Analysis of xx-top500-224-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 2..1...........43......87...3.74............1.5...........6.35.1.8..2............ initial

Autosolve

position: 27.1.48..81..7.43..94..871..3174528..8...35.1.5281...3.2.461358148..2..7.6.987124 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* PRF # C1: 5,6 => SOL
* DIS # C1: 3 => CTR => C1: 5,6
* PRF # D2: 5,6 => SOL
* DIS # D2: 2 => CTR => D2: 5,6
* DIS # I2: 5,6 => CTR => I2: 2,9
* PRF # C1: 3,5 => SOL
* DIS # C1: 6 => CTR => C1: 3,5
* DIS # D3: 3,5 => CTR => D3: 2,6
* PRF # D3: 2,6 => SOL
* DIS # E3: 3,5 => CTR => E3: 2
* PRF # E3: 2 => SOL
* DIS # I2: 6,9 => CTR => I2: 2,5
* PRF # I2: 2,5 => SOL
* PRF # I1: 6,9 => SOL
* DIS # I2: 6,9 => CTR => I2: 2,5
* PRF # I2: 2,5 => SOL
* DIS # A5: 4,7 => CTR => A5: 6,9
* DIS # A5: 7,9 => CTR => A5: 4,6
* DIS # A5: 4,7 => CTR => A5: 6,9
* DIS # D2: 2,6 => CTR => D2: 5
* PRF # D2: 5 => SOL
* PRF # D3: 2,6 => SOL
* DIS # D3: 3,5 => CTR => D3: 2,6
* PRF # I1: 6,9 => SOL
* DIS # I2: 6,9 => CTR => I2: 2,5
* PRF # I2: 2,5 => SOL
* DIS # A5: 4,7 => CTR => A5: 6,9
* DIS # A5: 7,9 => CTR => A5: 4,6
* PRF # C1: 3,5 => SOL
* DIS # C1: 6 => CTR => C1: 3,5
* DIS # D3: 3,5 => CTR => D3: 2,6
* PRF # D3: 2,6 => SOL
* PRF # E1: 3,5 => SOL
* DIS # E1: 9 => CTR => E1: 3,5
* DIS # E3: 3,5 => CTR => E3: 2
* PRF # E3: 2 => SOL
* CNT  36 HDP CHAINS /  44 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: 5,6 => SOL
* STA C1: 5,6
* CNT   1 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

