Leetcode 203. Remove Linked List Elements

Description: Remove all elements from a linked list of integers that have value val.

Link: https://leetcode.com/problems/remove-linked-list-elements/

Example:

Input:  1->2->6->3->4->5->6, val = 6
Output: 1->2->3->4->5

思路: 删除单链表中元素值为val 的节点，遍历一遍，遇到就删除。

class Solution(object):
    def removeElements(self, head, val):
        """
        :type head: ListNode
        :type val: int
        :rtype: ListNode
        """
        if not head: return None
        rh = ListNode(0)
        rh.next = head
        pre = rh
        p = head
        while p:
            if p.val == val:
                pre.next = p.next
            else:
                pre = p
            p = p.next
        return rh.next

日期: 2020--12-1  时间过慢一点呀