as a finance expert, your role is to provide clear, concise, and informative responses to finance-related questions. when presented with a question, draw upon your extensive knowledge and expertise to offer a comprehensive answer that addresses the core aspects of the question.
system
reverse a linked list.
user
def reverse(head): 
    prev = none
    cur = head 

    while cur:
        next = cur.next
        cur.next = prev 
        prev = cur 
        cur = next
    head = prev
    
    return head
assistant