Analysis of xx-top500-169-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 5.....7.2.4....5......1.....2.5.........3..8........1.1.86........7..4..3........ initial

Autosolve

position: 51.8.473284.3..591.37.15846.215.837...513..8..834...15158643927...781453374.5.168 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # F2: 7 => CTR => F2: 2,6
* PRF # A8: 2,9 => SOL
* DIS # A8: 6 => CTR => A8: 2,9
* DIS # F2: 2,7 => CTR => F2: 6
* PRF # F2: 6 => SOL
* DIS # A4: 6,9 => CTR => A4: 4
* PRF # A4: 4 => SOL
* PRF # A5: 6,9 => SOL
* DIS # A6: 6,9 => CTR => A6: 7
* PRF # A6: 7 => SOL
* DIS # F5: 6,9 => CTR => F5: 2,7
* DIS # F5: 6,9 => CTR => F5: 2,7
* DIS # A4: 6,9 => CTR => A4: 4
* PRF # A4: 4 => SOL
* DIS # F6: 2,7 => CTR => F6: 6,9
* PRF # A4: 4,9 => SOL
* DIS # A4: 6 => CTR => A4: 4,9
* DIS # F5: 2,6 => CTR => F5: 7,9
* PRF # F5: 7,9 => SOL
* DIS # A5: 4,9 => CTR => A5: 6,7
* PRF # A5: 6,7 => SOL
* DIS # F6: 2,6 => CTR => F6: 7,9
* DIS # A8: 6,9 => CTR => A8: 2
* PRF # A8: 2 => SOL
* PRF # A8: 2,9 => SOL
* DIS # A8: 6 => CTR => A8: 2,9
* DIS # F5: 2,9 => CTR => F5: 6,7
* CNT  27 HDP CHAINS /  37 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 # F2: 7 => CTR => F2: 2,6
* PRF F2: 2,6 # A8: 2,9 => SOL
* STA F2: 2,6 + A8: 2,9
* CNT   2 HDP CHAINS /   3 HYP OPENED

