# 206. Reverse Linked List """ given the 'head' of a singly linked list, reverse the list, and return the reversed list. """ # Definition for singly-linked list. class ListNode(object): def __init__(self, val=0, next=None): self.val = val self.next = next class Solution(object): def reverseList(self, head): """ :type head: ListNode :rtype: ListNode """ prev = None while head: curr = head head = head.next curr.next = prev prev = curr return prev if __name__ == "__main__": obj = Solution() print(obj.reverseList(head=[1, 2, 3, 4, 5])) print(obj.reverseList(head=[1, 2])) print(obj.reverseList(head=[]))