Analysis of xx-top500-107-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 8.....1.....3........7......39..........1.2....7....5..1....47.2...8.......6...3. initial

Autosolve

position: 87..5.1.39..3..7..3..7......39.7.61..86.132.7127...35.618.3.472243187...7956..831 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # D1: 2,4 => SOL
* DIS # D1: 9 => CTR => D1: 2,4
* DIS # F1: 2,4 => CTR => F1: 6,9
* DIS # H1: 2,4 => CTR => H1: 6,9
* PRF # H1: 6,9 => SOL
* PRF # I2: 5,6 => SOL
* DIS # I2: 4 => CTR => I2: 5,6
* DIS # I3: 5,6 => CTR => I3: 4,9
* PRF # I3: 4,9 => SOL
* DIS # I3: 5,9 => CTR => I3: 4,6
* DIS # D4: 4,5 => CTR => D4: 2,8
* DIS # D5: 4,5 => CTR => D5: 9
* PRF # D5: 9 => SOL
* DIS # I6: 4,8 => CTR => I6: 9
* PRF # I6: 9 => SOL
* DIS # D4: 4,8 => CTR => D4: 2,5
* DIS # I6: 8 => CTR => I6: 4,9
* DIS # D5: 5 => CTR => D5: 4,9
* PRF # H1: 4,9 => SOL
* DIS # H1: 2,6 => CTR => H1: 4,9
* DIS # H3: 4,9 => CTR => H3: 2,6,8
* PRF # D5: 5,9 => SOL
* DIS # D5: 4 => CTR => D5: 5,9
* PRF # E2: 2,4 => SOL
* DIS # E2: 6 => CTR => E2: 2,4
* DIS # E3: 2,4 => CTR => E3: 6,9
* PRF # E3: 6,9 => SOL
* DIS # F1: 2,4 => CTR => F1: 6,9
* DIS # F4: 2,4 => CTR => F4: 5
* PRF # I8: 5,9 => SOL
* DIS # I8: 6 => CTR => I8: 5,9
* DIS # I8: 6,9 => CTR => I8: 5
* PRF # I8: 5 => SOL
* PRF # H1: 6,9 => SOL
* DIS # H1: 2,4 => CTR => H1: 6,9
* DIS # H3: 6,9 => CTR => H3: 2,4,8
* CNT  36 HDP CHAINS /  49 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 # D1: 2,4 => SOL
* STA D1: 2,4
* CNT   1 HDP CHAINS /   3 HYP OPENED

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

Details

Positions

8.....1.....3........7......39..........1.2....7....5..1....47.2...8.......6...3. initial
87..5.1.39..3..7..3..7......39.7.61..86.132.7127...35.618.3.472243187...7956..831 autosolve
872456193954321786361798524439275618586913247127864359618539472243187965795642831 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (16)
C1: 2,4
B2: 5,6
B3: 5,6
F2: 1,8
F3: 1,8
G3: 5,9
A4: 4,5
A5: 4,5
I4: 4,8
H5: 4,9
D7: 5,9
F7: 5,9
E9: 2,4
F9: 2,4
G8: 5,9
H8: 6,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
C2,C3: 1.. / C2 = 1  => 15 pairs (_) / C3 = 1  => 15 pairs (_)
F2,F3: 1.. / F2 = 1  => 15 pairs (_) / F3 = 1  => 15 pairs (_)
C2,F2: 1.. / C2 = 1  => 15 pairs (_) / F2 = 1  => 15 pairs (_)
C3,F3: 1.. / C3 = 1  => 15 pairs (_) / F3 = 1  => 15 pairs (_)
D4,F4: 2.. / D4 = 2  => 18 pairs (_) / F4 = 2  =>  0 pairs (X)
E9,F9: 2.. / E9 = 2  =>  0 pairs (X) / F9 = 2  =>  0 pairs (_)
D1,D4: 2.. / D1 = 2  =>  0 pairs (X) / D4 = 2  => 18 pairs (_)
A4,A5: 4.. / A4 = 4  => 17 pairs (_) / A5 = 4  =>  0 pairs (X)
E9,F9: 4.. / E9 = 4  =>  0 pairs (*) / F9 = 4  =>  0 pairs (X)
B2,B3: 5.. / B2 = 5  => 15 pairs (_) / B3 = 5  =>  0 pairs (X)
A4,A5: 5.. / A4 = 5  =>  0 pairs (X) / A5 = 5  => 17 pairs (_)
D7,F7: 5.. / D7 = 5  => 15 pairs (_) / F7 = 5  =>  0 pairs (X)
G8,I8: 5.. / G8 = 5  =>  0 pairs (X) / I8 = 5  =>  0 pairs (_)
B2,I2: 5.. / B2 = 5  => 15 pairs (_) / I2 = 5  =>  0 pairs (X)
A5,D5: 5.. / A5 = 5  => 17 pairs (_) / D5 = 5  =>  0 pairs (X)
F4,F7: 5.. / F4 = 5  => 15 pairs (_) / F7 = 5  =>  0 pairs (X)
G3,G8: 5.. / G3 = 5  =>  0 pairs (*) / G8 = 5  =>  0 pairs (X)
B2,B3: 6.. / B2 = 6  =>  0 pairs (X) / B3 = 6  => 15 pairs (_)
E6,F6: 6.. / E6 = 6  =>  0 pairs (*) / F6 = 6  =>  0 pairs (X)
H8,I8: 6.. / H8 = 6  =>  0 pairs (*) / I8 = 6  =>  0 pairs (X)
F1,H1: 6.. / F1 = 6  =>  0 pairs (*) / H1 = 6  =>  0 pairs (X)
F1,F6: 6.. / F1 = 6  =>  0 pairs (*) / F6 = 6  =>  0 pairs (X)
F2,F3: 8.. / F2 = 8  => 15 pairs (_) / F3 = 8  => 15 pairs (_)
H2,H3: 8.. / H2 = 8  => 15 pairs (_) / H3 = 8  => 15 pairs (_)
D4,D6: 8.. / D4 = 8  =>  0 pairs (X) / D6 = 8  => 16 pairs (_)
I4,I6: 8.. / I4 = 8  => 16 pairs (_) / I6 = 8  =>  0 pairs (X)
F2,H2: 8.. / F2 = 8  => 15 pairs (_) / H2 = 8  => 15 pairs (_)
F3,H3: 8.. / F3 = 8  => 15 pairs (_) / H3 = 8  => 15 pairs (_)
D4,I4: 8.. / D4 = 8  =>  0 pairs (X) / I4 = 8  => 16 pairs (_)
D6,I6: 8.. / D6 = 8  => 16 pairs (_) / I6 = 8  =>  0 pairs (X)
H5,I6: 9.. / H5 = 9  =>  0 pairs (X) / I6 = 9  =>  0 pairs (_)
D7,F7: 9.. / D7 = 9  =>  0 pairs (X) / F7 = 9  => 15 pairs (_)
D5,H5: 9.. / D5 = 9  =>  0 pairs (*) / H5 = 9  =>  0 pairs (X)
E3,E6: 9.. / E3 = 9  =>  0 pairs (*) / E6 = 9  =>  0 pairs (X)
G3,G8: 9.. / G3 = 9  =>  0 pairs (X) / G8 = 9  =>  0 pairs (_)
* DURATION: 0:01:00.846119  START: 06:25:19.047569  END: 06:26:19.893688 2017-05-04
* CP COUNT: (35)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A4,A5,B2,B3,C1,D7,E9,F2,F3,F7,F9,G3,G8,H5,H8,I4)
* 87..5.1.39..3..7..3..7......39.7.61..86.132.7127...35.618.3.472243187...7956..831
* PAIR C1: 2,4 BLK 1
C2: 2,4,1                                # reduction candidate for 2,4
C2: 2,4                                  # 15 pairs
C3: 2,4,1                                # reduction candidate for 2,4
C3: 2,4                                  # 15 pairs
* PAIR C1: 2,4 ROW 1
D1: 2,4,9                                # reduction candidate for 2,4
D1: 2,4 => SOLVED
* 872456193954321786361798524439275618586913247127864359618539472243187965795642831
D1: 9 => CTR
* 87.95.1.39..3..7..3..7......3927.618.86.13297127896354618539472243187.6.7956..831
F1: 2,4,6,9                              # reduction candidate for 2,4
F1: 2,4 => CTR
* 87.95.1639..3..7..3..7..9...392756185864132.7127..635.618.39472243187.967956..831
F1: 6,9                                  # 17 pairs
