diff --git a/.gitignore b/.gitignore
index 5222c2f..80f665a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,3 @@
-highscores.txt
+doble_initial.exe
+*.o
+*.exe
\ No newline at end of file
diff --git a/highscores.txt b/highscores.txt
index 058b28c..ca5950d 100644
--- a/highscores.txt
+++ b/highscores.txt
@@ -1,9 +1,2 @@
-Max02.12;19860
-max;19374
-Max02.12;11910
-kristin;9935
-Max02.12;7966
-player_name;7961
-max;5989
-Max02.12;4988
+krisp;4986
 player1;3999
diff --git a/makefile b/makefile
index c816795..a27e9b1 100644
--- a/makefile
+++ b/makefile
@@ -1,5 +1,6 @@
 CC = gcc
 FLAGS = -g -Wall -lm
+ASAN_FLAGS = -fsanitize=address 
 
 ifeq ($(OS),Windows_NT)
 	include makefile_windows.variables
@@ -29,7 +30,7 @@ program_obj_files = stack.o bintree.o numbers.o timer.o highscore.o
 doble : main.o $(program_obj_files)
 	$(CC) $(FLAGS) $^ -o doble
 
-$(program_obj_filesobj_files): %.o: %.c
+$(program_obj_files): %.o: %.c
 	$(CC) -c $(FLAGS) $^ -o $@
 
 # --------------------------
@@ -39,7 +40,7 @@ unitTests:
 TEST_BIN = runTests
 
 unitTests: stack.o test_stack.o
-	$(CC) $(FLAGS) -I$(unityfolder) -o $(TEST_BIN) stack.o test_stack.o $(unityfolder)/unity.c
+	$(CC) $(FLAGS) $(ASAN_FLAGS) -I$(unityfolder) -o $(TEST_BIN) stack.o test_stack.o $(unityfolder)/unity.c
 
 test_stack.o: test_stack.c
 	$(CC) $(FLAGS) -I$(unityfolder) -c test_stack.c -o test_stack.o
@@ -49,7 +50,7 @@ test_stack.o: test_stack.c
 # --------------------------
 clean:
 ifeq ($(OS),Windows_NT)
-	del /f *.o doble
+	rm -f *.o doble
 else
 	rm -f *.o doble
 endif
\ No newline at end of file
diff --git a/stack.c b/stack.c
index 324faa4..5cd0d1a 100644
--- a/stack.c
+++ b/stack.c
@@ -1,5 +1,13 @@
-#include <stdlib.h>
 #include "stack.h"
+#include <stdio.h>
+#include <stdlib.h>
+
+/*typedef struct {
+
+  void *data;
+  struct StackNode *next;
+
+} StackNode;*/
 
 // TODO: grundlegende Stackfunktionen implementieren:
 /*  * `push`: legt ein Element oben auf den Stack,
@@ -60,17 +68,18 @@ StackNode *pop(StackNode *stack)
 void *top(StackNode *stack) { return stack != NULL ? stack->data : NULL; }
 
 // Clears stack and releases all memory.
-void clearStack(StackNode *stack)
+void clearStack(StackNode **stack)
 {
-    while (stack != NULL)
+    while (*stack != NULL)
     {
 
-        StackNode *next = (stack)->next;
-        free(stack);
-        stack = next;
-        (stack)->data = NULL;
-        (stack)->next = NULL;
-        (stack)->prev = NULL;
+        StackNode *next = (*stack)->next;
+        free(*stack);
+        (*stack)->data = NULL;
+        (*stack)->next = NULL;
+        (*stack)->prev = NULL;
+        (*stack) = next;
+
     }
     
 }
\ No newline at end of file
diff --git a/stack.h b/stack.h
index c835596..8119b2c 100644
--- a/stack.h
+++ b/stack.h
@@ -1,13 +1,23 @@
 #ifndef STACK_H
 #define STACK_H
 
-/* A stack is a special type of queue which uses the LIFO (last in, first out) principle. 
-This means that with each new element all other elements are pushed deeper into the stack. 
-The latest element is taken from the stack. */
+/* A stack is a special type of queue which uses the LIFO (last in, first out)
+principle. This means that with each new element all other elements are pushed
+deeper into the stack. The latest element is taken from the stack. */
 
 #include <stdlib.h>
 
-//TODO: passenden Datentyp als struct anlegen
+// TODO: passenden Datentyp als struct anlegen
+
+typedef struct StackNode {
+
+  void *data;
+  struct StackNode *next;
+  struct StackNode *prev;
+
+} StackNode;
+
+StackNode *createNode(void *data);
 
 typedef struct StackNode {
 
@@ -22,14 +32,14 @@ StackNode *createNode(void *data);
 // Pushes data as pointer onto the stack.
 StackNode *push(StackNode *stack, void *data);
 
-// Deletes the top element of the stack (latest added element) and releases its memory. (Pointer to data has to be
-// freed by caller.)
+// 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);
 
 // Returns the data of the top element.
 void *top(StackNode *stack);
 
 // Clears stack and releases all memory.
-void clearStack(StackNode *stack);
+void clearStack(StackNode **stack);
 
 #endif
diff --git a/test_stack.c b/test_stack.c
index a5b69af..a9f9914 100644
--- a/test_stack.c
+++ b/test_stack.c
@@ -37,7 +37,7 @@ void test_clearStack(void) {
   }
   //printf("testints: %d,%d,%d,%d,%d",testInts[0],testInts[1],testInts[2],testInts[3],testInts[4]);
 
-  clearStack(testStack);
+  clearStack(&testStack);
   TEST_ASSERT_NULL(testStack);
 }
 
@@ -57,4 +57,4 @@ int main(void) {
   RUN_TEST(test_clearStack);
 
   return UNITY_END();
-}
\ No newline at end of file
+}