Analysis of xx-top500-243-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: ...5....1...3.2...89...........9.75.12.........3......6...7.4.......3.2.......... initial

Autosolve

position: 23.5.9.717.13.259.895.173.24..291753129735...5738..2196129784359...5312.35.12.9.. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # E1: 8 => CTR => E1: 4,6
* DIS # E2: 4,6 => CTR => E2: 8
* DIS # E2: 4,6 => CTR => E2: 8
* DIS # I2: 6,8 => CTR => I2: 4
* PRF # I2: 4 => SOL
* PRF # E1: 6,8 => SOL
* DIS # E1: 4 => CTR => E1: 6,8
* DIS # I2: 8 => CTR => I2: 4,6
* DIS # H5: 8 => CTR => H5: 4,6
* DIS # E2: 4,6 => CTR => E2: 8
* DIS # H5: 6,8 => CTR => H5: 4
* PRF # H5: 4 => SOL
* PRF # I5: 6,8 => SOL
* DIS # I5: 4 => CTR => I5: 6,8
* PRF # C8: 4,8 => SOL
* PRF # I9: 6,8 => SOL
* DIS # H5: 6,8 => CTR => H5: 4
* PRF # H5: 4 => SOL
* CNT  18 HDP CHAINS /  31 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: 8 => CTR => E1: 4,6
* PRF E1: 4,6 # C8: 4,8 => SOL
* STA E1: 4,6 + C8: 4,8
* CNT   2 HDP CHAINS /   3 HYP OPENED

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

Details

Positions

...5....1...3.2...89...........9.75.12.........3......6...7.4.......3.2.......... initial
23.5.9.717.13.259.895.173.24..291753129735...5738..2196129784359...5312.35.12.9.. autosolve
234569871761382594895417362486291753129735648573846219612978435948653127357124986 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (14)
C1: 4,6
B2: 4,6
D3: 4,6
G1: 6,8
H3: 4,6
B4: 6,8
C4: 6,8
E6: 4,6
F6: 4,6
G5: 6,8
B8: 4,8
D8: 4,6
F9: 4,6
H9: 6,8

