Analysis of xx-top500-226-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: .8..7.1..5....4..3..........7....82...13........5.....6...8..7.3..2.............. initial

Autosolve

position: .8..731525128.47.373.152.8..73.1.8252513.8..786.527.31625.8137.3.72..5181.87352.. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # C1: 4,9 => SOL
* DIS # C1: 6 => CTR => C1: 4,9
* DIS # C1: 6,9 => CTR => C1: 4
* PRF # C1: 4 => SOL
* PRF # G3: 6,9 => SOL
* DIS # G3: 4 => CTR => G3: 6,9
* DIS # I3: 6,9 => CTR => I3: 4
* PRF # I3: 4 => SOL
* DIS # C1: 6,9 => CTR => C1: 4
* PRF # C1: 4 => SOL
* PRF # D4: 6,9 => SOL
* DIS # D4: 4 => CTR => D4: 6,9
* PRF # E8: 6,9 => SOL
* DIS # E8: 4 => CTR => E8: 6,9
* PRF # G3: 6,9 => SOL
* DIS # G3: 4 => CTR => G3: 6,9
* DIS # I3: 6,9 => CTR => I3: 4
* PRF # I3: 4 => SOL
* PRF # H5: 6,9 => SOL
* DIS # H5: 4 => CTR => H5: 6,9
* DIS # H9: 6,9 => CTR => H9: 4
* PRF # H9: 4 => SOL
* PRF # D4: 4,9 => SOL
* DIS # D4: 6 => CTR => D4: 4,9
* PRF # C1: 4,9 => SOL
* DIS # C1: 6 => CTR => C1: 4,9
* PRF # D4: 6,9 => SOL
* DIS # D4: 4 => CTR => D4: 6,9
* PRF # D4: 4,9 => SOL
* DIS # D4: 6 => CTR => D4: 4,9
* DIS # G5: 4,9 => CTR => G5: 6
* DIS # E8: 4,9 => CTR => E8: 6
* PRF # E8: 6 => SOL
* DIS # G5: 4,9 => CTR => G5: 6
* DIS # G3: 6 => CTR => G3: 4,9
* DIS # E8: 4,9 => CTR => E8: 6
* PRF # E8: 6 => SOL
* DIS # I9: 4,9 => CTR => I9: 6
* DIS # E8: 4,9 => CTR => E8: 6
* PRF # E8: 6 => SOL
* PRF # D4: 4,9 => SOL
* DIS # D4: 6 => CTR => D4: 4,9
* PRF # E8: 6,9 => SOL
* DIS # E8: 4 => CTR => E8: 6,9
* DIS # I9: 4,9 => CTR => I9: 6
* DIS # I3: 6 => CTR => I3: 4,9
* CNT  46 HDP CHAINS /  56 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 # C1: 4,9 => SOL
* STA C1: 4,9
* CNT   1 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

.8..7.1..5....4..3..........7....82...13........5.....6...8..7.3..2.............. initial
.8..731525128.47.373.152.8..73.1.8252513.8..786.527.31625.8137.3.72..5181.87352.. autosolve
984673152512894763736152984473916825251348697869527431625481379347269518198735246 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (15)
A1: 4,9
C3: 6,9
D1: 6,9
E2: 6,9
H2: 6,9
A4: 4,9
C6: 4,9
F4: 6,9
E5: 4,9
G6: 4,9
B8: 4,9
B9: 4,9
D7: 4,9
F8: 6,9
I7: 4,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
A1,C1: 4.. / A1 = 4  =>  0 pairs (X) / C1 = 4  =>  0 pairs (_)
G3,I3: 4.. / G3 = 4  =>  0 pairs (X) / I3 = 4  =>  0 pairs (_)
