C++UCS301
Complexity Lab C++ Setup Visualizer
Practice arena
C++17·2 s·128 MB
HeapsFoundation

Is it a min heap?

Determine whether every parent in an array representation is less than or equal to its children, making the array a valid min heap.

Input

  • — The first line contains T.
  • — Each case contains n followed by n integers in level order.

Output

Print YES for a valid min heap; otherwise print NO.

Technique

parent-child index checks

Target

O(n)

Constraints & sample
  • 1 ≤ n ≤ 200,000
  • Equal parent and child values are allowed

Sample input

3
6
1 3 2 7 6 4
4
2 1 3 4
5
1 1 2 3 4

Expected output

YES
NO
YES
Review the concept

Before you submit

  • Test the smallest valid input and one awkward edge case.
  • Keep the solution within O(n).
  • Match spacing and line breaks exactly before checking 8 hidden cases.
main.cpp
Draft saved locally · 455 / 30,000
Ln 1, Col 1Spaces: 4UTF-8LFC++17

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