203. Remove Linked List Elements

[DNPotapov]

# 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: Optional[ListNode], val: int) -> Optional[ListNode]:
        res = ListNode(None)
        cur = head
        s = res
        while cur:
            if cur.val != val:
                s.next = cur
                s = s.next
            else:
                s.next = cur.next
            cur = cur.next
        return res.next

[DNPotapov]

Given the head of a linked list and an integer val, remove all the nodes of the linked list that has Node.val == val, and return the new head.

Example 1:

Input: head = [1,2,6,3,4,5,6], val = 6 Output: [1,2,3,4,5] Example 2:

Input: head = [], val = 1 Output: [] Example 3:

Input: head = [7,7,7,7], val = 7 Output: []

Constraints:

The number of nodes in the list is in the range [0, 104]. 1 <= Node.val <= 50 0 <= val <= 50