Analysis of xx-top500-036-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 1......6....2...........7.....8..2.7.7....4..3.............6.31.2..3..5...8...... initial

Autosolve

position: 1.2..736.7.32..14.8..3..72..168.329727.6..48338..72516..7.26831.21738.54.381...72 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # E3: 4,5 => CTR => E3: 1,6,9
* DIS # F3: 4,5 => CTR => F3: 1,9
* DIS # E1: 5,9 => CTR => E1: 4,8
* DIS # E2: 5,9 => CTR => E2: 6,8
* DIS # E3: 5,9 => CTR => E3: 1,4,6
* DIS # F3: 5,9 => CTR => F3: 1,4
* DIS # F9: 5,9 => CTR => F9: 4
* PRF # B3: 5,9 => SOL
* DIS # E3: 5,9 => CTR => E3: 1,4,6
* DIS # F3: 5,9 => CTR => F3: 1,4
* DIS # A7: 4,5 => CTR => A7: 9
* PRF # E1: 4,5 => SOL
* DIS # E3: 4,5 => CTR => E3: 1,6,9
* PRF # D1: 4,9 => SOL
* DIS # A7: 4,5 => CTR => A7: 9
* DIS # D7: 9 => CTR => D7: 4,5
* DIS # A9: 6,9 => CTR => A9: 4,5
* DIS # A9: 6,9 => CTR => A9: 4,5
* CNT  18 HDP CHAINS /  52 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 # E3: 4,5 => CTR => E3: 1,6,9
* DIS E3: 1,6,9 # F3: 4,5 => CTR => F3: 1,9
* PRF E3: 1,6,9 + F3: 1,9 # B3: 6,9 => SOL
* STA E3: 1,6,9 + F3: 1,9 + B3: 6,9
* CNT   3 HDP CHAINS /   6 HYP OPENED

