changed numbers.c so that it works with new nextTreeData() function

numbers.c

@@ -31,13 +31,14 @@ static int existsInTree(TreeNode *root, unsigned int value)
     unsigned int *data;
 
     // Traversierung initialisieren
-    nextTreeData(root);
+    data = nextTreeData(root);
 
-    while ((data = nextTreeData(NULL)) != NULL)
+    do    
     {
         if (*data == value)
             return 1;
-    }
+    } while ((data = nextTreeData(NULL)) != NULL);
+
     return 0;
 }