Deduplicate Adjacent

EasyData EngineeringArraySorting

Description

Given an array, collapse each run of consecutive equal values into a single value, preserving order. Non-adjacent repeats are kept.

Examples

Input:[1,1,2,2,1]
Output:[1,2,1]
Explanation:

A run of identical neighbours is reduced to one copy, but a value that reappears later after a change is kept.

Input:[5,5,5]
Output:[5]
Explanation:

A run of identical neighbours is reduced to one copy, but a value that reappears later after a change is kept.

Input:[1,2,3]
Output:[1,2,3]
Explanation:

A run of identical neighbours is reduced to one copy, but a value that reappears later after a change is kept.

Constraints

  • 0 ≤ length ≤ 10⁴

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