS # F3: 1,7 => CTR => F3: 4
* DIS # I2: 1,7 => CTR => I2: 5,9
* PRF # I2: 5,9 => SOL
* DIS # I6: 2,9 => CTR => I6: 5,7
* PRF # I6: 5,7 => SOL
* PRF # I2: 5,9 => SOL
* DIS # I2: 1,7 => CTR => I2: 5,9
* DIS # I3: 2,7 => CTR => I3: 1
* DIS # E3: 4 => CTR => E3: 2,7
* DIS # D6: 7,9 => CTR => D6: 2
* PRF # D6: 2 => SOL
* PRF # I6: 7,9 => SOL
* DIS # D6: 7,9 => CTR => D6: 2
* PRF # D6: 2 => SOL
* PRF # I6: 2,7 => SOL
* DIS # I6: 5,9 => CTR => I6: 2,7
* PRF # I6: 7,9 => SOL
* DIS # I2: 7,9 => CTR => I2: 1,5
* DIS # I6: 5,9 => CTR => I6: 2,7
* PRF # I6: 2,7 => SOL
* DIS # E3: 4,7 => CTR => E3: 2
* PRF # E3: 2 => SOL
* DIS # F3: 1 => CTR => F3: 4,7
* PRF # D6: 2,9 => SOL
* DIS # D6: 7 => CTR => D6: 2,9
* CNT  28 HDP CHAINS /  42 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 # I2: 5,9 => SOL
* STA I2: 5,9
* CNT   1 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

17.....4.2..8........6......38.....6....1..3...4......5.....2.8...3...........7.. initial
17653.84.24.8..36.38.6......384..1.6652.1843..14.63.8.5631..2988.73..6144.1.86753 autosolve
176539842249871365385624971738495126652718439914263587563147298897352614421986753 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (19)
C2: 5,9
C3: 5,9
F1: 2,9
E2: 7,9
F2: 1,7
I1: 2,9
G3: 5,9
H3: 2,7
A4: 7,9
A6: 7,9
D5: 7,9
H4: 2,7
I5: 7,9
G6: 5,9
B8: 2,9
B9: 2,9
E7: 4,7
F7: 4,7
D9: 2,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
F2,F3: 1.. / F2 = 1  => 19 pairs (_) / F3 = 1  =>  0 pairs (X)
I2,I3: 1.. / I2 = 1  =>  0 pairs (X) / I3 = 1  => 19 pairs (_)
F2,I2: 1.. / F2 = 1  => 19 pairs (_) / I2 = 1  =>  0 pairs (X)
F3,I3: 1.. / F3 = 1  =>  0 pairs (X) / I3 = 1  => 19 pairs (_)
F1,E3: 2.. / F1 = 2  =>  0 pairs (X) / E3 = 2  =>  0 pairs (_)
H4,I6: 2.. / H4 = 2  =>  0 pairs (*) / I6 = 2  =>  0 pairs (X)
B8,B9: 2.. / B8 = 2  =>  0 pairs (X) / B9 = 2  =>  0 pairs (_)
F1,I1: 2.. / F1 = 2  =>  0 pairs (X) / I1 = 2  =>  0 pairs (_)
D6,I6: 2.. / D6 = 2  =>  0 pairs (*) / I6 = 2  =>  0 pairs (X)
B9,D9: 2.. / B9 = 2  =>  0 pairs (*) / D9 = 2  =>  0 pairs (X)
D6,D9: 2.. / D6 = 2  =>  0 pairs (*) / D9 = 2  =>  0 pairs (X)
H3,H4: 2.. / H3 = 2  =>  0 pairs (X) / H4 = 2  =>  0 pairs (_)
E3,F3: 4.. / E3 = 4  =>  0 pairs (X) / F3 = 4  => 17 pairs (_)
E7,F7: 4.. / E7 = 4  => 17 pairs (_) / F7 = 4  =>  0 pairs (X)
E3,E7: 4.. / E3 = 4  =>  0 pairs (X) / E7 = 4  => 17 pairs (_)
F3,F7: 4.. / F3 = 4  => 17 pairs (_) / F7 = 4  =>  0 pairs (X)
C2,C3: 5.. / C2 = 5  =>  0 pairs (X) / C3 = 5  =>  0 pairs (_)
I2,G3: 5.. / I2 = 5  =>  0 pairs (*) / G3 = 5  =>  0 pairs (X)
E4,F4: 5.. / E4 = 5  => 21 pairs (_) / F4 = 5  => 21 pairs (_)
G6,I6: 5.. / G6 = 5  =>  0 pairs (*) / I6 = 5  =>  0 pairs (X)