A4,C6: 4.. / A4 = 4  =>  0 pairs (*) / C6 = 4  =>  0 pairs (X)
D4,E5: 4.. / D4 = 4  =>  0 pairs (X) / E5 = 4  =>  0 pairs (_)
B8,B9: 4.. / B8 = 4  =>  0 pairs (*) / B9 = 4  =>  0 pairs (X)
D7,E8: 4.. / D7 = 4  =>  0 pairs (*) / E8 = 4  =>  0 pairs (X)
A4,D4: 4.. / A4 = 4  =>  0 pairs (*) / D4 = 4  =>  0 pairs (X)
C6,G6: 4.. / C6 = 4  =>  0 pairs (X) / G6 = 4  =>  0 pairs (_)
D7,I7: 4.. / D7 = 4  =>  0 pairs (*) / I7 = 4  =>  0 pairs (X)
B8,E8: 4.. / B8 = 4  =>  0 pairs (*) / E8 = 4  =>  0 pairs (X)
A1,A4: 4.. / A1 = 4  =>  0 pairs (X) / A4 = 4  =>  0 pairs (_)
C1,C6: 4.. / C1 = 4  =>  0 pairs (*) / C6 = 4  =>  0 pairs (X)
D4,D7: 4.. / D4 = 4  =>  0 pairs (X) / D7 = 4  =>  0 pairs (_)
E5,E8: 4.. / E5 = 4  =>  0 pairs (*) / E8 = 4  =>  0 pairs (X)
H5,H9: 4.. / H5 = 4  =>  0 pairs (X) / H9 = 4  =>  0 pairs (_)
C1,C3: 6.. / C1 = 6  =>  0 pairs (X) / C3 = 6  =>  0 pairs (_)
D1,E2: 6.. / D1 = 6  =>  0 pairs (*) / E2 = 6  =>  0 pairs (X)
D4,F4: 6.. / D4 = 6  =>  0 pairs (X) / F4 = 6  =>  0 pairs (_)
G5,H5: 6.. / G5 = 6  => 17 pairs (_) / H5 = 6  =>  0 pairs (X)
E8,F8: 6.. / E8 = 6  =>  0 pairs (*) / F8 = 6  =>  0 pairs (X)
H9,I9: 6.. / H9 = 6  =>  0 pairs (X) / I9 = 6  => 17 pairs (_)
C1,D1: 6.. / C1 = 6  =>  0 pairs (X) / D1 = 6  =>  0 pairs (_)
E2,H2: 6.. / E2 = 6  =>  0 pairs (X) / H2 = 6  =>  0 pairs (_)
D1,D4: 6.. / D1 = 6  =>  0 pairs (*) / D4 = 6  =>  0 pairs (X)
E2,E8: 6.. / E2 = 6  =>  0 pairs (X) / E8 = 6  =>  0 pairs (_)
F4,F8: 6.. / F4 = 6  =>  0 pairs (*) / F8 = 6  =>  0 pairs (X)
G3,G5: 6.. / G3 = 6  =>  0 pairs (X) / G5 = 6  => 17 pairs (_)
I3,I9: 6.. / I3 = 6  =>  0 pairs (X) / I9 = 6  => 17 pairs (_)
D1,E2: 9.. / D1 = 9  =>  0 pairs (X) / E2 = 9  =>  0 pairs (_)
A4,C6: 9.. / A4 = 9  =>  0 pairs (X) / C6 = 9  =>  0 pairs (_)
B8,B9: 9.. / B8 = 9  =>  0 pairs (X) / B9 = 9  =>  0 pairs (_)
E2,H2: 9.. / E2 = 9  =>  0 pairs (*) / H2 = 9  =>  0 pairs (X)
C6,G6: 9.. / C6 = 9  =>  0 pairs (*) / G6 = 9  =>  0 pairs (X)
D7,I7: 9.. / D7 = 9  =>  0 pairs (X) / I7 = 9  =>  0 pairs (_)
A1,A4: 9.. / A1 = 9  =>  0 pairs (*) / A4 = 9  =>  0 pairs (X)
F4,F8: 9.. / F4 = 9  =>  0 pairs (X) / F8 = 9  =>  0 pairs (_)
* DURATION: 0:00:59.004030  START: 10:34:32.902944  END: 10:35:31.906974 2017-05-04
* CP COUNT: (36)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,A4,B8,B9,C3,C6,D1,D7,E2,E5,F4,F8,G6,H2,I7)
* .8..731525128.47.373.152.8..73.1.8252513.8..786.527.31625.8137.3.72..5181.87352..