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
C1,B2: 4.. / C1 = 4  =>  0 pairs (*) / B2 = 4  =>  0 pairs (X)
I2,H3: 4.. / I2 = 4  =>  0 pairs (*) / H3 = 4  =>  0 pairs (X)
E6,F6: 4.. / E6 = 4  =>  0 pairs (*) / F6 = 4  =>  0 pairs (X)
H5,I5: 4.. / H5 = 4  =>  0 pairs (*) / I5 = 4  =>  0 pairs (X)
D8,F9: 4.. / D8 = 4  =>  0 pairs (X) / F9 = 4  =>  0 pairs (_)
C1,E1: 4.. / C1 = 4  =>  0 pairs (*) / E1 = 4  =>  0 pairs (X)
D3,H3: 4.. / D3 = 4  =>  0 pairs (*) / H3 = 4  =>  0 pairs (X)
C9,F9: 4.. / C9 = 4  =>  0 pairs (X) / F9 = 4  =>  0 pairs (_)
B2,B8: 4.. / B2 = 4  =>  0 pairs (X) / B8 = 4  =>  0 pairs (_)
D3,D8: 4.. / D3 = 4  =>  0 pairs (*) / D8 = 4  =>  0 pairs (X)
F6,F9: 4.. / F6 = 4  =>  0 pairs (X) / F9 = 4  =>  0 pairs (_)
H3,H5: 4.. / H3 = 4  =>  0 pairs (X) / H5 = 4  =>  0 pairs (_)
I2,I5: 4.. / I2 = 4  =>  0 pairs (*) / I5 = 4  =>  0 pairs (X)
C1,B2: 6.. / C1 = 6  =>  0 pairs (X) / B2 = 6  =>  0 pairs (_)
B4,C4: 6.. / B4 = 6  =>  0 pairs (X) / C4 = 6  =>  0 pairs (_)
E6,F6: 6.. / E6 = 6  =>  0 pairs (X) / F6 = 6  =>  0 pairs (_)
D8,F9: 6.. / D8 = 6  =>  0 pairs (*) / F9 = 6  =>  0 pairs (X)
D3,H3: 6.. / D3 = 6  =>  0 pairs (X) / H3 = 6  =>  0 pairs (_)
D8,I8: 6.. / D8 = 6  =>  0 pairs (*) / I8 = 6  =>  0 pairs (X)
B2,B4: 6.. / B2 = 6  =>  0 pairs (*) / B4 = 6  =>  0 pairs (X)
C1,C4: 6.. / C1 = 6  =>  0 pairs (X) / C4 = 6  =>  0 pairs (_)
D3,D8: 6.. / D3 = 6  =>  0 pairs (X) / D8 = 6  =>  0 pairs (_)
F6,F9: 6.. / F6 = 6  =>  0 pairs (*) / F9 = 6  =>  0 pairs (X)
G1,G5: 6.. / G1 = 6  =>  0 pairs (X) / G5 = 6  => 16 pairs (_)
C8,C9: 7.. / C8 = 7  => 16 pairs (_) / C9 = 7  =>  0 pairs (*)
I8,I9: 7.. / I8 = 7  =>  0 pairs (*) / I9 = 7  =>  0 pairs (X)
C8,I8: 7.. / C8 = 7  => 16 pairs (_) / I8 = 7  =>  0 pairs (*)
C9,I9: 7.. / C9 = 7  =>  0 pairs (*) / I9 = 7  =>  0 pairs (X)
E1,E2: 8.. / E1 = 8  =>  0 pairs (X) / E2 = 8  => 16 pairs (_)
G1,I2: 8.. / G1 = 8  => 16 pairs (_) / I2 = 8  =>  0 pairs (X)
B4,C4: 8.. / B4 = 8  =>  0 pairs (*) / C4 = 8  =>  0 pairs (X)
E1,G1: 8.. / E1 = 8  =>  0 pairs (X) / G1 = 8  => 16 pairs (_)
E2,I2: 8.. / E2 = 8  => 16 pairs (_) / I2 = 8  =>  0 pairs (X)
B4,B8: 8.. / B4 = 8  =>  0 pairs (*) / B8 = 8  =>  0 pairs (X)
G1,G5: 8.. / G1 = 8  => 16 pairs (_) / G5 = 8  =>  0 pairs (X)
H5,H9: 8.. / H5 = 8  =>  0 pairs (X) / H9 = 8  => 19 pairs (_)
* DURATION: 0:00:58.727044  START: 11:06:22.480009  END: 11:07:21.207053 2017-05-04
* CP COUNT: (36)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B2,B4,B8,C1,C4,D3,D8,E6,F6,F9,G1,G5,H3,H9)
* 23.5.9.717.13.259.895.173.24..291753129735...5738..2196129784359...5312.35.12.9..
* PAIR C1: 4,6 ROW 1
E1: 4,6,8                                # reduction candidate for 4,6
E1: 8 => CTR
* 2345896717613425988956173424862917531297358645738642196129784359...5312.35.12.9..
E1: 4,6                                  # 16 pairs
* PAIR B2: 4,6 ROW 2
E2: 4,6,8                                # reduction candidate for 4,6
E2: 4,6 => CTR
* 23.58967176134259889561734248629175312973586457386421961297843594..5312.35.12.9..
E2: 8                                    # 16 pairs
I2: 4,6,8                                # reduction candidate for 4,6
I2: 4,6                                  # 16 pairs
* PAIR D3: 4,6 BLK 2
E1: 4,6,8                                # reduction candidate for 4,6
E1: 4,6                                  # 16 pairs
E2: 4,6,8                                # reduction candidate for 4,6
E2: 4,6 => CTR
* 23.58967176134259889561734248629175312973586457386421961297843594..5312.35.12.9..
E2: 8                                    # 16 pairs
* PAIR G1: 6,8 BLK 3
I2: 6,8,4                                # reduction candidate for 6,8
I2: 6,8 => CTR
* 2365498717.13.259.895.173424..291753129735..45738..2196129784359..453126354126987
I2: 4 => SOLVED
* 234569871761382594895417362486291753129735648573846219612978435948653127357124986
* PAIR G1: 6,8 ROW 1
E1: 6,8,4                                # reduction candidate for 6,8
E1: 6,8 => SOLVED
* 234569871761382594895417362486291753129735648573846219612978435948653127357124986
