Analysis of xx-top95-076-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: ....1.78.5....9..........4..2..........6....3.74.8.........3..2.8..4..1.6..5..... initial

Autosolve

position: 2.9.1.78.5487.9...7.18.2.4..26..7..889562..73.74.8....457193862983246517612578..4 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # E3: 3,6 => CTR => E3: 5
* PRF # E3: 5 => SOL
* PRF # G3: 3,6 => SOL
* DIS # G3: 9 => CTR => G3: 3,6
* PRF # D4: 3,4 => SOL
* DIS # D4: 9 => CTR => D4: 3,4
* DIS # E3: 3,6 => CTR => E3: 5
* PRF # E3: 5 => SOL
* DIS # G2: 3,6 => CTR => G2: 1,2
* DIS # I3: 5,6 => CTR => I3: 9
* PRF # I3: 9 => SOL
* DIS # G2: 1,6 => CTR => G2: 2,3
* DIS # G2: 1,6 => CTR => G2: 2,3
* PRF # I6: 1,6 => SOL
* DIS # I6: 9 => CTR => I6: 1,6
* DIS # E3: 6 => CTR => E3: 3,5
* DIS # D4: 3,9 => CTR => D4: 4
* PRF # D4: 4 => SOL
* DIS # H6: 5,9 => CTR => H6: 2
* PRF # H6: 2 => SOL
* PRF # G4: 9 => SOL
* PRF # G3: 6 => SOL
* CNT  22 HDP CHAINS /  28 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: 3,6 => CTR => E3: 5
* PRF E3: 5 => SOL
* STA E3: 5
* CNT   2 HDP CHAINS /   1 HYP OPENED

