diff --git a/R3.01/tp/tp4/ex2/helpers.php b/R3.01/tp/tp4/ex2/helpers.php
index 211e12c..f733f64 100644
--- a/R3.01/tp/tp4/ex2/helpers.php
+++ b/R3.01/tp/tp4/ex2/helpers.php
@@ -1,54 +1,83 @@
 <?php
+function initializeGame()
+{
+	// Une grille vide contient 9 cases valant 0.
+	$_SESSION['grid'] = array_fill(0, 9, 0);
+	$_SESSION['playerTurn'] = 1;
+}
+
+function nextPlayer($player)
+{
+	return $player === 1 ? 2 : 1;
+}
+
 function isWinner($grid, $player)
 {
-	$winStates = array
-		(
-			array(0, 1, 2), array(3, 4, 5), array(6, 7, 8),     // Horizontal
-			array(0, 3, 6), array(1, 4, 7), array(2, 5, 8),     // Vertical
-			array(0, 4, 8), array(2, 4, 6)                      // Diagonal
-		);
+	$winStates = array(
+		array(0, 1, 2), array(3, 4, 5), array(6, 7, 8),
+		array(0, 3, 6), array(1, 4, 7), array(2, 5, 8),
+		array(0, 4, 8), array(2, 4, 6)
+	);
 
-	foreach ($winStates as $winState)
-	{
-		if ($grid[$winState[0]] == $player &&
+	foreach ($winStates as $winState) {
+		if (
+			$grid[$winState[0]] == $player &&
 			$grid[$winState[1]] == $player &&
-			$grid[$winState[2]] == $player)
-		{
+			$grid[$winState[2]] == $player
+		) {
 			return true;
 		}
 	}
+
 	return false;
 }
 
 function noWinner($grid)
 {
-	for($i = 0; $i < 9; $i++)
-		if ($grid[$i] == 0) 
+	for ($i = 0; $i < 9; $i++) {
+		if ($grid[$i] == 0) {
 			return false;
+		}
+	}
 
 	return true;
 }
 
-function displayGrid($grid)
+function getWinner($grid)
+{
+	if (isWinner($grid, 1)) {
+		return 1;
+	}
+
+	if (isWinner($grid, 2)) {
+		return 2;
+	}
+
+	return 0;
+}
+
+function displayGrid($grid, $isInteractive = true)
 {
 	echo '<table class="morpion">';
-	for ($i = 0; $i < 3; $i ++){
-		echo "<tr>";
-		for ($j = 0; $j < 3; $j ++){
+	for ($i = 0; $i < 3; $i++) {
+		echo '<tr>';
+		for ($j = 0; $j < 3; $j++) {
+			echo '<td>';
 
-			echo "<td>";
-
-			$pos = 3*$i + $j;
-			if ($grid[$pos] == 0)
+			$pos = 3 * $i + $j;
+			if ($grid[$pos] == 0 && $isInteractive) {
 				echo "<a href='?pos=$pos'></a>";
-			if ($grid[$pos] == 1)
+			}
+			if ($grid[$pos] == 1) {
 				echo '<i class="fa fa-times" aria-hidden="true"></i>';
-			if ($grid[$pos] == 2)
+			}
+			if ($grid[$pos] == 2) {
 				echo '<i class="fa fa-circle-o" aria-hidden="true"></i>';
+			}
 
-			echo "</td>";
+			echo '</td>';
 		}
-		echo "</tr>";
+		echo '</tr>';
 	}
-	echo "</table>";
+	echo '</table>';
 }
diff --git a/R3.01/tp/tp4/ex2/index.php b/R3.01/tp/tp4/ex2/index.php
index 2c1717b..6222985 100644
--- a/R3.01/tp/tp4/ex2/index.php
+++ b/R3.01/tp/tp4/ex2/index.php
@@ -1,11 +1,70 @@
 <?php
-include 'helpers.php';
+session_start();
 
-// view variables 
-$message = "";
-$grid = [0,1,0,1,0,2,2,0,0]; 
-$playerTurn = 1; // 1 or 2
+include_once 'helpers.php';
 
+// Si on demande une nouvelle partie, on réinitialise l'état stocké
+// en session puis on recharge la page sans paramètre.
+if (isset($_GET['reset'])) {
+    initializeGame();
+    header('Location: .');
+    exit;
+}
 
