Remove Duplicate Characters | Dataford Interview Questions

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Problem

Spotify metadata pipelines sometimes need to reduce repetitive characters in playlist and track text without changing the original order. Given a string and a non-negative integer max_duplicates, remove excess occurrences so that each character appears at most max_duplicates + 1 times.

The first occurrence is not considered a duplicate. Keep the earliest occurrences and discard later ones once the limit is reached.

Formal Specification

Implement limit_duplicates(s, max_duplicates).

Input: s, a string, and max_duplicates, a non-negative integer.
Output: a string containing the retained characters in their original order.
Character comparisons are case-sensitive, and each Unicode code point is treated as one character.

Constraints

0 <= len(s) <= 10^5
0 <= max_duplicates <= 10^5
Input characters may be arbitrary Unicode code points
Character comparisons are case-sensitive
Retain the earliest occurrences and preserve their order

Function Signature

def limit_duplicates(s, max_duplicates):