Analysis of zz-www.sudokuwiki.org-0030-base.sdk

Contents

Sudoku from http://www.sudokuwiki.org/Print_Weekly_Sudoku.asp?unsolvable=30

level: medium

Sudoku from http://www.sudokuwiki.org/Print_Weekly_Sudoku.asp?unsolvable=30

position: .3.....1...91.24......7.9..9..82....85.....94....96..5..3.8......83.97...1.....3. initial

Autosolve

position: .3.9...1...91.24..1...7.9..9..8253..85.7...943..496.85.93.8......83.97...1....839 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # H3: 5,6 => CTR => H3: 2
* DIS # H3: 5,6 => CTR => H3: 2
* DIS # A1: 5,6 => CTR => A1: 2,4,7
* PRF # G7: 1 => SOL
* PRF # C4: 4,6 => SOL
* PRF # C6: 1 => SOL
* PRF # I4: 1 => SOL
* DIS # C6: 7 => CTR => C6: 1,2
* CNT   8 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 # H3: 5,6 => CTR => H3: 2
* DIS H3: 2 # D9: 5,6 => CTR => D9: 2
* PRF H3: 2 + D9: 2 # E2: 5,6 => SOL
* STA H3: 2 + D9: 2 + E2: 5,6
* CNT   3 HDP CHAINS /  12 HYP OPENED

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

Details

Positions

.3.....1...91.24......7.9..9..82....85.....94....96..5..3.8......83.97...1.....3. initial
.3.9...1...91.24..1...7.9..9..8253..85.7...943..496.85.93.8......83.97...1....839 autosolve
236948517789152463145673928964825371852731694371496285693587142428319756517264839 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (12)
F1: 4,8
D3: 5,6
G1: 5,6
B4: 4,6
C5: 2,6
B6: 2,7
E5: 1,3
F5: 1,3
H4: 6,7
G5: 2,6
G6: 1,2
F9: 4,7