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

Details

Positions

....1.78.5....9..........4..2..........6....3.74.8.........3..2.8..4..1.6..5..... initial
2.9.1.78.5487.9...7.18.2.4..26..7..889562..73.74.8....457193862983246517612578..4 autosolve
269314785548769231731852649126437958895621473374985126457193862983246517612578394 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (18)
B1: 3,6
B3: 3,6
D1: 3,4
F1: 4,5
E2: 3,6
I1: 5,6
H2: 2,3
I2: 1,6
A4: 1,3
A6: 1,3
E4: 3,5
F5: 1,4
D6: 3,9
F6: 1,5
H4: 5,9
G5: 1,4
G9: 3,9
H9: 3,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
G2,I2: 1.. / G2 = 1  =>  0 pairs (X) / I2 = 1  => 18 pairs (_)
A4,A6: 1.. / A4 = 1  =>  0 pairs (*) / A6 = 1  =>  0 pairs (X)
F5,F6: 1.. / F5 = 1  =>  0 pairs (*) / F6 = 1  =>  0 pairs (X)
A4,G4: 1.. / A4 = 1  =>  0 pairs (*) / G4 = 1  =>  0 pairs (X)
F5,G5: 1.. / F5 = 1  =>  0 pairs (*) / G5 = 1  =>  0 pairs (X)
I2,I6: 1.. / I2 = 1  => 18 pairs (_) / I6 = 1  =>  0 pairs (X)
G2,H2: 2.. / G2 = 2  =>  0 pairs (*) / H2 = 2  =>  0 pairs (X)
G6,H6: 2.. / G6 = 2  =>  0 pairs (X) / H6 = 2  =>  0 pairs (_)
G2,G6: 2.. / G2 = 2  =>  0 pairs (*) / G6 = 2  =>  0 pairs (X)
H2,H6: 2.. / H2 = 2  =>  0 pairs (X) / H6 = 2  =>  0 pairs (_)
B1,B3: 3.. / B1 = 3  =>  0 pairs (X) / B3 = 3  =>  0 pairs (_)
A4,A6: 3.. / A4 = 3  =>  0 pairs (X) / A6 = 3  =>  0 pairs (_)
G9,H9: 3.. / G9 = 3  =>  0 pairs (*) / H9 = 3  =>  0 pairs (X)
B1,D1: 3.. / B1 = 3  =>  0 pairs (X) / D1 = 3  =>  0 pairs (_)
A6,D6: 3.. / A6 = 3  =>  0 pairs (*) / D6 = 3  =>  0 pairs (X)
H2,H9: 3.. / H2 = 3  =>  0 pairs (*) / H9 = 3  =>  0 pairs (X)
D1,F1: 4.. / D1 = 4  =>  0 pairs (X) / F1 = 4  =>  0 pairs (_)
D4,F5: 4.. / D4 = 4  =>  0 pairs (*) / F5 = 4  =>  0 pairs (X)
G4,G5: 4.. / G4 = 4  =>  0 pairs (X) / G5 = 4  =>  0 pairs (_)
D4,G4: 4.. / D4 = 4  =>  0 pairs (*) / G4 = 4  =>  0 pairs (X)
F5,G5: 4.. / F5 = 4  =>  0 pairs (X) / G5 = 4  =>  0 pairs (_)
D1,D4: 4.. / D1 = 4  =>  0 pairs (X) / D4 = 4  =>  0 pairs (_)
F1,F5: 4.. / F1 = 4  =>  0 pairs (*) / F5 = 4  =>  0 pairs (X)
F1,E3: 5.. / F1 = 5  =>  0 pairs (X) / E3 = 5  =>  0 pairs (_)
I1,I3: 5.. / I1 = 5  =>  0 pairs (*) / I3 = 5  =>  0 pairs (X)
E4,F6: 5.. / E4 = 5  =>  0 pairs (X) / F6 = 5  =>  0 pairs (_)
H4,H6: 5.. / H4 = 5  =>  0 pairs (*) / H6 = 5  =>  0 pairs (X)
F1,I1: 5.. / F1 = 5  =>  0 pairs (X) / I1 = 5  =>  0 pairs (_)
E3,I3: 5.. / E3 = 5  =>  0 pairs (*) / I3 = 5  =>  0 pairs (X)
E4,H4: 5.. / E4 = 5  =>  0 pairs (X) / H4 = 5  =>  0 pairs (_)
F6,H6: 5.. / F6 = 5  =>  0 pairs (*) / H6 = 5  =>  0 pairs (X)
E3,E4: 5.. / E3 = 5  =>  0 pairs (*) / E4 = 5  =>  0 pairs (X)
F1,F6: 5.. / F1 = 5  =>  0 pairs (X) / F6 = 5  =>  0 pairs (_)
B1,B3: 6.. / B1 = 6  =>  0 pairs (*) / B3 = 6  =>  0 pairs (X)
E2,E3: 6.. / E2 = 6  => 20 pairs (_) / E3 = 6  =>  0 pairs (X)
G6,I6: 6.. / G6 = 6  =>  0 pairs (X) / I6 = 6  =>  0 pairs (_)
B1,I1: 6.. / B1 = 6  =>  0 pairs (*) / I1 = 6  =>  0 pairs (X)
G3,I3: 9.. / G3 = 9  =>  0 pairs (X) / I3 = 9  =>  0 pairs (_)
D4,D6: 9.. / D4 = 9  =>  0 pairs (X) / D6 = 9  =>  0 pairs (_)
G9,H9: 9.. / G9 = 9  =>  0 pairs (X) / H9 = 9  =>  0 pairs (_)
I3,I6: 9.. / I3 = 9  =>  0 pairs (*) / I6 = 9  =>  0 pairs (X)
* DURATION: 0:01:52.369644  START: 00:39:44.520192  END: 00:41:36.889836 2017-05-04
* CP COUNT: (41)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A4,A6,B1,B3,D1,D6,E2,E4,F1,F5,F6,G5,G9,H2,H4,H9,I1,I2)
* 2.9.1.78.5487.9...7.18.2.4..26..7..889562..73.74.8....457193862983246517612578..4
* PAIR B3: 3,6 ROW 3
E3: 3,6,5                                # reduction candidate for 3,6
E3: 3,6 => CTR
* 2.9.15786548769..1761832945.26.57.9889562..73.74.8....457193862983246517612578..4
E3: 5 => SOLVED
* 269314785548769231731852649126437958895621473374985126457193862983246517612578394
G3: 3,6,9                                # reduction candidate for 3,6
G3: 3,6 => SOLVED
* 269314785548769231731852649126437958895621473374985126457193862983246517612578394
G3: 9 => CTR
* 2.9.1.78.5487.9.317.18.294..269.7458895624173.7438...9457193862983246517612578394
* PAIR D1: 3,4 COL D
D4: 3,4,9                                # reduction candidate for 3,4
D4: 3,4 => SOLVED
* 269314785548769231731852649126437958895621473374985126457193862983246517612578394
D4: 9 => CTR
* 2.9415786548769..17618329453269.7..889562..73.74.8....457193862983246517612578..4
* PAIR E2: 3,6 BLK 2
