Analysis of xx-top500-016-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 1.....8....2.7........3.5..43.....7....5..1.....6.....6..1......5.....3.....2.... initial

Autosolve

position: 175...8.33.2.75.1.....315.743.....752.75.31..5..6.73.262315.7...5.7..23.7..32..5. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # B2: 8,9 => CTR => B2: 4,6
* PRF # C3: 8,9 => SOL
* DIS # D3: 8,9 => CTR => D3: 2,4
* DIS # F1: 6,9 => CTR => F1: 2
* DIS # E8: 6,9 => CTR => E8: 8
* DIS # F4: 2,9 => CTR => F4: 8
* PRF # D1: 2,9 => SOL
* DIS # I5: 6,9 => CTR => I5: 4,8
* DIS # C4: 1,8 => CTR => C4: 6,9
* DIS # C8: 8,9 => CTR => C8: 1,4
* DIS # F8: 8,9 => CTR => F8: 4,6
* DIS # I8: 8,9 => CTR => I8: 1,4,6
* CNT  12 HDP CHAINS /  32 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 # B2: 8,9 => CTR => B2: 4,6
* PRF B2: 4,6 # C3: 8,9 => SOL
* STA B2: 4,6 + C3: 8,9
* CNT   2 HDP CHAINS /   3 HYP OPENED

