Analysis of cracking-the-cryptic-beyond-diabolical-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 1..4..7...2..5..8...3..6..9.1..4..7...2..5..89..3..6..7....8..28..2..9...9..7..1. initial

Autosolve

position: 1..4..7...2..5..8...3..6..9.1..4..7...2..5.989..3..6..7....8..28..2..9.729..7.81. autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # C2: 4,6 => CTR => C2: 7,9
* DIS # A5: 4,6 => CTR => A5: 3
* PRF # B3: 4,5 => SOL
* DIS # F1: 3 => CTR => F1: 2,9
* DIS # D5: 7 => CTR => D5: 1,6
* DIS # E7: 1,6 => CTR => E7: 3,9
* DIS # G4: 3,5 => CTR => G4: 2
* DIS # F8: 1 => CTR => F8: 3,4
* CNT   8 HDP CHAINS /  31 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 # C2: 4,6 => CTR => C2: 7,9
* DIS C2: 7,9 # A5: 4,6 => CTR => A5: 3
* DIS C2: 7,9 + A5: 3 # I2: 1,3 => CTR => I2: 4,6
* PRF C2: 7,9 + A5: 3 + I2: 4,6 # H3: 2 => SOL
* STA C2: 7,9 + A5: 3 + I2: 4,6 + H3: 2
* CNT   4 HDP CHAINS /   8 HYP OPENED

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

Details

Positions

1..4..7...2..5..8...3..6..9.1..4..7...2..5..89..3..6..7....8..28..2..9...9..7..1. initial
1..4..7...2..5..8...3..6..9.1..4..7...2..5.989..3..6..7....8..28..2..9.729..7.81. autosolve
189432765627951384453786129516849273372165498948327651731698542865214937294573816 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (7)
A2: 4,6
A3: 4,5
F4: 2,9
E5: 1,6
I4: 3,5
D9: 5,6
F9: 3,4

