# LeetCode 1171. Remove Zero Sum Consecutive Nodes from LinkedList

## Question

Given the `head`

of a linked list, we repeatedly delete consecutive sequences of nodes that sum to `0`

until there are no such sequences.

After doing so, return the head of the final linked list. You may return any such answer.

## Solution

We need to maintain the hashmap to record the prefix sum to ListNode.

- if we didnâ€™t seen it before, just record.
- otherwise, it shows the range sum between it would be zero, and we have to move our current pointer, at the end, we can skip the range we find.

## Code

1 | // time:O(n) space:O(n) |