diff --git a/bintree.c b/bintree.c
index 4fc5e59..1da97a8 100644
--- a/bintree.c
+++ b/bintree.c
@@ -80,31 +80,33 @@ void *nextTreeData(TreeNode *root)
 
         if (stack)
         {
-            freeStack(stack);
+            clearStack(&stack);
             stack = NULL;
         }
-
-        stack = createStack();
+        //leeren Stack initialisieren
+        stack = NULL;
 
         // alle linken Knoten vom Wurzelknoten pushen
         currentNode = root;
         while (currentNode)
         {
-            push(stack, currentNode);
+            stack = push(stack, currentNode);
             currentNode = currentNode->left;
         }
     }
     // Stack ist leer, keine Daten mehr
-    if (!stack || isEmpty(stack))
+    if (!stack)
         return NULL;
 
-    TreeNode *newNode = pop(stack); // nächster Knoten
+    TreeNode *newNode = (TreeNode *)top(stack);
+    // Stack-Knoten entfernen
+    stack = pop(stack);
 
     // Wenn rechter Teilbaum vorhanden → alle linken Knoten pushen
     currentNode = newNode->right;
     while (currentNode)
     {
-        push(stack, currentNode);
+        stack = push(stack, currentNode);
         currentNode = currentNode->left;
     }
     return newNode->data; // Daten zurückgeben
diff --git a/main.o b/main.o
new file mode 100644
index 0000000..a5219de
Binary files /dev/null and b/main.o differ
diff --git a/numbers.o b/numbers.o
deleted file mode 100644
index 371b158..0000000
Binary files a/numbers.o and /dev/null differ
diff --git a/stack.o b/stack.o
new file mode 100644
index 0000000..50cf531
Binary files /dev/null and b/stack.o differ