2..1...........43......87...3.74............1.5...........6.35.1.8..2............ initial
27.1.48..81..7.43..94..871..3174528..8...35.1.5281...3.2.461358148..2..7.6.987124 autosolve
275134869816579432394628715931745286687293541452816973729461358148352697563987124 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (22)
C2: 5,6
A3: 3,5
F2: 6,9
H1: 6,9
A4: 6,9
C5: 7,9
A6: 4,7
D5: 2,6
E5: 2,9
F6: 6,9
I4: 6,9
H5: 4,7
G6: 6,9
H6: 4,7
A7: 7,9
C7: 7,9
A9: 3,5
C9: 3,5
D8: 3,5
E8: 3,5
G8: 6,9
H8: 6,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
I2,I3: 2.. / I2 = 2  =>  0 pairs (*) / I3 = 2  =>  0 pairs (X)
D5,E5: 2.. / D5 = 2  =>  0 pairs (*) / E5 = 2  =>  0 pairs (X)
D2,I2: 2.. / D2 = 2  =>  0 pairs (X) / I2 = 2  =>  0 pairs (_)
E3,E5: 2.. / E3 = 2  =>  0 pairs (*) / E5 = 2  =>  0 pairs (X)
C1,A3: 3.. / C1 = 3  =>  0 pairs (X) / A3 = 3  =>  0 pairs (_)
A9,C9: 3.. / A9 = 3  =>  0 pairs (X) / C9 = 3  =>  0 pairs (_)
D8,E8: 3.. / D8 = 3  => 22 pairs (_) / E8 = 3  =>  0 pairs (X)
C1,E1: 3.. / C1 = 3  =>  0 pairs (X) / E1 = 3  =>  0 pairs (_)
A3,A9: 3.. / A3 = 3  =>  0 pairs (*) / A9 = 3  =>  0 pairs (X)
C1,C9: 3.. / C1 = 3  =>  0 pairs (X) / C9 = 3  =>  0 pairs (_)
D3,D8: 3.. / D3 = 3  =>  0 pairs (X) / D8 = 3  => 22 pairs (_)
A5,A6: 4.. / A5 = 4  =>  0 pairs (X) / A6 = 4  => 19 pairs (_)
H5,H6: 4.. / H5 = 4  => 19 pairs (_) / H6 = 4  =>  0 pairs (X)
A5,H5: 4.. / A5 = 4  =>  0 pairs (X) / H5 = 4  => 19 pairs (_)
A6,H6: 4.. / A6 = 4  => 19 pairs (_) / H6 = 4  =>  0 pairs (X)
A9,C9: 5.. / A9 = 5  =>  0 pairs (*) / C9 = 5  =>  0 pairs (X)
D8,E8: 5.. / D8 = 5  =>  0 pairs (X) / E8 = 5  => 22 pairs (_)
A3,A9: 5.. / A3 = 5  =>  0 pairs (X) / A9 = 5  =>  0 pairs (_)
C1,C2: 6.. / C1 = 6  =>  0 pairs (X) / C2 = 6  =>  0 pairs (_)
A4,A5: 6.. / A4 = 6  =>  0 pairs (X) / A5 = 6  =>  0 pairs (_)
D5,F6: 6.. / D5 = 6  =>  0 pairs (X) / F6 = 6  =>  0 pairs (_)
I4,G6: 6.. / I4 = 6  =>  0 pairs (*) / G6 = 6  =>  0 pairs (X)
G8,H8: 6.. / G8 = 6  =>  0 pairs (*) / H8 = 6  =>  0 pairs (X)
D3,I3: 6.. / D3 = 6  =>  0 pairs (*) / I3 = 6  =>  0 pairs (X)
A4,I4: 6.. / A4 = 6  =>  0 pairs (X) / I4 = 6  =>  0 pairs (_)
A5,D5: 6.. / A5 = 6  =>  0 pairs (*) / D5 = 6  =>  0 pairs (X)
F6,G6: 6.. / F6 = 6  =>  0 pairs (*) / G6 = 6  =>  0 pairs (X)
F2,F6: 6.. / F2 = 6  =>  0 pairs (X) / F6 = 6  =>  0 pairs (_)
G6,G8: 6.. / G6 = 6  =>  0 pairs (X) / G8 = 6  =>  0 pairs (_)
H1,H8: 6.. / H1 = 6  =>  0 pairs (*) / H8 = 6  =>  0 pairs (X)
H5,H6: 7.. / H5 = 7  =>  0 pairs (X) / H6 = 7  => 19 pairs (_)
A7,C7: 7.. / A7 = 7  => 17 pairs (_) / C7 = 7  =>  0 pairs (X)
A6,H6: 7.. / A6 = 7  =>  0 pairs (X) / H6 = 7  => 19 pairs (_)
C5,C7: 7.. / C5 = 7  => 17 pairs (_) / C7 = 7  =>  0 pairs (X)
E1,F2: 9.. / E1 = 9  =>  0 pairs (X) / F2 = 9  =>  0 pairs (_)
E5,F6: 9.. / E5 = 9  =>  0 pairs (*) / F6 = 9  =>  0 pairs (X)
I4,G6: 9.. / I4 = 9  =>  0 pairs (X) / G6 = 9  =>  0 pairs (_)
A7,C7: 9.. / A7 = 9  =>  0 pairs (X) / C7 = 9  => 17 pairs (_)
G8,H8: 9.. / G8 = 9  =>  0 pairs (X) / H8 = 9  =>  0 pairs (_)
F2,I2: 9.. / F2 = 9  =>  0 pairs (*) / I2 = 9  =>  0 pairs (X)
A4,I4: 9.. / A4 = 9  =>  0 pairs (*) / I4 = 9  =>  0 pairs (X)
F6,G6: 9.. / F6 = 9  =>  0 pairs (X) / G6 = 9  =>  0 pairs (_)
C5,C7: 9.. / C5 = 9  =>  0 pairs (X) / C7 = 9  => 17 pairs (_)
E1,E5: 9.. / E1 = 9  =>  0 pairs (X) / E5 = 9  =>  0 pairs (_)
F2,F6: 9.. / F2 = 9  =>  0 pairs (*) / F6 = 9  =>  0 pairs (X)
G6,G8: 9.. / G6 = 9  =>  0 pairs (*) / G8 = 9  =>  0 pairs (X)
H1,H8: 9.. / H1 = 9  =>  0 pairs (X) / H8 = 9  =>  0 pairs (_)
* DURATION: 0:02:06.169345  START: 10:28:24.016261  END: 10:30:30.185606 2017-05-04
* CP COUNT: (47)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A3,A4,A6,A7,A9,C2,C5,C7,C9,D5,D8,E5,E8,F2,F6,G6,G8,H1,H5,H6,H8,I4)
* 27.1.48..81..7.43..94..871..3174528..8...35.1.5281...3.2.461358148..2..7.6.987124
* PAIR C2: 5,6 BLK 1