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
C4,C6: 1.. / C4 = 1  => 12 pairs (_) / C6 = 1  =>  0 pairs (*)
E5,F5: 1.. / E5 = 1  => 14 pairs (_) / F5 = 1  => 16 pairs (_)
I4,G6: 1.. / I4 = 1  =>  0 pairs (*) / G6 = 1  =>  0 pairs (X)
F7,E8: 1.. / F7 = 1  => 14 pairs (_) / E8 = 1  => 16 pairs (_)
C4,I4: 1.. / C4 = 1  => 12 pairs (_) / I4 = 1  =>  0 pairs (*)
C6,G6: 1.. / C6 = 1  =>  0 pairs (*) / G6 = 1  =>  0 pairs (X)
E8,I8: 1.. / E8 = 1  => 16 pairs (_) / I8 = 1  => 14 pairs (_)
E5,E8: 1.. / E5 = 1  => 14 pairs (_) / E8 = 1  => 16 pairs (_)
F5,F7: 1.. / F5 = 1  => 16 pairs (_) / F7 = 1  => 14 pairs (_)
G6,G7: 1.. / G6 = 1  => 12 pairs (_) / G7 = 1  =>  0 pairs (*)
G5,G6: 2.. / G5 = 2  => 12 pairs (_) / G6 = 2  =>  0 pairs (*)
D7,D9: 2.. / D7 = 2  => 17 pairs (_) / D9 = 2  => 13 pairs (_)
C5,G5: 2.. / C5 = 2  =>  0 pairs (*) / G5 = 2  =>  0 pairs (X)
E2,F3: 3.. / E2 = 3  => 14 pairs (_) / F3 = 3  => 16 pairs (_)
I2,I3: 3.. / I2 = 3  => 16 pairs (_) / I3 = 3  => 14 pairs (_)
E5,F5: 3.. / E5 = 3  => 16 pairs (_) / F5 = 3  => 14 pairs (_)
E2,I2: 3.. / E2 = 3  => 14 pairs (_) / I2 = 3  => 16 pairs (_)
F3,I3: 3.. / F3 = 3  => 16 pairs (_) / I3 = 3  => 14 pairs (_)
E2,E5: 3.. / E2 = 3  => 14 pairs (_) / E5 = 3  => 16 pairs (_)
F3,F5: 3.. / F3 = 3  => 16 pairs (_) / F5 = 3  => 14 pairs (_)
B4,C4: 4.. / B4 = 4  => 13 pairs (_) / C4 = 4  =>  0 pairs (*)
H7,H8: 4.. / H7 = 4  => 13 pairs (_) / H8 = 4  => 18 pairs (_)
G1,G7: 5.. / G1 = 5  => 16 pairs (_) / G7 = 5  => 14 pairs (_)
C5,G5: 6.. / C5 = 6  => 12 pairs (_) / G5 = 6  =>  0 pairs (*)
B6,C6: 7.. / B6 = 7  => 13 pairs (_) / C6 = 7  =>  0 pairs (X)
H4,I4: 7.. / H4 = 7  => 15 pairs (_) / I4 = 7  => 12 pairs (_)
F7,F9: 7.. / F7 = 7  => 14 pairs (_) / F9 = 7  => 13 pairs (_)
A7,F7: 7.. / A7 = 7  => 13 pairs (_) / F7 = 7  => 14 pairs (_)
B2,B6: 7.. / B2 = 7  =>  0 pairs (X) / B6 = 7  => 13 pairs (_)
H2,H4: 7.. / H2 = 7  => 12 pairs (_) / H4 = 7  => 15 pairs (_)
B2,B3: 8.. / B2 = 8  => 15 pairs (_) / B3 = 8  => 16 pairs (_)
F1,F3: 8.. / F1 = 8  => 14 pairs (_) / F3 = 8  =>  0 pairs (X)
F1,I1: 8.. / F1 = 8  => 14 pairs (_) / I1 = 8  =>  0 pairs (X)
B2,I2: 8.. / B2 = 8  => 15 pairs (_) / I2 = 8  => 16 pairs (_)
* DURATION: 0:00:56.926482  START: 03:58:03.754512  END: 03:59:00.680994 2017-05-01
* CP COUNT: (34)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B4,B6,C5,D3,E5,F1,F5,F9,G1,G5,G6,H4)
* .3.9...1...91.24..1...7.9..9..8253..85.7...943..496.85.93.8......83.97...1....839
* PAIR F1: 4,8 BLK 2
F3: 4,8,3                                # reduction candidate for 4,8
F3: 3                                    # 16 pairs
F3: 4,8                                  # 14 pairs
* PAIR D3: 5,6 BLK 2
E1: 5,6,4                                # reduction candidate for 5,6
E1: 5,6                                  # 14 pairs
E2: 5,6,3                                # reduction candidate for 5,6
E2: 5,6                                  # 16 pairs
* PAIR D3: 5,6 ROW 3
C3: 5,6,2,4                              # reduction candidate for 5,6
C3: 5,6                                  # 15 pairs
H3: 5,6,2                                # reduction candidate for 5,6
H3: 5,6 => CTR
* .359..61.6891524731.4673958941825367856731294372496185.9328.5....83.97...1.5..839
H3: 2                                    # 12 pairs
* PAIR D3: 5,6 COL D
D7: 5,6,2                                # reduction candidate for 5,6
D7: 5,6                                  # 13 pairs
D9: 5,6,2                                # reduction candidate for 5,6
D9: 5,6                                  # 17 pairs
* PAIR G1: 5,6 BLK 3
H2: 5,6,7                                # reduction candidate for 5,6
H2: 5,6                                  # 15 pairs
H3: 5,6,2                                # reduction candidate for 5,6
H3: 5,6 => CTR
* .359..61.6891524731.4673958941825367856731294372496185.9328.5....83.97...1.5..839
H3: 2                                    # 12 pairs
* PAIR G1: 5,6 ROW 1
A1: 5,6,2,4,7                            # reduction candidate for 5,6
A1: 5,6 => CTR
* .32948.1...91.24..1.4.739.894.8253..85.731.943..496.85.93.8.....683197.2.15.6.839
A1: 2,4,7                                # 12 pairs
C1: 5,6,2,4,7                            # reduction candidate for 5,6
C1: 5,6                                  # 18 pairs
E1: 5,6,4                                # reduction candidate for 5,6
E1: 5,6                                  # 14 pairs
* PAIR G1: 5,6 COL G
G7: 5,6,1                                # reduction candidate for 5,6
G7: 1 => SOLVED
* 236948517789152463145673928964825371852731694371496285693587142428319756517264839
G7: 5,6                                  # 12 pairs
* PAIR B4: 4,6 BLK 4
C4: 4,6,1                                # reduction candidate for 4,6
