Find X-Wings.
[X,C,L] = sudoku_findxwing ( X , C , L ) [X,C,L] = sudoku_findxwing ( X , C , L , stopatfirst ) [X,C,L] = sudoku_findxwing ( X , C , L , stopatfirst , verbose )
a 9-by-9 matrix, with 0 for unknown entries
a 9 x 9 cell of candidates
the 9 x 9 matrix of number candidates
if %t, then stop after one or more candidates have been removed. (default = %t)
a boolean. Set to %t to display the state of the matrix. (default = %f)
Search for x-wings.
http://www.sadmansoftware.com/sudoku/xwing.htm