DSA Doctor
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Twitter DSA Interview Questions
51 curated coding interview questions directly asked in Twitter technical rounds, sorted by frequency with recency and difficulty diagnostics.
51
Total Questions
8 (16%)
Easy Problems
31 (61%)
Medium Problems
12 (24%)
Hard Problems
🔥 Most Tested Topics:
Core DSA (22)Strings (8)Arrays (7)Design (5)Linked List (4)
📂 Sourced Datasets:
All questionsOlder than 6 months
| ID | Problem | Difficulty | Topic | Pattern | Acceptance | Frequency | Recency |
|---|---|---|---|---|---|---|---|
| 10 | Regular Expression Matching | Hard | Core DSA | Implementation / Reasoning | 31.0% | 100.0% | all |
| 12 | Integer to Roman | Medium | Strings | Hashing / Sliding Window | 71.0% | 100.0% | all |
| 20 | Valid Parentheses | Easy | Strings | Hashing / Sliding Window | 44.2% | 100.0% | all |
| 23 | Merge k Sorted Lists | Hard | Arrays; Linked List; Heap | Sorting / Prefix / Scan; Two Pointers; Priority Queue | 59.6% | 100.0% | all |
| 42 | Trapping Rain Water | Hard | Core DSA | Two Pointers | 67.4% | 100.0% | all |
| 43 | Multiply Strings | Medium | Strings | Hashing / Sliding Window | 44.2% | 100.0% | all |
| 44 | Wildcard Matching | Hard | Core DSA | Implementation / Reasoning | 32.0% | 100.0% | all |
| 56 | Merge Intervals | Medium | Arrays | Sorting / Prefix / Scan | 51.8% | 100.0% | all |
| 60 | Permutation Sequence | Hard | Backtracking | Backtracking | 53.1% | 100.0% | all |
| 118 | Pascal's Triangle | Easy | Core DSA | Implementation / Reasoning | 78.9% | 100.0% | all |
| 140 | Word Break II | Hard | Strings; Dynamic Programming | Hashing / Sliding Window; State Transition | 55.6% | 100.0% | all |
| 146 | LRU Cache | Medium | Design | Data Structure Design | 47.4% | 100.0% | all |
| 2073 | Time Needed to Buy Tickets | Easy | Core DSA | Implementation / Reasoning | 72.6% | 100.0% | all |
| 149 | Max Points on a Line | Hard | Core DSA | Implementation / Reasoning | 30.7% | 100.0% | all |
| 161 | One Edit Distance | Medium | Dynamic Programming | State Transition | 34.6% | 100.0% | all |
| 202 | Happy Number | Easy | Core DSA | Implementation / Reasoning | 59.7% | 100.0% | all |
| 206 | Reverse Linked List | Easy | Linked List | Two Pointers | 80.6% | 100.0% | all |
| 208 | Implement Trie (Prefix Tree) | Medium | Trees | DFS / BFS | 69.5% | 100.0% | all |
| 218 | The Skyline Problem | Hard | Core DSA | Implementation / Reasoning | 45.4% | 100.0% | all |
| 235 | Lowest Common Ancestor of a Binary Search Tree | Medium | Trees; Binary Search | DFS / BFS; Binary Search | 70.6% | 100.0% | all |
| 251 | Flatten 2D Vector | Medium | Core DSA | Implementation / Reasoning | 50.5% | 100.0% | all |
| 269 | Alien Dictionary | Hard | Graphs | BFS / DFS / Topological Sort | 37.2% | 100.0% | all |
| 296 | Best Meeting Point | Hard | Greedy | Greedy | 61.4% | 100.0% | all |
| 1206 | Design Skiplist | Hard | Linked List; Design | Two Pointers; Data Structure Design | 59.7% | 100.0% | all |
| 323 | Number of Connected Components in an Undirected Graph | Medium | Graphs | BFS / DFS / Topological Sort | 65.0% | 100.0% | all |
| 341 | Flatten Nested List Iterator | Medium | Linked List; Design | Two Pointers; Data Structure Design | 65.7% | 100.0% | all |
| 355 | Design Twitter | Medium | Design | Data Structure Design | 44.7% | 100.0% | all |
| 378 | Kth Smallest Element in a Sorted Matrix | Medium | Arrays; Heap | Sorting / Prefix / Scan; Priority Queue | 64.6% | 100.0% | all |
| 380 | Insert Delete GetRandom O(1) | Medium | Core DSA | Implementation / Reasoning | 55.4% | 100.0% | all |
| 407 | Trapping Rain Water II | Hard | Core DSA | Two Pointers | 64.1% | 100.0% | all |
| 433 | Minimum Genetic Mutation | Medium | Arrays | Sorting / Prefix / Scan | 56.6% | 100.0% | all |
| 1347 | Minimum Number of Steps to Make Two Strings Anagram | Medium | Arrays; Strings | Sorting / Prefix / Scan; Hashing / Sliding Window | 82.5% | 100.0% | all |
| 1348 | Tweet Counts Per Frequency | Medium | Core DSA | Implementation / Reasoning | 46.1% | 100.0% | all |
| 468 | Validate IP Address | Medium | Strings | Hashing / Sliding Window | 28.3% | 100.0% | all |
| 580 | Count Student Number in Departments | Medium | Core DSA | Implementation / Reasoning | 60.0% | 100.0% | all |
| 1459 | Rectangles Area | Medium | Core DSA | Implementation / Reasoning | 68.8% | 100.0% | all |
| 585 | Investments in 2016 | Medium | Core DSA | Implementation / Reasoning | 51.1% | 100.0% | all |
| 586 | Customer Placing the Largest Number of Orders | Easy | Core DSA | Implementation / Reasoning | 64.4% | 100.0% | all |
| 608 | Tree Node | Medium | Trees | DFS / BFS | 75.7% | 100.0% | all |
| 1683 | Invalid Tweets | Easy | Strings | Hashing / Sliding Window | 85.1% | 100.0% | all |
| 2768 | Number of Black Blocks | Medium | Core DSA | Implementation / Reasoning | 41.8% | 100.0% | all |
| 831 | Masking Personal Information | Medium | Core DSA | Implementation / Reasoning | 55.2% | 100.0% | all |
| 1797 | Design Authentication Manager | Medium | Design | Data Structure Design | 58.6% | 100.0% | all |
| 1785 | Minimum Elements to Add to Form a Given Sum | Medium | Arrays | Sorting / Prefix / Scan | 45.2% | 100.0% | all |
| 868 | Binary Gap | Easy | Core DSA | Implementation / Reasoning | 74.3% | 100.0% | all |
| 1817 | Finding the Users Active Minutes | Medium | Core DSA | Implementation / Reasoning | 80.8% | 100.0% | all |
| 1882 | Process Tasks Using Servers | Medium | Core DSA | Implementation / Reasoning | 41.9% | 100.0% | all |
| 1910 | Remove All Occurrences of a Substring | Medium | Strings; Trees | Hashing / Sliding Window; DFS / BFS | 78.5% | 100.0% | all |
| 1905 | Count Sub Islands | Medium | Graphs | BFS / DFS / Topological Sort | 73.0% | 100.0% | all |
| 764 | Largest Plus Sign | Medium | Core DSA | Implementation / Reasoning | 49.2% | 62.5% | all |
| 1167 | Minimum Cost to Connect Sticks | Medium | Arrays | Sorting / Prefix / Scan | 71.9% | 50.0% | all |