Analysis of xx-top500-099-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: .7.24..3.2...5..........8...3.8.6...........1......5.....3...8.1.4......5........ initial

Autosolve

position: .71248.35248.53.1.35.1..842.3581642.8..5.43.141..3.5.8...3.51841.4....535.34.1... autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # A7: 7 => CTR => A7: 6,9
* PRF # E3: 7 => SOL
* DIS # C7: 6,9 => CTR => C7: 2,7
* PRF # E3: 7 => SOL
* DIS # D8: 7 => CTR => D8: 6,9
* PRF # E3: 7,9 => SOL
* PRF # A7: 6 => SOL
* DIS # H6: 7,9 => CTR => H6: 6
* PRF # D8: 7,9 => SOL
* DIS # H6: 7,9 => CTR => H6: 6
* DIS # I9: 7,9 => CTR => I9: 6
* DIS # I9: 7,9 => CTR => I9: 6
* DIS # H6: 7,9 => CTR => H6: 6
* CNT  13 HDP CHAINS /  48 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 # A7: 7 => CTR => A7: 6,9
* PRF A7: 6,9 # E3: 7 => SOL
* STA A7: 6,9 + E3: 7
* CNT   2 HDP CHAINS /   4 HYP OPENED

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

Details

Positions

.7.24..3.2...5..........8...3.8.6...........1......5.....3...8.1.4......5........ initial
.71248.35248.53.1.35.1..842.3581642.8..5.43.141..3.5.8...3.51841.4....535.34.1... autosolve
971248635248653917356179842735816429862594371419732568697325184184967253523481796 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (9)
A1: 6,9
C3: 6,9
D2: 6,9
F3: 7,9
G1: 6,9
A4: 7,9
D6: 7,9
I4: 7,9
H9: 7,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
E5,F6: 2.. / E5 = 2  => 13 pairs (_) / F6 = 2  => 11 pairs (_)
G8,G9: 2.. / G8 = 2  => 13 pairs (_) / G9 = 2  =>  9 pairs (_)
C6,F6: 2.. / C6 = 2  => 13 pairs (_) / F6 = 2  => 11 pairs (_)
F6,F8: 2.. / F6 = 2  => 11 pairs (_) / F8 = 2  => 13 pairs (_)
A1,C3: 6.. / A1 = 6  => 16 pairs (_) / C3 = 6  =>  0 pairs (*)
D2,E3: 6.. / D2 = 6  =>  0 pairs (*) / E3 = 6  =>  0 pairs (X)
H5,H6: 6.. / H5 = 6  =>  0 pairs (X) / H6 = 6  => 10 pairs (_)
A1,G1: 6.. / A1 = 6  => 16 pairs (_) / G1 = 6  =>  0 pairs (*)
C3,E3: 6.. / C3 = 6  =>  0 pairs (*) / E3 = 6  =>  0 pairs (X)
C6,H6: 6.. / C6 = 6  =>  0 pairs (X) / H6 = 6  => 10 pairs (_)
A1,A7: 6.. / A1 = 6  => 16 pairs (_) / A7 = 6  =>  0 pairs (*)
D2,D8: 6.. / D2 = 6  =>  0 pairs (*) / D8 = 6  =>  0 pairs (X)
I2,I9: 6.. / I2 = 6  =>  0 pairs (X) / I9 = 6  => 10 pairs (_)
E3,F3: 7.. / E3 = 7  =>  0 pairs (*) / F3 = 7  =>  0 pairs (X)
G2,I2: 7.. / G2 = 7  => 10 pairs (_) / I2 = 7  => 14 pairs (_)
A7,C7: 7.. / A7 = 7  =>  0 pairs (X) / C7 = 7  => 12 pairs (_)
A4,I4: 7.. / A4 = 7  => 12 pairs (_) / I4 = 7  =>  0 pairs (X)
A4,A7: 7.. / A4 = 7  => 12 pairs (_) / A7 = 7  =>  0 pairs (X)
D6,D8: 7.. / D6 = 7  => 12 pairs (_) / D8 = 7  =>  0 pairs (X)
B8,B9: 8.. / B8 = 8  =>  9 pairs (_) / B9 = 8  =>  9 pairs (_)
E8,E9: 8.. / E8 = 8  =>  9 pairs (_) / E9 = 8  =>  9 pairs (_)
B8,E8: 8.. / B8 = 8  =>  9 pairs (_) / E8 = 8  =>  9 pairs (_)
B9,E9: 8.. / B9 = 8  =>  9 pairs (_) / E9 = 8  =>  9 pairs (_)
A1,C3: 9.. / A1 = 9  =>  0 pairs (*) / C3 = 9  =>  0 pairs (X)
A1,G1: 9.. / A1 = 9  =>  0 pairs (*) / G1 = 9  =>  0 pairs (X)
A4,I4: 9.. / A4 = 9  =>  0 pairs (X) / I4 = 9  => 12 pairs (_)
* DURATION: 0:00:41.886385  START: 06:09:13.923936  END: 06:09:55.810321 2017-05-04
* CP COUNT: (26)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,A4,C3,D2,D6,F3,G1,H9,I4)
* .71248.35248.53.1.35.1..842.3581642.8..5.43.141..3.5.8...3.51841.4....535.34.1...
* PAIR A1: 6,9 COL A
A7: 6,9,7                                # reduction candidate for 6,9
A7: 7 => CTR
* 6712489352489537163591678429358164278.75.43.141.7325987.23.51841.467.2535.3481679
