diff --git a/du6/list_ops.c b/du6/list_ops.c
index 197cd6a..ec448f1 100644
--- a/du6/list_ops.c
+++ b/du6/list_ops.c
@@ -1,6 +1,6 @@
-#include <stdlib.h>
-#include <stddef.h>
-#include <stdbool.h> // pre bool
+ #include <stdlib.h> 
+#include <stddef.h> 
+#include <stdbool.h> 
 
 typedef int list_element_t;
 
@@ -9,109 +9,128 @@ typedef struct {
     list_element_t elements[];
 } list_t;
 
-// ==== Deklarácie funkcií (tzv. prototypy) ====
-
+// Deklarácie funkcií
 list_t *new_list(size_t length, list_element_t default_value);
 list_t *map_list(list_t *list, list_element_t (*map_fn)(list_element_t));
 list_t *filter_list(list_t *list, bool (*filter_fn)(list_element_t));
-list_element_t foldl_list(list_t *list, list_element_t initial, list_element_t (*fold_fn)(list_element_t, list_element_t));
-list_element_t foldr_list(list_t *list, list_element_t initial, list_element_t (*fold_fn)(list_element_t, list_element_t));
+list_element_t foldl_list(list_t *list, list_element_t initial,
+                          list_element_t (*fold_fn)(list_element_t, list_element_t));
+list_element_t foldr_list(list_t *list, list_element_t initial,
+                          list_element_t (*fold_fn)(list_element_t, list_element_t));
 list_t *reverse_list(list_t *list);
 void delete_list(list_t *list);
+list_t *append_list(list_t *list1, list_t *list2);
+size_t length_list(list_t *list);
 
-// ==== Implementácie ====
-
+// Vytvorí nový zoznam a naplní ho default hodnotou
 list_t *new_list(size_t length, list_element_t default_value) {
     list_t *list = malloc(sizeof(list_t) + length * sizeof(list_element_t));
-    if (list == NULL) {
-        return NULL;
-    }
+    if (!list) return NULL;
 
     list->length = length;
     for (size_t i = 0; i < length; i++) {
         list->elements[i] = default_value;
     }
-
     return list;
 }
 
+// Mapovanie: aplikuje funkciu na každý prvok zoznamu
 list_t *map_list(list_t *list, list_element_t (*map_fn)(list_element_t)) {
-    list_t *result = malloc(sizeof(list_t) + sizeof(list_element_t) * list->length);
-    if (result == NULL) {
-        return NULL;
-    }
-
-    result->length = list->length;
+    list_t *new = malloc(sizeof(list_t) + list->length * sizeof(list_element_t));
+    if (!new) return NULL;
 
+    new->length = list->length;
     for (size_t i = 0; i < list->length; i++) {
-        result->elements[i] = map_fn(list->elements[i]);
+        new->elements[i] = map_fn(list->elements[i]);
     }
-
-    return result;
+    return new;
 }
 
+// Filter: ponechá len tie prvky, ktoré spĺňajú podmienku
 list_t *filter_list(list_t *list, bool (*filter_fn)(list_element_t)) {
     size_t count = 0;
 
+    // Zistíme koľko prvkov prejde filtrom
     for (size_t i = 0; i < list->length; i++) {
         if (filter_fn(list->elements[i])) {
             count++;
         }
     }
 
-    list_t *result = malloc(sizeof(list_t) + sizeof(list_element_t) * count);
-    if (result == NULL) {
-        return NULL;
-    }
+    list_t *filtered = malloc(sizeof(list_t) + count * sizeof(list_element_t));
+    if (!filtered) return NULL;
 
-    result->length = count;
-    size_t index = 0;
+    filtered->length = count;
+    size_t j = 0;
 
     for (size_t i = 0; i < list->length; i++) {
         if (filter_fn(list->elements[i])) {
-            result->elements[index] = list->elements[i];
-            index++;
+            filtered->elements[j++] = list->elements[i];
         }
     }
 
-    return result;
+    return filtered;
 }
 
-list_element_t foldl_list(list_t *list, list_element_t initial, list_element_t (*fold_fn)(list_element_t, list_element_t)) {
+// Foldl: zľava doprava
+list_element_t foldl_list(list_t *list, list_element_t initial,
+                          list_element_t (*fold_fn)(list_element_t, list_element_t)) {
     list_element_t acc = initial;
-
     for (size_t i = 0; i < list->length; i++) {
         acc = fold_fn(acc, list->elements[i]);
     }
-
     return acc;
 }
 
-list_element_t foldr_list(list_t *list, list_element_t initial, list_element_t (*fold_fn)(list_element_t, list_element_t)) {
+// Foldr: sprava doľava
+list_element_t foldr_list(list_t *list, list_element_t initial,
+                          list_element_t (*fold_fn)(list_element_t, list_element_t)) {
     list_element_t acc = initial;
-
-    for (size_t i = list->length; i > 0; i--) {
-        acc = fold_fn(list->elements[i - 1], acc);
+    // pozor: `size_t` nemôže byť záporné, takže kontrolujeme ručne
+    for (size_t i = list->length; i-- > 0;) {
+        acc = fold_fn(list->elements[i], acc);
     }
-
     return acc;
 }
 
+// Otočí zoznam
 list_t *reverse_list(list_t *list) {
-    list_t *result = malloc(sizeof(list_t) + sizeof(list_element_t) * list->length);
-    if (result == NULL) {
-        return NULL;
-    }
+    list_t *reversed = malloc(sizeof(list_t) + list->length * sizeof(list_element_t));
+    if (!reversed) return NULL;
 
-    result->length = list->length;
+    reversed->length = list->length;
 
     for (size_t i = 0; i < list->length; i++) {
-        result->elements[i] = list->elements[list->length - 1 - i];
+        reversed->elements[i] = list->elements[list->length - 1 - i];
+    }
+    return reversed;
+}
+
+// Uvoľní pamäť zoznamu
+void delete_list(list_t *list) {
+    free(list);
+}
+
+// Spojí dva zoznamy
+list_t *append_list(list_t *list1, list_t *list2) {
+    size_t new_length = list1->length + list2->length;
+    list_t *result = malloc(sizeof(list_t) + new_length * sizeof(list_element_t));
+    if (!result) return NULL;
+
+    result->length = new_length;
+
+    for (size_t i = 0; i < list1->length; i++) {
+        result->elements[i] = list1->elements[i];
+    }
+
+    for (size_t i = 0; i < list2->length; i++) {
+        result->elements[list1->length + i] = list2->elements[i];
     }
 
     return result;
 }
 
-void delete_list(list_t *list) {
-    free(list);
-}
+// Vráti dĺžku zoznamu
+size_t length_list(list_t *list) {
+    return list->length;
+}
\ No newline at end of file