H1: 2,4,6,9                              # reduction candidate for 2,4
H1: 2,4 => CTR
* 87.9561.39..3..7..3..7......3927.618.86.1329712786935461853.472243187...7956..831
H1: 6,9 => SOLVED
* 872456193954321786361798524439275618586913247127864359618539472243187965795642831
* PAIR B2: 5,6 ROW 2
I2: 5,6,4                                # reduction candidate for 5,6
I2: 5,6 => SOLVED
* 872456193954321786361798524439275618586913247127864359618539472243187965795642831
I2: 4 => CTR
* 87..5.1.395.3..7.436.79.5...39.7.618.86.132471278..359618.3.472243187..67956..831
* PAIR B3: 5,6 ROW 3
I3: 5,6,4,9                              # reduction candidate for 5,6
I3: 5,6 => CTR
* 87..5.1639..3..7..3..7..9...39.7.61..86.132.7127.9635.618.3.4722431875.97956..831
I3: 4,9 => SOLVED
* 872456193954321786361798524439275618586913247127864359618539472243187965795642831
* PAIR G3: 5,9 BLK 3
I3: 5,9,4,6                              # reduction candidate for 5,9
I3: 5,9 => CTR
* 87..5.16395.36.7.436.7......39.7.618.86.132.7127.9635.618.3.472243187...7956..831
I3: 4,6                                  # 17 pairs
* PAIR A4: 4,5 ROW 4
D4: 4,5,2,8                              # reduction candidate for 4,5
D4: 4,5 => CTR
* 87425.1.39..3..7..3..7......39.72618.86.132971278..354618935472243187.6.795624831
D4: 2,8                                  # 17 pairs
F4: 4,5,2                                # reduction candidate for 4,5
F4: 4,5                                  # 18 pairs
* PAIR A5: 4,5 ROW 5
D5: 4,5,9                                # reduction candidate for 4,5
D5: 4,5 => CTR
* 87.9561.39..3..7..3..7......3927.618.86.1329712786935461853.472243187.6.7956..831
D5: 9 => SOLVED
* 872456193954321786361798524439275618586913247127864359618539472243187965795642831
* PAIR I4: 4,8 BLK 6
I6: 4,8,9                                # reduction candidate for 4,8
I6: 4,8 => CTR
* 87.9561.39..3..7..3..7......3927.618.86.1329712786935461853.472243187.6.7956..831
I6: 9 => SOLVED
* 872456193954321786361798524439275618586913247127864359618539472243187965795642831
* PAIR I4: 4,8 ROW 4
D4: 4,8,2,5                              # reduction candidate for 4,8
D4: 4,8 => CTR
* 87.25.1.39..3..7..3..7......39.7261..86513297127...35.618935472243187.6.795624831
D4: 2,5                                  # 17 pairs
* PAIR H5: 4,9 BLK 6
I6: 4,9,8                                # reduction candidate for 4,9
I6: 8 => CTR
* 87..561.39..3..7..3..7......39872614486513297127...358618.3.472243187.6.7956..831
I6: 4,9                                  # 16 pairs
* PAIR H5: 4,9 ROW 5
D5: 4,9,5                                # reduction candidate for 4,9
D5: 5 => CTR
* 87..5.1.39..3..7..3..7......39.7.61..86513297127...35.618935472243187.6.7956..831
D5: 4,9                                  # 17 pairs
* PAIR H5: 4,9 COL H
H1: 4,9,2,6                              # reduction candidate for 4,9
H1: 4,9 => SOLVED
* 872456193954321786361798524439275618586913247127864359618539472243187965795642831
H1: 2,6 => CTR
* 87..5.1.39..3..7..3..7......39.7.61..86.13297127.9635.618.3.472243187.6.7956..831
H3: 4,9,2,6,8                            # reduction candidate for 4,9
H3: 4,9 => CTR
* 87..5.1239..3.178.3.1728....3927.618.86.132.7127896354618.3.472243187.6.795642831
H3: 2,6,8                                # 16 pairs
* PAIR D7: 5,9 COL D
D5: 5,9,4                                # reduction candidate for 5,9
D5: 5,9 => SOLVED
* 872456193954321786361798524439275618586913247127864359618539472243187965795642831
D5: 4 => CTR
* 87..561.39..3..7..3..7.....439.7.618586413297127869354618935472243187.6.7956.4831
* PAIR E9: 2,4 COL E
E2: 2,4,6                                # reduction candidate for 2,4
E2: 2,4 => SOLVED
* 872456193954321786361798524439275618586913247127864359618539472243187965795642831
E2: 6 => CTR
* 87..5.16395.36.7.436.7....5.39.7.618.86.13247127846359618.3.472243187596795624831
