Remove Linked List Elements

Problem Given the head of a singly linked list and an integer val, remove every node whose value equals val and return the new head.

Input / Output

• Input: head of a singly linked list, int val.
• Output: the new head after all matching nodes are removed.

Constraints

• Up to 10^4 nodes.
• Solve in O(n) time and O(1) space.

Example

• 1→2→6→3→4→5→6, val = 6 → 1→2→3→4→5.
• 7→7→7, val = 7 → empty list.