Why is insertion/deletion at the head of a Linked List O(1)?

Difficulty: 2/10

head insertion, pointer manipulation, time complexity

Constant-Time Head Operations

Insertion or deletion at the head of a linked list is O(1) because it requires changing only a constant number of references. There is no need to shift or traverse the remaining elements.

javascript

1
Head insertion requires updating the new node's next reference and head.
2
Head deletion only requires moving head to the next node.
3
The operation does not depend on the number of nodes.
4
Therefore, both operations are O(1).

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0-2 years experience

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