E3: 2,4,6,9                              # reduction candidate for 2,4
E3: 2,4 => CTR
* 87..5.1639..36.7..36.7......39.7.61..86.13297127.9635.618.3.472243187...7956..831
E3: 6,9 => SOLVED
* 872456193954321786361798524439275618586913247127864359618539472243187965795642831
* PAIR F9: 2,4 COL F
F1: 2,4,6,9                              # reduction candidate for 2,4
F1: 2,4 => CTR
* 87.95.1639..3..7..3..7..9...392756185864132.7127..635.618.39472243187.967956..831
F1: 6,9                                  # 17 pairs
F4: 2,4,5                                # reduction candidate for 2,4
F4: 2,4 => CTR
* 87..5.1.39..3..7..3..7......39.7.61..86.13297127...35.618935472243187.6.7956..831
F4: 5                                    # 15 pairs
* PAIR G8: 5,9 BLK 9
I8: 5,9,6                                # reduction candidate for 5,9
I8: 5,9 => SOLVED
* 872456193954321786361798524439275618586913247127864359618539472243187965795642831
I8: 6 => CTR
* 87..5.1.39..3..7..3..7..9...39.7.61..86913247127...3596185394722431875967956..831
* PAIR H8: 6,9 BLK 9
I8: 6,9,5                                # reduction candidate for 6,9
I8: 6,9 => CTR
* 87..5.1639..3..7..3..7..9...39.7.61..86.132.7127.9635.618.3.4722431875.97956..831
I8: 5 => SOLVED
* 872456193954321786361798524439275618586913247127864359618539472243187965795642831
* PAIR H8: 6,9 COL H
H1: 6,9,2,4                              # reduction candidate for 6,9
H1: 6,9 => SOLVED
* 872456193954321786361798524439275618586913247127864359618539472243187965795642831
H1: 2,4 => CTR
* 87.9561.39..3..7..3..7......3927.618.86.1329712786935461853.472243187...7956..831
H3: 6,9,2,4,8                            # reduction candidate for 6,9
H3: 6,9 => CTR
* 87..5.1239..3.178.3.1728..4.3927.618.86.1324712789.35.618.3.472243187...7956..831
H3: 2,4,8                                # 16 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-107-base-pr-000.dot
* REASONING
* PRF # D1: 2,4 => SOL
* DIS # D1: 9 => CTR => D1: 2,4
* DIS # F1: 2,4 => CTR => F1: 6,9
* DIS # H1: 2,4 => CTR => H1: 6,9
* PRF # H1: 6,9 => SOL
* PRF # I2: 5,6 => SOL
* DIS # I2: 4 => CTR => I2: 5,6
* DIS # I3: 5,6 => CTR => I3: 4,9
* PRF # I3: 4,9 => SOL
* DIS # I3: 5,9 => CTR => I3: 4,6
* DIS # D4: 4,5 => CTR => D4: 2,8
* DIS # D5: 4,5 => CTR => D5: 9
* PRF # D5: 9 => SOL
* DIS # I6: 4,8 => CTR => I6: 9
* PRF # I6: 9 => SOL
* DIS # D4: 4,8 => CTR => D4: 2,5
* DIS # I6: 8 => CTR => I6: 4,9
* DIS # D5: 5 => CTR => D5: 4,9
* PRF # H1: 4,9 => SOL
* DIS # H1: 2,6 => CTR => H1: 4,9
* DIS # H3: 4,9 => CTR => H3: 2,6,8
* PRF # D5: 5,9 => SOL
* DIS # D5: 4 => CTR => D5: 5,9
* PRF # E2: 2,4 => SOL
* DIS # E2: 6 => CTR => E2: 2,4
* DIS # E3: 2,4 => CTR => E3: 6,9
* PRF # E3: 6,9 => SOL
* DIS # F1: 2,4 => CTR => F1: 6,9
* DIS # F4: 2,4 => CTR => F4: 5
* PRF # I8: 5,9 => SOL
* DIS # I8: 6 => CTR => I8: 5,9
* DIS # I8: 6,9 => CTR => I8: 5
* PRF # I8: 5 => SOL
* PRF # H1: 6,9 => SOL
* DIS # H1: 2,4 => CTR => H1: 6,9
* DIS # H3: 6,9 => CTR => H3: 2,4,8
* CNT  36 HDP CHAINS /  49 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A4,A5,B2,B3,C1,D7,E9,F2,F3,F7,F9,G3,G8,H5,H8,I4)
* 87..5.1.39..3..7..3..7......39.7.61..86.132.7127...35.618.3.472243187...7956..831
* PAIR C1: 2,4 BLK 1
C2: 2,4,1                                # reduction candidate for 2,4
C2: 2,4                                  # 15 pairs
C3: 2,4,1                                # reduction candidate for 2,4
C3: 2,4                                  # 15 pairs
* PAIR C1: 2,4 ROW 1
D1: 2,4,9                                # reduction candidate for 2,4
D1: 2,4 => SOLVED
* 872456193954321786361798524439275618586913247127864359618539472243187965795642831
* DURATION: 0:00:04.160883  START: 06:27:14.208645  END: 06:27:18.369528 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-107-base-pr-001.dot
* REASONING
* PRF # D1: 2,4 => SOL
* STA D1: 2,4
* CNT   1 HDP CHAINS /   3 HYP OPENED

