fix : countSolutions

app/src/main/java/sudoku/solver/Solver.java

@@ -42,6 +42,10 @@ public interface Solver {
             cellToFill.setSymbolIndex(symbol);
             if (solve(doku)) {
                 result++;
+                if (result > 1) {
+                    doku.getStateManager().popState();
+                    return result;
+                }
             }
             doku.getStateManager().popState();
         }

app/src/main/java/sudoku/structure/SudokuFactory.java

@@ -142,21 +142,14 @@ public class SudokuFactory {
 
 		List<Cell> cellsThatCanBeEmptied = doku.getFilledCells();
 
-		while (!cellsThatCanBeEmptied.isEmpty()) {
 		int index = random.nextInt(cellsThatCanBeEmptied.size());
 		Cell cellToEmpty = cellsThatCanBeEmptied.get(index);
 
-			int oldSymbol = cellToEmpty.empty();
+		cellToEmpty.empty();
 
 		int nbDokuSultions = solver.countSolution(doku);
 		if (nbDokuSultions == 1) {
-				if (newDokuFromFilledOne(doku, --nbCellsToEmpty, solver)) {
-					return true;
-				}
-			}
-
-			cellToEmpty.setSymbolIndex(oldSymbol);
-			cellsThatCanBeEmptied.remove(cellToEmpty);
+            return newDokuFromFilledOne(doku, --nbCellsToEmpty, solver);
 		}
 
 		return false;