diff --git a/Main.cpp b/Main.cpp
index 297d6ca..f3dfaf8 100644
--- a/Main.cpp
+++ b/Main.cpp
@@ -34,7 +34,7 @@ int main() {
     //==================================================
     // TEST INSERT AFTER
     P = findElm(L, 6);
-    insertLast(L, allocate(5));
+    insertAfter(L, P, allocate(5));
     printInfo(L);
     cout<<"output should be: 8, 3, 6, 5, 4, 2,"<<endl;
 
diff --git a/list.cpp b/list.cpp
index f61d73d..20baff7 100644
--- a/list.cpp
+++ b/list.cpp
@@ -5,9 +5,7 @@ void createList(List &L) {
     * FS : set first(L) with Null
     */
     //-------------your code here-------------
-    cout<<"your code here"<<endl;
-
-
+    first(L) = NULL;
     //----------------------------------------
 }
 
@@ -18,9 +16,9 @@ address allocate(infotype x) {
 
     address P = NULL;
     //-------------your code here-------------
-    cout<<"your code here"<<endl;
-
-
+    P = new elmlist;
+    info(P) = x;
+    next(P) = NULL;
     //----------------------------------------
     return P;
 }
@@ -30,9 +28,7 @@ void deallocate(address &P) {
     * FS : delete element pointed by P
     */
     //-------------your code here-------------
-    cout<<"your code here"<<endl;
-
-
+    delete(P);
     //----------------------------------------
 }
 
@@ -42,10 +38,8 @@ void insertFirst(List &L, address P) {
     * FS : element pointed by P became the first element in List L
     */
     //-------------your code here-------------
-    cout<<"your code here"<<endl;
-
-
-
+    next(P) = first(L);
+    first(L) = P;
     //----------------------------------------
 }
 
@@ -55,9 +49,12 @@ void insertLast(List &L, address P) {
     * FS : element pointed by P became the last element in List L
     */
     //-------------your code here-------------
-    cout<<"your code here"<<endl;
-
-
+    address Q;
+    Q = first(L);
+    while (next(Q) != NULL) {
+        Q = next(Q);
+    }
+    next(Q) = P;
     //----------------------------------------
 }
 
@@ -70,8 +67,10 @@ address findElm(List L, infotype x) {
 
     address P;
     //-------------your code here-------------
-    cout<<"your code here"<<endl;
-
+    P = first(L);
+    while (P != NULL && info(P) != x){
+        P = next(P);
+    }
 
     //----------------------------------------
     return P;
@@ -83,10 +82,11 @@ void deleteFirst(List &L, address &P) {
     * FS : first element in List L is removed and is pointed by P
     */
     //-------------your code here-------------
-    cout<<"your code here"<<endl;
-
-
-
+    if (first(L) != NULL){
+        P = first(L);
+        first(L) = next(P);
+        next(P) = NULL;
+    }
     //----------------------------------------
 }
 
@@ -96,10 +96,17 @@ void deleteLast(List &L, address &P) {
     * FS : last element in List L is removed and is pointed by P
     */
     //-------------your code here-------------
-    cout<<"your code here"<<endl;
-
-
-
+    address Q;
+    Q = first(L);
+    if (next(Q) == NULL) {
+        deleteFirst(L, P);
+    } else {
+        while (next(next(Q)) != NULL) {
+            Q = next(Q);
+        }
+        P = next(Q);
+        next(Q) = NULL;
+    }
     //----------------------------------------
 }
 
@@ -109,9 +116,12 @@ void printInfo(List L) {
     *      call the view_data function from my_data.h to print the info
     */
     //-------------your code here-------------
-    cout<<"your code here"<<endl;
-
-
+    address P;
+    P = first(L);
+    while (P != NULL){
+        cout<<info(P);
+        P = next(P);
+    }
     //----------------------------------------
     cout<<endl;
 }
@@ -124,8 +134,8 @@ void insertAfter(List &L, address Prec, address P) {
     *      pointed by pointer Prec
     */
     //-------------your code here-------------
-    cout<<"your code here"<<endl;
-
+    next(P) = next(Prec);
+    next(Prec) = P;
     //----------------------------------------
 
 }
@@ -136,9 +146,9 @@ void deleteAfter(List &L, address Prec, address &P) {
     *      is removed and pointed by pointer P
     */
     //-------------your code here-------------
-    cout<<"your code here"<<endl;
-
-
+    P = next(Prec);
+    next(Prec) = next(P);
+    next(P) = NULL;
     //----------------------------------------
 }
 
diff --git a/list.h b/list.h
index d021225..be28827 100644
--- a/list.h
+++ b/list.h
@@ -30,14 +30,14 @@ typedef struct elmlist *address;
 
 struct elmlist{
     //------------- your code here -----------
-
-
+    infotype info;
+    address next;
     //----------------------------------------
 };
 
 struct List{
     //------------- your code here -----------
-
+    address first;
     //----------------------------------------
 };
 
diff --git a/operation.cpp b/operation.cpp
index 0a0e067..36ffd5f 100644
--- a/operation.cpp
+++ b/operation.cpp
@@ -13,8 +13,16 @@ void insert_sorted(List &L, infotype x) {
     */
 
     //-------------your code here-------------
-    cout<<"your code here"<<endl;
-
-
+    address P, Q;
+    P = first(L);
+    if (P == NULL || info(P) > x) {
+        insertFirst(L, allocate(x));
+    } else if (findElm(L, x) == NULL) {
+        while (P != NULL && info(P) < x) {
+            Q = P;
+            P = next(P);
+        }
+        insertAfter(L, Q, allocate(x));
+    }
     //----------------------------------------
 }