Header Info

Top 500 Minimum 17 107

solution: 872456193954321786361798524439275618586913247127864359618539472243187965795642831
info: 1625     FNBHW    S8.f     37954

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

Solution

position: 872456193954321786361798524439275618586913247127864359618539472243187965795642831 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 # C2: 2,4 => UNS
* INC # C3: 2,4 => UNS
* PRF # D1: 2,4 => SOL
* DIS # D1: 9 => CTR => D1: 2,4
* DIS # F1: 2,4 => CTR => F1: 6,9
* INC # F1: 6,9 => UNS
* DIS # H1: 2,4 => CTR => H1: 6,9
* PRF # H1: 6,9 => SOL
* PRF # I2: 5,6 => SOL
* DIS # I2: 4 => CTR => I2: 5,6
* DIS # I3: 5,6 => CTR => I3: 4,9
* PRF # I3: 4,9 => SOL
* DIS # I3: 5,9 => CTR => I3: 4,6
* INC # I3: 4,6 => UNS
* DIS # D4: 4,5 => CTR => D4: 2,8
* INC # D4: 2,8 => UNS
* INC # F4: 4,5 => UNS
* DIS # D5: 4,5 => CTR => D5: 9
* PRF # D5: 9 => SOL
* DIS # I6: 4,8 => CTR => I6: 9
* PRF # I6: 9 => SOL
* DIS # D4: 4,8 => CTR => D4: 2,5
* INC # D4: 2,5 => UNS
* INC # I6: 4,9 => UNS
* DIS # I6: 8 => CTR => I6: 4,9
* INC # D5: 4,9 => UNS
* DIS # D5: 5 => CTR => D5: 4,9
* PRF # H1: 4,9 => SOL
* DIS # H1: 2,6 => CTR => H1: 4,9
* DIS # H3: 4,9 => CTR => H3: 2,6,8
* INC # H3: 2,6,8 => UNS
* PRF # D5: 5,9 => SOL
* DIS # D5: 4 => CTR => D5: 5,9
* PRF # E2: 2,4 => SOL
* DIS # E2: 6 => CTR => E2: 2,4
* DIS # E3: 2,4 => CTR => E3: 6,9
* PRF # E3: 6,9 => SOL
* DIS # F1: 2,4 => CTR => F1: 6,9
* INC # F1: 6,9 => UNS
* DIS # F4: 2,4 => CTR => F4: 5
* INC # F4: 5 => UNS
* PRF # I8: 5,9 => SOL
* DIS # I8: 6 => CTR => I8: 5,9
* DIS # I8: 6,9 => CTR => I8: 5
* PRF # I8: 5 => SOL
* PRF # H1: 6,9 => SOL
* DIS # H1: 2,4 => CTR => H1: 6,9
* DIS # H3: 6,9 => CTR => H3: 2,4,8
* INC # H3: 2,4,8 => UNS
* CNT  49 HDP CHAINS /  49 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # C2: 2,4 => UNS
* INC # C3: 2,4 => UNS
* PRF # D1: 2,4 => SOL
* STA D1: 2,4
* CNT   3 HDP CHAINS /   3 HYP OPENED