Improved collision checker

Also removed verbose logging

src/main/java/eu/m724/crossword/Generator.java

@@ -80,6 +80,11 @@ public class Generator {
         }
         System.out.println("Possible placements: " + possiblePlacements.size() + " * 2");
 
+        int totalCharacters = Arrays.stream(words).map(w -> w.length() + 1).reduce(0, Integer::sum);
+        if (totalCharacters > possiblePlacements.size()) {
+            System.out.printf("Warning: there might be no solution (%d > %d)", totalCharacters, possiblePlacements.size());
+        }
+
         /*for (Word word : words) {
             PlacedWord placedWord = null;
 
@@ -132,13 +137,13 @@ public class Generator {
     }
 
     private Set<PlacedWord> follow(Grid grid, Set<PlacedWord> placedChain, int wordIndex) {
-        System.out.println("Depth " + wordIndex);
+        //System.out.println("Depth " + wordIndex);
 
         if (wordIndex > peakDepth)
             peakDepth = wordIndex;
 
         if (wordIndex == words.length) {
-            System.out.println("  Completed");
+            //System.out.println("  Completed");
             return placedChain;
         }
 
@@ -163,8 +168,8 @@ public class Generator {
 
                 PlacedWord candidate = new PlacedWord(placement, vertical, word);
 
-                if (grid.canPlace(candidate)) {
+                if (grid.canPlace(candidate) != -1) {
-                    System.out.println("  Found candidate");
+                    //System.out.println("  Found candidate");
                     Set<PlacedWord> potentialChain = new HashSet<>(placedChain);
                     potentialChain.add(candidate);
 
@@ -172,20 +177,20 @@ public class Generator {
                     newGrid.placeWord(candidate);
 
                     Set<PlacedWord> newChain = follow(newGrid, potentialChain, wordIndex + 1);
-                    System.out.println("Back to depth " + wordIndex);
+                    //System.out.println("Back to depth " + wordIndex);
 
                     // if it's null it means there's no good placement, and we should continue searching at this depth
                     if (newChain != null) {
-                        System.out.println("  Unfolding"); // is that a correct word?
+                        //System.out.println("  Unfolding"); // is that a correct word?
                         return newChain;
                     } else {
-                        System.out.println("  Looking further");
+                        //System.out.println("  Looking further");
                     }
                 }
             }
         }
 
-        System.out.println("  No solution");
+        //System.out.println("  No solution");
         // no placement at this depth
         return null;
     }

src/main/java/eu/m724/crossword/Grid.java

@@ -46,9 +46,11 @@ public class Grid implements Cloneable {
      * Can a word be placed, will it not collide
      *
      * @param word The word
-     * @return can it be placed
+     * @return can it be placed. -1 = no, 0 = yes, >0 = yes and will be over n characters
      */
-    public boolean canPlace(PlacedWord word) {
+    public int canPlace(PlacedWord word) {
+        int cols = 0;
+
         int x = word.pos().x();
         int y = word.pos().y();
 
@@ -67,12 +69,16 @@ public class Grid implements Cloneable {
                 c = word.word().text().charAt(i);
             }
 
-            if (charArray[_x][_y] != 0 && charArray[_x][_y] != c) {
+            if (charArray[_x][_y] != 0) {
-                return false;
+                if (charArray[_x][_y] != c) {
+                    return -1;
+                } else {
+                    cols++;
+                }
             }
         }
 
-        return true;
+        return cols;
     }
 
     @Override