feat: good leaderboard

app/src/main/java/game/Game.java

@@ -1,6 +1,9 @@
 package game;
 
+import java.util.ArrayList;
+import java.util.Collections;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 
 import sudoku.structure.MultiDoku;
@@ -12,11 +15,13 @@ public class Game {
 	}
 
 	private final Map<Integer, Player> players;
+	private final List<Player> leaderboard;
 	private GameState gameState;
 	private MultiDoku doku;
 
 	public Game() {
 		this.players = new HashMap<>();
+		this.leaderboard = new ArrayList<>();
 		this.gameState = GameState.GameNotStarted;
 	}
 
@@ -26,10 +31,18 @@ public class Game {
 
 	public void addPlayer(Player player) {
 		players.put(player.getId(), player);
+		leaderboard.add(player);
+	}
+
+	public void setPlayerScore(Player player, int newScore) {
+		player.setScore(newScore);
+		Collections.sort(this.leaderboard,
+				(player1, player2) -> Integer.compare(player1.getScore(), player2.getScore()));
 	}
 
 	public void removePlayer(int id) {
-		players.remove(id);
+		this.leaderboard.remove(getPlayerById(id));
+		this.players.remove(id);
 	}
 
 	public Map<Integer, Player> getPlayers() {
@@ -49,4 +62,8 @@ public class Game {
 		return doku;
 	}
 
+	public List<Player> getLeaderboard() {
+		return leaderboard;
+	}
+
 }