E3: 3,6,5                                # reduction candidate for 3,6
E3: 3,6 => CTR
* 2.9.15786548769..1761832945.26.57.9889562..73.74.8....457193862983246517612578..4
E3: 5 => SOLVED
* 269314785548769231731852649126437958895621473374985126457193862983246517612578394
* PAIR E2: 3,6 ROW 2
G2: 3,6,1,2                              # reduction candidate for 3,6
G2: 3,6 => CTR
* 269314785548769321731852649.26437.58895621473.74.8.2.6457193862983246517612578.34
G2: 1,2                                  # 19 pairs
* PAIR I1: 5,6 BLK 3
I3: 5,6,9                                # reduction candidate for 5,6
I3: 5,6 => CTR
* 2.9.1.78.5487.9.317.18.294..269.7458895624173.7438...9457193862983246517612578394
I3: 9 => SOLVED
* 269314785548769231731852649126437958895621473374985126457193862983246517612578394
* PAIR H2: 2,3 BLK 3
G2: 2,3,1,6                              # reduction candidate for 2,3
G2: 1,6 => CTR
* 2.9.1.78.5487.9.2.7.18.2349.26..7..889562..73.74.8.2.6457193862983246517612578934
G2: 2,3                                  # 20 pairs
* PAIR I2: 1,6 BLK 3
G2: 1,6,2,3                              # reduction candidate for 1,6
G2: 1,6 => CTR
* 2.9.1.78.5487.9.2.7.18.2349.26..7..889562..73.74.8.2.6457193862983246517612578934
G2: 2,3                                  # 20 pairs
* PAIR I2: 1,6 COL I
I6: 1,6,9                                # reduction candidate for 1,6
I6: 1,6 => SOLVED
* 269314785548769231731852649126437958895621473374985126457193862983246517612578394
I6: 9 => CTR
* 2.9.1.78.5487692317.18.294..269.7458895624173.7438.629457193862983246517612578.94
* PAIR E4: 3,5 COL E
E3: 3,5,6                                # reduction candidate for 3,5
E3: 6 => CTR
* 2.9.15786548769...7.18.2.4..26..7..889562..73.74.8....457193862983246517612578..4
E3: 3,5                                  # 20 pairs
* PAIR D6: 3,9 BLK 5
D4: 3,9,4                                # reduction candidate for 3,9
D4: 3,9 => CTR
* 2.9415786548769..1761832945.26.5749889562..73.74.8....457193862983246517612578..4
D4: 4 => SOLVED
* 269314785548769231731852649126437958895621473374985126457193862983246517612578394
* PAIR H4: 5,9 BLK 6
H6: 5,9,2                                # reduction candidate for 5,9
H6: 5,9 => CTR
* 269314785548769321731852649.26437.58895621473.74.8.2.6457193862983246517612578.34
H6: 2 => SOLVED
* 269314785548769231731852649126437958895621473374985126457193862983246517612578394
* PAIR G5: 1,4 BLK 6
G4: 1,4,9                                # reduction candidate for 1,4
G4: 9 => SOLVED
* 269314785548769231731852649126437958895621473374985126457193862983246517612578394
G4: 1,4                                  # 19 pairs
* PAIR G9: 3,9 COL G
G3: 3,9,6                                # reduction candidate for 3,9
G3: 6 => SOLVED
* 269314785548769231731852649126437958895621473374985126457193862983246517612578394
G3: 3,9                                  # 22 pairs
* INCONCLUSIVE
* SAVE PR GRAPH xx-top95-076-base-pr-000.dot
* REASONING
* DIS # E3: 3,6 => CTR => E3: 5
* PRF # E3: 5 => SOL
* PRF # G3: 3,6 => SOL
* DIS # G3: 9 => CTR => G3: 3,6
* PRF # D4: 3,4 => SOL
* DIS # D4: 9 => CTR => D4: 3,4
* DIS # E3: 3,6 => CTR => E3: 5
* PRF # E3: 5 => SOL
* DIS # G2: 3,6 => CTR => G2: 1,2
* DIS # I3: 5,6 => CTR => I3: 9
* PRF # I3: 9 => SOL
* DIS # G2: 1,6 => CTR => G2: 2,3
* DIS # G2: 1,6 => CTR => G2: 2,3
* PRF # I6: 1,6 => SOL
* DIS # I6: 9 => CTR => I6: 1,6
* DIS # E3: 6 => CTR => E3: 3,5
* DIS # D4: 3,9 => CTR => D4: 4
* PRF # D4: 4 => SOL
* DIS # H6: 5,9 => CTR => H6: 2
* PRF # H6: 2 => SOL
* PRF # G4: 9 => SOL
* PRF # G3: 6 => SOL
* CNT  22 HDP CHAINS /  28 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A4,A6,B1,B3,D1,D6,E2,E4,F1,F5,F6,G5,G9,H2,H4,H9,I1,I2)
* 2.9.1.78.5487.9...7.18.2.4..26..7..889562..73.74.8....457193862983246517612578..4
* PAIR B3: 3,6 ROW 3
E3: 3,6,5                                # reduction candidate for 3,6
E3: 3,6 => CTR
* 2.9.15786548769..1761832945.26.57.9889562..73.74.8....457193862983246517612578..4
E3: 5 => SOLVED
* 269314785548769231731852649126437958895621473374985126457193862983246517612578394
* DURATION: 0:00:02.346315  START: 00:42:28.082482  END: 00:42:30.428797 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top95-076-base-pr-001.dot
* REASONING
* DIS # E3: 3,6 => CTR => E3: 5
* PRF E3: 5 => SOL
* STA E3: 5
* CNT   2 HDP CHAINS /   1 HYP OPENED