E8,F8: 5.. / E8 = 5  => 21 pairs (_) / F8 = 5  => 21 pairs (_)
C2,I2: 5.. / C2 = 5  =>  0 pairs (X) / I2 = 5  =>  0 pairs (_)
C3,G3: 5.. / C3 = 5  =>  0 pairs (*) / G3 = 5  =>  0 pairs (X)
E4,E8: 5.. / E4 = 5  => 21 pairs (_) / E8 = 5  => 21 pairs (_)
F4,F8: 5.. / F4 = 5  => 21 pairs (_) / F8 = 5  => 21 pairs (_)
G3,G6: 5.. / G3 = 5  =>  0 pairs (X) / G6 = 5  =>  0 pairs (_)
I2,I6: 5.. / I2 = 5  =>  0 pairs (*) / I6 = 5  =>  0 pairs (X)
A4,A6: 7.. / A4 = 7  =>  0 pairs (*) / A6 = 7  =>  0 pairs (X)
D5,D6: 7.. / D5 = 7  =>  0 pairs (*) / D6 = 7  =>  0 pairs (X)
E7,F7: 7.. / E7 = 7  =>  0 pairs (X) / F7 = 7  => 17 pairs (_)
A4,H4: 7.. / A4 = 7  =>  0 pairs (*) / H4 = 7  =>  0 pairs (X)
D5,I5: 7.. / D5 = 7  =>  0 pairs (*) / I5 = 7  =>  0 pairs (X)
H3,H4: 7.. / H3 = 7  =>  0 pairs (*) / H4 = 7  =>  0 pairs (X)
C2,C3: 9.. / C2 = 9  =>  0 pairs (*) / C3 = 9  =>  0 pairs (X)
F1,E2: 9.. / F1 = 9  =>  0 pairs (*) / E2 = 9  =>  0 pairs (X)
A4,A6: 9.. / A4 = 9  =>  0 pairs (X) / A6 = 9  =>  0 pairs (_)
B8,B9: 9.. / B8 = 9  =>  0 pairs (*) / B9 = 9  =>  0 pairs (X)
F1,I1: 9.. / F1 = 9  =>  0 pairs (*) / I1 = 9  =>  0 pairs (X)
C3,G3: 9.. / C3 = 9  =>  0 pairs (X) / G3 = 9  =>  0 pairs (_)
D5,I5: 9.. / D5 = 9  =>  0 pairs (X) / I5 = 9  =>  0 pairs (_)
B9,D9: 9.. / B9 = 9  =>  0 pairs (X) / D9 = 9  =>  0 pairs (_)
G3,G6: 9.. / G3 = 9  =>  0 pairs (*) / G6 = 9  =>  0 pairs (X)
* DURATION: 0:01:15.961645  START: 15:32:12.529171  END: 15:33:28.490816 2017-05-04
* CP COUNT: (42)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A4,A6,B8,B9,C2,C3,D5,D9,E2,E7,F1,F2,F7,G3,G6,H3,H4,I1,I5)
* 17653.84.24.8..36.38.6......384..1.6652.1843..14.63.8.5631..2988.73..6144.1.86753
* PAIR C2: 5,9 ROW 2
I2: 5,9,1,7                              # reduction candidate for 5,9
I2: 5,9 => SOLVED
* 176539842249871365385624971738495126652718439914263587563147298897352614421986753
I2: 1,7 => CTR
* 17653284924589.36.3896..5.29384.51.6652.1843..14.639855631..2988.73..6144.1.86753
* PAIR F1: 2,9 COL F
F4: 2,9,5                                # reduction candidate for 2,9
F4: 2,9                                  # 21 pairs
F8: 2,9,5                                # reduction candidate for 2,9
F8: 2,9                                  # 21 pairs
* PAIR E2: 7,9 ROW 2
I2: 7,9,1,5                              # reduction candidate for 7,9
I2: 7,9 => CTR
* 17653.8422458.1369389624571.384..1.6652.1843..14.639855631..2988.73..6144.1.86753
I2: 1,5                                  # 22 pairs
* PAIR F2: 1,7 BLK 2
F3: 1,7,4                                # reduction candidate for 1,7
F3: 1,7 => CTR
