dailysudoku.com :: View topic

dailysudoku.com
Discussion of Daily Sudoku puzzles

FAQ

Memberlist

Usergroups

Profile

Set H Puzzle 25

dailysudoku.com Forum Index -> Puzzles by daj

View previous topic :: View next topic

Author

Message

daj95376

Joined: 23 Aug 2008
Posts: 3854

Posted: Tue Dec 30, 2008 7:23 am Post subject: Set H Puzzle 25

Code:

+-----------------------+
| . 1 9 | . . 8 | . 2 . |
| 4 6 . | . 2 . | . 9 . |
| 2 . . | . . 7 | . 4 . |
|-------+-------+-------|
| . . . | 9 . 6 | . . . |
| . 9 . | . 8 . | . . . |
| 6 . 2 | 7 . 3 | . . 9 |
|-------+-------+-------|
| . . . | . . . | 7 . 4 |
| 5 8 6 | . . . | . . . |
| . . . | . . 9 | 6 . 2 |
+-----------------------+

Play this puzzle online at the Daily Sudoku site

Marty R.

Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA

Posted: Wed Dec 31, 2008 12:50 am Post subject:

Took me five steps, UR, XY-Wing, W-Wing, multi-coloring and Remote Pairs.

storm_norm

Joined: 18 Oct 2007
Posts: 1741

Posted: Wed Dec 31, 2008 8:31 am Post subject:

Code:

.---------------------.---------------------.---------------------.
| 37 1 9 | 4 356 8 | 35 2 67 |
| 4 6 78 | 135 2 *15 | 135 9 78 |
| 2 35 358 | 136 9 7 | 13 4 68 |
:---------------------+---------------------+---------------------:
| 8 U[3]45 135 | 9 U[1]45 6 | 2 7 *-35 |
| 137 9 1357 |*15 8 2 | 4 6 *35 |
| 6 U45 2 | 7 U45 3 | 8 1 9 |
:---------------------+---------------------+---------------------:
| 9 2 13 | 13568 1356 15 | 7 58 4 |
| 5 8 6 | 2 7 4 | 9 3 1 |
| 13 7 4 | 1358 135 9 | 6 58 2 |
'---------------------'---------------------'---------------------'

the UR on {4,5} r46c25 says (3)r4c2 = (1)r4c5
so lets use that...
step 1...45UR[(3)r4c2 = (1)r4c5] - (1=5)r5c4 - (5)r5c9 = (5)r4c9; r4c9 <> 3

Code:

.---------------------.---------------------.---------------------.
| 37 1 9 | 4 356 8 | 35 2 67 |
| 4 6 78 |U13[5] 2 15 |U13[5] 9 78 |
| 2 *35 *58 |U13[6] 9 7 |U13 4 *68 |
:---------------------+---------------------+---------------------:
| 8 *34 *13 | 9 14 6 | 2 7 5 |
| 17 9 57 | 15 8 2 | 4 6 3 |
| 6 45 2 | 7 45 3 | 8 1 9 |
:---------------------+---------------------+---------------------:
| 9 2 *13 | 13568 1356 -15 | 7 58 4 |
| 5 8 6 | 2 7 4 | 9 3 1 |
| 13 7 4 | 1358 135 9 | 6 58 2 |
'---------------------'---------------------'---------------------'

the 13UR in r23c47 says that if 6 is not in r3c4 then the 5's have to exist in r2c47... 13UR[(6)r3c4 = (5)r2c47]...and vice versa...
huge chain can be formed from this to eliminate 1 from r7c7

step2...(1=3)r7c3 - (3)r4c3 = (3)r4c2 - (3=5)r3c2 - (5=8)r3c3 - (8=6)r3c9 - 13UR[(6)r3c4 = (5)r2c47] - (5=1)r2c6; r7c6 <> 1
obviously this is overkill.

brings this bug+3 grid

Code:

.---------------.---------------.---------------.
| 37 1 9 | 4 356 8 | 35 2 67 |
| 4 6 78 | 35 2 1 | 35 9 78 |
| 2 35 58 | 36 9 7 | 1 4 68 |
:---------------+---------------+---------------:
| 8 34 13 | 9 14 6 | 2 7 5 |
| 17 9 57 | 15 8 2 | 4 6 3 |
| 6 45 2 | 7 45 3 | 8 1 9 |
:---------------+---------------+---------------:
| 9 2 13 | 136 136 5 | 7 8 4 |
| 5 8 6 | 2 7 4 | 9 3 1 |
| 13 7 4 | 8 13 9 | 6 5 2 |
'---------------'---------------'---------------'

but coloring on 1's does the trick eliminates the 1 from r4c5.
step3...(1)......r4c3 = r7c3 - r9c1 = r9c5; r4c5 <> 1

Display posts from previous:

	dailysudoku.com Forum Index -> Puzzles by daj	All times are GMT
Page 1 of 1

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum