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Remove Linked List Elements

Question​

Given a singly linked list and a value, delete all nodes containing this value, and return the head of the modified list.

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

Solution​

all//Remove Linked List Elements.py


# Definition for singly-linked list.
class ListNode:
    def __init__(self, val=0, next=None):
        self.val = val
        self.next = next

class Solution:
    def removeElements(self, head: ListNode, val: int) -> ListNode:
        if head is None:
            return None

        # create a dummy node to make sure head is not None
        dummyHead = ListNode(0)
        dummyHead.next = head
        p = dummyHead

        while p and p.next:
            if p.next.val == val:
                # remove the node
                p.next = p.next.next
            else:
                # move to next node
                p = p.next

        return dummyHead.next