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Qualcomm DSA Interview Questions
62 curated coding interview questions directly asked in Qualcomm technical rounds, sorted by frequency with recency and difficulty diagnostics.
62
Total Questions
28 (45%)
Easy Problems
25 (40%)
Medium Problems
9 (15%)
Hard Problems
🔥 Most Tested Topics:
Core DSA (19)Arrays (16)Strings (10)Trees (7)Linked List (7)
📂 Sourced Datasets:
Last 3 monthsLast 6 monthsAll questionsOlder than 6 months
| ID | Problem | Difficulty | Topic | Pattern | Acceptance | Frequency | Recency |
|---|---|---|---|---|---|---|---|
| 3 | Longest Substring Without Repeating Characters | Medium | Strings; Trees | Hashing / Sliding Window; DFS / BFS; Sliding Window | 39.1% | 100.0% | 3m |
| 9 | Palindrome Number | Easy | Strings | Hashing / Sliding Window | 60.6% | 100.0% | 3m |
| 852 | Peak Index in a Mountain Array | Medium | Arrays; Binary Search | Sorting / Prefix / Scan; Binary Search | 66.8% | 100.0% | 3m |
| 146 | LRU Cache | Medium | Design | Data Structure Design | 47.4% | 100.0% | 3m |
| 206 | Reverse Linked List | Easy | Linked List | Two Pointers | 80.6% | 100.0% | 6m |
| 15 | 3Sum | Medium | Arrays | Sorting / Prefix / Scan | 39.1% | 100.0% | 6m |
| 1163 | Last Substring in Lexicographical Order | Hard | Strings; Trees; Graphs | Hashing / Sliding Window; DFS / BFS; BFS / DFS / Topological Sort | 35.0% | 100.0% | 6m |
| 20 | Valid Parentheses | Easy | Strings | Hashing / Sliding Window | 44.2% | 100.0% | 6m |
| 25 | Reverse Nodes in k-Group | Hard | Trees; Linked List | DFS / BFS; Two Pointers | 66.1% | 100.0% | 6m |
| 62 | Unique Paths | Medium | Core DSA | Implementation / Reasoning | 66.8% | 100.0% | 6m |
| 1183 | Maximum Number of Ones | Hard | Arrays | Sorting / Prefix / Scan | 70.6% | 100.0% | all |
| 3163 | String Compression III | Medium | Strings | Hashing / Sliding Window | 67.1% | 100.0% | all |
| 190 | Reverse Bits | Easy | Core DSA | Implementation / Reasoning | 68.4% | 75.0% | all |
| 200 | Number of Islands | Medium | Graphs | BFS / DFS / Topological Sort | 64.4% | 75.0% | all |
| 19 | Remove Nth Node From End of List | Medium | Trees; Linked List | DFS / BFS; Two Pointers | 51.6% | 75.0% | all |
| 1 | Two Sum | Easy | Arrays | Sorting / Prefix / Scan; Two Pointers | 57.5% | 75.0% | all |
| 836 | Rectangle Overlap | Easy | Core DSA | Implementation / Reasoning | 46.7% | 75.0% | all |
| 141 | Linked List Cycle | Easy | Linked List | Two Pointers | 54.3% | 75.0% | all |
| 344 | Reverse String | Easy | Strings | Hashing / Sliding Window | 80.8% | 75.0% | all |
| 283 | Move Zeroes | Easy | Core DSA | Two Pointers | 63.8% | 75.0% | all |
| 48 | Rotate Image | Medium | Arrays | Sorting / Prefix / Scan | 80.1% | 62.5% | all |
| 231 | Power of Two | Easy | Core DSA | Implementation / Reasoning | 50.1% | 62.5% | all |
| 876 | Middle of the Linked List | Easy | Linked List | Two Pointers | 81.8% | 62.5% | all |
| 232 | Implement Queue using Stacks | Easy | Stack / Queue | Monotonic Stack / Simulation | 69.8% | 62.5% | all |
| 50 | Pow(x, n) | Medium | Core DSA | Implementation / Reasoning | 38.7% | 62.5% | all |
| 8 | String to Integer (atoi) | Medium | Strings | Hashing / Sliding Window | 21.0% | 62.5% | all |
| 88 | Merge Sorted Array | Easy | Arrays | Sorting / Prefix / Scan | 54.9% | 62.5% | all |
| 169 | Majority Element | Easy | Core DSA | Implementation / Reasoning | 66.3% | 62.5% | all |
