... by: Frans Goosens
#679Calculate 2-digits cells
A1=2
( B5=4 ) Solved,
Total solving time is : 12 sec.
Number of logical steps is : 1418
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#679, January 3 - January 9, 2026:
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WARNING: This is the Weekly 'Unsolvable' Sudoku, rated above 'Extreme'. This is currently unsolvable by my solver, except perhaps with trial and error strategies. Using the solver will not help you. (much). |
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Post an idea here...Saturday 3-Jan-2026
Calculate 2-digits cells
A1=2
( B5=4 ) Solved,
Total solving time is : 12 sec.
Number of logical steps is : 1418
Saturday 3-Jan-2026
... by: Dieter
#679 - initially populated cells: 25 = 30,9 %No solver used, solver = brain.
basics: A5=1; A8=9
populated cells: 27 = 33,3 %
Strategy: numbers 9,1,3,5,6,8 occur most frequently, combine two cells.
combinations of C3 = (1,5,8,9) and C9 = (3,4,5,6)
after basic checks 6 matrices C3/C9 left: 1/5, 5/6, 8/5, 8/6, 9/5 and 9/6
C3/C9 = 9/6 solves with A4=7
Optimization:
C3=9 & A4=7 solve.
Saturday 3-Jan-2026
... by: Serban
# 679 A5=1 A8=9 basics 271. Number 2 n=2 e=7 N=27 Nc=23 Ns=3 => G6=2 solve
Note : E4=F7=2
1. Number 7 n=2 e=7 N=29 Nc=44 Ns=24 => B7=H2=7 solve
1. Number 8 n=3 e=6 N=22 Nc=18 Ns=9 => C6=F5=8 solve