1. Verify if Array is Sorted
Difficulty: Easy | Concept: Sorting
Problem: Write a function to check if a given array is sorted in ascending order.
QA Angle: Often used to validate API responses or test reports where results must appear in sorted order (e.g., products by price, logs by timestamp).
2. Implement Binary Search
Difficulty: Easy-Medium | Concept: Searching
Problem: Given a sorted array of integers and a target, implement binary search to return the index of the target or -1 if not found.
QA Angle: Used in defect isolation — finding the first failing build or log entry faster than linear scans.
3. First and Last Occurrence
Difficulty: Medium | Concept: Binary Search Variants
Problem: In a sorted array with duplicates, find the first and last occurrence of a target element.
QA Angle: Useful in verifying counts of repeated test cases, duplicate log entries, or multiple defect IDs.
4. Kth Smallest Element
Difficulty: Medium | Concept: QuickSelect / Heap
Problem: Find the Kth smallest element in an unsorted array.
QA Angle: Often applied in performance testing (e.g., find 95th percentile response time).
5. Top-K Frequent Elements
Difficulty: Medium | Concept: Heap / Sorting
Problem: Given an array of log entries (strings), return the top K most frequent entries.
QA Angle: Helps in analyzing logs and identifying the most common failures in automation runs.
6. Search in Rotated Sorted Array
Difficulty: Medium | Concept: Binary Search
Problem: Search for a target element in a rotated sorted array.
QA Angle: Used to test data that shifts over releases or cyclic execution orders in regression suites.
7. Merge Intervals
Difficulty: Medium | Concept: Sorting + Greedy
Problem: Given overlapping test execution time intervals, merge them into non-overlapping intervals.
QA Angle: Useful for analyzing overlapping automation jobs, scheduling conflicts, or test bench usage.
8. Meeting Rooms / Minimum Platforms
Difficulty: Medium | Concept: Sorting + Sweep Line
Problem: Given start and end times of multiple test runs, determine the minimum number of labs/benches required.
QA Angle: Practical for resource allocation in test labs — ensures no overbooking of execution environments.
9. Median of Two Sorted Arrays
Difficulty: Hard | Concept: Binary Search Partition
Problem: Find the median of two sorted arrays in O(log(min(m,n))).
QA Angle: Used to analyze and compare median response times from two different environments or releases.
10. Inversion Count
Difficulty: Hard | Concept: Merge Sort
Problem: Count inversions in an array (pairs where arr[i] > arr[j], i < j).
QA Angle: Can represent how much a test sequence deviates from expected sorted order, useful for defect trend analysis.