Find minimum subarray length with k distinct integers
Company: IBM
Role: Software Engineer
Category: Coding & Algorithms
Difficulty: medium
Interview Round: Technical Screen
Given an integer array `arr` and an integer `k`, find the **minimum length** of a contiguous subarray that contains **exactly `k` distinct** integer values.
Return the minimum length, or `-1` if no such subarray exists.
Constraints/notes:
- `arr` can contain duplicates.
- A subarray is a contiguous slice of the array.
Quick Answer: This question evaluates a candidate's proficiency in array manipulation, distinct-element counting, and windowing techniques for optimizing contiguous-subarray queries. It is common in Coding & Algorithms interviews because it assesses algorithmic efficiency, the use of frequency-tracking data structures, and practical application-level problem solving rather than purely conceptual reasoning.