refactor solvers

app/src/main/java/gui/menu/SudokuView.java

@@ -1,12 +1,14 @@
 package gui.menu;
 
-import java.util.Random;
 import java.util.concurrent.CancellationException;
 
 import gui.SudokuRenderer;
 import imgui.ImGui;
 import imgui.ImGuiStyle;
 import sudoku.io.SudokuSerializer;
+import sudoku.solver.BacktrackingSolver;
+import sudoku.solver.HumanSolver;
+import sudoku.solver.MixedSolver;
 import sudoku.solver.Solver;
 import sudoku.structure.MultiDoku;
 
@@ -66,41 +68,29 @@ public class SudokuView extends BaseView {
 			stopResolve();
 	}
 
+	private void startSolve(Solver solver) {
+		resolveThread = new Thread(() -> {
+			try {
+				solver.solve(this.doku);
+			} catch (CancellationException e) {
+				System.out.println("The user is bored !");
+			}
+			stopResolve();
+		});
+	}
+
 	private void renderSolvePopup() {
 		if (ImGui.beginPopup("solve")) {
 			if (ImGui.button("Résoudre avec backtrace")) {
-				resolveThread = new Thread(() -> {
+				startSolve(new BacktrackingSolver());
-					try {
-						Random rand = new Random();
-						Solver.randomSolve(doku, rand);
-					} catch (CancellationException e) {
-						System.out.println("The user is bored !");
-					}
-					stopResolve();
-				});
 				ImGui.closeCurrentPopup();
 			}
 			if (ImGui.button("Résoudre avec déduction")) {
-				resolveThread = new Thread(() -> {
+				startSolve(new HumanSolver());
-					try {
-						Solver.humanSolve(doku);
-					} catch (CancellationException e) {
-						System.out.println("The user is bored !");
-					}
-					stopResolve();
-				});
 				ImGui.closeCurrentPopup();
 			}
 			if (ImGui.button("Résoudre avec déduction et backtrace")) {
-				resolveThread = new Thread(() -> {
+				startSolve(new MixedSolver());
-					try {
-						Random rand = new Random();
-						Solver.mixedSolve(doku, rand);
-					} catch (CancellationException e) {
-						System.out.println("The user is bored !");
-					}
-					stopResolve();
-				});
 				ImGui.closeCurrentPopup();
 			}
 			ImGui.endPopup();

app/src/main/java/sudoku/io/ConsoleInterface.java

@@ -1,17 +1,16 @@
 package sudoku.io;
 
-import sudoku.constraint.*;
+import java.util.ArrayList;
-import sudoku.solver.Solver;
+import java.util.List;
+import java.util.Scanner;
+
+import sudoku.constraint.Constraint;
+import sudoku.solver.RandomSolver;
 import sudoku.structure.Difficulty;
 import sudoku.structure.MultiDoku;
 import sudoku.structure.Sudoku;
 import sudoku.structure.SudokuFactory;
 
-import java.util.ArrayList;
-import java.util.List;
-import java.util.Random;
-import java.util.Scanner;
-
 public class ConsoleInterface {
     public Scanner reader = new Scanner(System.in);
 
@@ -133,7 +132,7 @@ public class ConsoleInterface {
     }
 
     private void generateFullDoku(MultiDoku doku) {
-        Solver.randomSolve(doku, new Random());
+        new RandomSolver().solve(doku);
     }
 
