1 files changed, 12 insertions, 7 deletions
diff --git a/src/jrummikub/ai/fdsolver/Solver.java b/src/jrummikub/ai/fdsolver/Solver.java
index c47b1c1..c3ede1b 100644
--- a/src/jrummikub/ai/fdsolver/Solver.java
+++ b/src/jrummikub/ai/fdsolver/Solver.java
@@ -11,6 +11,10 @@ import java.util.Map;
 import java.util.Set;
 import static jrummikub.ai.fdsolver.Satisfiability.*;
 
+/**
+ * The Solver class is the Main Constraint Propagator (MCP) that tries to find a
+ * labeling of all variables that satisfies all given constraints.
+ */
 public class Solver {
 	Set<Var<?>> vars = new HashSet<Var<?>>();
 
@@ -80,9 +84,10 @@ public class Solver {
 	}
 
 	public void propagateOnce() {
-		Var<?> dirtyVar = Collections.max(dirtyVars);
+		Var<?> dirtyVar = Collections.min(dirtyVars);
 		dirtyVars.remove(dirtyVar);
-		outerLoop: for (Iterator<Constraint> i = dirtyVar.getConstraints().iterator(); i.hasNext();) {
+		outerLoop: for (Iterator<Constraint> i = dirtyVar.getConstraints()
+				.iterator(); i.hasNext();) {
 			Constraint constraint = i.next();
 			Satisfiability sat = constraint.getSatisfiability();
 			if (sat == UNSAT) {
@@ -130,14 +135,14 @@ public class Solver {
 	// backtracking and logging
 
 	void branch() {
-		branchOn(unsolvedVars.iterator().next());
+		branchOn(Collections.min(unsolvedVars));
 	}
 
 	@SuppressWarnings("unchecked")
 	void branchOn(Var<?> var) {
-		
+
 		Set<?> range = var.getRange();
-		int n = (int)(Math.random() * range.size()); 
+		int n = (int) (Math.random() * range.size());
 		Iterator<?> it = range.iterator();
 		for (int i = 0; i < n; i++) {
 			it.next();
@@ -230,13 +235,13 @@ public class Solver {
 	public <T> Var<T> makeVar(T... range) {
 		return makeVar(Arrays.asList(range));
 	}
-	
+
 	public void record() {
 		for (Var<?> var : vars) {
 			var.record();
 		}
 	}
-	
+
 	public void restore() {
 		for (Var<?> var : vars) {
 			var.restore();