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

Details

Positions

1......6....2...........7.....8..2.7.7....4..3.............6.31.2..3..5...8...... initial
1.2..736.7.32..14.8..3..72..168.329727.6..48338..72516..7.26831.21738.54.381...72 autosolve
152947368763285149894361725416853297275619483389472516947526831621738954538194672 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (12)
C3: 4,5
F2: 5,9
I3: 5,9
A4: 4,5
C5: 5,9
C6: 4,9
E4: 4,5
D6: 4,9
B7: 4,5
A8: 6,9
G8: 6,9
G9: 6,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
E3,F3: 1.. / E3 = 1  => 16 pairs (_) / F3 = 1  => 15 pairs (_)
E5,F5: 1.. / E5 = 1  => 15 pairs (_) / F5 = 1  => 16 pairs (_)
E3,E5: 1.. / E3 = 1  => 16 pairs (_) / E5 = 1  => 15 pairs (_)
F3,F5: 1.. / F3 = 1  => 15 pairs (_) / F5 = 1  => 16 pairs (_)
A4,C6: 4.. / A4 = 4  =>  0 pairs (*) / C6 = 4  =>  0 pairs (X)
E4,D6: 4.. / E4 = 4  =>  0 pairs (X) / D6 = 4  =>  0 pairs (_)
A4,E4: 4.. / A4 = 4  =>  0 pairs (*) / E4 = 4  =>  0 pairs (X)
C6,D6: 4.. / C6 = 4  =>  0 pairs (X) / D6 = 4  =>  0 pairs (_)
C3,C6: 4.. / C3 = 4  =>  0 pairs (*) / C6 = 4  =>  0 pairs (X)
F3,F9: 4.. / F3 = 4  =>  0 pairs (X) / F9 = 4  => 14 pairs (_)
A4,C5: 5.. / A4 = 5  =>  0 pairs (X) / C5 = 5  =>  0 pairs (_)
A4,E4: 5.. / A4 = 5  =>  0 pairs (X) / E4 = 5  =>  0 pairs (_)
C3,C5: 5.. / C3 = 5  =>  0 pairs (X) / C5 = 5  =>  0 pairs (_)
D1,D7: 5.. / D1 = 5  => 21 pairs (_) / D7 = 5  =>  0 pairs (*)
B2,B3: 6.. / B2 = 6  => 16 pairs (_) / B3 = 6  => 14 pairs (_)
E2,E3: 6.. / E2 = 6  => 14 pairs (_) / E3 = 6  => 16 pairs (_)
A8,A9: 6.. / A8 = 6  =>  9 pairs (_) / A9 = 6  =>  0 pairs (X)
G8,G9: 6.. / G8 = 6  =>  0 pairs (X) / G9 = 6  =>  9 pairs (_)
B2,E2: 6.. / B2 = 6  => 16 pairs (_) / E2 = 6  => 14 pairs (_)
B3,E3: 6.. / B3 = 6  => 14 pairs (_) / E3 = 6  => 16 pairs (_)
A8,G8: 6.. / A8 = 6  =>  9 pairs (_) / G8 = 6  =>  0 pairs (X)
A9,G9: 6.. / A9 = 6  =>  0 pairs (X) / G9 = 6  =>  9 pairs (_)
E1,E2: 8.. / E1 = 8  => 13 pairs (_) / E2 = 8  => 17 pairs (_)
I1,I2: 8.. / I1 = 8  => 17 pairs (_) / I2 = 8  => 13 pairs (_)
E1,I1: 8.. / E1 = 8  => 13 pairs (_) / I1 = 8  => 17 pairs (_)
E2,I2: 8.. / E2 = 8  => 17 pairs (_) / I2 = 8  => 13 pairs (_)
C5,C6: 9.. / C5 = 9  =>  0 pairs (X) / C6 = 9  =>  0 pairs (_)
G8,G9: 9.. / G8 = 9  =>  9 pairs (_) / G9 = 9  =>  0 pairs (X)
C6,D6: 9.. / C6 = 9  =>  0 pairs (*) / D6 = 9  =>  0 pairs (X)
A7,D7: 9.. / A7 = 9  => 11 pairs (_) / D7 = 9  =>  0 pairs (X)
A8,G8: 9.. / A8 = 9  =>  0 pairs (X) / G8 = 9  =>  9 pairs (_)
* DURATION: 0:00:53.688069  START: 03:54:04.710477  END: 03:54:58.398546 2017-05-04
* CP COUNT: (31)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A4,A8,B7,C3,C5,C6,D6,E4,F2,G8,G9,I3)
* 1.2..736.7.32..14.8..3..72..168.329727.6..48338..72516..7.26831.21738.54.381...72
* PAIR C3: 4,5 BLK 1
B1: 4,5,9                                # reduction candidate for 4,5
B1: 4,5                                  # 15 pairs
B3: 4,5,6,9                              # reduction candidate for 4,5
B3: 4,5                                  # 18 pairs
* PAIR C3: 4,5 ROW 3
E3: 4,5,1,6,9                            # reduction candidate for 4,5
E3: 4,5 => CTR
* 1.2.873657532691488643.1729.168.329727.61.48338..72516..7526831.21738.54538194672
E3: 1,6,9                                # 12 pairs
F3: 4,5,1,9                              # reduction candidate for 4,5
F3: 4,5 => CTR
* 1.2.8736575326914886431572941685329727.6.148338..72516..7526831.21738.545381..672
F3: 1,9                                  # 15 pairs
* PAIR F2: 5,9 BLK 2
D1: 5,9,4                                # reduction candidate for 5,9
D1: 5,9                                  # 16 pairs
E1: 5,9,4,8                              # reduction candidate for 5,9