C4: 4,6 => SOLVED
* 236948517789152463145673928964825371852731694371496285693587142428319756517264839
C4: 1                                    # 12 pairs
* PAIR B4: 4,6 COL B
B3: 4,6,2,8                              # reduction candidate for 4,6
B3: 4,6                                  # 17 pairs
B8: 4,6,2                                # reduction candidate for 4,6
B8: 4,6                                  # 15 pairs
* PAIR C5: 2,6 COL C
C1: 2,6,4,5,7                            # reduction candidate for 2,6
C1: 2,6                                  # 16 pairs
C3: 2,6,4,5                              # reduction candidate for 2,6
C3: 2,6                                  # 17 pairs
C9: 2,6,4,5,7                            # reduction candidate for 2,6
C9: 2,6                                  # 20 pairs
* PAIR B6: 2,7 BLK 4
C6: 2,7,1                                # reduction candidate for 2,7
C6: 1 => SOLVED
* 236948517789152463145673928964825371852731694371496285693587142428319756517264839
C6: 2,7                                  # 12 pairs
* PAIR H4: 6,7 BLK 6
I4: 6,7,1                                # reduction candidate for 6,7
I4: 1 => SOLVED
* 236948517789152463145673928964825371852731694371496285693587142428319756517264839
I4: 6,7                                  # 12 pairs
* PAIR H4: 6,7 COL H
H2: 6,7,5                                # reduction candidate for 6,7
H2: 5                                    # 20 pairs
H2: 6,7                                  # 14 pairs
* PAIR G6: 1,2 ROW 6
C6: 1,2,7                                # reduction candidate for 1,2
C6: 7 => CTR
* .329.8.17.791324.818.674923941825376856713294327496185793581642268349751.14267839
C6: 1,2                                  # 13 pairs
* PAIR F9: 4,7 BLK 8
F7: 4,7,1                                # reduction candidate for 4,7
F7: 4,7                                  # 16 pairs
F7: 1                                    # 14 pairs
* PAIR F9: 4,7 ROW 9
A9: 4,7,2,5,6                            # reduction candidate for 4,7
A9: 4,7                                  # 16 pairs
C9: 4,7,2,5,6                            # reduction candidate for 4,7
C9: 4,7                                  # 16 pairs
* INCONCLUSIVE
* SAVE PR GRAPH zz-www.sudokuwiki.org-0030-base-pr-000.dot
* REASONING
* DIS # H3: 5,6 => CTR => H3: 2
* DIS # H3: 5,6 => CTR => H3: 2
* DIS # A1: 5,6 => CTR => A1: 2,4,7
* PRF # G7: 1 => SOL
* PRF # C4: 4,6 => SOL
* PRF # C6: 1 => SOL
* PRF # I4: 1 => SOL
* DIS # C6: 7 => CTR => C6: 1,2
* CNT   8 HDP CHAINS /  37 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (B4,B6,C5,D3,E5,F1,F5,F9,G1,G5,G6,H4)
* .3.9...1...91.24..1...7.9..9..8253..85.7...943..496.85.93.8......83.97...1....839
* PAIR F1: 4,8 BLK 2
F3: 4,8,3                                # reduction candidate for 4,8
F3: 3                                    # 16 pairs
F3: 4,8                                  # 14 pairs
* PAIR D3: 5,6 BLK 2
E1: 5,6,4                                # reduction candidate for 5,6
E1: 5,6                                  # 14 pairs
E2: 5,6,3                                # reduction candidate for 5,6
E2: 5,6                                  # 16 pairs
* PAIR D3: 5,6 ROW 3
C3: 5,6,2,4                              # reduction candidate for 5,6
C3: 5,6                                  # 15 pairs
H3: 5,6,2                                # reduction candidate for 5,6
H3: 5,6 => CTR
* .359..61.6891524731.4673958941825367856731294372496185.9328.5....83.97...1.5..839
* RESTART
* PAIR D3: 5,6 ROW 3
C3: 5,6,4                                # reduction candidate for 5,6
C3: 4                                    # 19 pairs
C3: 5,6                                  # 15 pairs
* PAIR D3: 5,6 COL D
D7: 5,6,2                                # reduction candidate for 5,6
D7: 5,6                                  # 13 pairs
D9: 5,6,2                                # reduction candidate for 5,6
D9: 5,6 => CTR
* .3.9...1..791.24.818..7.9239.18253768567...94327496185.9328...1..83197.2.1....839
* RESTART
* PAIR RESTART
* PAIR D3: 5,6 BLK 2
E1: 5,6,4                                # reduction candidate for 5,6
E1: 5,6                                  # 20 pairs
E2: 5,6,3                                # reduction candidate for 5,6
E2: 5,6 => SOLVED
* 236948517789152463145673928964825371852731694371496285693587142428319756517264839
* DURATION: 0:00:11.847511  START: 03:59:33.802965  END: 03:59:45.650476 2017-05-01
* SOLUTION FOUND
* SAVE PR GRAPH zz-www.sudokuwiki.org-0030-base-pr-001.dot
* REASONING
* DIS # H3: 5,6 => CTR => H3: 2
* DIS H3: 2 # D9: 5,6 => CTR => D9: 2
* PRF H3: 2 + D9: 2 # E2: 5,6 => SOL
* STA H3: 2 + D9: 2 + E2: 5,6
* CNT   3 HDP CHAINS /  12 HYP OPENED

