diff --git a/bintree.c b/bintree.c
index 5cf82a9..32555c8 100644
--- a/bintree.c
+++ b/bintree.c
@@ -8,11 +8,12 @@
     * `treeSize`: zählt die Knoten im Baum (rekursiv),
     * `nextTreeData`: Traversierung mit Hilfe des zuvor implementierten Stacks. */
 
+
 // Adds a copy of data's pointer destination to the tree using compareFct for ordering. Accepts duplicates
 // if isDuplicate is NULL, otherwise ignores duplicates and sets isDuplicate to 1 (or to 0 if a new entry is added).
 TreeNode *addToTree(TreeNode *root, const void *data, size_t dataSize, CompareFctType compareFct, int *isDuplicate)
 {
-
+    TreeNode newNode = createNode(data);
 }
 
 // Iterates over the tree given by root. Follows the usage of strtok. If tree is NULL, the next entry of the last tree given is returned in ordering direction.
diff --git a/numbers.c b/numbers.c
index f59d9a2..9d44531 100644
--- a/numbers.c
+++ b/numbers.c
@@ -16,7 +16,17 @@
 // creating random numbers.
 unsigned int *createNumbers(unsigned int len)
 {
+  //hier wird das array angelegt soll Einträge (zahlen) haben die zwichen 1 und 2* len liegen
+  // ran % 2*len
+  int *numbers[] = calloc(len, sizeof(int)); 
+  if(!numbers)
+    return NULL;
 
+  srand(time(NULL));
+
+  for(size_t i = 0; i < len; i++) {
+    numbers[i] = rand() % 2*len + 1;
+  }
 }
 
 // Returns only the only number in numbers which is present twice. Returns zero on errors.
diff --git a/stack.c b/stack.c
index d0105c7..226a36f 100644
--- a/stack.c
+++ b/stack.c
@@ -8,17 +8,16 @@
     * `clearStack`: gibt den gesamten Speicher frei. */
 
 // Pushes data as pointer onto the stack.
-StackNode *push(StackNode *stack, void *data) // es gibt bereits ein stack element, dieses wird übergeben + die daten, die in den stack müssen
+StackNode* push(StackNode* stack, void* data) // es gibt bereits ein stack element, dieses wird übergeben + die daten, die in den stack müssen
 {
-    if(!data)
-        return 0;
+    //if(!data)
+        //return 0; -> nicht notwendig
         
-    StackNode *newNode = calloc(1, sizeof(StackNode)); //Speicher reserviert für data und prev, jeweils nur zeiger
+    StackNode* newNode = calloc(1, sizeof(StackNode)); //Speicher reserviert für data und prev, jeweils nur zeiger
     if (!newNode)
-        return 0;
+        return NULL;
     
     newNode->prev = stack;
-
     newNode->data = data;
 
     return newNode;
@@ -26,20 +25,21 @@ StackNode *push(StackNode *stack, void *data) // es gibt bereits ein stack eleme
 
 // Deletes the top element of the stack (latest added element) and releases its memory. (Pointer to data has to be
 // freed by caller.)
-StackNode *pop(StackNode *stack)
+StackNode* pop(StackNode* stack)
 {
     if(!stack)
-        return 0;
-    StackNode *prev = stack->prev;
+        return NULL;
+    StackNode* prev = stack->prev;
     free(stack);
+
     return prev;
 }
 
 // Returns the data of the top element.
-void *top(StackNode *stack)
+void* top(StackNode* stack)
 {
     if(!stack)
-        return 0;
+        return NULL;
     return stack->data;
 }
 
@@ -49,9 +49,6 @@ void clearStack(StackNode *stack) //Annahme: erstes Element: prev = NULL;
     if(!stack)
         return;
 
-    StackNode *stack_tmp = stack;
-
-    while(stack_tmp) {
-        stack_tmp = pop(stack_tmp);
-    }
+    clearStack(stack->prev);
+    free(stack);
 }
\ No newline at end of file
diff --git a/test_stack.c b/test_stack.c
index 0461a78..f0f8790 100644
--- a/test_stack.c
+++ b/test_stack.c
@@ -20,7 +20,7 @@ void test_pushFailsOnNullPointer(StackNode *stack, void *data) {
     return;
 }
 
-void test_popFailsOnNullPointer() {
+void test_popFailsOnNullPointer() { //pop on null returns NULL
     
     StackNode* test = pop(NULL);
     if (test == 0) {