sudoku-set.rb in gecoder-0.9.0

- old
+ new

@@ -21,17 +21,17 @@
     # given numbers from 1 to 81. Each set therefore has an empty lower bound 
     # (since we have no guarantees where a number will end up) and 1..81 as 
     # upper bound (as it may potentially occurr in any square). We know that
     # each assignable number must occurr 9 times in a solved sudoku, so we 
     # set the cardinality to 9..9 .
-    @sets = set_var_array(n, [], 1..n*n, n..n)
+    sets_is_an set_var_array(n, [], 1..n*n, n..n)
     predefined_values.row_size.times do |i|
       predefined_values.column_size.times do |j|
         unless predefined_values[i,j].zero?
           # We add the constraint that the square position must occurr in the 
           # set corresponding to the predefined value.
-          @sets[predefined_values[i,j] - 1].must_be.superset_of [i*n + j+1]
+          sets[predefined_values[i,j] - 1].must_be.superset_of [i*n + j+1]
         end
       end
     end
 
     # Build arrays containing the square positions of each row and column.
@@ -56,38 +56,37 @@
 
     # All sets must be pairwise disjoint since two numbers can't be assigned to
     # the same square.
     n.times do |i|
       (i + 1).upto(n - 1) do |j|
-        @sets[i].must_be.disjoint_with @sets[j]
+        sets[i].must_be.disjoint_with sets[j]
       end
     end
 
     # The sets must intersect in exactly one element with each row column and
     # block. I.e. an assignable number must be assigned exactly once in each
-    # row, column and block. We specify the constraint by expressing that the 
-    # intersection must be equal with a set variable with cardinality 1.
-    @sets.each do |set|
+    # row, column and block. 
+    sets.each do |set|
       rows.each do |row|
-        set.intersection(row).must == set_var([], 1..n*n, 1..1)
+        set.intersection(row).size.must == 1
       end
       columns.each do |column|
-        set.intersection(column).must == set_var([], 1..n*n, 1..1)
+        set.intersection(column).size.must == 1
       end
       blocks.each do |block|
-        set.intersection(block).must == set_var([], 1..n*n, 1..1)
+        set.intersection(block).size.must == 1
       end
     end
 
     # Branching.
-    branch_on @sets, :variable => :none, :value => :min
+    branch_on sets, :variable => :none, :value => :min
   end
   
   # Outputs the assigned numbers in a grid.
   def to_s
     squares = []
-    @sets.values.each_with_index do |positions, i|
+    sets.values.each_with_index do |positions, i|
       positions.each{ |square_position| squares[square_position - 1] = i + 1 }
     end
     squares.enum_slice(@size).map{ |slice| slice.join(' ') }.join("\n")
   end
 end
@@ -102,6 +101,6 @@
   [6,0,9, 0,0,0, 0,0,1],
       
   [0,8,0, 4,0,0, 1,0,0],
   [0,6,3, 0,0,0, 0,8,0],
   [0,0,0, 6,0,8, 0,0,0]]
-puts(SudokuSet.new(predefined_squares).solve! || 'Failed').to_s
\ No newline at end of file
+puts SudokuSet.new(predefined_squares).solve!.to_s