 }

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

@@ -0,0 +1,49 @@
+package sudoku.solver;
+
+import java.util.List;
+import java.util.concurrent.CancellationException;
+
+import sudoku.structure.Cell;
+import sudoku.structure.MultiDoku;
+
+public class BacktrackingSolver implements Solver {
+
+	/**
+	 * Résout le MultiDoku passé en paramètre, avec backtracking.
+	 *
+	 * @param doku MultiDoku, MultiDoku à résoudre.
+	 * @return boolean, valant true si le MultiDoku est résolu, false sinon.
+	 */
+	@Override
+	public boolean solve(MultiDoku doku) {
+		if (Thread.interrupted())
+			throw new CancellationException("User wants to stop the solver");
+
+		if (doku.isSolved()) {
+			return true;
+		}
+
+		Cell cellToFill = doku.getFirstEmptyCell();
+		if (cellToFill == null) {
+			return false;
+		}
+
+		List<Integer> possibleSymbols = cellToFill.getPossibleSymbols();
+		if (possibleSymbols.isEmpty()) {
+			return false;
+		}
+
+		for (int symbol : possibleSymbols) {
+
+			cellToFill.setSymbolIndex(symbol);
+			if (this.solve(doku)) {
+				return true;
+			} else {
+				cellToFill.setSymbolIndex(Cell.NOSYMBOL);
+			}
+
+		}
+		return false;
+	}
+
+}

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

@@ -0,0 +1,55 @@
+package sudoku.solver;
+
+import java.util.List;
+import java.util.concurrent.CancellationException;
+import java.util.logging.Level;
+
+import sudoku.io.SudokuPrinter;
+import sudoku.structure.Cell;
+import sudoku.structure.MultiDoku;
+import sudoku.structure.Sudoku;
+
+public class HumanSolver implements Solver {
+
+	/**
+	 * Résout le MultiDoku passé en paramètre, avec règles de déduction.
+	 *
+	 * @param doku MultiDoku, MultiDoku à résoudre.
+	 * @return boolean, valant true si le MultiDoku est résolu, false sinon.
+	 */
+	@Override
+	public boolean solve(MultiDoku doku) {
+		if (Thread.interrupted())
+			throw new CancellationException("User wants to stop the solver");
+
+		Sudoku sudoku = doku.getSubGrid(0);
+		logger.log(Level.FINE,
+				'\n' + SudokuPrinter.toStringRectangleSudoku(sudoku,
+						sudoku.getBlockWidth() == 0 ? sudoku.getSize() : sudoku.getBlockWidth(),
+						sudoku.getBlockWidth() == 0 ? sudoku.getSize() : sudoku.getSize() / sudoku.getBlockWidth()));
+
+		if (doku.isSolved()) {
+			return true;
+		}
+
+		List<Cell> cellsToFill = doku.getEmptyCells();
+		if (cellsToFill.isEmpty()) {
+			return false;
+		}
+
+		for (Cell cellToFill : cellsToFill) {
+
+			List<Integer> possibleSymbols = cellToFill.getPossibleSymbols();
+			if (possibleSymbols.size() != 1) {
+				continue;
+			}
+
+			cellToFill.setSymbolIndex(possibleSymbols.getFirst());
+
+			return this.solve(doku);
+		}
+
+		return doku.isSolved();
+	}
+
+}