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
G5,I6: 1.. / G5 = 1  =>  0 pairs (X) / I6 = 1  => 10 pairs (_)
C7,C8: 1.. / C7 = 1  =>  7 pairs (_) / C8 = 1  =>  0 pairs (X)
I2,I6: 1.. / I2 = 1  =>  0 pairs (X) / I6 = 1  => 10 pairs (_)
G4,H6: 2.. / G4 = 2  =>  9 pairs (_) / H6 = 2  =>  0 pairs (X)
F4,G4: 2.. / F4 = 2  =>  0 pairs (X) / G4 = 2  =>  9 pairs (_)
G3,G4: 2.. / G3 = 2  =>  0 pairs (X) / G4 = 2  =>  9 pairs (_)
A4,A5: 3.. / A4 = 3  =>  0 pairs (X) / A5 = 3  =>  9 pairs (_)
B7,B8: 3.. / B7 = 3  =>  8 pairs (_) / B8 = 3  => 13 pairs (_)
A5,G5: 3.. / A5 = 3  =>  9 pairs (_) / G5 = 3  =>  0 pairs (X)
F9,I9: 3.. / F9 = 3  => 14 pairs (_) / I9 = 3  =>  0 pairs (X)
F8,F9: 4.. / F8 = 4  => 14 pairs (_) / F9 = 4  =>  0 pairs (X)
D7,D9: 5.. / D7 = 5  => 18 pairs (_) / D9 = 5  =>  7 pairs (_)
A3,A4: 5.. / A3 = 5  =>  9 pairs (_) / A4 = 5  =>  0 pairs (*)
C2,B3: 7.. / C2 = 7  => 15 pairs (_) / B3 = 7  =>  0 pairs (X)
D5,F6: 7.. / D5 = 7  =>  0 pairs (X) / F6 = 7  => 15 pairs (_)
B3,D3: 7.. / B3 = 7  =>  0 pairs (X) / D3 = 7  => 15 pairs (_)
B5,D5: 7.. / B5 = 7  => 15 pairs (_) / D5 = 7  =>  0 pairs (X)
C2,C6: 7.. / C2 = 7  => 15 pairs (_) / C6 = 7  =>  0 pairs (X)
F2,F6: 7.. / F2 = 7  =>  0 pairs (X) / F6 = 7  => 15 pairs (_)
D4,E6: 8.. / D4 = 8  => 16 pairs (_) / E6 = 8  =>  0 pairs (X)
C4,D4: 8.. / C4 = 8  =>  0 pairs (X) / D4 = 8  => 16 pairs (_)
D3,D4: 8.. / D3 = 8  =>  0 pairs (X) / D4 = 8  => 16 pairs (_)
C1,C2: 9.. / C1 = 9  =>  8 pairs (_) / C2 = 9  =>  0 pairs (X)
D4,F4: 9.. / D4 = 9  =>  0 pairs (X) / F4 = 9  =>  9 pairs (_)
D7,E7: 9.. / D7 = 9  =>  0 pairs (X) / E7 = 9  =>  7 pairs (_)
E1,E7: 9.. / E1 = 9  =>  0 pairs (X) / E7 = 9  =>  7 pairs (_)
* DURATION: 0:00:28.167039  START: 23:38:52.448787  END: 23:39:20.615826 2020-09-20
* CP COUNT: (26)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A2,A3,D9,E5,F4,F9,I4)
* 1..4..7...2..5..8...3..6..9.1..4..7...2..5.989..3..6..7....8..28..2..9.729..7.81.
* PAIR A2: 4,6 BLK 1
C2: 4,6,7,9                              # reduction candidate for 4,6
C2: 4,6 => CTR
* 1894..7...2..57.8.573..6..9.18.49275..27.53989573826417...985.28.52.19.729.574813
C2: 7,9                                  #  8 pairs
* PAIR A2: 4,6 ROW 2
I2: 4,6,1,3                              # reduction candidate for 4,6
I2: 4,6                                  # 13 pairs
I2: 1,3                                  #  9 pairs
* PAIR A2: 4,6 COL A
A5: 4,6,3                                # reduction candidate for 4,6
A5: 4,6 => CTR
* 1..43275662.951483543786129318.49275..2..53989..3..6417....85.28..2.49.7296573814
A5: 3                                    #  9 pairs
* PAIR A3: 4,5 BLK 1
B3: 4,5,7,8                              # reduction candidate for 4,5
B3: 4,5 => SOLVED
* 189432765627951384453786129516849273372165498948327651731698542865214937294573816
B3: 7,8                                  #  8 pairs
* PAIR A3: 4,5 ROW 3
G3: 4,5,1,2                              # reduction candidate for 4,5
G3: 4,5                                  # 14 pairs
H3: 4,5,2                                # reduction candidate for 4,5
H3: 4,5                                  # 10 pairs
* PAIR F4: 2,9 COL F
F1: 2,9,3                                # reduction candidate for 2,9
F1: 3 => CTR
* 1..4.37...2..5..8...3..6..9.1..4..7...2..5.989..3..6..7....8..28..2..9.729..74813
F1: 2,9                                  # 13 pairs
* PAIR E5: 1,6 BLK 5
D5: 1,6,7                                # reduction candidate for 1,6
D5: 7 => CTR
* 1..43.7...2.957381.73186..9.1.8492733427651989873216..7.1.98..28..2149.729..7381.
D5: 1,6                                  # 15 pairs
* PAIR E5: 1,6 COL E
E7: 1,6,3,9                              # reduction candidate for 1,6
E7: 1,6 => CTR
* 1..49.73..2915..8..73..6..9.1..4927...27.5.989.73..6..7..9.8..28..23.9.729.574813
E7: 3,9                                  #  8 pairs
E8: 1,6,3                                # reduction candidate for 1,6
E8: 1,6                                  # 12 pairs
* PAIR I4: 3,5 BLK 6
G4: 3,5,2                                # reduction candidate for 3,5
G4: 3,5 => CTR
* 1..42.73..2..53.8...38162.9.18942.75..2.65.989..38762173..985.28..2319.729.574813
G4: 2                                    #  9 pairs
* PAIR I4: 3,5 ROW 4
A4: 3,5,6                                # reduction candidate for 3,5
A4: 6                                    # 13 pairs
A4: 3,5                                  # 11 pairs
* PAIR I4: 3,5 COL I
I1: 3,5,6                                # reduction candidate for 3,5
I1: 3,5                                  # 22 pairs
I9: 3,5,4,6                              # reduction candidate for 3,5
I9: 3,5                                  # 11 pairs
* PAIR D9: 5,6 BLK 8
D7: 5,6,1,9                              # reduction candidate for 5,6
D7: 1,9                                  # 14 pairs
D7: 5,6                                  # 12 pairs
* PAIR D9: 5,6 ROW 9
C9: 5,6,4                                # reduction candidate for 5,6
C9: 5,6                                  #  9 pairs
I9: 5,6,3,4                              # reduction candidate for 5,6
I9: 5,6                                  # 22 pairs
* PAIR F9: 3,4 BLK 8
F8: 3,4,1                                # reduction candidate for 3,4
F8: 1 => CTR
* 1..4..736.27953.8.5.3716..9.1.849275.721653989..3276417.1.98..28..2.19.729..74813
F8: 3,4                                  # 14 pairs
* PAIR F9: 3,4 ROW 9
I9: 3,4,5,6                              # reduction candidate for 3,4
I9: 5,6                                  # 22 pairs
I9: 3,4                                  #  9 pairs
* INCONCLUSIVE
* SAVE PR GRAPH cracking-the-cryptic-beyond-diabolical-base-pr-000.dot
* REASONING
* DIS # C2: 4,6 => CTR => C2: 7,9
* DIS # A5: 4,6 => CTR => A5: 3
* PRF # B3: 4,5 => SOL
* DIS # F1: 3 => CTR => F1: 2,9
* DIS # D5: 7 => CTR => D5: 1,6
* DIS # E7: 1,6 => CTR => E7: 3,9
* DIS # G4: 3,5 => CTR => G4: 2
* DIS # F8: 1 => CTR => F8: 3,4
* CNT   8 HDP CHAINS /  31 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A2,A3,D9,E5,F4,F9,I4)
* 1..4..7...2..5..8...3..6..9.1..4..7...2..5.989..3..6..7....8..28..2..9.729..7.81.
* PAIR A2: 4,6 BLK 1
C2: 4,6,7,9                              # reduction candidate for 4,6
C2: 4,6 => CTR
* 1894..7...2..57.8.573..6..9.18.49275..27.53989573826417...985.28.52.19.729.574813
* PAIR A2: 4,6 ROW 2
I2: 4,6,1,3                              # reduction candidate for 4,6
I2: 1,3                                  # 18 pairs
I2: 4,6                                  # 13 pairs
* PAIR A2: 4,6 COL A
A5: 4,6,3                                # reduction candidate for 4,6
A5: 4,6 => CTR
* 1..43275662.951483543786129318.49275..2..53989..3..6417....85.28..2.49.7296573814
* PAIR RESTART
* PAIR A2: 4,6 ROW 2
I2: 4,6,1,3                              # reduction candidate for 4,6
I2: 1,3 => CTR
* 1..4..7..62..5.48.4.3..6..951..4..733427651989..3..6..7....83.283.2149.729..7.81.
* PAIR RESTART
* PAIR A3: 4,5 ROW 3
H3: 4,5,2                                # reduction candidate for 4,5
H3: 2 => SOLVED
* 189432765627951384453786129516849273372165498948327651731698542865214937294573816
* DURATION: 0:00:06.594310  START: 23:39:37.380321  END: 23:39:43.974631 2020-09-20
* SOLUTION FOUND
* SAVE PR GRAPH cracking-the-cryptic-beyond-diabolical-base-pr-001.dot
* REASONING
* DIS # C2: 4,6 => CTR => C2: 7,9
* DIS C2: 7,9 # A5: 4,6 => CTR => A5: 3
* DIS C2: 7,9 + A5: 3 # I2: 1,3 => CTR => I2: 4,6
* PRF C2: 7,9 + A5: 3 + I2: 4,6 # H3: 2 => SOL
* STA C2: 7,9 + A5: 3 + I2: 4,6 + H3: 2
* CNT   4 HDP CHAINS /   8 HYP OPENED

