diff --git a/AppLaser.java b/AppLaser.java
index 4689f6f..468c4a7 100644
--- a/AppLaser.java
+++ b/AppLaser.java
@@ -17,17 +17,25 @@ public class AppLaser {
 
         universe.print();
 
+        int i = 0;
+
         do {
+            System.out.printf("%d %d %d %d %d", currentState.pos_i, currentState.pos_j, currentState.direction, currentState.nb_choix, universe.possibleChoices(currentState));
+
             if (universe.canEvolve(currentState)) {
                 stack.push(currentState.copy(universe.possibleChoices(currentState)));
                 currentState = universe.evolve(currentState);
             }
             else {
                 currentState = stack.pop();
+                universe.reset(currentState);
+
+                System.out.println("\n\n");
+                universe.print();
             }
 
-            universe.print();
-        } while (stack.size() != 0);
+
+        } while (!universe.isSolved());
     }
 
 }
diff --git a/Universe.java b/Universe.java
index be3bad2..cd164fa 100644
--- a/Universe.java
+++ b/Universe.java
@@ -5,6 +5,7 @@ public class Universe {
 
     private int[][] grid;
     private int length, height;
+    private int boxes_to_fill;
 
     // Constructors
 
@@ -30,6 +31,14 @@ public class Universe {
         }
 
         this.grid[i_start][j_start] = dir_start;
+
+        this.boxes_to_fill = 0;
+
+        for (i = 1; i < this.height - 1; i++) {
+            for (j = 1; j < this.length - 1; j++) {
+                if (this.grid[i][j] == 0) this.boxes_to_fill++;
+            }
+        }
     }
 
     // Methods
@@ -41,10 +50,6 @@ public class Universe {
         else {}
     }
 
-    public boolean isSolved() {
-        return true;
-    }
-
     public int possibleChoices(Situation s) {
         int i = s.pos_i;
         int j = s.pos_j;
@@ -173,21 +178,27 @@ public class Universe {
             j ++;
             d = 12;
         }
-        else if (c == 1 && d == 12 || c == 2 && d == 10 || c == 3 && d == 11) {
+        else if (c == 1 && d == 13 || c == 2 && d == 10 || c == 3 && d == 11) {
             j --;
             d = 13;
         }
 
-        return new Situation(i, j, d, c);
+        this.boxes_to_fill++;
+
+        return new Situation(i, j, d, 0);
     }
 
-    public void reset(int i, int j) {
-        this.grid[i][j] = -1;
+    public void reset(Situation s) {
+        this.grid[s.pos_i][s.pos_j] = 0;
     }
 
-    public Situation restore(Situation current, Situation prev) {
+    public boolean isSolved() {
+        return this.boxes_to_fill == 0;
+    }
+
+    /*public Situation restore(Situation current, Situation prev) {
         
-    }
+    }*/
 
     public void print() {
         int i, j;