E1: 5,9 => CTR
* 1.24.736876328.14.8..36172..1684329727.615483384972516..7.26831.21738.54.381.4.72
E1: 4,8                                  # 13 pairs
E2: 5,9,6,8                              # reduction candidate for 5,9
E2: 5,9 => CTR
* 1.248736.7632..1488..36172..1684329727.615483384972516..7.26831.21738.54.381.4.72
E2: 6,8                                  # 13 pairs
E3: 5,9,1,4,6                            # reduction candidate for 5,9
E3: 5,9 => CTR
* 1.2.8736.7.326.1488643.172.416853297275619483389472516.47526831.21738.54538194.72
E3: 1,4,6                                # 12 pairs
F3: 5,9,1,4                              # reduction candidate for 5,9
F3: 5,9 => CTR
* 1.2..736.7.326.14886431.72.41685329727.6.148338..72516..7.26831.21738.54.381.4.72
F3: 1,4                                  # 13 pairs
* PAIR F2: 5,9 ROW 2
B2: 5,9,6                                # reduction candidate for 5,9
B2: 5,9                                  # 14 pairs
I2: 5,9,8                                # reduction candidate for 5,9
I2: 5,9                                  # 17 pairs
* PAIR F2: 5,9 COL F
F5: 5,9,1                                # reduction candidate for 5,9
F5: 5,9                                  # 15 pairs
F9: 5,9,4                                # reduction candidate for 5,9
F9: 5,9 => CTR
* 1425.736.7.32.914.8953.472..168.329727.6.14833849725169.74268316217389544381..672
F9: 4                                    # 14 pairs
* PAIR I3: 5,9 BLK 3
I1: 5,9,8                                # reduction candidate for 5,9
I1: 5,9                                  # 13 pairs
I2: 5,9,8                                # reduction candidate for 5,9
I2: 5,9                                  # 17 pairs
* PAIR I3: 5,9 ROW 3
B3: 5,9,4,6                              # reduction candidate for 5,9
B3: 5,9 => SOLVED
* 152947368763285149894361725416853297275619483389472516947526831621738954538194672
B3: 4,6                                  # 13 pairs
E3: 5,9,1,4,6                            # reduction candidate for 5,9
E3: 5,9 => CTR
* 1.2.8736.7.326.1488643.172.416853297275619483389472516.47526831.21738.54538194.72
E3: 1,4,6                                # 12 pairs
F3: 5,9,1,4                              # reduction candidate for 5,9
F3: 5,9 => CTR
* 1.2..736.7.326.14886431.72.41685329727.6.148338..72516..7.26831.21738.54.381.4.72
F3: 1,4                                  # 13 pairs
* PAIR A4: 4,5 COL A
A7: 4,5,9                                # reduction candidate for 4,5
A7: 4,5 => CTR
* 1.25.736.7.32.914.8.43..72..168.329727.691483389472516..7926831.21738.54.381.5.72
A7: 9                                    # 11 pairs
A9: 4,5,6,9                              # reduction candidate for 4,5
A9: 4,5                                  # 11 pairs
* PAIR C5: 5,9 ROW 5
E5: 5,9,1                                # reduction candidate for 5,9
E5: 5,9                                  # 16 pairs
F5: 5,9,1                                # reduction candidate for 5,9
F5: 5,9                                  # 15 pairs
* PAIR E4: 4,5 COL E
E1: 4,5,8,9                              # reduction candidate for 4,5
E1: 4,5 => SOLVED
* 152947368763285149894361725416853297275619483389472516947526831621738954538194672
E1: 8,9                                  # 13 pairs
E3: 4,5,1,6,9                            # reduction candidate for 4,5
E3: 4,5 => CTR
* 1.2.873657532691488643.1729.168.329727.61.48338..72516..7526831.21738.54538194672
E3: 1,6,9                                # 12 pairs
E9: 4,5,9                                # reduction candidate for 4,5
E9: 4,5                                  # 15 pairs
* PAIR D6: 4,9 COL D
D1: 4,9,5                                # reduction candidate for 4,9