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

Details

Positions

5.....7.2.4....5......1.....2.5.........3..8........1.1.86........7..4..3........ initial
51.8.473284.3..591.37.15846.215.837...513..8..834...15158643927...781453374.5.168 autosolve
516894732842376591937215846421568379695137284783429615158643927269781453374952168 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (17)
C1: 6,9
C2: 2,6
A3: 2,9
E1: 6,9
E2: 2,7
D3: 2,9
B5: 6,9
E4: 6,9
E6: 2,7
I4: 4,9
G5: 2,6
I5: 4,9
G6: 2,6
B8: 6,9
C8: 2,9
D9: 2,9
F9: 2,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
C2,A3: 2.. / C2 = 2  =>  0 pairs (*) / A3 = 2  =>  0 pairs (X)
G5,G6: 2.. / G5 = 2  => 16 pairs (_) / G6 = 2  =>  0 pairs (X)
A8,C8: 2.. / A8 = 2  =>  0 pairs (*) / C8 = 2  =>  0 pairs (X)
D9,F9: 2.. / D9 = 2  =>  0 pairs (X) / F9 = 2  =>  0 pairs (_)
A3,D3: 2.. / A3 = 2  =>  0 pairs (X) / D3 = 2  =>  0 pairs (_)
F5,G5: 2.. / F5 = 2  =>  0 pairs (X) / G5 = 2  => 16 pairs (_)
A3,A8: 2.. / A3 = 2  =>  0 pairs (X) / A8 = 2  =>  0 pairs (_)
C2,C8: 2.. / C2 = 2  =>  0 pairs (*) / C8 = 2  =>  0 pairs (X)
D3,D9: 2.. / D3 = 2  =>  0 pairs (*) / D9 = 2  =>  0 pairs (X)
E2,E6: 2.. / E2 = 2  =>  0 pairs (X) / E6 = 2  => 16 pairs (_)
A4,A5: 4.. / A4 = 4  =>  0 pairs (*) / A5 = 4  =>  0 pairs (X)
I4,I5: 4.. / I4 = 4  =>  0 pairs (X) / I5 = 4  =>  0 pairs (_)
A4,I4: 4.. / A4 = 4  =>  0 pairs (*) / I4 = 4  =>  0 pairs (X)
A5,I5: 4.. / A5 = 4  =>  0 pairs (X) / I5 = 4  =>  0 pairs (_)
C1,C2: 6.. / C1 = 6  =>  0 pairs (*) / C2 = 6  =>  0 pairs (X)
E1,F2: 6.. / E1 = 6  =>  0 pairs (X) / F2 = 6  =>  0 pairs (_)
G5,G6: 6.. / G5 = 6  =>  0 pairs (X) / G6 = 6  => 16 pairs (_)
A8,B8: 6.. / A8 = 6  =>  0 pairs (X) / B8 = 6  =>  0 pairs (_)
C1,E1: 6.. / C1 = 6  =>  0 pairs (*) / E1 = 6  =>  0 pairs (X)
C2,F2: 6.. / C2 = 6  =>  0 pairs (X) / F2 = 6  =>  0 pairs (_)
A4,E4: 6.. / A4 = 6  =>  0 pairs (X) / E4 = 6  =>  0 pairs (_)
B5,B8: 6.. / B5 = 6  =>  0 pairs (X) / B8 = 6  =>  0 pairs (_)
E1,E4: 6.. / E1 = 6  =>  0 pairs (X) / E4 = 6  =>  0 pairs (_)
E2,F2: 7.. / E2 = 7  => 16 pairs (_) / F2 = 7  =>  0 pairs (X)
A5,A6: 7.. / A5 = 7  =>  0 pairs (X) / A6 = 7  =>  0 pairs (_)
A5,F5: 7.. / A5 = 7  =>  0 pairs (X) / F5 = 7  =>  0 pairs (_)
E2,E6: 7.. / E2 = 7  => 16 pairs (_) / E6 = 7  =>  0 pairs (X)
C1,A3: 9.. / C1 = 9  =>  0 pairs (X) / A3 = 9  =>  0 pairs (_)
E1,D3: 9.. / E1 = 9  =>  0 pairs (*) / D3 = 9  =>  0 pairs (X)
I4,I5: 9.. / I4 = 9  =>  0 pairs (*) / I5 = 9  =>  0 pairs (X)
D9,F9: 9.. / D9 = 9  =>  0 pairs (*) / F9 = 9  =>  0 pairs (X)
C1,E1: 9.. / C1 = 9  =>  0 pairs (X) / E1 = 9  =>  0 pairs (_)
A3,D3: 9.. / A3 = 9  =>  0 pairs (*) / D3 = 9  =>  0 pairs (X)
A6,F6: 9.. / A6 = 9  =>  0 pairs (X) / F6 = 9  =>  0 pairs (_)
B5,B8: 9.. / B5 = 9  =>  0 pairs (*) / B8 = 9  =>  0 pairs (X)
C1,C8: 9.. / C1 = 9  =>  0 pairs (X) / C8 = 9  =>  0 pairs (_)
D3,D9: 9.. / D3 = 9  =>  0 pairs (X) / D9 = 9  =>  0 pairs (_)
E1,E4: 9.. / E1 = 9  =>  0 pairs (*) / E4 = 9  =>  0 pairs (X)
* DURATION: 0:01:14.958834  START: 08:30:35.764236  END: 08:31:50.723070 2017-05-04
* CP COUNT: (38)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A3,B5,B8,C1,C2,C8,D3,D9,E1,E2,E4,E6,F9,G5,G6,I4,I5)
* 51.8.473284.3..591.37.15846.215.837...513..8..834...15158643927...781453374.5.168
* PAIR C2: 2,6 ROW 2
F2: 2,6,7                                # reduction candidate for 2,6
F2: 7 => CTR
* 51.864732846327591237915846621598374..513..8..834...15158643927...781453374.5.168
F2: 2,6                                  # 16 pairs
* PAIR A3: 2,9 COL A
A8: 2,9,6                                # reduction candidate for 2,9
A8: 2,9 => SOLVED
* 516894732842376591937215846421568379695137284783429615158643927269781453374952168
A8: 6 => CTR
* 51.8.473284.3..591237915846.215983744.5137289.834...15158643927...781453374.5.168
* PAIR E2: 2,7 BLK 2
F2: 2,7,6                                # reduction candidate for 2,7
F2: 2,7 => CTR
* 51.8647328463..59123791584662159837449513..8..834...15158643927...781453374.5.168
F2: 6 => SOLVED
* 516894732842376591937215846421568379695137284783429615158643927269781453374952168
* PAIR B5: 6,9 BLK 4
A4: 6,9,4                                # reduction candidate for 6,9
A4: 6,9 => CTR
* 51.8.473284.3..591.37.15846.215.83744.5137289783429615158643927.92781453374952168
A4: 4 => SOLVED
* 516894732842376591937215846421568379695137284783429615158643927269781453374952168
A5: 6,9,4,7                              # reduction candidate for 6,9
A5: 6,9 => SOLVED
* 516894732842376591937215846421568379695137284783429615158643927269781453374952168
A5: 4,7                                  # 18 pairs
A6: 6,9,7                                # reduction candidate for 6,9
A6: 6,9 => CTR
* 516894732842376591937215846421568379795132.84.834...15158643927...781453374.5.168
A6: 7 => SOLVED
* 516894732842376591937215846421568379695137284783429615158643927269781453374952168
* PAIR B5: 6,9 ROW 5
F5: 6,9,2,7                              # reduction candidate for 6,9
F5: 6,9 => CTR