-include './views/tictactoe.php';
+if (!isset($_SESSION['grid']) || !isset($_SESSION['playerTurn'])) {
+    initializeGame();
+}
+
+// Variables transmises à la vue.
+$message = '';
+$grid = $_SESSION['grid'];
+$playerTurn = (int) $_SESSION['playerTurn'];
+
+$winner = getWinner($grid);
+$isGameOver = $winner !== 0 || noWinner($grid);
+
+// On joue uniquement si la partie est encore en cours.
+if (!$isGameOver && isset($_GET['pos'])) {
+    $pos = filter_input(
+        INPUT_GET,
+        'pos',
+        FILTER_VALIDATE_INT,
+        array('options' => array('min_range' => 0, 'max_range' => 8))
+    );
+
+    if ($pos === false || $pos === null) {
+        $message = 'Coup invalide.';
+    } elseif ($grid[$pos] !== 0) {
+        $message = 'Cette case est déjà occupée.';
+    } else {
+        // On enregistre le coup du joueur courant dans la grille.
+        $grid[$pos] = $playerTurn;
+
+        if (isWinner($grid, $playerTurn)) {
+            $message = "Le joueur $playerTurn gagne la partie.";
+        } elseif (noWinner($grid)) {
+            $message = 'Match nul.';
+        } else {
+            $playerTurn = nextPlayer($playerTurn);
+        }
+
+        $_SESSION['grid'] = $grid;
+        $_SESSION['playerTurn'] = $playerTurn;
+    }
+
+    $winner = getWinner($grid);
+    $isGameOver = $winner !== 0 || noWinner($grid);
+}
+
+// Si la page est simplement rafraîchie, on recalcule un message cohérent
+// à partir de l'état stocké en session.
+if ($message === '') {
+    if ($winner !== 0) {
+        $message = "Le joueur $winner gagne la partie.";
+    } elseif (noWinner($grid)) {
+        $message = 'Match nul.';
+    }
+}
+
+include_once './views/tictactoe.php';
 
diff --git a/R3.01/tp/tp4/ex2/views/tictactoe.php b/R3.01/tp/tp4/ex2/views/tictactoe.php
index 130bf00..8b16508 100644
--- a/R3.01/tp/tp4/ex2/views/tictactoe.php
+++ b/R3.01/tp/tp4/ex2/views/tictactoe.php
@@ -1,23 +1,35 @@
-<html>
+<!DOCTYPE html>
+<html lang="fr">
 	<head>
 		<meta charset="UTF-8">
+		<title>Tic Tac Toe</title>
 		<link
-	  rel="stylesheet"
-   href="https://cdn.jsdelivr.net/npm/@picocss/pico@2/css/pico.min.css"
-   />
+			rel="stylesheet"
+			href="https://cdn.jsdelivr.net/npm/@picocss/pico@2/css/pico.min.css"
+		/>
 		<link rel="stylesheet" href="./css/style.css">
 		<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/font-awesome/4.7.0/css/font-awesome.min.css">
-
 	</head>
 	<body>
 		<main class="container center">
-			<h4>Tic Tac Toe : <?php echo "player $playerTurn turn";?></h4>
+			<h4>
+				<?php if ($isGameOver) { ?>
+					Partie terminée
+				<?php } else { ?>
+					Tic Tac Toe : joueur <?php echo $playerTurn; ?> à vous de jouer
+				<?php } ?>
+			</h4>
 			<?php
-				displayGrid($grid);
+				// Quand la partie est finie, les liens dans les cases vides
+				// disparaissent pour empêcher tout coup supplémentaire.
+				displayGrid($grid, !$isGameOver);
 
-				if ($message != "")
-					echo "<h5>$message  <a  href='.'>new game</a></h5>";
-			  ?>
+				if ($message != '') {
+					echo '<h5>' . htmlspecialchars($message, ENT_QUOTES) . "  <a href='?reset=1'>nouvelle partie</a></h5>";
+				} else {
+					echo "<p><a href='?reset=1'>Recommencer la partie</a></p>";
+				}
+			?>
 		</main>
 	</body>
 </html>