Purge Banned Values

Medium

You get an array banned of distinct forbidden numbers and the head head of a singly linked list. Remove every node whose value appears in banned and return the head of the resulting list. The remaining nodes must keep their original order. At least one node is guaranteed to survive.

Example 1

banned=[4, 9], head=list_node([9, 2, 4, 4, 7]) → [2, 7]

All nodes holding 9 or 4 are removed; the rest keep their order: 2, 7.

Example 2

banned=[6], head=list_node([1, 3, 5]) → [1, 3, 5]

There are no 6s in the list, so it stays the same.

Example 3

banned=[1, 2], head=list_node([2, 8, 1, 8]) → [8, 8]

Constraints

1 ≤ len(banned) ≤ 10⁵
1 ≤ banned[i] ≤ 10⁵, all distinct
The list has between 1 and 10⁵ nodes
1 ≤ node value ≤ 10⁵
At least one node's value is not in banned

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Topics

Array Hash Table Linked List

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Input

banned=[4, 9], head=list_node([9, 2, 4, 4, 7])

Expected

[2, 7]

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