给定一个排序链表,删除所有重复的元素,使得每个元素只出现一次。
示例 1:
输入: 1->1->2
输出: 1->2
示例 2:
输入: 1->1->2->3->3
输出: 1->2->3
思路: 判断链表表头是否为空,然后逐个判断当前节点和前一个节点是否相等
class Solution:
def deleteDuplicates(self, head):
"""
:type head: ListNode
:rtype: ListNode
"""
if head == None or head.next == None:
return head
pre = None
cur = head
while cur != None:
pre = cur
cur = cur.next
while cur != None and cur.val == pre.val:
pre.next = cur.next
cur = cur.next
return head