DSA SectionEasy

Counting Sort

Detailed guide and Python implementation for the 'Counting Sort' problem.

Problem Statement

Easy

Write a function counting_sort(arr) that sorts a list of non-negative integers arr using the Counting Sort algorithm. You may assume that the elements are integers in a small range [0, k]. The function should return the sorted list.

Constraints
  • 0 <= len(arr) <= 10^4
  • 0 <= arr[i] <= 1000

Examples

Example 1
Input
arr = [4, 2, 2, 8, 3, 3, 1]
Output
[1, 2, 2, 3, 3, 4, 8]
Explanation

Frequencies of each element are counted, and cumulative counts are used to place elements in the sorted output array.

Need a Hint?
Consider using Sorting-specific data structures like sets or heaps.
Edge Cases to Watch
  • Empty input structures
  • Single element inputs
  • Large numerical bounds

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