Header Info

Top 95 Sudokus 076
[sudoku:top95] “95 Hard Puzzles”, http://magictour.free.fr/top95, or http://norvig.com/top95.txt

Solution

position: 269314785548769231731852649126437958895621473374985126457193862983246517612578394 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:

* DIS # E3: 3,6 => CTR => E3: 5
* PRF # E3: 5 => SOL
* PRF # G3: 3,6 => SOL
* DIS # G3: 9 => CTR => G3: 3,6
* PRF # D4: 3,4 => SOL
* DIS # D4: 9 => CTR => D4: 3,4
* DIS # E3: 3,6 => CTR => E3: 5
* PRF # E3: 5 => SOL
* DIS # G2: 3,6 => CTR => G2: 1,2
* INC # G2: 1,2 => UNS
* DIS # I3: 5,6 => CTR => I3: 9
* PRF # I3: 9 => SOL
* INC # G2: 2,3 => UNS
* DIS # G2: 1,6 => CTR => G2: 2,3
* DIS # G2: 1,6 => CTR => G2: 2,3
* INC # G2: 2,3 => UNS
* PRF # I6: 1,6 => SOL
* DIS # I6: 9 => CTR => I6: 1,6
* INC # E3: 3,5 => UNS
* DIS # E3: 6 => CTR => E3: 3,5
* DIS # D4: 3,9 => CTR => D4: 4
* PRF # D4: 4 => SOL
* DIS # H6: 5,9 => CTR => H6: 2
* PRF # H6: 2 => SOL
* INC # G4: 1,4 => UNS
* PRF # G4: 9 => SOL
* INC # G3: 3,9 => UNS
* PRF # G3: 6 => SOL
* CNT  28 HDP CHAINS /  28 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # E3: 3,6 => CTR => E3: 5
* PRF E3: 5 => SOL
* STA E3: 5
* CNT   2 HDP CHAINS /   1 HYP OPENED