initial

src/signpost/Model.java

@@ -123,15 +123,20 @@ class Model implements Iterable<Model.Sq> {
         for(int w = 0; w <width(); w++ ){
             for( int h=0; h<height(); h++){
                 int sn = solution[w][h];
-                Sq sq = new Sq(w,h,0,false,0,-1);
+                _solnNumToPlace[sn] = pl(w,h);
+                Sq sq ;
+                if(sn==1||sn==last){
+                    sq = new Sq(w,h,sn,true,0,0);
+                }else {
+                    sq = new Sq(w,h,0,false,0,-1);
+                }
                 _board[w][h] = sq;
                 allNums.set(sn);
                 _allSquares.add(sq);
-                _solnNumToPlace[sn] = pl(w,h);
             }
         }
-        solnNumToSq(1).setFixedNum(1);
-        solnNumToSq(last).setFixedNum(last);
+        //solnNumToSq(1).setFixedNum(1);
+        //solnNumToSq(last).setFixedNum(last);
         for(int i = 1; i<= last; i ++){
             if( !allNums.get(i) ){
                 throw badArgs("the sequence number"+i+"has not set");
@@ -148,16 +153,14 @@ class Model implements Iterable<Model.Sq> {
             sq._dir = arrowDirection(sq.x,sq.y);
             sq._successors = allSuccessors(sq.x,sq.y,sq._dir);
         }
-        for(int i=2; i<=last; i++){
-            Sq sq=solnNumToSq(i);
-            sq._predecessors = new PlaceList();
-            for(int j=1; j<=last; j++){
-                if( j==i ) continue;
-                Sq fromSq = solnNumToSq(j);
-                if( fromSq._dir == dirOf(fromSq.x,fromSq.y,sq.x,sq.y) ){
-                    Place fromPlace = solnNumToPlace(j);
-                    sq._predecessors.add(fromPlace);
+        for(Sq sq:_allSquares){
+            if( sq.successors() ==null ) continue;
+            for(Place target:sq.successors()){
+                Sq tsq = get(target);
+                if( tsq.predecessors()==null){
+                    tsq._predecessors = new PlaceList();
                 }
+                tsq._predecessors.add(sq.pl);
             }
         }
 
@@ -586,7 +589,7 @@ PlaceList predecessors() {
          */
         boolean connectable(Sq s1) {
             // FIXME
-            if(direction() != pl.dirOf(s1.pl)){
+            if(direction()==0 || direction() != pl.dirOf(s1.pl)){
                 return false;
             }
             if(s1.predecessor() != null || successor() != null ){
@@ -599,14 +602,13 @@ boolean connectable(Sq s1) {
                 return false;
             }
             if( this.sequenceNum()==0 && s1.sequenceNum()==0 ){
-                if( group()>0 || s1.group()>0)
-                {
-                    if(group() == s1.group())
-                    {
-                        return false;
-                    }
+                if( _head == s1._head){
+                    return false;
                 }
             }
+            if( s1.sequenceNum() == 1 || sequenceNum()==width()*height()){
+                return false;
+            }
             return true;
         }
 

src/signpost/PuzzleGenerator.java

@@ -25,7 +25,6 @@ public Model getPuzzle(int width, int height, boolean allowFreeEnds) {
         Model model =
             new Model(makePuzzleSolution(width, height, allowFreeEnds));
         // FIXME: Remove the "//" on the following two lines.
-        System.out.println(model);
         makeSolutionUnique(model);
         model.autoconnect();
         return model;
@@ -142,7 +141,6 @@ static Sq findUniqueSuccessor(Model model, Sq start) {
         // FIXME: Fill in to satisfy the comment.
         int cnt = 0;
         Sq found = null;
-        cnt = start.successors().size();
 
         for(Place p : start.successors()){
             Sq sq = model.get(p);
@@ -155,6 +153,8 @@ static Sq findUniqueSuccessor(Model model, Sq start) {
             if( start.sequenceNum()>0 && start.sequenceNum() == sq.sequenceNum()-1 ){
                 return sq;
             }
+
+
         }
         if( cnt==1 ){
             return found;