* PAIR A1: 4,9 BLK 1
C1: 4,9,6                                # reduction candidate for 4,9
C1: 4,9 => SOLVED
* 984673152512894763736152984473916825251348697869527431625481379347269518198735246
C1: 6 => CTR
* 4869731525128.47.373.152.8..73.1.8252513.8..786.527.31625.8137.3.72..5181.87352..
* PAIR C3: 6,9 BLK 1
C1: 6,9,4                                # reduction candidate for 6,9
C1: 6,9 => CTR
* 48..731525128.47.373.152.8.973416825251398..786.527.31625.8137.3.72..5181.87352..
C1: 4 => SOLVED
* 984673152512894763736152984473916825251348697869527431625481379347269518198735246
* PAIR C3: 6,9 ROW 3
G3: 6,9,4                                # reduction candidate for 6,9
G3: 6,9 => SOLVED
* 984673152512894763736152984473916825251348697869527431625481379347269518198735246
G3: 4 => CTR
* .8..731525128.47.373.15248..73.1.8252513.8647864527931625.8137.3.72465181487352..
I3: 6,9,4                                # reduction candidate for 6,9
I3: 6,9 => CTR
* .8..731525128.47.373.15248..73.1.8252513.8647864527931625.8137.3.72465181487352..
I3: 4 => SOLVED
* 984673152512894763736152984473916825251348697869527431625481379347269518198735246
* PAIR D1: 6,9 ROW 1
C1: 6,9,4                                # reduction candidate for 6,9
C1: 6,9 => CTR
* 48..731525128.47.373.152.8.973416825251398..786.527.31625.8137.3.72..5181.87352..
C1: 4 => SOLVED
* 984673152512894763736152984473916825251348697869527431625481379347269518198735246
* PAIR D1: 6,9 COL D
D4: 6,9,4                                # reduction candidate for 6,9
D4: 6,9 => SOLVED
* 984673152512894763736152984473916825251348697869527431625481379347269518198735246
D4: 4 => CTR
* .8.673152512894763736152.8..7341.8252513.8..786.527.31625.8137.3.72..5181.87352..
* PAIR E2: 6,9 COL E
E8: 6,9,4                                # reduction candidate for 6,9
E8: 6,9 => SOLVED
* 984673152512894763736152984473916825251348697869527431625481379347269518198735246
E8: 4 => CTR
* .8..73152512864793739152.8.973.1.8252513.8..786.527.31625.8137.3.72..5181.87352..
* PAIR H2: 6,9 BLK 3
G3: 6,9,4                                # reduction candidate for 6,9
G3: 6,9 => SOLVED
* 984673152512894763736152984473916825251348697869527431625481379347269518198735246
G3: 4 => CTR
* .8..731525128.47.373.15248..73.1.8252513.8647864527931625.8137.3.72465181487352..
I3: 6,9,4                                # reduction candidate for 6,9
I3: 6,9 => CTR
* .8..731525128.47.373.15248..73.1.8252513.8647864527931625.8137.3.72465181487352..
I3: 4 => SOLVED
* 984673152512894763736152984473916825251348697869527431625481379347269518198735246
* PAIR H2: 6,9 COL H
H5: 6,9,4                                # reduction candidate for 6,9
H5: 6,9 => SOLVED
* 984673152512894763736152984473916825251348697869527431625481379347269518198735246
H5: 4 => CTR
* .8..731525128.47.373.152.8..73.1.8252513.8647864527931625.8137.3.72465181487352..
H9: 6,9,4                                # reduction candidate for 6,9
H9: 6,9 => CTR
* .8..731525128.47.373.152.8..73.1.8252513.8.47864527931625.8137.3.72465181487352..