A7: 6,9                                  # 12 pairs
* PAIR C3: 6,9 ROW 3
E3: 6,9,7                                # reduction candidate for 6,9
E3: 7 => SOLVED
* 971248635248653917356179842735816429862594371419732568697325184184967253523481796
E3: 6,9                                  # 11 pairs
* PAIR C3: 6,9 COL C
C5: 6,9,2,7                              # reduction candidate for 6,9
C5: 6,9                                  # 14 pairs
C6: 6,9,2,7                              # reduction candidate for 6,9
C6: 6,9                                  # 14 pairs
C7: 6,9,2,7                              # reduction candidate for 6,9
C7: 6,9 => CTR
* 6712489352489537163591678429358164278675243914127395687263951841946...535.34.1.79
C7: 2,7                                  # 10 pairs
* PAIR D2: 6,9 BLK 2
E3: 6,9,7                                # reduction candidate for 6,9
E3: 7 => SOLVED
* 971248635248653917356179842735816429862594371419732568697325184184967253523481796
E3: 6,9                                  # 11 pairs
* PAIR D2: 6,9 ROW 2
G2: 6,9,7                                # reduction candidate for 6,9
G2: 6,9                                  # 14 pairs
I2: 6,9,7                                # reduction candidate for 6,9
I2: 6,9                                  # 10 pairs
* PAIR D2: 6,9 COL D
D8: 6,9,7                                # reduction candidate for 6,9
D8: 7 => CTR
* 971248635248653.1.3561..8427358164298695243714129375686273951841.47629535.34.1..6
D8: 6,9                                  # 12 pairs
* PAIR F3: 7,9 BLK 2
E3: 7,9,6                                # reduction candidate for 7,9
E3: 7,9 => SOLVED
* 971248635248653917356179842735816429862594371419732568697325184184967253523481796
E3: 6                                    # 16 pairs
* PAIR F3: 7,9 COL F
F6: 7,9,2                                # reduction candidate for 7,9
F6: 7,9                                  # 13 pairs
F8: 7,9,2                                # reduction candidate for 7,9
F8: 7,9                                  # 11 pairs
* PAIR G1: 6,9 BLK 3
G2: 6,9,7                                # reduction candidate for 6,9
G2: 6,9                                  # 14 pairs
I2: 6,9,7                                # reduction candidate for 6,9
I2: 6,9                                  # 10 pairs
* PAIR G1: 6,9 COL G
G8: 6,9,2,7                              # reduction candidate for 6,9
G8: 6,9                                  # 11 pairs
G9: 6,9,2,7                              # reduction candidate for 6,9
G9: 6,9                                  # 15 pairs
* PAIR A4: 7,9 BLK 4
C5: 7,9,2,6                              # reduction candidate for 7,9
C5: 7,9                                  # 13 pairs
C6: 7,9,2,6                              # reduction candidate for 7,9
C6: 7,9                                  # 16 pairs
* PAIR A4: 7,9 COL A
A7: 7,9,6                                # reduction candidate for 7,9
A7: 6 => SOLVED
* 971248635248653917356179842735816429862594371419732568697325184184967253523481796
A7: 7,9                                  # 16 pairs
* PAIR D6: 7,9 BLK 5
E5: 7,9,2                                # reduction candidate for 7,9
E5: 7,9                                  # 11 pairs
F6: 7,9,2                                # reduction candidate for 7,9
F6: 7,9                                  # 13 pairs
* PAIR D6: 7,9 ROW 6
C6: 7,9,2,6                              # reduction candidate for 7,9
C6: 7,9                                  # 16 pairs
H6: 7,9,6                                # reduction candidate for 7,9