E1: 4 => CTR
* 23.5498717413825968956173.24..291753129735...5738..2196129784359...5312.35.12.9..
* PAIR H3: 4,6 BLK 3
I2: 4,6,8                                # reduction candidate for 4,6
I2: 8 => CTR
* 23.5.9.717.13.2598895.173424..2917531297358645738..2196129784359..453126354126987
I2: 4,6                                  # 16 pairs
* PAIR H3: 4,6 COL H
H5: 4,6,8                                # reduction candidate for 4,6
H5: 8 => CTR
* 23.5.9.717.13.259.895.173424..291753129735.845738..2196129784359..45312635.12.9..
H5: 4,6                                  # 19 pairs
* PAIR E6: 4,6 COL E
E1: 4,6,8                                # reduction candidate for 4,6
E1: 4,6                                  # 16 pairs
E2: 4,6,8                                # reduction candidate for 4,6
E2: 4,6 => CTR
* 23.58967176134259889561734248629175312973586457386421961297843594..5312.35.12.9..
E2: 8                                    # 16 pairs
* PAIR G5: 6,8 BLK 6
H5: 6,8,4                                # reduction candidate for 6,8
H5: 6,8 => CTR
* 2365498717.13.259.895.173424..291753129735..45738..2196129784359..453126354126987
H5: 4 => SOLVED
* 234569871761382594895417362486291753129735648573846219612978435948653127357124986
I5: 6,8,4                                # reduction candidate for 6,8
I5: 6,8 => SOLVED
* 234569871761382594895417362486291753129735648573846219612978435948653127357124986
I5: 4 => CTR
* 2365498717.13.259.895.173424..291753129735..45738..2196129784359..453126354126987
* PAIR B8: 4,8 BLK 7
C8: 4,8,7                                # reduction candidate for 4,8
C8: 4,8 => SOLVED
* 234569871761382594895417362486291753129735648573846219612978435948653127357124986
C8: 7                                    # 16 pairs
C9: 4,8,7                                # reduction candidate for 4,8
C9: 4,8                                  # 16 pairs
* PAIR H9: 6,8 BLK 9
I8: 6,8,7                                # reduction candidate for 6,8
I8: 6,8                                  # 16 pairs
I9: 6,8,7                                # reduction candidate for 6,8
I9: 6,8 => SOLVED
* 234569871761382594895417362486291753129735648573846219612978435948653127357124986
I9: 7                                    # 16 pairs
* PAIR H9: 6,8 COL H
H5: 6,8,4                                # reduction candidate for 6,8
H5: 6,8 => CTR
* 2365498717.13.259.895.173424..291753129735..45738..2196129784359..453126354126987
H5: 4 => SOLVED
* 234569871761382594895417362486291753129735648573846219612978435948653127357124986
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-243-base-pr-000.dot
* REASONING
* DIS # E1: 8 => CTR => E1: 4,6
* DIS # E2: 4,6 => CTR => E2: 8
* DIS # E2: 4,6 => CTR => E2: 8
* DIS # I2: 6,8 => CTR => I2: 4
* PRF # I2: 4 => SOL
* PRF # E1: 6,8 => SOL
* DIS # E1: 4 => CTR => E1: 6,8
* DIS # I2: 8 => CTR => I2: 4,6
* DIS # H5: 8 => CTR => H5: 4,6
* DIS # E2: 4,6 => CTR => E2: 8
* DIS # H5: 6,8 => CTR => H5: 4
* PRF # H5: 4 => SOL
* PRF # I5: 6,8 => SOL
* DIS # I5: 4 => CTR => I5: 6,8
* PRF # C8: 4,8 => SOL
* PRF # I9: 6,8 => SOL
* DIS # H5: 6,8 => CTR => H5: 4
* PRF # H5: 4 => SOL
* CNT  18 HDP CHAINS /  31 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B2,B4,B8,C1,C4,D3,D8,E6,F6,F9,G1,G5,H3,H9)
* 23.5.9.717.13.259.895.173.24..291753129735...5738..2196129784359...5312.35.12.9..
* PAIR C1: 4,6 ROW 1
E1: 4,6,8                                # reduction candidate for 4,6
E1: 8 => CTR
* 2345896717613425988956173424862917531297358645738642196129784359...5312.35.12.9..
* PAIR RESTART
* PAIR B8: 4,8 BLK 7
C8: 4,8,7                                # reduction candidate for 4,8
C8: 4,8 => SOLVED
* 234569871761382594895417362486291753129735648573846219612978435948653127357124986
* DURATION: 0:00:04.298193  START: 11:07:53.044815  END: 11:07:57.343008 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-243-base-pr-001.dot
* REASONING
* DIS # E1: 8 => CTR => E1: 4,6
* PRF E1: 4,6 # C8: 4,8 => SOL
* STA E1: 4,6 + C8: 4,8
* CNT   2 HDP CHAINS /   3 HYP OPENED