H9: 4 => SOLVED
* 984673152512894763736152984473916825251348697869527431625481379347269518198735246
* PAIR A4: 4,9 ROW 4
D4: 4,9,6                                # reduction candidate for 4,9
D4: 4,9 => SOLVED
* 984673152512894763736152984473916825251348697869527431625481379347269518198735246
D4: 6 => CTR
* .8..731525128.47.373.152.8.473619825251348..7869527.31625.8137.3.72..5181.87352..
* PAIR C6: 4,9 COL C
C1: 4,9,6                                # reduction candidate for 4,9
C1: 4,9 => SOLVED
* 984673152512894763736152984473916825251348697869527431625481379347269518198735246
C1: 6 => CTR
* 4869731525128.47.373.152.8..73.1.8252513.8..786.527.31625.8137.3.72..5181.87352..
* PAIR F4: 6,9 BLK 5
D4: 6,9,4                                # reduction candidate for 6,9
D4: 6,9 => SOLVED
* 984673152512894763736152984473916825251348697869527431625481379347269518198735246
D4: 4 => CTR
* .8.673152512894763736152.8..7341.8252513.8..786.527.31625.8137.3.72..5181.87352..
* PAIR E5: 4,9 BLK 5
D4: 4,9,6                                # reduction candidate for 4,9
D4: 4,9 => SOLVED
* 984673152512894763736152984473916825251348697869527431625481379347269518198735246
D4: 6 => CTR
* .8..731525128.47.373.152.8.473619825251348..7869527.31625.8137.3.72..5181.87352..
* PAIR E5: 4,9 ROW 5
G5: 4,9,6                                # reduction candidate for 4,9
G5: 4,9 => CTR
* .86973152512864793739152684.73.1.8252513.8.6786.527.316254813793472..518198735246
G5: 6                                    # 17 pairs
H5: 4,9,6                                # reduction candidate for 4,9
H5: 4,9                                  # 17 pairs
* PAIR E5: 4,9 COL E
E8: 4,9,6                                # reduction candidate for 4,9
E8: 4,9 => CTR
* .8..73152512864793739152.8.973.1.8252513.8..786.527.31625.8137.3.72..5181.87352..
E8: 6 => SOLVED
* 984673152512894763736152984473916825251348697869527431625481379347269518198735246
* PAIR G6: 4,9 BLK 6
G5: 4,9,6                                # reduction candidate for 4,9
G5: 4,9 => CTR
* .86973152512864793739152684.73.1.8252513.8.6786.527.316254813793472..518198735246
G5: 6                                    # 17 pairs
H5: 4,9,6                                # reduction candidate for 4,9
H5: 4,9                                  # 17 pairs
* PAIR G6: 4,9 COL G
G3: 4,9,6                                # reduction candidate for 4,9
G3: 6 => CTR
* .86973152512864793739152684.73.1.8252513.8.6786.527.316254813793472..518198735246
G3: 4,9                                  # 17 pairs
* PAIR B8: 4,9 ROW 8
E8: 4,9,6                                # reduction candidate for 4,9
E8: 4,9 => CTR
* .8..73152512864793739152.8.973.1.8252513.8..786.527.31625.8137.3.72..5181.87352..
E8: 6 => SOLVED
* 984673152512894763736152984473916825251348697869527431625481379347269518198735246
* PAIR B9: 4,9 ROW 9
H9: 4,9,6                                # reduction candidate for 4,9
H9: 4,9                                  # 17 pairs
I9: 4,9,6                                # reduction candidate for 4,9
I9: 4,9 => CTR
* .86973152512864793739152486973.1.8252513.86.786.527.31625.8137.3.72..5181.873526.
I9: 6                                    # 17 pairs
* PAIR D7: 4,9 BLK 8
E8: 4,9,6                                # reduction candidate for 4,9
E8: 4,9 => CTR
* .8..73152512864793739152.8.973.1.8252513.8..786.527.31625.8137.3.72..5181.87352..
