diff --git a/.idea/workspace.xml b/.idea/workspace.xml
index d135dd9cb5c3f30e45ade41a17f983f8b90b25bf..f54d405b94bf16855fa3c4d8c364ae884e24e560 100644
--- a/.idea/workspace.xml
+++ b/.idea/workspace.xml
@@ -9,7 +9,18 @@
     </configurations>
   </component>
   <component name="ChangeListManager">
-    <list default="true" id="43aff179-c306-46b9-b69f-eca5306fbf96" name="Default Changelist" comment="" />
+    <list default="true" id="43aff179-c306-46b9-b69f-eca5306fbf96" name="Default Changelist" comment="">
+      <change beforePath="$PROJECT_DIR$/.idea/workspace.xml" beforeDir="false" afterPath="$PROJECT_DIR$/.idea/workspace.xml" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/Box.o" beforeDir="false" />
+      <change beforePath="$PROJECT_DIR$/Star.o" beforeDir="false" />
+      <change beforePath="$PROJECT_DIR$/Vector.o" beforeDir="false" />
+      <change beforePath="$PROJECT_DIR$/galaxy.o" beforeDir="false" />
+      <change beforePath="$PROJECT_DIR$/galaxy_simulation.c" beforeDir="false" afterPath="$PROJECT_DIR$/galaxy_simulation.c" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/galaxy_simulation.o" beforeDir="false" />
+      <change beforePath="$PROJECT_DIR$/makefile" beforeDir="false" afterPath="$PROJECT_DIR$/makefile" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/quad_tree.c" beforeDir="false" afterPath="$PROJECT_DIR$/quad_tree.c" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/quad_tree.h" beforeDir="false" afterPath="$PROJECT_DIR$/quad_tree.h" afterDir="false" />
+    </list>
     <option name="EXCLUDED_CONVERTED_TO_IGNORED" value="true" />
     <option name="SHOW_DIALOG" value="false" />
     <option name="HIGHLIGHT_CONFLICTS" value="true" />
@@ -18,29 +29,11 @@
   </component>
   <component name="FileEditorManager">
     <leaf SIDE_TABS_SIZE_LIMIT_KEY="300">
-      <file pinned="false" current-in-tab="false">
-        <entry file="file://$PROJECT_DIR$/Vector.c">
-          <provider selected="true" editor-type-id="text-editor">
-            <state relative-caret-position="-542">
-              <caret line="39" column="18" selection-start-line="39" selection-start-column="18" selection-end-line="39" selection-end-column="18" />
-            </state>
-          </provider>
-        </entry>
-      </file>
-      <file pinned="false" current-in-tab="false">
-        <entry file="file://$PROJECT_DIR$/Vector.h">
-          <provider selected="true" editor-type-id="text-editor">
-            <state relative-caret-position="153">
-              <caret line="9" column="53" selection-start-line="9" selection-start-column="53" selection-end-line="9" selection-end-column="53" />
-            </state>
-          </provider>
-        </entry>
-      </file>
       <file pinned="false" current-in-tab="false">
         <entry file="file://$PROJECT_DIR$/Box.c">
           <provider selected="true" editor-type-id="text-editor">
-            <state relative-caret-position="1632">
-              <caret line="111" selection-start-line="111" selection-end-line="111" />
+            <state relative-caret-position="272">
+              <caret line="55" column="40" lean-forward="true" selection-start-line="55" selection-start-column="40" selection-end-line="55" selection-end-column="40" />
             </state>
           </provider>
         </entry>
@@ -75,8 +68,8 @@
       <file pinned="false" current-in-tab="false">
         <entry file="file://$PROJECT_DIR$/galaxy.c">
           <provider selected="true" editor-type-id="text-editor">
-            <state relative-caret-position="223">
-              <caret line="120" column="8" selection-start-line="120" selection-start-column="8" selection-end-line="120" selection-end-column="8" />
+            <state>
+              <caret selection-end-line="4" selection-end-column="17" />
             </state>
           </provider>
         </entry>
@@ -93,17 +86,35 @@
       <file pinned="false" current-in-tab="false">
         <entry file="file://$PROJECT_DIR$/galaxy_simulation.c">
           <provider selected="true" editor-type-id="text-editor">
-            <state relative-caret-position="425">
-              <caret line="25" column="18" selection-start-line="25" selection-start-column="18" selection-end-line="25" selection-end-column="18" />
+            <state relative-caret-position="68">
+              <caret line="4" column="21" selection-start-line="4" selection-start-column="21" selection-end-line="4" selection-end-column="21" />
+            </state>
+          </provider>
+        </entry>
+      </file>
+      <file pinned="false" current-in-tab="false">
+        <entry file="file://$PROJECT_DIR$/quad_tree.c">
+          <provider selected="true" editor-type-id="text-editor">
+            <state relative-caret-position="153">
+              <caret line="9" column="49" selection-start-line="9" selection-start-column="49" selection-end-line="9" selection-end-column="49" />
             </state>
           </provider>
         </entry>
       </file>
       <file pinned="false" current-in-tab="true">
+        <entry file="file://$PROJECT_DIR$/quad_tree.h">
+          <provider selected="true" editor-type-id="text-editor">
+            <state relative-caret-position="238">
+              <caret line="14" column="35" selection-start-line="14" selection-start-column="35" selection-end-line="14" selection-end-column="35" />
+            </state>
+          </provider>
+        </entry>
+      </file>
+      <file pinned="false" current-in-tab="false">
         <entry file="file://$PROJECT_DIR$/makefile">
           <provider selected="true" editor-type-id="text-editor">
-            <state relative-caret-position="306">
-              <caret line="18" lean-forward="true" selection-start-line="18" selection-end-line="18" />
+            <state relative-caret-position="51">
+              <caret line="3" column="71" selection-start-line="3" selection-start-column="71" selection-end-line="3" selection-end-column="71" />
             </state>
           </provider>
         </entry>
@@ -122,12 +133,14 @@
         <option value="$PROJECT_DIR$/Vector.c" />
         <option value="$PROJECT_DIR$/Star.c" />
         <option value="$PROJECT_DIR$/Star.h" />
-        <option value="$PROJECT_DIR$/galaxy_simulation.c" />
-        <option value="$PROJECT_DIR$/makefile" />
         <option value="$PROJECT_DIR$/Box.h" />
-        <option value="$PROJECT_DIR$/Box.c" />
         <option value="$PROJECT_DIR$/galaxy.h" />
         <option value="$PROJECT_DIR$/galaxy.c" />
+        <option value="$PROJECT_DIR$/galaxy_simulation.c" />
+        <option value="$PROJECT_DIR$/Box.c" />
+        <option value="$PROJECT_DIR$/makefile" />
+        <option value="$PROJECT_DIR$/quad_tree.c" />
+        <option value="$PROJECT_DIR$/quad_tree.h" />
       </list>
     </option>
   </component>
@@ -185,12 +198,12 @@
       <option name="presentableId" value="Default" />
       <updated>1559227081243</updated>
       <workItem from="1559227084365" duration="53793000" />
-      <workItem from="1560336527698" duration="28820000" />
+      <workItem from="1560336527698" duration="32701000" />
     </task>
     <servers />
   </component>
   <component name="TimeTrackingManager">
-    <option name="totallyTimeSpent" value="82613000" />
+    <option name="totallyTimeSpent" value="86494000" />
   </component>
   <component name="ToolWindowManager">
     <frame x="-7" y="-7" width="1550" height="838" extended-state="6" />
@@ -254,13 +267,6 @@
         </state>
       </provider>
     </entry>
-    <entry file="file://$PROJECT_DIR$/galaxy_simulation.c">
-      <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="425">
-          <caret line="25" column="18" selection-start-line="25" selection-start-column="18" selection-end-line="25" selection-end-column="18" />
-        </state>
-      </provider>
-    </entry>
     <entry file="file://$PROJECT_DIR$/Star.c">
       <provider selected="true" editor-type-id="text-editor">
         <state relative-caret-position="833">
@@ -284,15 +290,22 @@
     </entry>
     <entry file="file://$PROJECT_DIR$/Box.c">
       <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="1632">
-          <caret line="111" selection-start-line="111" selection-end-line="111" />
+        <state relative-caret-position="272">
+          <caret line="55" column="40" lean-forward="true" selection-start-line="55" selection-start-column="40" selection-end-line="55" selection-end-column="40" />
+        </state>
+      </provider>
+    </entry>
+    <entry file="file://$PROJECT_DIR$/makefile">
+      <provider selected="true" editor-type-id="text-editor">
+        <state relative-caret-position="51">
+          <caret line="3" column="71" selection-start-line="3" selection-start-column="71" selection-end-line="3" selection-end-column="71" />
         </state>
       </provider>
     </entry>
     <entry file="file://$PROJECT_DIR$/galaxy.c">
       <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="223">
-          <caret line="120" column="8" selection-start-line="120" selection-start-column="8" selection-end-line="120" selection-end-column="8" />
+        <state>
+          <caret selection-end-line="4" selection-end-column="17" />
         </state>
       </provider>
     </entry>
@@ -303,10 +316,24 @@
         </state>
       </provider>
     </entry>
-    <entry file="file://$PROJECT_DIR$/makefile">