* 51.8.473284.3..591.37.158464215683797651392849834..615158643927692781453374.5.168
F5: 2,7                                  # 19 pairs
* PAIR E4: 6,9 BLK 5
F5: 6,9,2,7                              # reduction candidate for 6,9
F5: 6,9 => CTR
* 51.8.473284.3..591.37.158464215683797651392849834..615158643927692781453374.5.168
F5: 2,7                                  # 19 pairs
F6: 6,9,2,7                              # reduction candidate for 6,9
F6: 6,9                                  # 19 pairs
* PAIR E4: 6,9 ROW 4
A4: 6,9,4                                # reduction candidate for 6,9
A4: 6,9 => CTR
* 51.8.473284.3..591.37.15846.215.83744.5137289783429615158643927.92781453374952168
A4: 4 => SOLVED
* 516894732842376591937215846421568379695137284783429615158643927269781453374952168
* PAIR E6: 2,7 BLK 5
F5: 2,7,6,9                              # reduction candidate for 2,7
F5: 2,7                                  # 19 pairs
F6: 2,7,6,9                              # reduction candidate for 2,7
F6: 2,7 => CTR
* 5198647328463..5912379158466215.837...513..8.9834..615158643927.92781453374.5.168
F6: 6,9                                  # 19 pairs
* PAIR I4: 4,9 ROW 4
A4: 4,9,6                                # reduction candidate for 4,9
A4: 4,9 => SOLVED
* 516894732842376591937215846421568379695137284783429615158643927269781453374952168
A4: 6 => CTR
* 51.8.473284.3..591.37.1584662159837449513..8..834...15158643927...781453374.5.168
* PAIR G5: 2,6 ROW 5
F5: 2,6,7,9                              # reduction candidate for 2,6
F5: 2,6 => CTR
* 51.8.473284.3..591.37.15846421568379795132684683479.15158643927...781453374.5.168
F5: 7,9 => SOLVED
* 516894732842376591937215846421568379695137284783429615158643927269781453374952168
* PAIR I5: 4,9 ROW 5
A5: 4,9,6,7                              # reduction candidate for 4,9
A5: 4,9 => CTR
* 51.894732842376591937215846.215683794.513728.783429615158643927...781453374952168
A5: 6,7 => SOLVED
* 516894732842376591937215846421568379695137284783429615158643927269781453374952168
* PAIR G6: 2,6 ROW 6
F6: 2,6,7,9                              # reduction candidate for 2,6
F6: 2,6 => CTR
* 5198647328463275912379158466215.837...513..8.98347..15158643927.92781453374.5.168
F6: 7,9                                  # 18 pairs
* PAIR B8: 6,9 BLK 7
A8: 6,9,2                                # reduction candidate for 6,9
A8: 6,9 => CTR
* 51.8.473284.3..591237915846.215983744.5137289.834...15158643927...781453374.5.168
A8: 2 => SOLVED
* 516894732842376591937215846421568379695137284783429615158643927269781453374952168
* PAIR C8: 2,9 BLK 7
A8: 2,9,6                                # reduction candidate for 2,9
A8: 2,9 => SOLVED
* 516894732842376591937215846421568379695137284783429615158643927269781453374952168
A8: 6 => CTR
* 51.8.473284.3..591237915846.215983744.5137289.834...15158643927...781453374.5.168
* PAIR F9: 2,9 COL F
F5: 2,9,6,7                              # reduction candidate for 2,9
F5: 2,9 => CTR
* 516894732842376591937215846421568379795132.84.834...15158643927...781453374.5.168
F5: 6,7                                  # 17 pairs
F6: 2,9,6,7                              # reduction candidate for 2,9
F6: 2,9                                  # 19 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-169-base-pr-000.dot
* REASONING
* DIS # F2: 7 => CTR => F2: 2,6
* PRF # A8: 2,9 => SOL
* DIS # A8: 6 => CTR => A8: 2,9
* DIS # F2: 2,7 => CTR => F2: 6
* PRF # F2: 6 => SOL
* DIS # A4: 6,9 => CTR => A4: 4
* PRF # A4: 4 => SOL
* PRF # A5: 6,9 => SOL
* DIS # A6: 6,9 => CTR => A6: 7
* PRF # A6: 7 => SOL
* DIS # F5: 6,9 => CTR => F5: 2,7
* DIS # F5: 6,9 => CTR => F5: 2,7
* DIS # A4: 6,9 => CTR => A4: 4
* PRF # A4: 4 => SOL
* DIS # F6: 2,7 => CTR => F6: 6,9
* PRF # A4: 4,9 => SOL
* DIS # A4: 6 => CTR => A4: 4,9
* DIS # F5: 2,6 => CTR => F5: 7,9
* PRF # F5: 7,9 => SOL
* DIS # A5: 4,9 => CTR => A5: 6,7
* PRF # A5: 6,7 => SOL
* DIS # F6: 2,6 => CTR => F6: 7,9
* DIS # A8: 6,9 => CTR => A8: 2
* PRF # A8: 2 => SOL
* PRF # A8: 2,9 => SOL
* DIS # A8: 6 => CTR => A8: 2,9
* DIS # F5: 2,9 => CTR => F5: 6,7
* CNT  27 HDP CHAINS /  37 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A3,B5,B8,C1,C2,C8,D3,D9,E1,E2,E4,E6,F9,G5,G6,I4,I5)
* 51.8.473284.3..591.37.15846.215.837...513..8..834...15158643927...781453374.5.168
* PAIR C2: 2,6 ROW 2
F2: 2,6,7                                # reduction candidate for 2,6
F2: 7 => CTR
* 51.864732846327591237915846621598374..513..8..834...15158643927...781453374.5.168
* PAIR RESTART
* PAIR A3: 2,9 COL A
A8: 2,9,6                                # reduction candidate for 2,9
A8: 2,9 => SOLVED
* 516894732842376591937215846421568379695137284783429615158643927269781453374952168
* DURATION: 0:00:04.626999  START: 08:32:37.661330  END: 08:32:42.288329 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-169-base-pr-001.dot
* REASONING
* DIS # F2: 7 => CTR => F2: 2,6
* PRF F2: 2,6 # A8: 2,9 => SOL
* STA F2: 2,6 + A8: 2,9
* CNT   2 HDP CHAINS /   3 HYP OPENED