* 17653284924.89.36.38964.5...384..1.6652918437.1476398.5631742988.73..6144.1.86753
F3: 4                                    # 17 pairs
* PAIR F2: 1,7 ROW 2
I2: 1,7,5,9                              # reduction candidate for 1,7
I2: 1,7 => CTR
* 17653284924589.36.3896..5.29384.51.6652.1843..14.639855631..2988.73..6144.1.86753
I2: 5,9 => SOLVED
* 176539842249871365385624971738495126652718439914263587563147298897352614421986753
* PAIR I1: 2,9 COL I
I6: 2,9,5,7                              # reduction candidate for 2,9
I6: 2,9 => CTR
* 17653.84.24.8..3653856..9.1.384..1.6652.18437.1476358.5631..2988.73..6144.1.86753
I6: 5,7 => SOLVED
* 176539842249871365385624971738495126652718439914263587563147298897352614421986753
* PAIR G3: 5,9 BLK 3
I2: 5,9,1,7                              # reduction candidate for 5,9
I2: 5,9 => SOLVED
* 176539842249871365385624971738495126652718439914263587563147298897352614421986753
I2: 1,7 => CTR
* 17653284924589.36.3896..5.29384.51.6652.1843..14.639855631..2988.73..6144.1.86753
* PAIR H3: 2,7 BLK 3
I3: 2,7,1                                # reduction candidate for 2,7
I3: 2,7 => CTR
* 17653.8492458973613896415.29384..1.6652.1843..14.639855631.42988.73..6144.1.86753
I3: 1                                    # 19 pairs
* PAIR H3: 2,7 ROW 3
E3: 2,7,4                                # reduction candidate for 2,7
E3: 4 => CTR
* 17653284924.89.36.38964.5...384..1.6652918437.1476398.5631..2988.73..6144.1.86753
E3: 2,7                                  # 17 pairs
* PAIR A6: 7,9 ROW 6
D6: 7,9,2                                # reduction candidate for 7,9
D6: 7,9 => CTR
* 17653284924.89.36538.6......384..1.6652.1843..14.63.825631..2988.73..6144.1286753
D6: 2 => SOLVED
* 176539842249871365385624971738495126652718439914263587563147298897352614421986753
I6: 7,9,2,5                              # reduction candidate for 7,9
I6: 7,9 => SOLVED
* 176539842249871365385624971738495126652718439914263587563147298897352614421986753
I6: 2,5                                  # 20 pairs
* PAIR D5: 7,9 BLK 5
D6: 7,9,2                                # reduction candidate for 7,9
D6: 7,9 => CTR
* 17653284924.89.36538.6......384..1.6652.1843..14.63.825631..2988.73..6144.1286753
D6: 2 => SOLVED
* 176539842249871365385624971738495126652718439914263587563147298897352614421986753
* PAIR H4: 2,7 BLK 6
I6: 2,7,5,9                              # reduction candidate for 2,7
I6: 2,7 => SOLVED
* 176539842249871365385624971738495126652718439914263587563147298897352614421986753
I6: 5,9 => CTR
* 17653.84.24.8..36.38.6......384..126652.18437.14.63.8.5631..2988.73..6144.1.86753
* PAIR I5: 7,9 BLK 6
