【Leetcode】82. 删除排序链表中的重复元素 II

输入: 1->2->3->3->4->4->5
输出: 1->2->5

输入: 1->1->1->2->3
输出: 2->3

public class Solution {
    public ListNode deleteDuplicates(ListNode head) {
        if (head == null) return null;
        ListNode fakeHead = new ListNode(0);
        fakeHead.next = head;
        ListNode pre = fakeHead;
        ListNode cur = head;
        while (cur != null) {
            while (cur.next != null && cur.val == cur.next.val) {
                cur = cur.next;
            }
            if (pre.next == cur) {
                pre = pre.next;
            } else {
                pre.next = cur.next;
            }
            cur = cur.next;
        }
        return fakeHead.next;
    }
}

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

class Solution:
    def deleteDuplicates(self, head):
        """
        :type head: ListNode
        :rtype: ListNode
        """
        if head is None:
            return None
        fakeHead = ListNode(0)
        fakeHead.next = head
        pre = fakeHead
        cur = head
        while cur is not None:
            while cur.next is not None and cur.val == cur.next.val:
                cur = cur.next
            if pre.next == cur:
                pre = pre.next
            else:
                pre.next = cur.next
            cur = cur.next
        return fakeHead.next