Kth Largest Element in an Array Mock Interview

  1. ✓Problem→
  2. 2Clarifying Questions→
  3. 3Constraints→
  4. 4Brute Force→
  5. 5Complexity Analysis→
  6. 6Pattern Recognition→
  7. 7Optimized Solution→
  8. 8Implementation→
  9. 9Testing→
  10. 10Follow-Up→
  11. 11Evaluation
Problem

Given an integer array nums and an integer k, return the k-th largest element in the array in sorted order (not the k-th distinct element). For example, in [3,2,1,5,6,4] with k = 2 the answer is 5. Try to do better than sorting the whole array.

Constraints
  • 1 ≤ k ≤ n ≤ 10^5
  • -10^4 ≤ nums[i] ≤ 10^4
Example
in: nums = [3,2,1,5,6,4], k = 2
out: 5

Clarify

Before choosing anything: what would you ask the interviewer? What assumptions are you making? (Duplicates? Empty input? Value ranges? What to return when there is no answer?)