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

@@ -0,0 +1,82 @@
+package sudoku.solver;
+
+import java.util.List;
+import java.util.Random;
+import java.util.concurrent.CancellationException;
+import java.util.logging.Level;
+
+import sudoku.io.SudokuPrinter;
+import sudoku.structure.Cell;
+import sudoku.structure.MultiDoku;
+import sudoku.structure.Sudoku;
+
+public class MixedSolver implements Solver{
+
+	/**
+     * Résout le MultiDoku passé en paramètre, avec règles de déduction et
+     * backtracking.
+     *
+     * @param doku MultiDoku, MultiDoku à résoudre.
+     * @param rand Random, pour tester aléatoirement les symboles, lors du
+     *             backtracking.
+     * @return boolean, valant true si le MultiDoku est résolu, false sinon.
+     */
+	@Override
+    public boolean solve(MultiDoku doku) {
+        Random rand = new Random();
+
+        if (Thread.interrupted()) {
+            throw new CancellationException("User wants to stop the solver");
+        }
+
+        Sudoku sudoku = doku.getSubGrid(0);
+        logger.log(Level.FINE,
+                '\n' + SudokuPrinter.toStringRectangleSudoku(
+                        sudoku,
+                        sudoku.getBlockWidth() == 0 ? sudoku.getSize() : sudoku.getBlockWidth(),
+                        sudoku.getBlockWidth() == 0 ? sudoku.getSize() : sudoku.getSize() / sudoku.getBlockWidth()));
+
+        if (doku.isSolved()) {
+            return true;
+        }
+
+        List<Cell> cellsToFill = doku.getEmptyCells();
+        if (cellsToFill.isEmpty()) {
+            return false;
+        }
+
+        // Règles de déduction
+        for (Cell cellToFill : cellsToFill) {
+
+            List<Integer> possibleSymbols = cellToFill.getPossibleSymbols();
+            if (possibleSymbols.size() != 1) {
+                continue;
+            }
+
+            cellToFill.setSymbolIndex(possibleSymbols.getFirst());
+
+            return this.solve(doku);
+        }
+
+        // Si ça ne marche pas
+        // On fait du backtracking
+        Cell cellToFill = doku.getRandomEmptyCell(rand);
+        List<Integer> possibleSymbols = cellToFill.getPossibleSymbols();
+
+        while (!possibleSymbols.isEmpty()) {
+            int nextPossibleSymbolIndex = rand.nextInt(possibleSymbols.size());
+            int nextSymbol = possibleSymbols.get(nextPossibleSymbolIndex);
+
+            cellToFill.setSymbolIndex(nextSymbol);
+            if (this.solve(doku)) {
+                return true;
+            }
+
+            cellToFill.setSymbolIndex(Cell.NOSYMBOL);
+            possibleSymbols.remove(nextPossibleSymbolIndex);
+        }
+
+        return false;
+    }
+
+}

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

@@ -0,0 +1,63 @@
+package sudoku.solver;
+
+import java.util.List;
+import java.util.Random;
+import java.util.concurrent.CancellationException;
+import java.util.logging.Level;
+
+import sudoku.io.SudokuPrinter;
+import sudoku.structure.Cell;
+import sudoku.structure.MultiDoku;
+import sudoku.structure.Sudoku;
+
+public class RandomSolver implements Solver {
+
+	/**
+     * Résout, si possible, le multidoku passé en paramètre
+     * en testant toutes les possibilités, de manière aléatoire, avec un algorithme
+     * de backtracking.
+     *
+     * @param doku Multidoku, à résoudre
+     * @param rand Random, pour tester aléatoirement les symboles
+     * @return boolean, true s'il est résolu ou false s'il ne l'est pas.
+     */
+	@Override
+    public boolean solve(MultiDoku doku) {
+        Random rand = new Random();
+
+        if (Thread.interrupted())
+            throw new CancellationException("User wants to stop the solver");
+
+        Sudoku sudoku = doku.getSubGrid(0);
+        logger.log(Level.FINE,
+                '\n' + SudokuPrinter.toStringRectangleSudoku(sudoku,
+                        sudoku.getBlockWidth() == 0 ? sudoku.getSize() : sudoku.getBlockWidth(),
+                        sudoku.getBlockWidth() == 0 ? sudoku.getSize() : sudoku.getSize() / sudoku.getBlockWidth()));
+
+        if (doku.isSolved()) {
+            return true;
+        }
+
+        Cell cellToFill = doku.getFirstEmptyCell();
+        if (cellToFill == null) {
+            return false;
+        }
+
+        List<Integer> possibleSymbols = cellToFill.getPossibleSymbols();
+
+        while (!possibleSymbols.isEmpty()) {
+            int nextPossibleSymbolIndex = rand.nextInt(possibleSymbols.size());
+            int nextSymbol = possibleSymbols.get(nextPossibleSymbolIndex);
+
+            cellToFill.setSymbolIndex(nextSymbol);
+            if (this.solve(doku)) {
+                return true;
+            }
+            cellToFill.setSymbolIndex(Cell.NOSYMBOL);
+            possibleSymbols.remove(nextPossibleSymbolIndex);
+
+        }
+        return false;
+    }
+
+}

