modified: src/llist.c

modified:   src/llist.h

src/llist.c

@@ -15,6 +15,7 @@ llist *llistNew(void *data, int (*cmpFN)(void *a, void *b)) {
     r->data = data;
     r->prev = NULL;
     r->next = NULL;
+    r->tail = r;
   }
   return r;
 }
@@ -22,11 +23,11 @@ llist *llistNew(void *data, int (*cmpFN)(void *a, void *b)) {
 /*return  last node of linked list;
  */
 llist *llistTail(llist *head) {
-  llist *tail = head;
-  while (tail->next != NULL) {
-    tail = tail->next;
-  }
-  return tail;
+  // llist *tail = head;
+  // while (tail->next != NULL) {
+  //   tail = tail->next;
+  // }
+  return head->tail;
 }
 
 /* creates new node from data and appends it to tail
@@ -40,6 +41,7 @@ llist *llistAppend(llist *head, void *data) {
     new->next = NULL;
     new->prev = tail;
     tail->next = new;
+    head->tail = new;
   }
   return new;
 }

src/llist.h

@@ -6,6 +6,7 @@ typedef struct llist {
   void *data;
   struct llist *next;
   struct llist *prev;
+  struct llist *tail;
   int (*cmpFn)(void *a, void *b); // function that compares data
 } llist;