链表_leetcode203

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

class Solution(object):
    def removeElements(self, head, val):
        """
        :type head: ListNode
        :type val: int
        :rtype: ListNode
        """

        dummyHead = ListNode(0)
        dummyHead.next = head

        pre = dummyHead

        while pre.next:
            if pre.next.val == val :
                delNode = pre.next
                pre.next = delNode.next
            else:
                pre = pre.next


        return dummyHead.next