reverse linked list

topic

Define a function that takes as input the head node of a linked list, reverses the linked list and outputs the head node of the reversed linked list.

Python problem solving

def reverse_list(head):
   q = None
   p = head
   reverse_head = None
   while p:
       r = p.next
       if r is None:
           reverse_head = p
       p.next = q
       q = p
       p = r
   return reverse_head