## x wings

Advanced methods and approaches for solving Sudoku puzzles

### x wings

I am having trouble recognizing the X wing in a puzzle. Is there a resource or website that will supply me with several puzzles requiring this strategy so that I might get some practice? (but not so difficult I can't get anywhere) ? Thanks all.
Steve
woof

Posts: 1
Joined: 12 December 2007

You may have a look at SadMan's X-Wing page
Jean-Christophe

Posts: 149
Joined: 22 January 2006

Here are some easy ones, although one of them may require 2 x-wings.

Code: Select all
`. . .|. . 5|. . 2. . 6|4 7 .|. 1 .. 1 .|. 2 .|8 . .-----+-----+-----. 6 .|8 . .|. . 1. 8 7|. . .|5 9 .5 . .|. . 4|. 8 .-----+-----+-----. . 8|. 3 .|. 2 .. 3 .|. 8 2|4 . .1 . .|9 . .|. . .. 7 .|4 8 2|. . .6 . .|. . 3|2 . .. . .|6 . .|. 5 .-----+-----+-----7 . 1|. . .|. 8 38 . .|. . .|. . 44 3 .|. . .|9 . 2-----+-----+-----. 2 .|. . 6|. . .. . 8|2 . .|. . 7. . .|1 7 5|. 2 .. . .|. . .|6 . .. 9 6|. 1 .|2 5 .. 4 .|. . 5|. 9 3-----+-----+-----. . .|. 4 .|1 . .. 7 .|1 . 9|. 8 .. . 5|. 6 .|. . .-----+-----+-----9 6 .|3 . .|. 2 .. 2 4|. 8 .|9 6 .. . 8|. . .|. . .. 6 .|. . 4|9 8 .9 . 2|. 3 .|. . 7. 7 .|. . .|. . 3-----+-----+-----. . .|5 4 8|. . 9. 9 .|2 . 3|. 4 .3 . .|1 7 9|. . .-----+-----+-----7 . .|. . .|. 9 .2 . .|. 1 .|8 . 6. 1 9|3 . .|. 5 .. . 4|9 1 .|. . 7. 5 .|. . .|9 1 .1 . .|. . 7|. 8 .-----+-----+-----2 . .|. 9 .|1 . .4 . .|1 . 5|. . 8. . 1|. 6 .|. . 4-----+-----+-----. 4 .|7 . .|. . 1. 2 8|. . .|. 4 .7 . .|. 4 3|6 . .`
wintder

Posts: 297
Joined: 24 April 2007

Another dozen.

.9..8.........2.9...21.34..617..85....3.5.1....53..947..16.97...2.8.........7..5.
...3.2.6...2...7.....615...38...94..5..231..8..18...39...984.....5...9...4.5.3...
9.56.28.3.4.........69.12...5.2...4.6.......2.8...5.6...45.91.........3.5.14.37.9
1..2.3..5.4.91..2.....65.1...6...1..4...5...2..5...6...8.52.....9..76.8.6..3.8..4
.3.96..1.9....2..5..64...3....389.5...1...8...9.514....7...35..6..2....1.8..95.6.
.5..2...4...4.9.....6.8.2..3.4..6.2.2..354..6.1.2..4.9..9.4.6.....5.1...1...9..8.
.6..2......5.78...7.34..6.25....4..18...9...63..7....59.7..35.4...18.3......4..6.
3.........8.61.7....639...4...2763..67.....85..3854...9...231....4.89.6.........7
.1..5..6.5..6.4..3......5..2.416..8..9.7.2.1..6..397.5..1......9..8.6..1.3..9..5.
....2.9..9....7.8548...6.21....6...361.....495...1....74.6...5225.3....6..6.8....
..6489.........6...1.7.2.8...8.1.9.2.5.2.3.7.2.9.7.1...8.6.5.4...2.........1372..
68.9.4.75.7.....8...1........914.6.7...3.2...3.5.698........7...9.....4.24.8.7.53
wintder

Posts: 297
Joined: 24 April 2007

Pat

Posts: 3493
Joined: 18 July 2005

wintder wrote:
A. puzzle number ( 1 - 17 )
B. the puzzle
C. number of clues
Code: Select all
`01,.....5..2..647..1..1..2.8...6.8....1.87...59.5....4.8...8.3..2..3..824..1..9.....,2802,.7.482...6....32.....6...5.7.1....838.......443....9.2.2...6.....82....7...175.2.,2803,......6...96.1.25..4...5.93....4.1...7.1.9.8...5.6....96.3...2..24.8.96...8......,2804,.6...498.9.2.3...7.7......3...548..9.9.2.3.4.3..179...7......9.2...1.8.6.193...5.,3205,..491...7.5....91.1....7.8.2...9.1..4..1.5..8..1.6...4.4.7....1.28....4.7...436..,3006,.9..8.........2.9...21.34..617..85....3.5.1....53..947..16.97...2.8.........7..5.,2907,...3.2.6...2...7.....615...38...94..5..231..8..18...39...984.....5...9...4.5.3...,2908,9.56.28.3.4.........69.12...5.2...4.6.......2.8...5.6...45.91.........3.5.14.37.9,3009,1..2.3..5.4.91..2.....65.1...6...1..4...5...2..5...6...8.52.....9..76.8.6..3.8..4,2910,.3.96..1.9....2..5..64...3....389.5...1...8...9.514....7...35..6..2....1.8..95.6.,3011,.5..2...4...4.9.....6.8.2..3.4..6.2.2..354..6.1.2..4.9..9.4.6.....5.1...1...9..8.,2912,.6..2......5.78...7.34..6.25....4..18...9...63..7....59.7..35.4...18.3......4..6.,2913,3.........8.61.7....639...4...2763..67.....85..3854...9...231....4.89.6.........7,3014,.1..5..6.5..6.4..3......5..2.416..8..9.7.2.1..6..397.5..1......9..8.6..1.3..9..5.,3015,....2.9..9....7.8548...6.21....6...361.....495...1....74.6...5225.3....6..6.8....,3016,..6489.........6...1.7.2.8...8.1.9.2.5.2.3.7.2.9.7.1...8.6.5.4...2.........1372..,3017,68.9.4.75.7.....8...1........914.6.7...3.2...3.5.698........7...9.....4.24.8.7.53,30`

1,4 too easy ( don't need X-wing )

2-3 need X-wings, "superior" puzzles

5-17 bonus: "pure" X-wing puzzles ( can be solved by "singles" + X-wings )

Pat

Posts: 3493
Joined: 18 July 2005