C1: 5,6,3                                # reduction candidate for 5,6
C1: 5,6 => SOLVED
* 275134869816579432394628715931745286687293541452816973729461358148352697563987124
C1: 3 => CTR
* 2731.48..816.7943.594638712.3174528.68...35.1.5281...3.2.461358148..2..7.6.987124
* PAIR C2: 5,6 ROW 2
D2: 5,6,2                                # reduction candidate for 5,6
D2: 5,6 => SOLVED
* 275134869816579432394628715931745286687293541452816973729461358148352697563987124
D2: 2 => CTR
* 27.1.48..81.27.43..94..8712.3174528..8.6235.1.528196.3.2.461358148..2967.6.987124
I2: 5,6,2,9                              # reduction candidate for 5,6
I2: 5,6 => CTR
* 27.1.48..81.27943..946.871..3174528..8...35.1.5281...3.2.461358148..2..7.6.987124
I2: 2,9                                  # 23 pairs
* PAIR A3: 3,5 BLK 1
C1: 3,5,6                                # reduction candidate for 3,5
C1: 3,5 => SOLVED
* 275134869816579432394628715931745286687293541452816973729461358148352697563987124
C1: 6 => CTR
* 276134895815.7943.394..871..31745289.8..935.1.52816..3.2.461358148..2..7.6.987124
* PAIR A3: 3,5 ROW 3
D3: 3,5,2,6                              # reduction candidate for 3,5
D3: 3,5 => CTR
* 27.1.48..81..7.43..94..8716631745289.8.6235.1.52819..3.2.461358148..2..7.6.987124
D3: 2,6 => SOLVED
* 275134869816579432394628715931745286687293541452816973729461358148352697563987124
E3: 3,5,2                                # reduction candidate for 3,5
E3: 3,5 => CTR
* 27.1948..81..7.43..94..871..3174528..8..235.1.528196.3.2.461358148..2967.6.987124
E3: 2 => SOLVED
* 275134869816579432394628715931745286687293541452816973729461358148352697563987124
* PAIR F2: 6,9 ROW 2
I2: 6,9,2,5                              # reduction candidate for 6,9
I2: 6,9 => CTR
* 27.1.48..81.27.43..94..8712.3174528..8.6235.1.528196.3.2.461358148..2967.6.987124
I2: 2,5 => SOLVED
* 275134869816579432394628715931745286687293541452816973729461358148352697563987124
* PAIR H1: 6,9 BLK 3
I1: 6,9,5                                # reduction candidate for 6,9
I1: 6,9 => SOLVED
* 275134869816579432394628715931745286687293541452816973729461358148352697563987124
I1: 5                                    # 25 pairs
I2: 6,9,2,5                              # reduction candidate for 6,9
I2: 6,9 => CTR
* 27.1.48..81.27.43..94..8712.3174528..8.6235.1.528196.3.2.461358148..2967.6.987124
I2: 2,5 => SOLVED
* 275134869816579432394628715931745286687293541452816973729461358148352697563987124
* PAIR A4: 6,9 BLK 4
A5: 6,9,4,7                              # reduction candidate for 6,9
A5: 4,7 => CTR
* 27.1.48..81..7.43..94..871.631745289.896235.1.52819..3.2.461358148..2..7.6.987124
A5: 6,9                                  # 17 pairs
* PAIR C5: 7,9 BLK 4
A5: 7,9,4,6                              # reduction candidate for 7,9
A5: 7,9 => CTR
* 27.1.48..81..7.43..94..871.631745289.8.623541452819..3.2.461358148..2..7.6.987124
A5: 4,6                                  # 23 pairs
* PAIR A6: 4,7 BLK 4
A5: 4,7,6,9                              # reduction candidate for 4,7
A5: 4,7 => CTR
* 27.1.48..81..7.43..94..871.631745289.896235.1.52819..3.2.461358148..2..7.6.987124
A5: 6,9                                  # 17 pairs
* PAIR D5: 2,6 COL D
D2: 2,6,5                                # reduction candidate for 2,6
D2: 2,6 => CTR
* 27.1.48..81..7.43..94..8716631745289.8.6235.1.52819..3.2.461358148..2..7.6.987124
D2: 5 => SOLVED
* 275134869816579432394628715931745286687293541452816973729461358148352697563987124
D3: 2,6,3,5                              # reduction candidate for 2,6
D3: 2,6 => SOLVED
* 275134869816579432394628715931745286687293541452816973729461358148352697563987124
D3: 3,5 => CTR
* 27.1.48..81..7.43..94..8716631745289.8.6235.1.52819..3.2.461358148..2..7.6.987124
* PAIR I4: 6,9 COL I
I1: 6,9,5                                # reduction candidate for 6,9
I1: 6,9 => SOLVED
* 275134869816579432394628715931745286687293541452816973729461358148352697563987124
I1: 5                                    # 25 pairs
I2: 6,9,2,5                              # reduction candidate for 6,9
I2: 6,9 => CTR
* 27.1.48..81.27.43..94..8712.3174528..8.6235.1.528196.3.2.461358148..2967.6.987124
I2: 2,5 => SOLVED
* 275134869816579432394628715931745286687293541452816973729461358148352697563987124
* PAIR H5: 4,7 ROW 5
A5: 4,7,6,9                              # reduction candidate for 4,7
A5: 4,7 => CTR
* 27.1.48..81..7.43..94..871.631745289.896235.1.52819..3.2.461358148..2..7.6.987124
A5: 6,9                                  # 17 pairs
* PAIR A7: 7,9 COL A
A5: 7,9,4,6                              # reduction candidate for 7,9
A5: 7,9 => CTR
* 27.1.48..81..7.43..94..871.631745289.8.623541452819..3.2.461358148..2..7.6.987124
A5: 4,6                                  # 23 pairs
* PAIR C9: 3,5 COL C
C1: 3,5,6                                # reduction candidate for 3,5
C1: 3,5 => SOLVED
* 275134869816579432394628715931745286687293541452816973729461358148352697563987124
C1: 6 => CTR
* 276134895815.7943.394..871..31745289.8..935.1.52816..3.2.461358148..2..7.6.987124
* PAIR D8: 3,5 COL D
D3: 3,5,2,6                              # reduction candidate for 3,5
D3: 3,5 => CTR
* 27.1.48..81..7.43..94..8716631745289.8.6235.1.52819..3.2.461358148..2..7.6.987124
D3: 2,6 => SOLVED
* 275134869816579432394628715931745286687293541452816973729461358148352697563987124
* PAIR E8: 3,5 COL E
E1: 3,5,9                                # reduction candidate for 3,5
E1: 3,5 => SOLVED
* 275134869816579432394628715931745286687293541452816973729461358148352697563987124
E1: 9 => CTR
* 273194865816.7.43..94..871..3174528..8...35.1.5281...3.2.461358148..2..7.6.987124
E3: 3,5,2                                # reduction candidate for 3,5
E3: 3,5 => CTR
* 27.1948..81..7.43..94..871..3174528..8..235.1.528196.3.2.461358148..2967.6.987124
E3: 2 => SOLVED
* 275134869816579432394628715931745286687293541452816973729461358148352697563987124
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-224-base-pr-000.dot
* REASONING
* PRF # C1: 5,6 => SOL
* DIS # C1: 3 => CTR => C1: 5,6
* PRF # D2: 5,6 => SOL
* DIS # D2: 2 => CTR => D2: 5,6
* DIS # I2: 5,6 => CTR => I2: 2,9
* PRF # C1: 3,5 => SOL
* DIS # C1: 6 => CTR => C1: 3,5
* DIS # D3: 3,5 => CTR => D3: 2,6
* PRF # D3: 2,6 => SOL
* DIS # E3: 3,5 => CTR => E3: 2
* PRF # E3: 2 => SOL
* DIS # I2: 6,9 => CTR => I2: 2,5
* PRF # I2: 2,5 => SOL
* PRF # I1: 6,9 => SOL
* DIS # I2: 6,9 => CTR => I2: 2,5
* PRF # I2: 2,5 => SOL
* DIS # A5: 4,7 => CTR => A5: 6,9
* DIS # A5: 7,9 => CTR => A5: 4,6
* DIS # A5: 4,7 => CTR => A5: 6,9
* DIS # D2: 2,6 => CTR => D2: 5
* PRF # D2: 5 => SOL
* PRF # D3: 2,6 => SOL
* DIS # D3: 3,5 => CTR => D3: 2,6
* PRF # I1: 6,9 => SOL
* DIS # I2: 6,9 => CTR => I2: 2,5
* PRF # I2: 2,5 => SOL
* DIS # A5: 4,7 => CTR => A5: 6,9
* DIS # A5: 7,9 => CTR => A5: 4,6
* PRF # C1: 3,5 => SOL
* DIS # C1: 6 => CTR => C1: 3,5
* DIS # D3: 3,5 => CTR => D3: 2,6
* PRF # D3: 2,6 => SOL
* PRF # E1: 3,5 => SOL
* DIS # E1: 9 => CTR => E1: 3,5
* DIS # E3: 3,5 => CTR => E3: 2
* PRF # E3: 2 => SOL
* CNT  36 HDP CHAINS /  44 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A3,A4,A6,A7,A9,C2,C5,C7,C9,D5,D8,E5,E8,F2,F6,G6,G8,H1,H5,H6,H8,I4)
* 27.1.48..81..7.43..94..871..3174528..8...35.1.5281...3.2.461358148..2..7.6.987124
* PAIR C2: 5,6 BLK 1
C1: 5,6,3                                # reduction candidate for 5,6
C1: 5,6 => SOLVED
* 275134869816579432394628715931745286687293541452816973729461358148352697563987124
* DURATION: 0:00:02.678759  START: 10:31:43.810867  END: 10:31:46.489626 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-224-base-pr-001.dot
* REASONING
* PRF # C1: 5,6 => SOL
* STA C1: 5,6
* CNT   1 HDP CHAINS /   1 HYP OPENED