Header Info

https://www.youtube.com/watch?v=8C-A7xmBLRU

Solution

position: 189432765627951384453786129516849273372165498948327651731698542865214937294573816 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 # C2: 4,6 => CTR => C2: 7,9
* INC # C2: 7,9 => UNS
* INC # I2: 4,6 => UNS
* INC # I2: 1,3 => UNS
* DIS # A5: 4,6 => CTR => A5: 3
* INC # A5: 3 => UNS
* PRF # B3: 4,5 => SOL
* INC # B3: 7,8 => UNS
* INC # G3: 4,5 => UNS
* INC # H3: 4,5 => UNS
* INC # F1: 2,9 => UNS
* DIS # F1: 3 => CTR => F1: 2,9
* INC # D5: 1,6 => UNS
* DIS # D5: 7 => CTR => D5: 1,6
* DIS # E7: 1,6 => CTR => E7: 3,9
* INC # E7: 3,9 => UNS
* INC # E8: 1,6 => UNS
* DIS # G4: 3,5 => CTR => G4: 2
* INC # G4: 2 => UNS
* INC # A4: 3,5 => UNS
* INC # A4: 6 => UNS
* INC # I1: 3,5 => UNS
* INC # I9: 3,5 => UNS
* INC # D7: 5,6 => UNS
* INC # D7: 1,9 => UNS
* INC # C9: 5,6 => UNS
* INC # I9: 5,6 => UNS
* INC # F8: 3,4 => UNS
* DIS # F8: 1 => CTR => F8: 3,4
* INC # I9: 3,4 => UNS
* INC # I9: 5,6 => UNS
* CNT  31 HDP CHAINS /  31 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # C2: 4,6 => CTR => C2: 7,9
* INC C2: 7,9 # I2: 4,6 => UNS
* INC C2: 7,9 # I2: 1,3 => UNS
* DIS C2: 7,9 # A5: 4,6 => CTR => A5: 3
* INC C2: 7,9 + A5: 3 # I2: 4,6 => UNS
* DIS C2: 7,9 + A5: 3 # I2: 1,3 => CTR => I2: 4,6
* INC C2: 7,9 + A5: 3 + I2: 4,6 # H3: 4,5 => UNS
* PRF C2: 7,9 + A5: 3 + I2: 4,6 # H3: 2 => SOL
* STA C2: 7,9 + A5: 3 + I2: 4,6 + H3: 2
* CNT   8 HDP CHAINS /   8 HYP OPENED