From 99c3d48f1021e59d8db0873ae9b626594954e44f Mon Sep 17 00:00:00 2001
From: Jannis Harder <harder@informatik.uni-luebeck.de>
Date: Tue, 14 Jun 2011 17:48:26 +0200
Subject: Several speed optimizations

git-svn-id: svn://sunsvr01.isp.uni-luebeck.de/swproj13/trunk@438 72836036-5685-4462-b002-a69064685172
---
 .../fdsolver/constraint/ComparatorConstraint.java  | 39 +++++++++++++---------
 1 file changed, 23 insertions(+), 16 deletions(-)

(limited to 'src/jrummikub/ai/fdsolver/constraint/ComparatorConstraint.java')

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;
 	}
 
 }
-- 
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