Header Info

Top 500 Minimum 17 224

solution: 275134869816579432394628715931745286687293541452816973729461358148352697563987124
info: 2007     FNBTHWX  S8.f     40363

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

Solution

position: 275134869816579432394628715931745286687293541452816973729461358148352697563987124 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: 5,6 => SOL
* DIS # C1: 3 => CTR => C1: 5,6
* PRF # D2: 5,6 => SOL
* DIS # D2: 2 => CTR => D2: 5,6
* DIS # I2: 5,6 => CTR => I2: 2,9
* INC # I2: 2,9 => UNS
* PRF # C1: 3,5 => SOL
* DIS # C1: 6 => CTR => C1: 3,5
* DIS # D3: 3,5 => CTR => D3: 2,6
* PRF # D3: 2,6 => SOL
* DIS # E3: 3,5 => CTR => E3: 2
* PRF # E3: 2 => SOL
* DIS # I2: 6,9 => CTR => I2: 2,5
* PRF # I2: 2,5 => SOL
* PRF # I1: 6,9 => SOL
* INC # I1: 5 => UNS
* DIS # I2: 6,9 => CTR => I2: 2,5
* PRF # I2: 2,5 => SOL
* INC # A5: 6,9 => UNS
* DIS # A5: 4,7 => CTR => A5: 6,9
* DIS # A5: 7,9 => CTR => A5: 4,6
* INC # A5: 4,6 => UNS
* DIS # A5: 4,7 => CTR => A5: 6,9
* INC # A5: 6,9 => UNS
* DIS # D2: 2,6 => CTR => D2: 5
* PRF # D2: 5 => SOL
* PRF # D3: 2,6 => SOL
* DIS # D3: 3,5 => CTR => D3: 2,6
* PRF # I1: 6,9 => SOL
* INC # I1: 5 => UNS
* DIS # I2: 6,9 => CTR => I2: 2,5
* PRF # I2: 2,5 => SOL
* DIS # A5: 4,7 => CTR => A5: 6,9
* INC # A5: 6,9 => UNS
* DIS # A5: 7,9 => CTR => A5: 4,6
* INC # A5: 4,6 => UNS
* PRF # C1: 3,5 => SOL
* DIS # C1: 6 => CTR => C1: 3,5
* DIS # D3: 3,5 => CTR => D3: 2,6
* PRF # D3: 2,6 => SOL
* PRF # E1: 3,5 => SOL
* DIS # E1: 9 => CTR => E1: 3,5
* DIS # E3: 3,5 => CTR => E3: 2
* PRF # E3: 2 => SOL
* CNT  44 HDP CHAINS /  44 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* PRF # C1: 5,6 => SOL
* STA C1: 5,6
* CNT   1 HDP CHAINS /   1 HYP OPENED