H6: 7,9 => CTR
* 671248935248953.1.359167842.3581642.8..594361416732598.6.3251841.46.9.5359348127.
H6: 6                                    # 10 pairs
* PAIR D6: 7,9 COL D
D8: 7,9,6                                # reduction candidate for 7,9
D8: 7,9 => SOLVED
* 971248635248653917356179842735816429862594371419732568697325184184967253523481796
D8: 6                                    # 16 pairs
* PAIR I4: 7,9 BLK 6
H5: 7,9,6                                # reduction candidate for 7,9
H5: 7,9                                  # 10 pairs
H6: 7,9,6                                # reduction candidate for 7,9
H6: 7,9 => CTR
* 671248935248953.1.359167842.3581642.8..594361416732598.6.3251841.46.9.5359348127.
H6: 6                                    # 10 pairs
* PAIR I4: 7,9 COL I
I2: 7,9,6                                # reduction candidate for 7,9
I2: 7,9                                  # 10 pairs
I9: 7,9,6                                # reduction candidate for 7,9
I9: 7,9 => CTR
* 671248935248953716359167842.3581642.8..5.43.141.732598...325184184679253523481679
I9: 6                                    # 10 pairs
* PAIR H9: 7,9 BLK 9
G8: 7,9,2,6                              # reduction candidate for 7,9
G8: 7,9                                  # 12 pairs
G9: 7,9,2,6                              # reduction candidate for 7,9
G9: 7,9                                  # 15 pairs
I9: 7,9,6                                # reduction candidate for 7,9
I9: 7,9 => CTR
* 671248935248953716359167842.3581642.8..5.43.141.732598...325184184679253523481679
I9: 6                                    # 10 pairs
* PAIR H9: 7,9 ROW 9
E9: 7,9,2,6,8                            # reduction candidate for 7,9
E9: 7,9                                  # 12 pairs
E9: 2,6,8                                #  9 pairs
* PAIR H9: 7,9 COL H
H5: 7,9,6                                # reduction candidate for 7,9
H5: 7,9                                  # 10 pairs
H6: 7,9,6                                # reduction candidate for 7,9
H6: 7,9 => CTR
* 671248935248953.1.359167842.3581642.8..594361416732598.6.3251841.46.9.5359348127.
H6: 6                                    # 10 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-099-base-pr-000.dot
* REASONING
* DIS # A7: 7 => CTR => A7: 6,9
* PRF # E3: 7 => SOL
* DIS # C7: 6,9 => CTR => C7: 2,7
* PRF # E3: 7 => SOL
* DIS # D8: 7 => CTR => D8: 6,9
* PRF # E3: 7,9 => SOL
* PRF # A7: 6 => SOL
* DIS # H6: 7,9 => CTR => H6: 6
* PRF # D8: 7,9 => SOL
* DIS # H6: 7,9 => CTR => H6: 6
* DIS # I9: 7,9 => CTR => I9: 6
* DIS # I9: 7,9 => CTR => I9: 6
* DIS # H6: 7,9 => CTR => H6: 6
* CNT  13 HDP CHAINS /  48 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A1,A4,C3,D2,D6,F3,G1,H9,I4)
* .71248.35248.53.1.35.1..842.3581642.8..5.43.141..3.5.8...3.51841.4....535.34.1...
* PAIR A1: 6,9 COL A
A7: 6,9,7                                # reduction candidate for 6,9
A7: 7 => CTR
* 6712489352489537163591678429358164278.75.43.141.7325987.23.51841.467.2535.3481679
* PAIR RESTART
* PAIR C3: 6,9 ROW 3
E3: 6,9,7                                # reduction candidate for 6,9
E3: 7 => SOLVED
* 971248635248653917356179842735816429862594371419732568697325184184967253523481796
* DURATION: 0:00:04.973179  START: 06:10:40.096914  END: 06:10:45.070093 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-099-base-pr-001.dot
* REASONING
* DIS # A7: 7 => CTR => A7: 6,9
* PRF A7: 6,9 # E3: 7 => SOL
* STA A7: 6,9 + E3: 7
* CNT   2 HDP CHAINS /   4 HYP OPENED