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

@@ -1,67 +1,19 @@
 package sudoku.solver;
 
 import java.util.List;
-import java.util.Random;
-import java.util.concurrent.CancellationException;
-import java.util.logging.Level;
 import java.util.logging.Logger;
 
-import sudoku.io.SudokuPrinter;
 import sudoku.structure.Cell;
 import sudoku.structure.MultiDoku;
-import sudoku.structure.Sudoku;
 
-public class Solver {
+public interface Solver {
 
 	/**
      * Log du Solver, qui garde trace des actions réalisées.
      */
-    private static final Logger logger = Logger.getLogger("SolverLogger");
+    public static final Logger logger = Logger.getLogger("SolverLogger");
 
-    /**
+	boolean solve(MultiDoku doku);
-     * Résout, si possible, le multidoku passé en paramètre
-     * en testant toutes les possibilités, de manière aléatoire, avec un algorithme
-     * de backtracking.
-     *
-     * @param doku Multidoku, à résoudre
-     * @param rand Random, pour tester aléatoirement les symboles
-     * @return boolean, true s'il est résolu ou false s'il ne l'est pas.
-     */
-    public static boolean randomSolve(MultiDoku doku, Random rand) {
-        if (Thread.interrupted())
-            throw new CancellationException("User wants to stop the solver");
-
-        Sudoku sudoku = doku.getSubGrid(0);
-        logger.log(Level.FINE,
-                '\n' + SudokuPrinter.toStringRectangleSudoku(sudoku,
-                        sudoku.getBlockWidth() == 0 ? sudoku.getSize() : sudoku.getBlockWidth(),
-                        sudoku.getBlockWidth() == 0 ? sudoku.getSize() : sudoku.getSize() / sudoku.getBlockWidth()));
-
-        if (doku.isSolved()) {
-            return true;
-        }
-
-        Cell cellToFill = doku.getFirstEmptyCell();
-        if (cellToFill == null) {
-            return false;
-        }
-
-        List<Integer> possibleSymbols = cellToFill.getPossibleSymbols();
-
-        while (!possibleSymbols.isEmpty()) {
-            int nextPossibleSymbolIndex = rand.nextInt(possibleSymbols.size());
-            int nextSymbol = possibleSymbols.get(nextPossibleSymbolIndex);
-
-            cellToFill.setSymbolIndex(nextSymbol);
-            if (Solver.randomSolve(doku, rand)) {
-                return true;
-            }
-            cellToFill.setSymbolIndex(Cell.NOSYMBOL);
-            possibleSymbols.remove(nextPossibleSymbolIndex);
-
-        }
-        return false;
-    }
 
 	 /**
      * Compte le nombre de solutions possibles au MultiDoku passé en paramètres.
@@ -69,168 +21,27 @@ public class Solver {
      * @param doku MultiDoku, MultiDoku dont on veut le nombre de solutions.
      * @return int, nombre de solutions possibles.
      */
-    public static int countSolution(MultiDoku doku) {
+    default int countSolution(MultiDoku doku) {
         int result = 0;
 
-
         if (doku.isSolved()) {
             return 1;
         }
 
         Cell cellToFill = doku.getFirstEmptyCell();
-        assert(cellToFill != null);
+        assert (cellToFill != null);
 
         List<Integer> possibleSymbols = cellToFill.getPossibleSymbols();
 
         for (int symbol : possibleSymbols) {
             doku.getStateManager().pushState();
             cellToFill.setSymbolIndex(symbol);
-            if (Solver.solve(doku)) {
+            if (solve(doku)) {
                 result++;
             }
             doku.getStateManager().popState();
         }
-
         return result;
     }
 
