Finding Repeating elements in an Array
Detailed guide and Python implementation for the 'Finding Repeating elements in an Array' problem.
Problem Statement
Write a function find_repeating(arr) that takes a list of integers arr and returns a sorted list of all elements that appear more than once in the array. If no element repeats, return an empty list.
- •0 <= len(arr) <= 10^5
- •-10^6 <= arr[i] <= 10^6
Examples
arr = [1, 2, 3, 2, 4, 3]
[2, 3]
2 appears twice and 3 appears twice. Both are repeating elements.
arr = [1, 2, 3, 4]
[]
All elements appear exactly once. No repeating elements.
arr = [5, 5, 5, 5]
[5]
5 repeats (appears 4 times).
Need a Hint?
Edge Cases to Watch
- Empty input structures
- Single element inputs
- Large numerical bounds
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