Header Info

Top 500 Minimum 17 169

solution: 516894732842376591937215846421568379695137284783429615158643927269781453374952168
info: 1824     FNBTWY   S8.f     32155

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

Solution

position: 516894732842376591937215846421568379695137284783429615158643927269781453374952168 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 # F2: 2,6 => UNS
* DIS # F2: 7 => CTR => F2: 2,6
* PRF # A8: 2,9 => SOL
* DIS # A8: 6 => CTR => A8: 2,9
* DIS # F2: 2,7 => CTR => F2: 6
* PRF # F2: 6 => SOL
* DIS # A4: 6,9 => CTR => A4: 4
* PRF # A4: 4 => SOL
* PRF # A5: 6,9 => SOL
* INC # A5: 4,7 => UNS
* DIS # A6: 6,9 => CTR => A6: 7
* PRF # A6: 7 => SOL
* DIS # F5: 6,9 => CTR => F5: 2,7
* INC # F5: 2,7 => UNS
* DIS # F5: 6,9 => CTR => F5: 2,7
* INC # F5: 2,7 => UNS
* INC # F6: 6,9 => UNS
* DIS # A4: 6,9 => CTR => A4: 4
* PRF # A4: 4 => SOL
* INC # F5: 2,7 => UNS
* DIS # F6: 2,7 => CTR => F6: 6,9
* INC # F6: 6,9 => UNS
* PRF # A4: 4,9 => SOL
* DIS # A4: 6 => CTR => A4: 4,9
* DIS # F5: 2,6 => CTR => F5: 7,9
* PRF # F5: 7,9 => SOL
* DIS # A5: 4,9 => CTR => A5: 6,7
* PRF # A5: 6,7 => SOL
* DIS # F6: 2,6 => CTR => F6: 7,9
* INC # F6: 7,9 => UNS
* DIS # A8: 6,9 => CTR => A8: 2
* PRF # A8: 2 => SOL
* PRF # A8: 2,9 => SOL
* DIS # A8: 6 => CTR => A8: 2,9
* DIS # F5: 2,9 => CTR => F5: 6,7
* INC # F5: 6,7 => UNS
* INC # F6: 2,9 => UNS
* CNT  37 HDP CHAINS /  37 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # F2: 2,6 => UNS
* DIS # F2: 7 => CTR => F2: 2,6
* PRF F2: 2,6 # A8: 2,9 => SOL
* STA F2: 2,6 + A8: 2,9
* CNT   3 HDP CHAINS /   3 HYP OPENED