This is a curated, evolving list of real data structures and algorithms interview questions and answers, designed by a Staff ML Scientist who is still actively interviewing candidates. Practicing these questions will help you prepare for ML Scientist, ML Engineer, Applied Scientist, and Data Scientist roles at FAANG and similar-tier companies.
| Problem | Topics | Difficulty |
|---|---|---|
| Minimum remove to make valid parentheses (Leetcode 1249) | Stack | Medium |
| Remove duplicates in place (Leetcode 26) | Array, Two pointers | Easy |
| ( Login required ) K Closest Points to Origin (Leetcode 973) | Heap | Easy |
| ( Login required ) Longest substring without repeating characters (Leetcode 3) | Hash, Sliding Window | Medium |
| ( Login required ) Number of recent calls (Leetcode 933) | Queue, DEQueue | Easy |
| ( Subscription required ) Climbing stairs (Leetcode 70) | Recursion, Dynamic programming | Easy |
| ( Subscription required ) Find if Path Exists in Graph (Leetcode 1971) | DFS, BFS | Medium |
| ( Subscription required ) Search in Binary Search Tree (Leetcode 700) | Binary Search, Binary Search Tree | Easy |
| ( Subscription required ) Sort an Array (Leetcode 912) | Recursion, Sorting | Medium |