203. Remove Linked List Elements.py

# 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.

# 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, T):
        dummy = ListNode(-1, head)
        prev = dummy
        while head:
            if head.val != T:
                prev = head
            else:
                prev.next = head.next
            head = head.next
        return dummy.next