-    /**
-     * Résout le MultiDoku passé en paramètre, avec backtracking.
-     *
-     * @param doku MultiDoku, MultiDoku à résoudre.
-     * @return boolean, valant true si le MultiDoku est résolu, false sinon.
-     */
-    public static boolean solve(MultiDoku doku) {
-        if (Thread.interrupted())
-            throw new CancellationException("User wants to stop the solver");
-
-        if (doku.isSolved()) {
-            return true;
-        }
-
-        Cell cellToFill = doku.getFirstEmptyCell();
-        if (cellToFill == null) {
-            return false;
-        }
-
-        List<Integer> possibleSymbols = cellToFill.getPossibleSymbols();
-        if (possibleSymbols.isEmpty()) {
-            return false;
-        }
-
-        for (int symbol : possibleSymbols) {
-
-            cellToFill.setSymbolIndex(symbol);
-            if (Solver.solve(doku)) {
-                return true;
-            } else {
-                cellToFill.setSymbolIndex(Cell.NOSYMBOL);
-            }
-
-        }
-        return false;
-    }
-
-    /**
-     * Résout le MultiDoku passé en paramètre, avec règles de déduction.
-     *
-     * @param doku MultiDoku, MultiDoku à résoudre.
-     * @return boolean, valant true si le MultiDoku est résolu, false sinon.
-     */
-    public static boolean humanSolve(MultiDoku doku) {
-        if (Thread.interrupted())
-            throw new CancellationException("User wants to stop the solver");
-
-        Sudoku sudoku = doku.getSubGrid(0);
-        logger.log(Level.FINE,
-                '\n' + SudokuPrinter.toStringRectangleSudoku(sudoku,
-                        sudoku.getBlockWidth() == 0 ? sudoku.getSize() : sudoku.getBlockWidth(),
-                        sudoku.getBlockWidth() == 0 ? sudoku.getSize() : sudoku.getSize() / sudoku.getBlockWidth()));
-
-        if (doku.isSolved()) {
-            return true;
-        }
-
-        List<Cell> cellsToFill = doku.getEmptyCells();
-        if (cellsToFill.isEmpty()) {
-            return false;
-        }
-
-        for (Cell cellToFill : cellsToFill) {
-
-            List<Integer> possibleSymbols = cellToFill.getPossibleSymbols();
-            if (possibleSymbols.size() != 1) {
-                continue;
-            }
-
-            cellToFill.setSymbolIndex(possibleSymbols.getFirst());
-
-            return Solver.humanSolve(doku);
-        }
-
-        return doku.isSolved();
-    }
-
-    /**
-     * Résout le MultiDoku passé en paramètre, avec règles de déduction et backtracking.
-     *
-     * @param doku MultiDoku, MultiDoku à résoudre.
-     * @param rand Random, pour tester aléatoirement les symboles, lors du backtracking.
-     * @return boolean, valant true si le MultiDoku est résolu, false sinon.
-     */
-    public static boolean mixedSolve(MultiDoku doku, Random rand) {
-        if (Thread.interrupted()) {
-            throw new CancellationException("User wants to stop the solver");
-        }
-
-        Sudoku sudoku = doku.getSubGrid(0);
-        logger.log(Level.FINE,
-                '\n' + SudokuPrinter.toStringRectangleSudoku(
-                        sudoku,
-                        sudoku.getBlockWidth() == 0 ? sudoku.getSize() : sudoku.getBlockWidth(),
-                        sudoku.getBlockWidth() == 0 ? sudoku.getSize() : sudoku.getSize() / sudoku.getBlockWidth())
-        );
-
-        if (doku.isSolved()) {
-            return true;
-        }
-
-        List<Cell> cellsToFill = doku.getEmptyCells();
-        if (cellsToFill.isEmpty()) {
-            return false;
-        }
-
-        //Règles de déduction
-        for (Cell cellToFill : cellsToFill) {
-
-            List<Integer> possibleSymbols = cellToFill.getPossibleSymbols();
-            if (possibleSymbols.size() != 1) {
-                continue;
-            }
-
-            cellToFill.setSymbolIndex(possibleSymbols.getFirst());
-
-            return Solver.mixedSolve(doku, rand);
-        }
-
-        //Si ça ne marche pas
-        //On fait du backtracking
-        Cell cellToFill = doku.getRandomEmptyCell(rand);
-        List<Integer> possibleSymbols = cellToFill.getPossibleSymbols();
-
-        while (!possibleSymbols.isEmpty()) {
-            int nextPossibleSymbolIndex = rand.nextInt(possibleSymbols.size());
-            int nextSymbol = possibleSymbols.get(nextPossibleSymbolIndex);
-
-            cellToFill.setSymbolIndex(nextSymbol);
-            if (Solver.mixedSolve(doku, rand)) {
-                return true;
-            }
-
-            cellToFill.setSymbolIndex(Cell.NOSYMBOL);
-            possibleSymbols.remove(nextPossibleSymbolIndex);
-        }
-
-        return false;
-    }
 }

