Flipkart | Remove Zero Sum Consecutive Nodes from Linked List

link:- https://leetcode.com/problems/remove-zero-sum-consecutive-nodes-from-linked-list/

class Solution:
    def removeZeroSumSublists(self, head: Optional[ListNode]) -> Optional[ListNode]:
        cur = dummy = ListNode(0)
        dummy.next = head
        prefix = 0
        seen = collections.OrderedDict()
        while cur:
            prefix += cur.val
            node = seen.get(prefix, cur)
            while prefix in seen:
                seen.popitem()
            seen[prefix] = node
            node.next = cur = cur.next
        return dummy.next