Reverse Linked List——Linked List

Reverse a singly linked list.

# Definition for singly-linked list.
# class ListNode(object):
#     def __init__(self, x):
#         self.val = x
#         self.next = None

class Solution(object):
    def reverseList(self, head):
        """
        :type head: ListNode
        :rtype: ListNode
        """
        if head is None or head.next is None:
        	return head 
        elif head.next.next is None:
        	t = head.next
        	head.next.next = head
        	head.next = None 
        	return t 
        else:
        	t = self.reverseList(head.next)
        	head.next.next = head
        	head.next = None 
        	return t