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Coding/Arrays and strings

First-time buyers

Write codeEasy11 min

Your task

A shop compares today's buyers against its history. Given the list of customer IDs that have ever purchased before and the list of IDs that purchased today (repeats possible in both), return the IDs of today's first-time buyers, those that appear today but nowhere in the history, as an ascending list without duplicates. Example: history [1, 2, 3], today [3, 4, 4, 5] gives [4, 5].

Examples

first_time_buyers(history: list[int], today: list[int]) -> list[int]
Example 1
Inputfirst_time_buyers([1, 2, 3], [3, 4, 4, 5])
Output[4, 5]