diff --git a/cv4/list-ops.c b/cv4/list-ops.c
deleted file mode 100644
index 59bb2a9..0000000
--- a/cv4/list-ops.c
+++ /dev/null
@@ -1,62 +0,0 @@
-#include "list_ops.h"
-
-// constructs a new list
-list_t *new_list(size_t length, list_element_t elements[]){
-  return NULL;
-
-}
-
-// append entries to a list and return the new list
-list_t *append_list(list_t *list1, list_t *list2){
-  return NULL;
-
-}
-
-// filter list returning only values that satisfy the filter function
-list_t *filter_list(list_t *list, bool (*filter)(list_element_t)){
-  return NULL;
-
-}
-
-// returns the length of the list
-size_t length_list(list_t *list){
-  return 0;
-
-}
-
-// return a list of elements whose values equal the list value transformed by
-// the mapping function
-list_t *map_list(list_t *list, list_element_t (*map)(list_element_t)){
-  return NULL;
-
-}
-
-// folds (reduces) the given list from the left with a function
-list_element_t foldl_list(list_t *list, list_element_t initial,
-                          list_element_t (*foldl)(list_element_t,
-                                                  list_element_t)){
-  list_element_t res=0;
-  return res;
-
-}
-
-// folds (reduces) the given list from the right with a function
-list_element_t foldr_list(list_t *list, list_element_t initial,
-                          list_element_t (*foldr)(list_element_t,
-                                                  list_element_t)){
-  list_element_t res=0;
-  return res;
-
-}
-
-// reverse the elements of the list
-list_t *reverse_list(list_t *list){
-  return NULL;
-
-}
-
-// destroy the entire list
-// list will be a dangling pointer after calling this method on it
-void delete_list(list_t *list){
-
-} 
diff --git a/cv4/list_ops.c b/cv4/list_ops.c
index 670b8e5..a488be1 100644
--- a/cv4/list_ops.c
+++ b/cv4/list_ops.c
@@ -1,61 +1,91 @@
 #include "list_ops.h"
+#include <string.h>
 
-// comstruct a new list
-
-list_t *new_list(size_t lenght, list_element_t elements[]){
-	return NULL;
+// constructs a new list
+list_t *new_list(size_t length, list_element_t elements[]) {
+    list_t *newList = malloc(sizeof(list_t) + length * sizeof(list_element_t));
+    if (newList != NULL) {
+        newList->length = length;
+        if (length > 0 && elements != NULL) {
+            memcpy(newList->elements, elements, length * sizeof(list_element_t));
+        }
+    }
+    return newList;
 }
 
-// append entries to a new list and return the new list
 
-list_t *append_list(list_t *list1, list_t *list2){
-	return NULL;
+// append entries to a list and return the new list
+list_t *append_list(list_t *list1, list_t *list2) {
+    if (list1 == NULL && list2 == NULL) {
+        return NULL; // Both lists are empty
+    } else if (list1 == NULL) {
+        return list2; // Only list1 is empty, return list2
+    } else if (list2 == NULL) {
+        return list1; // Only list2 is empty, return list1
+    }
+
+    size_t new_length = list1->length + list2->length;
+    list_t *new_list = malloc(sizeof(list_t) + new_length * sizeof(list_element_t));
+    if (new_list == NULL) {
+        return NULL; // Memory allocation failed
+    }
+
+    memcpy(new_list->elements, list1->elements, list1->length * sizeof(list_element_t));
+    memcpy(new_list->elements + list1->length, list2->elements, list2->length * sizeof(list_element_t));
+
+    new_list->length = new_length;
+
+    return new_list;
 }
 
-//filter list returninf only values that satisfy the filter function
-
+// filter list returning only values that satisfy the filter function
 list_t *filter_list(list_t *list, bool (*filter)(list_element_t)){
-	return NULL;
-}
-
-//returns the lenght of the list
-
-size_t lenght_list(list_t *list){
-	return 0;
-}
-
-//return a list of elements whose values equal the list value transformed by
-//the maaping function
-
-list_t *map_list(list_t *list, list_element_t (*map)(list_element_t)){
-	return NULL;
-}
-
-//folds (reduces) the given list from the left with a function
-
-list_element_t foldl_list(list_t *list, list_element_t initial, list_element_t (*foldl)(list_element_t, 
-			list_element_t)){
-	list_element_t res=0;
-	return res;
-}
-
-//folds (reduces) the given list from the right with a function
-
-list_element_t foldr_list(list_t *list, list_element_t initial, list_element_t (*foldr)(list_element_t, 
-			 list_element_t)){
-	list_element_t res=0;
-	return res;
-}
-
-//reverse elements of the list
-
-list_t *reserve_list(list_t *list){
-	return NULL;
-}
-
-//destroy the entire list
-//list will ve a dangling pointer after calling this method on it
-
-void delete_list(list_t list*){
+  return NULL;
 
 }
+
+// returns the length of the list
+size_t length_list(list_t *list) {
+    return (list != NULL) ? list->length : 0;
+}
+
+// return a list of elements whose values equal the list value transformed by
+// the mapping function
+list_t *map_list(list_t *list, list_element_t (*map)(list_element_t)) {
+    if (list == NULL) return NULL;
+    
+    list_t *mappedList = new_list(list->length, list->elements);
+    if (mappedList != NULL) {
+        for (size_t i = 0; i < list->length; ++i) {
+            mappedList->elements[i] = map(list->elements[i]);
+        }
+    }
+    return mappedList;
+}
+
+// folds (reduces) the given list from the left with a function
+list_element_t foldl_list(list_t *list, list_element_t initial, list_element_t (*foldl)(list_element_t, list_element_t)){
+  list_element_t accumulator = initial;
+  
+  return res;
+
+}
+
+// folds (reduces) the given list from the right with a function
+list_element_t foldr_list(list_t *list, list_element_t initial,list_element_t (*foldr)(list_element_t, list_element_t)){
+  list_element_t res=0;
+  return res;
+
+}
+
+// reverse the elements of the list
+list_t *reverse_list(list_t *list){
+  return NULL;
+
+}
+
+// destroy the entire list
+// list will be a dangling pointer after calling this method on it
+void delete_list(list_t *list){
+
+} 
\ No newline at end of file
diff --git a/cv4/list-ops/list_ops.h b/cv4/list_ops.h
similarity index 100%
rename from cv4/list-ops/list_ops.h
rename to cv4/list_ops.h
diff --git a/cv4/list-ops/makefile b/cv4/makefile
similarity index 100%
rename from cv4/list-ops/makefile
rename to cv4/makefile
diff --git a/cv4/list-ops/test-framework/unity.c b/cv4/test-framework/unity.c
similarity index 100%
rename from cv4/list-ops/test-framework/unity.c
rename to cv4/test-framework/unity.c
diff --git a/cv4/list-ops/test-framework/unity.h b/cv4/test-framework/unity.h
similarity index 100%
rename from cv4/list-ops/test-framework/unity.h
rename to cv4/test-framework/unity.h
diff --git a/cv4/list-ops/test-framework/unity_internals.h b/cv4/test-framework/unity_internals.h
similarity index 100%
rename from cv4/list-ops/test-framework/unity_internals.h
rename to cv4/test-framework/unity_internals.h
diff --git a/cv4/list-ops/test_list_ops.c b/cv4/test_list_ops.c
similarity index 100%
rename from cv4/list-ops/test_list_ops.c
rename to cv4/test_list_ops.c