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

@@ -2,7 +2,6 @@ package sudoku.solver;
 
 import java.util.concurrent.CancellationException;
 
-import sudoku.structure.Coordinate;
 import sudoku.structure.MultiDoku;
 import sudoku.structure.Sudoku;
 

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

@@ -9,9 +9,9 @@ import java.util.List;
 import java.util.Map;
 import java.util.Random;
 
-import sudoku.io.SudokuSerializer;
-
 import sudoku.constraint.Constraint;
+import sudoku.io.SudokuSerializer;
+import sudoku.solver.RandomSolver;
 import sudoku.solver.Solver;
 
 public class SudokuFactory {
@@ -116,7 +116,7 @@ public class SudokuFactory {
 	 * @return boolean, valant true si un MultiDoku de difficulté donnée peut être créée, false sinon.
 	 * @throws Exception si la difficulté n'est pas compatible avec la taille du MultiDoku.
 	 */
-	public static boolean newDokuFromFilledOne(MultiDoku doku, int nbCellsToEmpty) throws Exception {
+	public static boolean newDokuFromFilledOne(MultiDoku doku, int nbCellsToEmpty, Solver solver) throws Exception {
 
 		if (nbCellsToEmpty >= doku.getCells().size()) {
 			throw new Exception();
@@ -134,9 +134,9 @@ public class SudokuFactory {
 
 			int oldSymbol = cellToEmpty.empty();
 
-			int nbDokuSultions = Solver.countSolution(doku);
+			int nbDokuSultions = solver.countSolution(doku);
 			if (nbDokuSultions == 1) {
-				if (newDokuFromFilledOne(doku, --nbCellsToEmpty)) {
+				if (newDokuFromFilledOne(doku, --nbCellsToEmpty, solver)) {
 					return true;
 				}
 			}
@@ -145,7 +145,7 @@ public class SudokuFactory {
 			cellsThatCanBeEmptied.remove(cellToEmpty);
 		}
 
-		return newDokuFromFilledOne(doku, --nbCellsToEmpty);
+		return newDokuFromFilledOne(doku, --nbCellsToEmpty, solver);
 	}
 
 	/**
@@ -272,9 +272,10 @@ public class SudokuFactory {
 	}
 
 	public static void fillDoku(MultiDoku doku, Difficulty difficulty) throws Exception {
-		Solver.randomSolve(doku, random);
+		Solver solver = new RandomSolver();
+		solver.solve(doku);
 		int nbCellsToEmpty = (int) (difficulty.getFactor() * doku.getNbCells());
-		boolean successfull = newDokuFromFilledOne(doku, nbCellsToEmpty);
+		boolean successfull = newDokuFromFilledOne(doku, nbCellsToEmpty, solver);
 		if (!successfull) {
 			throw new Exception("Canno't create this doku with this difficulty");
 		}

app/src/test/java/sudoku/SudokuSerializerTest.java

@@ -10,7 +10,7 @@ import org.json.JSONObject;
 import org.junit.jupiter.api.Test;
 
 import sudoku.io.SudokuSerializer;
-import sudoku.solver.Solver;
+import sudoku.solver.RandomSolver;
 import sudoku.structure.MultiDoku;
 import sudoku.structure.SudokuFactory;
 