E8: 6 => SOLVED
* 984673152512894763736152984473916825251348697869527431625481379347269518198735246
* PAIR D7: 4,9 COL D
D4: 4,9,6                                # reduction candidate for 4,9
D4: 4,9 => SOLVED
* 984673152512894763736152984473916825251348697869527431625481379347269518198735246
D4: 6 => CTR
* .8..731525128.47.373.152.8.473619825251348..7869527.31625.8137.3.72..5181.87352..
* PAIR F8: 6,9 BLK 8
E8: 6,9,4                                # reduction candidate for 6,9
E8: 6,9 => SOLVED
* 984673152512894763736152984473916825251348697869527431625481379347269518198735246
E8: 4 => CTR
* .8..73152512864793739152.8.973.1.8252513.8..786.527.31625.8137.3.72..5181.87352..
* PAIR I7: 4,9 BLK 9
H9: 4,9,6                                # reduction candidate for 4,9
H9: 4,9                                  # 17 pairs
I9: 4,9,6                                # reduction candidate for 4,9
I9: 4,9 => CTR
* .86973152512864793739152486973.1.8252513.86.786.527.31625.8137.3.72..5181.873526.
I9: 6                                    # 17 pairs
* PAIR I7: 4,9 COL I
I3: 4,9,6                                # reduction candidate for 4,9
I3: 6 => CTR
* .8..731525128.47.373.152486.73.1.8252513.8647864527931625.8137.3.7246518148735269
I3: 4,9                                  # 17 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-226-base-pr-000.dot
* REASONING
* PRF # C1: 4,9 => SOL
* DIS # C1: 6 => CTR => C1: 4,9
* DIS # C1: 6,9 => CTR => C1: 4
* PRF # C1: 4 => SOL
* PRF # G3: 6,9 => SOL
* DIS # G3: 4 => CTR => G3: 6,9
* DIS # I3: 6,9 => CTR => I3: 4
* PRF # I3: 4 => SOL
* DIS # C1: 6,9 => CTR => C1: 4
* PRF # C1: 4 => SOL
* PRF # D4: 6,9 => SOL
* DIS # D4: 4 => CTR => D4: 6,9
* PRF # E8: 6,9 => SOL
* DIS # E8: 4 => CTR => E8: 6,9
* PRF # G3: 6,9 => SOL
* DIS # G3: 4 => CTR => G3: 6,9
* DIS # I3: 6,9 => CTR => I3: 4
* PRF # I3: 4 => SOL
* PRF # H5: 6,9 => SOL
* DIS # H5: 4 => CTR => H5: 6,9
* DIS # H9: 6,9 => CTR => H9: 4
* PRF # H9: 4 => SOL
* PRF # D4: 4,9 => SOL
* DIS # D4: 6 => CTR => D4: 4,9
* PRF # C1: 4,9 => SOL
* DIS # C1: 6 => CTR => C1: 4,9
* PRF # D4: 6,9 => SOL
* DIS # D4: 4 => CTR => D4: 6,9
* PRF # D4: 4,9 => SOL
* DIS # D4: 6 => CTR => D4: 4,9
* DIS # G5: 4,9 => CTR => G5: 6
* DIS # E8: 4,9 => CTR => E8: 6
* PRF # E8: 6 => SOL
* DIS # G5: 4,9 => CTR => G5: 6
* DIS # G3: 6 => CTR => G3: 4,9
* DIS # E8: 4,9 => CTR => E8: 6
* PRF # E8: 6 => SOL
* DIS # I9: 4,9 => CTR => I9: 6
* DIS # E8: 4,9 => CTR => E8: 6
* PRF # E8: 6 => SOL
* PRF # D4: 4,9 => SOL
* DIS # D4: 6 => CTR => D4: 4,9
* PRF # E8: 6,9 => SOL
* DIS # E8: 4 => CTR => E8: 6,9
* DIS # I9: 4,9 => CTR => I9: 6
* DIS # I3: 6 => CTR => I3: 4,9
* CNT  46 HDP CHAINS /  56 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,A4,B8,B9,C3,C6,D1,D7,E2,E5,F4,F8,G6,H2,I7)
* .8..731525128.47.373.152.8..73.1.8252513.8..786.527.31625.8137.3.72..5181.87352..