D1: 4,9 => SOLVED
* 152947368763285149894361725416853297275619483389472516947526831621738954538194672
D1: 5                                    # 21 pairs
D7: 4,9,5                                # reduction candidate for 4,9
D7: 4,9                                  # 21 pairs
* PAIR B7: 4,5 BLK 7
A7: 4,5,9                                # reduction candidate for 4,5
A7: 4,5 => CTR
* 1.25.736.7.32.914.8.43..72..168.329727.691483389472516..7926831.21738.54.381.5.72
A7: 9                                    # 11 pairs
A9: 4,5,6,9                              # reduction candidate for 4,5
A9: 4,5                                  # 11 pairs
* PAIR B7: 4,5 ROW 7
D7: 4,5,9                                # reduction candidate for 4,5
D7: 9 => CTR
* 1.25.736.7.32.914.8.43.172.41685329727.6..48338.472516..7926831.21738.54.381...72
D7: 4,5                                  # 11 pairs
* PAIR B7: 4,5 COL B
B1: 4,5,9                                # reduction candidate for 4,5
B1: 4,5                                  # 15 pairs
B3: 4,5,6,9                              # reduction candidate for 4,5
B3: 4,5                                  # 18 pairs
* PAIR A8: 6,9 BLK 7
A9: 6,9,4,5                              # reduction candidate for 6,9
A9: 6,9 => CTR
* 1.25.736.7.32.914.8.43.172.41685329727.6..48338.472516..7926831.21738.54.381...72
A9: 4,5                                  # 11 pairs
* PAIR G9: 6,9 ROW 9
A9: 6,9,4,5                              # reduction candidate for 6,9
A9: 6,9 => CTR
* 1.25.736.7.32.914.8.43.172.41685329727.6..48338.472516..7926831.21738.54.381...72
A9: 4,5                                  # 11 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-036-base-pr-000.dot
* REASONING
* DIS # E3: 4,5 => CTR => E3: 1,6,9
* DIS # F3: 4,5 => CTR => F3: 1,9
* DIS # E1: 5,9 => CTR => E1: 4,8
* DIS # E2: 5,9 => CTR => E2: 6,8
* DIS # E3: 5,9 => CTR => E3: 1,4,6
* DIS # F3: 5,9 => CTR => F3: 1,4
* DIS # F9: 5,9 => CTR => F9: 4
* PRF # B3: 5,9 => SOL
* DIS # E3: 5,9 => CTR => E3: 1,4,6
* DIS # F3: 5,9 => CTR => F3: 1,4
* DIS # A7: 4,5 => CTR => A7: 9
* PRF # E1: 4,5 => SOL
* DIS # E3: 4,5 => CTR => E3: 1,6,9
* PRF # D1: 4,9 => SOL
* DIS # A7: 4,5 => CTR => A7: 9
* DIS # D7: 9 => CTR => D7: 4,5
* DIS # A9: 6,9 => CTR => A9: 4,5
* DIS # A9: 6,9 => CTR => A9: 4,5
* CNT  18 HDP CHAINS /  52 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A4,A8,B7,C3,C5,C6,D6,E4,F2,G8,G9,I3)
* 1.2..736.7.32..14.8..3..72..168.329727.6..48338..72516..7.26831.21738.54.381...72
* PAIR C3: 4,5 BLK 1
B1: 4,5,9                                # reduction candidate for 4,5
B1: 4,5                                  # 15 pairs
B3: 4,5,6,9                              # reduction candidate for 4,5
B3: 4,5                                  # 18 pairs
* PAIR C3: 4,5 ROW 3
E3: 4,5,1,6,9                            # reduction candidate for 4,5
E3: 4,5 => CTR
* 1.2.873657532691488643.1729.168.329727.61.48338..72516..7526831.21738.54538194672
F3: 4,5,1,9                              # reduction candidate for 4,5
F3: 4,5 => CTR
* 1.2.8736575326914886431572941685329727.6.148338..72516..7526831.21738.545381..672
* RESTART
* PAIR RESTART
* PAIR C3: 4,5 BLK 1
B3: 4,5,6,9                              # reduction candidate for 4,5
B3: 6,9 => SOLVED
* 152947368763285149894361725416853297275619483389472516947526831621738954538194672
* DURATION: 0:00:06.965479  START: 03:55:45.638416  END: 03:55:52.603895 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-036-base-pr-001.dot
* REASONING
* DIS # E3: 4,5 => CTR => E3: 1,6,9
* DIS E3: 1,6,9 # F3: 4,5 => CTR => F3: 1,9
* PRF E3: 1,6,9 + F3: 1,9 # B3: 6,9 => SOL
* STA E3: 1,6,9 + F3: 1,9 + B3: 6,9
* CNT   3 HDP CHAINS /   6 HYP OPENED

