diff options
Diffstat (limited to 'src/jrummikub/ai/fdsolver/constraint/ComparatorConstraint.java')
-rw-r--r-- | src/jrummikub/ai/fdsolver/constraint/ComparatorConstraint.java | 39 |
1 files changed, 23 insertions, 16 deletions
diff --git a/src/jrummikub/ai/fdsolver/constraint/ComparatorConstraint.java b/src/jrummikub/ai/fdsolver/constraint/ComparatorConstraint.java index ab0edde..019de92 100644 --- a/src/jrummikub/ai/fdsolver/constraint/ComparatorConstraint.java +++ b/src/jrummikub/ai/fdsolver/constraint/ComparatorConstraint.java @@ -6,6 +6,7 @@ import java.util.Arrays; import java.util.Collection; import java.util.Collections; import java.util.Comparator; +import java.util.NoSuchElementException; import jrummikub.ai.fdsolver.Constraint; import jrummikub.ai.fdsolver.Propagator; @@ -17,8 +18,9 @@ public class ComparatorConstraint<T> extends Constraint { Comparator<T> comparator, reverseComparator; ComparatorPropagator<T> trueX, trueY, falseX, falseY; boolean allowEqual; - - ComparatorConstraint(final Comparator<T> comparator, boolean allowEqual, Var<T> x, Var<T> y) { + + ComparatorConstraint(final Comparator<T> comparator, boolean allowEqual, + Var<T> x, Var<T> y) { this.x = x; this.y = y; this.comparator = comparator; @@ -31,37 +33,42 @@ public class ComparatorConstraint<T> extends Constraint { }; trueX = new ComparatorPropagator<T>(comparator, allowEqual, x, y); trueY = new ComparatorPropagator<T>(reverseComparator, allowEqual, y, x); - falseX = new ComparatorPropagator<T>(reverseComparator, !allowEqual, x, y); + falseX = new ComparatorPropagator<T>(reverseComparator, !allowEqual, x, + y); falseY = new ComparatorPropagator<T>(comparator, !allowEqual, y, x); } - + @Override public Collection<Var<?>> getWatchedVars() { - return Arrays.<Var<?>>asList(x,y); + return Arrays.<Var<?>> asList(x, y); } @Override public Collection<Propagator> getPropagators(boolean negate) { if (negate) { - return Arrays.<Propagator>asList(falseX,falseY); + return Arrays.<Propagator> asList(falseX, falseY); } else { - return Arrays.<Propagator>asList(trueX,trueY); + return Arrays.<Propagator> asList(trueX, trueY); } } @Override public Satisfiability getSatisfiability() { - T maxX = Collections.max(x.getRange(), comparator); - T minY = Collections.min(y.getRange(), comparator); - if (comparator.compare(maxX, minY) < (allowEqual ? 1 : 0)) { - return TAUT; - } - T minX = Collections.min(x.getRange(), comparator); - T maxY = Collections.max(y.getRange(), comparator); - if (comparator.compare(maxY, minX) < (allowEqual ? 0 : 1)) { + try { + T maxX = Collections.max(x.getRange(), comparator); + T minY = Collections.min(y.getRange(), comparator); + if (comparator.compare(maxX, minY) < (allowEqual ? 1 : 0)) { + return TAUT; + } + T minX = Collections.min(x.getRange(), comparator); + T maxY = Collections.max(y.getRange(), comparator); + if (comparator.compare(maxY, minX) < (allowEqual ? 0 : 1)) { + return UNSAT; + } + return SAT; + } catch (NoSuchElementException e) { return UNSAT; } - return SAT; } } |