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

Details

Positions

1.....8....2.7........3.5..43.....7....5..1.....6.....6..1......5.....3.....2.... initial
175...8.33.2.75.1.....315.743.....752.75.31..5..6.73.262315.7...5.7..23.7..32..5. autosolve
175962843342875619869431527436218975287593164591647382623154798954786231718329456 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (5)
A3: 8,9
E1: 6,9
D4: 2,9
G4: 6,9
A8: 8,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
E4,E6: 1.. / E4 = 1  =>  5 pairs (_) / E6 = 1  =>  0 pairs (X)
I8,I9: 1.. / I8 = 1  =>  5 pairs (_) / I9 = 1  => 10 pairs (_)
C4,E4: 1.. / C4 = 1  =>  0 pairs (X) / E4 = 1  =>  5 pairs (_)
C8,I8: 1.. / C8 = 1  => 10 pairs (_) / I8 = 1  =>  5 pairs (_)
B6,B9: 1.. / B6 = 1  =>  6 pairs (_) / B9 = 1  =>  6 pairs (_)
H1,H3: 2.. / H1 = 2  =>  0 pairs (X) / H3 = 2  => 15 pairs (_)
D4,F4: 2.. / D4 = 2  => 15 pairs (_) / F4 = 2  =>  0 pairs (X)
D3,H3: 2.. / D3 = 2  =>  0 pairs (X) / H3 = 2  => 15 pairs (_)
F1,F4: 2.. / F1 = 2  => 15 pairs (_) / F4 = 2  =>  0 pairs (X)
E5,E6: 4.. / E5 = 4  =>  9 pairs (_) / E6 = 4  =>  7 pairs (_)
D1,H1: 4.. / D1 = 4  =>  7 pairs (_) / H1 = 4  =>  0 pairs (*)
E6,H6: 4.. / E6 = 4  =>  7 pairs (_) / H6 = 4  =>  9 pairs (_)
G2,G9: 4.. / G2 = 4  =>  9 pairs (_) / G9 = 4  => 10 pairs (_)
E1,F1: 6.. / E1 = 6  =>  8 pairs (_) / F1 = 6  =>  0 pairs (X)
C4,B5: 6.. / C4 = 6  => 15 pairs (_) / B5 = 6  =>  0 pairs (X)
C4,G4: 6.. / C4 = 6  => 15 pairs (_) / G4 = 6  =>  0 pairs (X)
C3,C4: 6.. / C3 = 6  =>  0 pairs (X) / C4 = 6  => 15 pairs (_)
E1,E8: 6.. / E1 = 6  =>  8 pairs (_) / E8 = 6  =>  0 pairs (X)
H3,H5: 6.. / H3 = 6  =>  0 pairs (X) / H5 = 6  => 15 pairs (_)
D2,D3: 8.. / D2 = 8  =>  5 pairs (_) / D3 = 8  =>  0 pairs (X)
B2,D2: 8.. / B2 = 8  =>  0 pairs (X) / D2 = 8  =>  5 pairs (_)
A3,A8: 8.. / A3 = 8  =>  6 pairs (_) / A8 = 8  =>  0 pairs (X)
A3,A8: 9.. / A3 = 9  =>  0 pairs (X) / A8 = 9  =>  6 pairs (_)
* DURATION: 0:00:35.688519  START: 03:08:22.813974  END: 03:08:58.502493 2017-05-04
* CP COUNT: (23)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A3,A8,D4,E1,G4)
* 175...8.33.2.75.1.....315.743.....752.75.31..5..6.73.262315.7...5.7..23.7..32..5.
* PAIR A3: 8,9 BLK 1
B2: 8,9,4,6                              # reduction candidate for 8,9
B2: 8,9 => CTR
* 1754628933928754168649315274362189752875931645..6.73.262315.7..95178.23.74832.651
B2: 4,6                                  #  8 pairs
B3: 8,9,4,6                              # reduction candidate for 8,9
B3: 8,9                                  # 10 pairs
C3: 8,9,4,6                              # reduction candidate for 8,9
C3: 8,9 => SOLVED
* 175962843342875619869431527436218975287593164591647382623154798954786231718329456
C3: 4,6                                  #  6 pairs
* PAIR A3: 8,9 ROW 3
D3: 8,9,2,4                              # reduction candidate for 8,9
D3: 8,9 => CTR
* 1754628933928754168649315274362189752875931645..6.73.262315.7..95178.23.74832.651
D3: 2,4                                  #  7 pairs
* PAIR E1: 6,9 BLK 2
F1: 6,9,2                                # reduction candidate for 6,9
F1: 6,9 => CTR
* 175...8.33.2.75.16..6.315.743.9.26752675.31..5..6.73.262315.7...5.7..23.7..326.5.
F1: 2                                    # 15 pairs
* PAIR E1: 6,9 COL E
E8: 6,9,8                                # reduction candidate for 6,9
E8: 6,9 => CTR
* 175...8.33.2.75.1...6.315.743....6752675.31..5..6.73.262315.7...5.7..23.7..32..5.
E8: 8                                    # 15 pairs
* PAIR D4: 2,9 BLK 5
F4: 2,9,8                                # reduction candidate for 2,9
F4: 2,9 => CTR
* 175...8.33.2.75.1...6.315.743....6752675.31..5..6.73.262315.7...5.7..23.7..32..5.
F4: 8                                    # 15 pairs
* PAIR D4: 2,9 COL D
D1: 2,9,4                                # reduction candidate for 2,9
D1: 2,9 => SOLVED
* 175962843342875619869431527436218975287593164591647382623154798954786231718329456
D1: 4                                    #  7 pairs
D3: 2,9,4,8                              # reduction candidate for 2,9
D3: 2,9                                  #  7 pairs
* PAIR G4: 6,9 BLK 6
H5: 6,9,4,8                              # reduction candidate for 6,9
H5: 6,9                                  #  8 pairs
I5: 6,9,4,8                              # reduction candidate for 6,9
I5: 6,9 => CTR
* 1754..8233.2.75.1....2315674369...752.75.31..5..6.73.262315.79..5.7..23.7..32..5.
I5: 4,8                                  #  6 pairs
* PAIR G4: 6,9 ROW 4
C4: 6,9,1,8                              # reduction candidate for 6,9
C4: 1,8 => CTR
* 175...8.33.2.75.1...6.315.743....6752675.31..5..6.73.262315.7...5.7..23.7..32..5.
C4: 6,9                                  # 15 pairs
* PAIR G4: 6,9 COL G
G2: 6,9,4                                # reduction candidate for 6,9
G2: 6,9                                  # 10 pairs
G9: 6,9,4                                # reduction candidate for 6,9
G9: 6,9                                  #  9 pairs
* PAIR A8: 8,9 BLK 7
C8: 8,9,1,4                              # reduction candidate for 8,9
C8: 8,9 => CTR
* 175.968.33.2.75.1.....315.743.9.26752675.31..5..6.73.262315.7...5.7642317..32..56
C8: 1,4                                  #  6 pairs
B9: 8,9,1,4                              # reduction candidate for 8,9
B9: 8,9                                  #  9 pairs
C9: 8,9,1,4                              # reduction candidate for 8,9
C9: 8,9                                  #  8 pairs
* PAIR A8: 8,9 ROW 8
E8: 8,9,6                                # reduction candidate for 8,9
E8: 8,9                                  #  8 pairs
F8: 8,9,4,6                              # reduction candidate for 8,9
F8: 8,9 => CTR
* 175.968.33.2.75.1.....315.743.9.26752675.31..5..6.73.262315.7...5.76.23.7..32..56
F8: 4,6                                  #  6 pairs
I8: 8,9,1,4,6                            # reduction candidate for 8,9
I8: 8,9 => CTR
* 175.968.33.2.7541.....315.743691..752.75.31..51.6.73.262315.7...5176423.7..32.651
I8: 1,4,6                                #  5 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-016-base-pr-000.dot
* REASONING
* DIS # B2: 8,9 => CTR => B2: 4,6
* PRF # C3: 8,9 => SOL
* DIS # D3: 8,9 => CTR => D3: 2,4
* DIS # F1: 6,9 => CTR => F1: 2
* DIS # E8: 6,9 => CTR => E8: 8
* DIS # F4: 2,9 => CTR => F4: 8
* PRF # D1: 2,9 => SOL
* DIS # I5: 6,9 => CTR => I5: 4,8
* DIS # C4: 1,8 => CTR => C4: 6,9
* DIS # C8: 8,9 => CTR => C8: 1,4
* DIS # F8: 8,9 => CTR => F8: 4,6
* DIS # I8: 8,9 => CTR => I8: 1,4,6
* CNT  12 HDP CHAINS /  32 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A3,A8,D4,E1,G4)
* 175...8.33.2.75.1.....315.743.....752.75.31..5..6.73.262315.7...5.7..23.7..32..5.
* PAIR A3: 8,9 BLK 1
B2: 8,9,4,6                              # reduction candidate for 8,9
B2: 8,9 => CTR
* 1754628933928754168649315274362189752875931645..6.73.262315.7..95178.23.74832.651
B3: 8,9,4,6                              # reduction candidate for 8,9
B3: 8,9                                  # 10 pairs
C3: 8,9,4,6                              # reduction candidate for 8,9
C3: 8,9 => SOLVED
* 175962843342875619869431527436218975287593164591647382623154798954786231718329456
* DURATION: 0:00:04.312290  START: 03:09:26.443094  END: 03:09:30.755384 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-016-base-pr-001.dot
* REASONING
* DIS # B2: 8,9 => CTR => B2: 4,6
* PRF B2: 4,6 # C3: 8,9 => SOL
* STA B2: 4,6 + C3: 8,9
* CNT   2 HDP CHAINS /   3 HYP OPENED

