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American Express DSA Interview Questions
24 curated coding interview questions directly asked in American Express technical rounds, sorted by frequency with recency and difficulty diagnostics.
24
Total Questions
9 (38%)
Easy Problems
11 (46%)
Medium Problems
4 (17%)
Hard Problems
🔥 Most Tested Topics:
Arrays (11)Strings (6)Core DSA (6)Trees (1)Backtracking (1)
📂 Sourced Datasets:
Last 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% | 6m |
| 242 | Valid Anagram | Easy | Strings | Hashing / Sliding Window | 68.1% | 100.0% | 6m |
| 1521 | Find a Value of a Mysterious Function Closest to Target | Hard | Core DSA | Implementation / Reasoning | 47.3% | 100.0% | all |
| 3013 | Divide an Array Into Subarrays With Minimum Cost II | Hard | Arrays | Sorting / Prefix / Scan | 54.7% | 100.0% | all |
| 3010 | Divide an Array Into Subarrays With Minimum Cost I | Easy | Arrays | Sorting / Prefix / Scan | 80.6% | 100.0% | all |
| 1647 | Minimum Deletions to Make Character Frequencies Unique | Medium | Arrays; Strings | Sorting / Prefix / Scan; Hashing / Sliding Window | 61.5% | 100.0% | all |
| 1201 | Ugly Number III | Medium | Core DSA | Implementation / Reasoning | 31.5% | 100.0% | all |
| 2278 | Percentage of Letter in String | Easy | Strings | Hashing / Sliding Window | 75.2% | 100.0% | all |
| 1224 | Maximum Equal Frequency | Hard | Arrays | Sorting / Prefix / Scan | 38.1% | 100.0% | all |
| 2202 | Maximize the Topmost Element After K Moves | Medium | Core DSA | Implementation / Reasoning | 24.1% | 100.0% | all |
| 2317 | Maximum XOR After Operations | Medium | Arrays | Sorting / Prefix / Scan | 79.9% | 100.0% | all |
| 1775 | Equal Sum Arrays With Minimum Number of Operations | Medium | Arrays | Sorting / Prefix / Scan | 54.6% | 100.0% | all |
| 2997 | Minimum Number of Operations to Make Array XOR Equal to K | Medium | Arrays | Sorting / Prefix / Scan | 85.5% | 100.0% | all |
| 1 | Two Sum | Easy | Arrays | Sorting / Prefix / Scan; Two Pointers | 57.5% | 87.5% | all |
| 125 | Valid Palindrome | Easy | Strings | Hashing / Sliding Window | 53.3% | 62.5% | all |
| 121 | Best Time to Buy and Sell Stock | Easy | Core DSA | Implementation / Reasoning | 56.8% | 62.5% | all |
| 1304 | Find N Unique Integers Sum up to Zero | Easy | Arrays | Sorting / Prefix / Scan | 78.4% | 62.5% | all |
| 15 | 3Sum | Medium | Arrays | Sorting / Prefix / Scan | 39.1% | 50.0% | all |
| 42 | Trapping Rain Water | Hard | Core DSA | Two Pointers | 67.4% | 50.0% | all |
| 189 | Rotate Array | Medium | Arrays | Sorting / Prefix / Scan | 44.9% | 50.0% | all |
| 46 | Permutations | Medium | Backtracking | Backtracking | 81.9% | 50.0% | all |
| 205 | Isomorphic Strings | Easy | Strings | Hashing / Sliding Window | 48.4% | 50.0% | all |
| 14 | Longest Common Prefix | Easy | Core DSA | Implementation / Reasoning | 47.6% | 50.0% | all |
| 142 | Linked List Cycle II | Medium | Linked List | Two Pointers | 57.9% | 50.0% | all |