+    <entry file="file://$PROJECT_DIR$/galaxy_simulation.c">
+      <provider selected="true" editor-type-id="text-editor">
+        <state relative-caret-position="68">
+          <caret line="4" column="21" selection-start-line="4" selection-start-column="21" selection-end-line="4" selection-end-column="21" />
+        </state>
+      </provider>
+    </entry>
+    <entry file="file://$PROJECT_DIR$/quad_tree.c">
+      <provider selected="true" editor-type-id="text-editor">
+        <state relative-caret-position="153">
+          <caret line="9" column="49" selection-start-line="9" selection-start-column="49" selection-end-line="9" selection-end-column="49" />
+        </state>
+      </provider>
+    </entry>
+    <entry file="file://$PROJECT_DIR$/quad_tree.h">
       <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="306">
-          <caret line="18" lean-forward="true" selection-start-line="18" selection-end-line="18" />
+        <state relative-caret-position="238">
+          <caret line="14" column="35" selection-start-line="14" selection-start-column="35" selection-end-line="14" selection-end-column="35" />
         </state>
       </provider>
     </entry>
diff --git a/Box.o b/Box.o
deleted file mode 100644
index be8e1ab4b244b8062cf5dfbcc70400524f9e3fbb..0000000000000000000000000000000000000000
Binary files a/Box.o and /dev/null differ
diff --git a/Star.o b/Star.o
deleted file mode 100644
index 31a31dd95f878f0d7ad4feda1d3dc2f5adeacf65..0000000000000000000000000000000000000000
Binary files a/Star.o and /dev/null differ
diff --git a/Vector.o b/Vector.o
deleted file mode 100644
index 1d169814ec132196c3f1ebd784a80ce7658c9ace..0000000000000000000000000000000000000000
Binary files a/Vector.o and /dev/null differ
diff --git a/galaxy.o b/galaxy.o
deleted file mode 100644
index 47541c9c5db45a005c1ab63853045e648c1c956c..0000000000000000000000000000000000000000
Binary files a/galaxy.o and /dev/null differ
diff --git a/galaxy_simulation.c b/galaxy_simulation.c
index 9ea6fde7b51fbc6202b4c4fa5e3ab6ac0dce994f..4f93d33e43154a0a016a6bc9f430dde349309773 100644
--- a/galaxy_simulation.c
+++ b/galaxy_simulation.c
@@ -2,7 +2,7 @@
 #include <stdlib.h>
 #include <stdbool.h>
 #include <math.h>
-#include "galaxy.h"
+#include "quad_tree.h"
 
 int main(int argc, char *argv[]) {
     if (argc == 2) {
diff --git a/galaxy_simulation.o b/galaxy_simulation.o
deleted file mode 100644
index e91aab0eeaa6bed8fe3271f75c8bb51a648b6499..0000000000000000000000000000000000000000
Binary files a/galaxy_simulation.o and /dev/null differ
diff --git a/makefile b/makefile
index 5e79790e992f67f7dec9b91138b348a9f7e7bf96..4096d34919662fc6dda6c1e2f559ffa7a8ba6172 100644
--- a/makefile
+++ b/makefile
@@ -1,7 +1,7 @@
 
 
-galaxy_simulation: vector.o Box.o Star.o galaxy.o galaxy_simulation.o
-	gcc -o galaxy_simulation Vector.o Box.o Star.o galaxy.o galaxy_simulation.o -lm
+galaxy_simulation: vector.o Box.o Star.o galaxy.o quad_tree.o galaxy_simulation.o
+	gcc -o galaxy_simulation Vector.o Box.o Star.o galaxy.o quad_tree.o galaxy_simulation.o -lm
 
 galaxy_simulation.o: galaxy_simulation.c
 	gcc -o galaxy_simulation.o -c galaxy_simulation.c
@@ -14,5 +14,7 @@ Star.o: Star.c
 	gcc -o Star.o -c Star.c
 galaxy.o: galaxy.c
 	gcc -o galaxy.o -c galaxy.c
+quad_tree.o: quad_tree.c
+	gcc -o quad_tree.o -c quad_tree.c
 clean:
 	rm -f noise *.o *.gch
diff --git a/quad_tree.c b/quad_tree.c
index e69de29bb2d1d6434b8b29ae775ad8c2e48c5391..4934535e80cf9055021792d56071c7934e0526bc 100644
--- a/quad_tree.c
+++ b/quad_tree.c
@@ -0,0 +1,13 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <math.h>
+#include <time.h>
+#include "quad_tree.h"
+
+quad_tree *create_quad_tree_from_galaxy(const galaxy *const g){
+
+    quad_tree* galaxy = malloc(sizeof(quad_tree));
+
+
+}
\ No newline at end of file
diff --git a/quad_tree.h b/quad_tree.h
index e69de29bb2d1d6434b8b29ae775ad8c2e48c5391..e127e3841ffe25b8aba661d7f0fd633bd4595441 100644
--- a/quad_tree.h
+++ b/quad_tree.h
@@ -0,0 +1,27 @@
+#include "galaxy.h"
+typedef struct quad_tree {
+    node *root;
+} quad_tree;
+
+typedef struct node {
+    struct node *children[4];
+    box b;
+    star *s;
+    star *super_s;
+    bool is_empty;
+} node;
+
+
+void insert_star(node *n, star *s);
+
+//Création du quad_tree:
+quad_tree *create_quad_tree_from_galaxy(const galaxy *const g);
+
+//Libération de la mémoire du quad_tree
+void free_quad_tree(quad_tree *t);
+
+//Mise à jour de l’accélération d’une étoile:
+void update_acceleration_from_node(const node *const n, star *s,double theta);
+
+//Mise à jour de l’accélération de toutes les étoiles:
+void update_accelerations_of_all_stars(const node *const n,galaxy *g, double theta);
\ No newline at end of file