Header Info

Top 500 Minimum 17 016

solution: 175962843342875619869431527436218975287593164591647382623154798954786231718329456
info: 1310     FNBWXY   S8.f     44468

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

Solution

position: 175962843342875619869431527436218975287593164591647382623154798954786231718329456 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:

* DIS # B2: 8,9 => CTR => B2: 4,6
* INC # B2: 4,6 => UNS
* INC # B3: 8,9 => UNS
* PRF # C3: 8,9 => SOL
* INC # C3: 4,6 => UNS
* DIS # D3: 8,9 => CTR => D3: 2,4
* INC # D3: 2,4 => UNS
* DIS # F1: 6,9 => CTR => F1: 2
* INC # F1: 2 => UNS
* DIS # E8: 6,9 => CTR => E8: 8
* INC # E8: 8 => UNS
* DIS # F4: 2,9 => CTR => F4: 8
* INC # F4: 8 => UNS
* PRF # D1: 2,9 => SOL
* INC # D1: 4 => UNS
* INC # D3: 2,9 => UNS
* INC # H5: 6,9 => UNS
* DIS # I5: 6,9 => CTR => I5: 4,8
* INC # I5: 4,8 => UNS
* INC # C4: 6,9 => UNS
* DIS # C4: 1,8 => CTR => C4: 6,9
* INC # G2: 6,9 => UNS
* INC # G9: 6,9 => UNS
* DIS # C8: 8,9 => CTR => C8: 1,4
* INC # C8: 1,4 => UNS
* INC # B9: 8,9 => UNS
* INC # C9: 8,9 => UNS
* INC # E8: 8,9 => UNS
* DIS # F8: 8,9 => CTR => F8: 4,6
* INC # F8: 4,6 => UNS
* DIS # I8: 8,9 => CTR => I8: 1,4,6
* INC # I8: 1,4,6 => UNS
* CNT  32 HDP CHAINS /  32 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # B2: 8,9 => CTR => B2: 4,6
* INC B2: 4,6 # B3: 8,9 => UNS
* PRF B2: 4,6 # C3: 8,9 => SOL
* STA B2: 4,6 + C3: 8,9
* CNT   3 HDP CHAINS /   3 HYP OPENED