Header Info

http://www.sudokuwiki.org/Print_Weekly_Sudoku.asp?unsolvable=30

Solution

position: 236948517789152463145673928964825371852731694371496285693587142428319756517264839 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 # F3: 4,8 => UNS
* INC # F3: 3 => UNS
* INC # E1: 5,6 => UNS
* INC # E2: 5,6 => UNS
* INC # C3: 5,6 => UNS
* DIS # H3: 5,6 => CTR => H3: 2
* INC # H3: 2 => UNS
* INC # D7: 5,6 => UNS
* INC # D9: 5,6 => UNS
* INC # H2: 5,6 => UNS
* DIS # H3: 5,6 => CTR => H3: 2
* INC # H3: 2 => UNS
* DIS # A1: 5,6 => CTR => A1: 2,4,7
* INC # A1: 2,4,7 => UNS
* INC # C1: 5,6 => UNS
* INC # E1: 5,6 => UNS
* INC # G7: 5,6 => UNS
* PRF # G7: 1 => SOL
* PRF # C4: 4,6 => SOL
* INC # C4: 1 => UNS
* INC # B3: 4,6 => UNS
* INC # B8: 4,6 => UNS
* INC # C1: 2,6 => UNS
* INC # C3: 2,6 => UNS
* INC # C9: 2,6 => UNS
* INC # C6: 2,7 => UNS
* PRF # C6: 1 => SOL
* INC # I4: 6,7 => UNS
* PRF # I4: 1 => SOL
* INC # H2: 6,7 => UNS
* INC # H2: 5 => UNS
* INC # C6: 1,2 => UNS
* DIS # C6: 7 => CTR => C6: 1,2
* INC # F7: 4,7 => UNS
* INC # F7: 1 => UNS
* INC # A9: 4,7 => UNS
* INC # C9: 4,7 => UNS
* CNT  37 HDP CHAINS /  37 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* INC # F3: 4,8 => UNS
* INC # F3: 3 => UNS
* INC # E1: 5,6 => UNS
* INC # E2: 5,6 => UNS
* INC # C3: 5,6 => UNS
* DIS # H3: 5,6 => CTR => H3: 2
* INC H3: 2 # C3: 5,6 => UNS
* INC H3: 2 # C3: 4 => UNS
* INC H3: 2 # D7: 5,6 => UNS
* DIS H3: 2 # D9: 5,6 => CTR => D9: 2
* INC H3: 2 + D9: 2 # E1: 5,6 => UNS
* PRF H3: 2 + D9: 2 # E2: 5,6 => SOL
* STA H3: 2 + D9: 2 + E2: 5,6
* CNT  12 HDP CHAINS /  12 HYP OPENED