The strange fishing hook

Everything about Sudoku that doesn't fit in one of the other sections

The strange fishing hook

Postby JPF » Sat Nov 11, 2006 6:53 pm

Here's a puzzle...
21 clues.
Code: Select all
 . . . . 3 2 9 . .
 . . . 5 . . . 6 .
 . . 1 7 . . . . 8
 . 5 7 6 . . . . .
 3 . . . 9 . . . .
 2 . . . . 4 . . .
 9 . . . . . 2 . .
 . 6 . . . . . 5 .
 . . 8 . . . . . 1


Part one :

It has 2 types of symmetry with the main diagonal :
pattern-symmetry
digits-symmetry

This puzle has exactly 2 solutions.
50 cells differ in the two solutions ; only 10 are the same.

More precisely :
Given clues : 21
Cells that differ in two solutions : 50
Cells that are the same : 10

see here.

Common cells (x) for the 2 solutions :

Code: Select all
 x . . | . 3 2 | 9 x .
 . x . | 5 . x | . 6 .
 . . 1 | 7 x x | . . 8
-------+-------+-------
 . 5 7 | 6 . . | . . .
 3 . x | . 9 . | . . .
 2 x x | . . 4 | . . .
-------+-------+-------
 9 . . | . . . | 2 . .
 x 6 . | . . . | . 5 .
 . . 8 | . . . | . . 1


6 in r1c1 can be obtained by SST
The 9 other cells (actually 5 due to the symmetry) need more advanced techniques.
Any solvers for these cells ?

JPF
JPF
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