Header Info

Top 500 Minimum 17 036

solution: 152947368763285149894361725416853297275619483389472516947526831621738954538194672
info: 1366     FNBHWXY  S8.f     47570

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

Solution

position: 152947368763285149894361725416853297275619483389472516947526831621738954538194672 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 # B1: 4,5 => UNS
* INC # B3: 4,5 => UNS
* DIS # E3: 4,5 => CTR => E3: 1,6,9
* INC # E3: 1,6,9 => UNS
* DIS # F3: 4,5 => CTR => F3: 1,9
* INC # F3: 1,9 => UNS
* INC # D1: 5,9 => UNS
* DIS # E1: 5,9 => CTR => E1: 4,8
* INC # E1: 4,8 => UNS
* DIS # E2: 5,9 => CTR => E2: 6,8
* INC # E2: 6,8 => UNS
* DIS # E3: 5,9 => CTR => E3: 1,4,6
* INC # E3: 1,4,6 => UNS
* DIS # F3: 5,9 => CTR => F3: 1,4
* INC # F3: 1,4 => UNS
* INC # B2: 5,9 => UNS
* INC # I2: 5,9 => UNS
* INC # F5: 5,9 => UNS
* DIS # F9: 5,9 => CTR => F9: 4
* INC # F9: 4 => UNS
* INC # I1: 5,9 => UNS
* INC # I2: 5,9 => UNS
* PRF # B3: 5,9 => SOL
* INC # B3: 4,6 => UNS
* DIS # E3: 5,9 => CTR => E3: 1,4,6
* INC # E3: 1,4,6 => UNS
* DIS # F3: 5,9 => CTR => F3: 1,4
* INC # F3: 1,4 => UNS
* DIS # A7: 4,5 => CTR => A7: 9
* INC # A7: 9 => UNS
* INC # A9: 4,5 => UNS
* INC # E5: 5,9 => UNS
* INC # F5: 5,9 => UNS
* PRF # E1: 4,5 => SOL
* INC # E1: 8,9 => UNS
* DIS # E3: 4,5 => CTR => E3: 1,6,9
* INC # E3: 1,6,9 => UNS
* INC # E9: 4,5 => UNS
* PRF # D1: 4,9 => SOL
* INC # D1: 5 => UNS
* INC # D7: 4,9 => UNS
* DIS # A7: 4,5 => CTR => A7: 9
* INC # A7: 9 => UNS
* INC # A9: 4,5 => UNS
* INC # D7: 4,5 => UNS
* DIS # D7: 9 => CTR => D7: 4,5
* INC # B1: 4,5 => UNS
* INC # B3: 4,5 => UNS
* DIS # A9: 6,9 => CTR => A9: 4,5
* INC # A9: 4,5 => UNS
* DIS # A9: 6,9 => CTR => A9: 4,5
* INC # A9: 4,5 => UNS
* CNT  52 HDP CHAINS /  52 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # B1: 4,5 => UNS
* INC # B3: 4,5 => UNS
* DIS # E3: 4,5 => CTR => E3: 1,6,9
* DIS E3: 1,6,9 # F3: 4,5 => CTR => F3: 1,9
* INC E3: 1,6,9 + F3: 1,9 # B3: 4,5 => UNS
* PRF E3: 1,6,9 + F3: 1,9 # B3: 6,9 => SOL
* STA E3: 1,6,9 + F3: 1,9 + B3: 6,9
* CNT   6 HDP CHAINS /   6 HYP OPENED