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Zero out duplicates and sort an array

AppleSoftware Engineer · Technical Screen
MediumSoftware EngineerTechnical ScreenCoding & Algorithms

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This question evaluates proficiency in array manipulation, duplicate handling, and custom sorting logic with attention to time and space complexity, and it falls within the Coding & Algorithms domain.

Coding question

You are given an integer array arr of length about 75.

  • The data is not sorted.
  • The array may contain duplicate values.
  • You must zero out duplicates and then sort the array.
  • Try to keep time and space complexity in mind.
  • Do not use built-in/native sorting utilities (e.g., sort()), and do not call library implementations of quicksort/bubblesort/etc.

Clarification to assume (if not specified)

If a value appears multiple times, keep exactly one occurrence and replace all other occurrences with 0. Then sort the entire array in non-decreasing order.

Input

  • An integer array arr.

Output

  • Return the transformed array after (1) zeroing duplicate occurrences and (2) sorting.

Example

  • Input: [3, 1, 3, 2, 2]
  • After zeroing duplicates (keeping first occurrence): [3, 1, 0, 2, 0]
  • After sorting: [0, 0, 1, 2, 3]