I6: 7,9,2,5                              # reduction candidate for 7,9
I6: 7,9 => SOLVED
* 176539842249871365385624971738495126652718439914263587563147298897352614421986753
I6: 2,5                                  # 20 pairs
* PAIR I5: 7,9 COL I
I2: 7,9,1,5                              # reduction candidate for 7,9
I2: 7,9 => CTR
* 17653.8422458.1369389624571.384..1.6652.1843..14.639855631..2988.73..6144.1.86753
I2: 1,5                                  # 22 pairs
* PAIR G6: 5,9 BLK 6
I6: 5,9,2,7                              # reduction candidate for 5,9
I6: 5,9 => CTR
* 17653.84.24.8..36.38.6......384..126652.18437.14.63.8.5631..2988.73..6144.1.86753
I6: 2,7 => SOLVED
* 176539842249871365385624971738495126652718439914263587563147298897352614421986753
* PAIR B8: 2,9 ROW 8
E8: 2,9,5                                # reduction candidate for 2,9
E8: 2,9                                  # 21 pairs
F8: 2,9,5                                # reduction candidate for 2,9
F8: 2,9                                  # 21 pairs
* PAIR E7: 4,7 COL E
E3: 4,7,2                                # reduction candidate for 4,7
E3: 4,7 => CTR
* 17653284924.89.36.3896..5...384..1.6652918437.1476398.5631..2988.73..6144.1.86753
E3: 2 => SOLVED
* 176539842249871365385624971738495126652718439914263587563147298897352614421986753
* PAIR F7: 4,7 COL F
F3: 4,7,1                                # reduction candidate for 4,7
F3: 1 => CTR
* 17653284924.8973613896415...384..1.6652918437.1476398.5631742988.73..6144.1.86753
F3: 4,7                                  # 19 pairs
* PAIR D9: 2,9 BLK 8
E8: 2,9,5                                # reduction candidate for 2,9
E8: 2,9                                  # 21 pairs
F8: 2,9,5                                # reduction candidate for 2,9
F8: 2,9                                  # 21 pairs
* PAIR D9: 2,9 COL D
D6: 2,9,7                                # reduction candidate for 2,9
D6: 2,9 => SOLVED
* 176539842249871365385624971738495126652718439914263587563147298897352614421986753
D6: 7 => CTR
* 17653284924.89.36538.6......384..1.6652.1843..14763.825631..2988.73..6144.1286753
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-371-base-pr-000.dot
* REASONING
* PRF # I2: 5,9 => SOL
* DIS # I2: 1,7 => CTR => I2: 5,9
* DIS # I2: 7,9 => CTR => I2: 1,5
* DIS # F3: 1,7 => CTR => F3: 4
* DIS # I2: 1,7 => CTR => I2: 5,9
* PRF # I2: 5,9 => SOL
* DIS # I6: 2,9 => CTR => I6: 5,7
* PRF # I6: 5,7 => SOL
* PRF # I2: 5,9 => SOL
* DIS # I2: 1,7 => CTR => I2: 5,9
* DIS # I3: 2,7 => CTR => I3: 1
* DIS # E3: 4 => CTR => E3: 2,7
* DIS # D6: 7,9 => CTR => D6: 2
* PRF # D6: 2 => SOL
* PRF # I6: 7,9 => SOL
* DIS # D6: 7,9 => CTR => D6: 2
