[203] Remove Linked List Elements

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

• algorithms
• Easy (34.61%)
• Source Code: 203.remove-linked-list-elements.py
• Total Accepted: 217.2K
• Total Submissions: 610.6K
• Testcase Example: '[1,2,6,3,4,5,6]\n6'

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

Example:

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

# 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
        """
        if not head: return None

        while head and head.val == val:
            head = head.next

        p = head
        while p and p.next:
            if p.next.val == val:
                p.next = p.next.next
            else:
                p = p.next

        return head
# [1,2,2,1]