Delete Nodes From Linked List Present In Array · Interview Problem

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Delete Nodes From Linked List Present In Array

Remove every node from a singly linked list whose value appears in a given array.

Acceptance 0%

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Problem Statement

Problem

You are given the head of a singly linked list and an array of integers. Delete every node from the linked list whose value is present in the array.

Return the head of the modified linked list.

The relative order of the remaining nodes should stay the same.

Notes

A node should be removed if its value matches any value in the array.
The linked list may become empty after all deletions.
The array may contain duplicate values; treat it as a set of values to remove.

Input Format

A linked list represented by its head node.
An integer array containing values to delete.

Output Format

The head node of the linked list after removing all matching nodes.

Constraints

The linked list contains at least 1 node unless all nodes are deleted.
Values can be any integers.
Aim for a solution that runs in linear time relative to the list length plus the array length.

Hints

Convert the array into a structure that supports fast membership checks.
Use a dummy head to simplify deletions near the front of the list.

Input Format

head: head of a singly linked list
nums: integer array of values to delete

Output Format

Head of the linked list after removing all nodes whose values appear in nums

Constraints

Preserve the order of remaining nodes
Duplicate values in nums should not change the result
Prefer an $O(n + m)$ approach, where $n$ is the list length and $m$ is the array length

Examples

Sample cases returned by the problem API.

Example 1

Input

head = [1,2,3,4,5], nums = [2,4]

Output

[1,3,5]

Explanation

Nodes with values 2 and 4 are removed.

Example 2

Input

head = [7,7,7], nums = [7]

Output

[]

Explanation

Every node matches a value to delete, so the list becomes empty.

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