Practice arena
C++17·2 s·128 MB
SortingChallenge

Kth smallest

Find the kth smallest value without fully sorting the input. k is one-based and duplicates count as separate positions.

Input

  • The first line contains T.
  • Each case contains n and k, followed by n integers.

Output

Print one kth-smallest value per case.

Technique

quickselect partition

Target

O(n) average

Constraints & sample
  • 1 ≤ k ≤ n ≤ 200,000
  • Values fit in a signed 32-bit integer

Sample input

3
6 2
7 10 4 3 20 15
5 3
5 5 1 2 9
1 1
-8

Expected output

4
5
-8
Review the concept

Before you submit

  • Test the smallest valid input and one awkward edge case.
  • Keep the solution within O(n) average.
  • Match spacing and line breaks exactly before checking 8 hidden cases.
main.cpp
Draft saved locally · 441 / 30,000
Ln 1, Col 1Spaces: 4UTF-8LFC++17

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