@@ -19,7 +19,7 @@ public class SudokuSerializerTest {
     void testSerializeWithSize(int blockWidth, int blockHeight) {
         var sudoku = SudokuFactory.createBasicEmptyRectangleDoku(blockWidth, blockHeight,
                 SudokuFactory.DEFAULT_CONSTRAINTS);
-        Solver.randomSolve(sudoku, new Random());
+        new RandomSolver().solve(sudoku);
         JSONObject data = SudokuSerializer.serializeSudoku(sudoku);
         MultiDoku multiDoku = SudokuSerializer.deserializeSudoku(data);
         assertTrue(data.toString().equals(SudokuSerializer.serializeSudoku(multiDoku).toString()));
@@ -28,14 +28,15 @@ public class SudokuSerializerTest {
     void testSaveWithSize(int blockWidth, int blockHeight) {
         MultiDoku doku = SudokuFactory.createBasicEmptyRectangleDoku(blockWidth, blockHeight,
                 SudokuFactory.DEFAULT_CONSTRAINTS);
-        Solver.randomSolve(doku, new Random());
+        new RandomSolver().solve(doku);
         String savePath = SudokuSerializer.saveMultiDoku(doku);
         MultiDoku otherDoku = null;
         try {
             otherDoku = SudokuFactory.fromfile(savePath);
             assert (otherDoku != null);
 
-            assertEquals(SudokuSerializer.serializeSudoku(doku).toString(), SudokuSerializer.serializeSudoku(otherDoku).toString());
+            assertEquals(SudokuSerializer.serializeSudoku(doku).toString(),
+                    SudokuSerializer.serializeSudoku(otherDoku).toString());
             // clean file after test
             File fileToDelete = new File(savePath);
             fileToDelete.delete();
@@ -47,7 +48,7 @@ public class SudokuSerializerTest {
 
     void testSerializeX(int size) {
         var sudoku = SudokuFactory.createBasicXShapedMultidoku(size, SudokuFactory.DEFAULT_CONSTRAINTS);
-        Solver.randomSolve(sudoku, new Random());
+        new RandomSolver().solve(sudoku);
         JSONObject data = SudokuSerializer.serializeSudoku(sudoku);
         MultiDoku multiDoku = SudokuSerializer.deserializeSudoku(data);
 

app/src/test/java/sudoku/solver/SolverTest.java

@@ -57,7 +57,7 @@ class SolverTest {
 
 		assert (dokuResult.isSolved());
 
-		Solver.randomSolve(dokuToTest, rand);
+		new RandomSolver().solve(dokuToTest);
 
 		System.out.println("\n****************************\nDoku solved");
 		SudokuPrinter.printRectangleSudoku(dokuToTest.getSubGrid(0), 3, 3);
@@ -89,13 +89,13 @@ class SolverTest {
 				5, ns, ns, ns, 3, 1, 0, ns, ns);
 		sudokuToTest2.setImmutableCellsSymbol(immutableCells2);
 
-		boolean isSolved = Solver.randomSolve(dokuToTest2, rand);
+		boolean isSolved = new RandomSolver().solve(dokuToTest2);
 
 		assert (!isSolved);
 
 		MultiDoku dokuToTest3 = SudokuFactory.createBasicEmptySquareDoku(3, SudokuFactory.DEFAULT_CONSTRAINTS);
 
-		Solver.randomSolve(dokuToTest3, rand);
+		new RandomSolver().solve(dokuToTest3);
 
 		SudokuPrinter.printRectangleSudoku(dokuToTest3.getSubGrid(0), 3, 3);
 	}