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[zaks]

13 Dec (vh) sdk
soln:

i use notations:

boxes (b1...b9):

box1 box 2 box3
box4 box 5 box6
box7 box 8 box9

columns (ca...ci) :

c c c c c c c c c
o o o o o o o o o
L L L L L L L L L
a b c d e f g h i

rows (r1...r9):

row 9
row 8
row 7
row 6
row 5
row 4
row 3
row 2
row 1

moves:
number-column-row (exactly as in chess)
e.g., 4b6 means "put number 4 in cell 6", etc

here's my solution (sorry without moves' numbers)

1b8 1i6 1g1 1a3 1f2 ( finished with 1's )
4c5 4h7 6i3
7i9 ( see row 9, col i, and box 2 = see r9+ci+b2 )
8g5 ( see r5 )
7g4 ( see cg ) => 9g7 6g9 6d7
3i7 (see r7 ) => 8h8
5c3 ( in box 7, 5 can't be in cells a1, c1 because
in box 8, 5 must be in row 1)
8c9 ( see box 1 and col c ) => now we fill box 1:
5a7 7b7 => now fill row 7:
8f7 8d4 8b6 ( finished with 8's )
4e4 ( box 5 )
6a6 ( box 4 )
6b2 ( box 7 ) 6e1 ( finished with 6's )
7a5 ( box 4 )
2i5 ( row 5 )
9e5 ( row 5 )
9i4 ( col 9 )
5h4 ( row 4 )
2b4 ( row 4 )
3a4 ( row 4 )
2a1 ( col a )
9c6 ( box 4 )
3c1 ( col 3 )
9b3 ( box 7 )
9h2 ( box 9 )
2h3 ( box 9 )
3h6 ( box 6 )

the rest moves are more/less easy:

2e2
3d2
2f9
3e8
4d9
5e9
7e6
5f6
4f3
7e3
5d1
9f1
7f8
9d8 x!

enjoy, zaks

[k-bizzle]

for the 5c3: why must the 5 in box 7 be in r1 and NOT in r3cd or r3cf?

[newbie]

5c3 is because of the 4's and 7's in rows 1 and 2 (ie Box 7 and Box 9 both contain 4's and 7's in rows 1 and 2 --> therefore box 8 must contain either a 4 or 7 in both r3cd and r3cf and there's already a 8 in r3ce --> hence there must be a 5 in row 1 of box . Couple the 5 in row 1 of Box 8 along with the 5 in r2cg of Box 9, that means the only place for the 5 in Box 7 is r3cc.

[alanr555]