* PAIR A1: 4,9 BLK 1
C1: 4,9,6                                # reduction candidate for 4,9
C1: 4,9 => SOLVED
* 984673152512894763736152984473916825251348697869527431625481379347269518198735246
* DURATION: 0:00:01.900833  START: 10:36:29.246038  END: 10:36:31.146871 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-226-base-pr-001.dot
* REASONING
* PRF # C1: 4,9 => SOL
* STA C1: 4,9
* CNT   1 HDP CHAINS /   1 HYP OPENED

Header Info

Top 500 Minimum 17 226

solution: 984673152512894763736152984473916825251348697869527431625481379347269518198735246
info: 2063     FNBWXY   S8.f     23620

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

Solution

position: 984673152512894763736152984473916825251348697869527431625481379347269518198735246 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 # C1: 4,9 => SOL
* DIS # C1: 6 => CTR => C1: 4,9
* DIS # C1: 6,9 => CTR => C1: 4
* PRF # C1: 4 => SOL
* PRF # G3: 6,9 => SOL
* DIS # G3: 4 => CTR => G3: 6,9
* DIS # I3: 6,9 => CTR => I3: 4
* PRF # I3: 4 => SOL
* DIS # C1: 6,9 => CTR => C1: 4
* PRF # C1: 4 => SOL
* PRF # D4: 6,9 => SOL
* DIS # D4: 4 => CTR => D4: 6,9
* PRF # E8: 6,9 => SOL
* DIS # E8: 4 => CTR => E8: 6,9
* PRF # G3: 6,9 => SOL
* DIS # G3: 4 => CTR => G3: 6,9
* DIS # I3: 6,9 => CTR => I3: 4
* PRF # I3: 4 => SOL
* PRF # H5: 6,9 => SOL
* DIS # H5: 4 => CTR => H5: 6,9
* DIS # H9: 6,9 => CTR => H9: 4
* PRF # H9: 4 => SOL
* PRF # D4: 4,9 => SOL
* DIS # D4: 6 => CTR => D4: 4,9
* PRF # C1: 4,9 => SOL
* DIS # C1: 6 => CTR => C1: 4,9
* PRF # D4: 6,9 => SOL
* DIS # D4: 4 => CTR => D4: 6,9
* PRF # D4: 4,9 => SOL
* DIS # D4: 6 => CTR => D4: 4,9
* DIS # G5: 4,9 => CTR => G5: 6
* INC # G5: 6 => UNS
* INC # H5: 4,9 => UNS
* DIS # E8: 4,9 => CTR => E8: 6
* PRF # E8: 6 => SOL
* DIS # G5: 4,9 => CTR => G5: 6
* INC # G5: 6 => UNS
* INC # H5: 4,9 => UNS
* INC # G3: 4,9 => UNS
* DIS # G3: 6 => CTR => G3: 4,9
* DIS # E8: 4,9 => CTR => E8: 6
* PRF # E8: 6 => SOL
* INC # H9: 4,9 => UNS
* DIS # I9: 4,9 => CTR => I9: 6
* INC # I9: 6 => UNS
* DIS # E8: 4,9 => CTR => E8: 6
* PRF # E8: 6 => SOL
* PRF # D4: 4,9 => SOL
* DIS # D4: 6 => CTR => D4: 4,9
* PRF # E8: 6,9 => SOL
* DIS # E8: 4 => CTR => E8: 6,9
* INC # H9: 4,9 => UNS
* DIS # I9: 4,9 => CTR => I9: 6
* INC # I9: 6 => UNS
* INC # I3: 4,9 => UNS
* DIS # I3: 6 => CTR => I3: 4,9
* CNT  56 HDP CHAINS /  56 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* PRF # C1: 4,9 => SOL
* STA C1: 4,9
* CNT   1 HDP CHAINS /   1 HYP OPENED