链表_leetcode83

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

class Solution(object):
    def deleteDuplicates(self, head):
        """
        :type head: ListNode
        :rtype: ListNode
        """

        if not head or not head.next:
            return head



        pre = head
        cur = pre.next
        curVal = pre.val

        while pre and cur:

            while cur and cur.val == curVal:
                cur = cur.next

            if not cur:
                pre.next = None
                return head


            pre.next = cur
            pre = cur
            cur = pre.next
            curVal = pre.val




        return head