Header Info

Top 500 Minimum 17 243

solution: 234569871761382594895417362486291753129735648573846219612978435948653127357124986
info: 2069     FNWXY    S8.f     44349

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

Solution

position: 234569871761382594895417362486291753129735648573846219612978435948653127357124986 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 # E1: 4,6 => UNS
* DIS # E1: 8 => CTR => E1: 4,6
* DIS # E2: 4,6 => CTR => E2: 8
* INC # E2: 8 => UNS
* INC # I2: 4,6 => UNS
* INC # E1: 4,6 => UNS
* DIS # E2: 4,6 => CTR => E2: 8
* INC # E2: 8 => UNS
* DIS # I2: 6,8 => CTR => I2: 4
* PRF # I2: 4 => SOL
* PRF # E1: 6,8 => SOL
* DIS # E1: 4 => CTR => E1: 6,8
* INC # I2: 4,6 => UNS
* DIS # I2: 8 => CTR => I2: 4,6
* INC # H5: 4,6 => UNS
* DIS # H5: 8 => CTR => H5: 4,6
* INC # E1: 4,6 => UNS
* DIS # E2: 4,6 => CTR => E2: 8
* INC # E2: 8 => UNS
* DIS # H5: 6,8 => CTR => H5: 4
* PRF # H5: 4 => SOL
* PRF # I5: 6,8 => SOL
* DIS # I5: 4 => CTR => I5: 6,8
* PRF # C8: 4,8 => SOL
* INC # C8: 7 => UNS
* INC # C9: 4,8 => UNS
* INC # I8: 6,8 => UNS
* PRF # I9: 6,8 => SOL
* INC # I9: 7 => UNS
* DIS # H5: 6,8 => CTR => H5: 4
* PRF # H5: 4 => SOL
* CNT  31 HDP CHAINS /  31 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # E1: 4,6 => UNS
* DIS # E1: 8 => CTR => E1: 4,6
* PRF E1: 4,6 # C8: 4,8 => SOL
* STA E1: 4,6 + C8: 4,8
* CNT   3 HDP CHAINS /   3 HYP OPENED