* PRF # D6: 2 => SOL
* PRF # I6: 2,7 => SOL
* DIS # I6: 5,9 => CTR => I6: 2,7
* PRF # I6: 7,9 => SOL
* DIS # I2: 7,9 => CTR => I2: 1,5
* DIS # I6: 5,9 => CTR => I6: 2,7
* PRF # I6: 2,7 => SOL
* DIS # E3: 4,7 => CTR => E3: 2
* PRF # E3: 2 => SOL
* DIS # F3: 1 => CTR => F3: 4,7
* PRF # D6: 2,9 => SOL
* DIS # D6: 7 => CTR => D6: 2,9
* CNT  28 HDP CHAINS /  42 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A4,A6,B8,B9,C2,C3,D5,D9,E2,E7,F1,F2,F7,G3,G6,H3,H4,I1,I5)
* 17653.84.24.8..36.38.6......384..1.6652.1843..14.63.8.5631..2988.73..6144.1.86753
* PAIR C2: 5,9 ROW 2
I2: 5,9,1,7                              # reduction candidate for 5,9
I2: 5,9 => SOLVED
* 176539842249871365385624971738495126652718439914263587563147298897352614421986753
* DURATION: 0:00:02.252758  START: 15:34:16.784521  END: 15:34:19.037279 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-371-base-pr-001.dot
* REASONING
* PRF # I2: 5,9 => SOL
* STA I2: 5,9
* CNT   1 HDP CHAINS /   1 HYP OPENED

Header Info

Top 500 Minimum 17 371

solution: 176539842249871365385624971738495126652718439914263587563147298897352614421986753
info: 5955     FNBTWXY  S8.f     42030

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

Solution

position: 176539842249871365385624971738495126652718439914263587563147298897352614421986753 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 # I2: 5,9 => SOL
* DIS # I2: 1,7 => CTR => I2: 5,9
* INC # F4: 2,9 => UNS
* INC # F8: 2,9 => UNS
* DIS # I2: 7,9 => CTR => I2: 1,5
* INC # I2: 1,5 => UNS
* DIS # F3: 1,7 => CTR => F3: 4
* INC # F3: 4 => UNS
* DIS # I2: 1,7 => CTR => I2: 5,9
* PRF # I2: 5,9 => SOL
* DIS # I6: 2,9 => CTR => I6: 5,7
* PRF # I6: 5,7 => SOL
* PRF # I2: 5,9 => SOL
* DIS # I2: 1,7 => CTR => I2: 5,9
* DIS # I3: 2,7 => CTR => I3: 1
* INC # I3: 1 => UNS
* INC # E3: 2,7 => UNS
* DIS # E3: 4 => CTR => E3: 2,7
* DIS # D6: 7,9 => CTR => D6: 2
* PRF # D6: 2 => SOL
* PRF # I6: 7,9 => SOL
* INC # I6: 2,5 => UNS
* DIS # D6: 7,9 => CTR => D6: 2
* PRF # D6: 2 => SOL
* PRF # I6: 2,7 => SOL
* DIS # I6: 5,9 => CTR => I6: 2,7
* PRF # I6: 7,9 => SOL
* INC # I6: 2,5 => UNS
* DIS # I2: 7,9 => CTR => I2: 1,5
* INC # I2: 1,5 => UNS
* DIS # I6: 5,9 => CTR => I6: 2,7
* PRF # I6: 2,7 => SOL
* INC # E8: 2,9 => UNS
* INC # F8: 2,9 => UNS
* DIS # E3: 4,7 => CTR => E3: 2
* PRF # E3: 2 => SOL
* INC # F3: 4,7 => UNS
* DIS # F3: 1 => CTR => F3: 4,7
* INC # E8: 2,9 => UNS
* INC # F8: 2,9 => UNS
* PRF # D6: 2,9 => SOL
* DIS # D6: 7 => CTR => D6: 2,9
* CNT  42 HDP CHAINS /  42 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* PRF # I2: 5,9 => SOL
* STA I2: 5,9
* CNT   1 HDP CHAINS /   1 HYP OPENED