Header Info

Top 500 Minimum 17 099

solution: 971248635248653917356179842735816429862594371419732568697325184184967253523481796
info: 1577     FNBTWXY  S8.f     22592

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

Solution

position: 971248635248653917356179842735816429862594371419732568697325184184967253523481796 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 # A7: 6,9 => UNS
* DIS # A7: 7 => CTR => A7: 6,9
* INC # E3: 6,9 => UNS
* PRF # E3: 7 => SOL
* INC # C5: 6,9 => UNS
* INC # C6: 6,9 => UNS
* DIS # C7: 6,9 => CTR => C7: 2,7
* INC # C7: 2,7 => UNS
* INC # E3: 6,9 => UNS
* PRF # E3: 7 => SOL
* INC # G2: 6,9 => UNS
* INC # I2: 6,9 => UNS
* INC # D8: 6,9 => UNS
* DIS # D8: 7 => CTR => D8: 6,9
* PRF # E3: 7,9 => SOL
* INC # E3: 6 => UNS
* INC # F6: 7,9 => UNS
* INC # F8: 7,9 => UNS
* INC # G2: 6,9 => UNS
* INC # I2: 6,9 => UNS
* INC # G8: 6,9 => UNS
* INC # G9: 6,9 => UNS
* INC # C5: 7,9 => UNS
* INC # C6: 7,9 => UNS
* INC # A7: 7,9 => UNS
* PRF # A7: 6 => SOL
* INC # E5: 7,9 => UNS
* INC # F6: 7,9 => UNS
* INC # C6: 7,9 => UNS
* DIS # H6: 7,9 => CTR => H6: 6
* INC # H6: 6 => UNS
* PRF # D8: 7,9 => SOL
* INC # D8: 6 => UNS
* INC # H5: 7,9 => UNS
* DIS # H6: 7,9 => CTR => H6: 6
* INC # H6: 6 => UNS
* INC # I2: 7,9 => UNS
* DIS # I9: 7,9 => CTR => I9: 6
* INC # I9: 6 => UNS
* INC # G8: 7,9 => UNS
* INC # G9: 7,9 => UNS
* DIS # I9: 7,9 => CTR => I9: 6
* INC # I9: 6 => UNS
* INC # E9: 7,9 => UNS
* INC # E9: 2,6,8 => UNS
* INC # H5: 7,9 => UNS
* DIS # H6: 7,9 => CTR => H6: 6
* INC # H6: 6 => UNS
* CNT  48 HDP CHAINS /  48 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # A7: 6,9 => UNS
* DIS # A7: 7 => CTR => A7: 6,9
* INC A7: 6,9 # E3: 6,9 => UNS
* PRF A7: 6,9 # E3: 7 => SOL
* STA A7: 6,9 + E3: 7
* CNT   4 HDP CHAINS /   4 HYP OPENED