leetcode -- Remove Duplicates from Sorted List II -- 簡單重點

https://leetcode.com/problems/remove-duplicates-from-sorted-list-ii/

two pointers連結清單操作就行

class Solution(object):
    def deleteDuplicates(self, head):
        """
        :type head: ListNode
        :rtype: ListNode
        """
        if not head: return None
        dummy = ListNode()
        dummy.next = None
        p = dummy
        i,j = head, head
        while i:
            while j and j.val == i.val:
                j = j.next
            if i.next == j:
                p.next = i
                p = p.next
                p.next = None
            i = j
        return dummy.next