Implemented All Functions, tested two

linked_list.c

 #include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+struct list_item {
+  int value;
+  struct list_item * next;
+};
 
 
 void append(struct list_item *first, int x){
@@ -7,54 +14,45 @@ void append(struct list_item *first, int x){
     current = current->next;
   }
   struct list_item * new_item = (struct list_item *) malloc(sizeof(struct list_item));
-  new_item.next = NULL;
-  new_item.value = x;
-  current.next = new_item;
+  new_item->next = NULL;
+  new_item->value = x;
+  current->next = new_item;
 }
 
 void prepend(struct list_item *first, int x){
   struct list_item * new_item = (struct list_item *) malloc(sizeof(struct list_item));
-  new_item.next = first;
-  new_item.value = x;
+  new_item->next = first;
+  new_item->value = x;
 }
 
 void print(struct list_item *first){
   struct list_item * current = first;
   while (current->next != NULL) {
     current = current->next;
-    printf("%d \n", current.value);
+    printf("%d \n", current->value);
   }
 }
 
 void input_sorted(struct list_item *first, int x){
   struct list_item * current = first;
-  bool found = false;
-  while ((current->next != NULL) && found == false) {
-    if (current->next.value > x){
-      struct list_item * new_item = (struct list_item *) malloc(sizeof(struct list_item));
-      new_item.next = current.next;
-      new_item.value = x;
-      current.next = new_item;
-      found = true;
-    }
+  while ((current->next != NULL) && (current->next->value < x)) {
     current = current->next;
   }
+  struct list_item * new_item = (struct list_item *) malloc(sizeof(struct list_item));
+  new_item->next = current->next;
+  new_item->value = x;
+  current->next = new_item;
 }
 
 void clear(struct list_item *first){
   struct list_item * current;
   while (first->next != NULL) {
     current = first;
-    first = current.next;
+    first = current->next;
     free(current);
   }
 }
 
-struct list_item {
-  int value;
-  struct list_item * next;
-};
-
 int main(int argc, char ** argv)
 {
   struct list_item root;
@@ -66,5 +64,6 @@ int main(int argc, char ** argv)
   input_sorted(&root, 4);
   input_sorted(&root, 3);
   input_sorted(&root, 1);
-  print(&root);  
+  print(&root);
+  return 0;
 }