| 622 | Design Circular Queue | Medium | Stack / Queue; Design | Monotonic Stack / Simulation; Data Structure Design | 54.7% | 62.5% | all |
| 2563 | Count the Number of Fair Pairs | Medium | Core DSA | Implementation / Reasoning | 52.7% | 62.5% | all |
| 215 | Kth Largest Element in an Array | Medium | Arrays; Heap | Sorting / Prefix / Scan; Priority Queue | 68.9% | 62.5% | all |
| 42 | Trapping Rain Water | Hard | Core DSA | Two Pointers | 67.4% | 62.5% | all |
| 2183 | Count Array Pairs Divisible by K | Hard | Arrays | Sorting / Prefix / Scan | 30.7% | 62.5% | all |
| 24 | Swap Nodes in Pairs | Medium | Trees | DFS / BFS | 69.5% | 50.0% | all |
| 70 | Climbing Stairs | Easy | Dynamic Programming | State Transition | 54.1% | 50.0% | all |
| 297 | Serialize and Deserialize Binary Tree | Hard | Trees; Design | DFS / BFS; Data Structure Design | 60.8% | 50.0% | all |
| 2502 | Design Memory Allocator | Medium | Design | Data Structure Design | 50.1% | 50.0% | all |
| 58 | Length of Last Word | Easy | Strings | Hashing / Sliding Window | 58.8% | 50.0% | all |
| 26 | Remove Duplicates from Sorted Array | Easy | Arrays | Sorting / Prefix / Scan; Two Pointers | 62.8% | 50.0% | all |
| 407 | Trapping Rain Water II | Hard | Core DSA | Two Pointers | 64.1% | 50.0% | all |
| 104 | Maximum Depth of Binary Tree | Easy | Arrays; Trees | Sorting / Prefix / Scan; DFS / BFS | 78.2% | 50.0% | all |
| 7 | Reverse Integer | Medium | Core DSA | Implementation / Reasoning | 31.9% | 50.0% | all |
| 210 | Course Schedule II | Medium | Graphs | BFS / DFS / Topological Sort | 55.5% | 50.0% | all |
| 392 | Is Subsequence | Easy | Core DSA | Implementation / Reasoning | 49.0% | 50.0% | all |
| 46 | Permutations | Medium | Backtracking | Backtracking | 81.9% | 50.0% | all |
| 342 | Power of Four | Easy | Core DSA | Implementation / Reasoning | 52.1% | 50.0% | all |
| 136 | Single Number | Easy | Core DSA | Implementation / Reasoning | 77.7% | 50.0% | all |
| 56 | Merge Intervals | Medium | Arrays | Sorting / Prefix / Scan | 51.8% | 50.0% | all |
| 560 | Subarray Sum Equals K | Medium | Arrays | Sorting / Prefix / Scan | 47.3% | 50.0% | all |
| 4 | Median of Two Sorted Arrays | Hard | Arrays; Heap | Sorting / Prefix / Scan; Priority Queue | 46.6% | 50.0% | all |
| 72 | Edit Distance | Medium | Dynamic Programming | State Transition | 60.6% | 50.0% | all |
| 28 | Find the Index of the First Occurrence in a String | Easy | Strings | Hashing / Sliding Window | 46.7% | 50.0% | all |
| 22 | Generate Parentheses | Medium | Strings | Hashing / Sliding Window | 78.7% | 50.0% | all |
| 225 | Implement Stack using Queues | Easy | Stack / Queue | Monotonic Stack / Simulation | 69.9% | 50.0% | all |
| 23 | Merge k Sorted Lists | Hard | Arrays; Linked List; Heap | Sorting / Prefix / Scan; Two Pointers; Priority Queue | 59.6% | 50.0% | all |
| 11 | Container With Most Water | Medium | Core DSA | Two Pointers | 60.0% | 50.0% | all |
| 21 | Merge Two Sorted Lists | Easy | Arrays; Linked List | Sorting / Prefix / Scan; Two Pointers | 68.3% | 50.0% | all |
| 346 | Moving Average from Data Stream | Easy | Core DSA | Implementation / Reasoning | 80.2% | 50.0% | all |
| 14 | Longest Common Prefix | Easy | Core DSA | Implementation / Reasoning | 47.6% | 50.0% | all |
| 338 | Counting Bits | Easy | Core DSA | Implementation / Reasoning | 80.6% | 50.0% | all |
| 152 | Maximum Product Subarray | Medium | Arrays | Sorting / Prefix / Scan | 36.4% | 50.0% | all |
| 191 | Number of 1 Bits | Easy | Core DSA | Implementation / Reasoning | 76.8% | 50.0% | all |