Bloomberg coding interview
questions, leaked.
191 problems reported across recent Bloomberg interviews. Top patterns: array, string, hash table. The list below is what most candidates actually saw, plus the honest play if you can't grind all of it.
Bloomberg asks 191 problems across its interview loop, and 60% of them are medium to hard. You're looking at a heavy array focus (96 problems), with string and hash-table work close behind. The easy problems (56 total) are a warm-up, not a safety net. Two Sum and Contains Duplicate sit alongside Trapping Rain Water and Median of Two Sorted Arrays. You need to be fast on arrays and hashing, solid on two-pointers and dynamic programming, and ready for curveballs. If you blank on a sliding-window or monotonic-stack problem mid-assessment, StealthCoder runs invisibly and surfaces a working solution in seconds.
Top problems at Bloomberg
| # | Problem | Diff | Frequency | Pass % | Patterns |
|---|---|---|---|---|---|
| 01 | Two Sum | EASY | 100.0 | 56% | Array · Hash Table |
| 02 | Decode String | MEDIUM | 0.0 | 61% | String · Stack · Recursion |
| 03 | Valid Anagram | EASY | 0.0 | 67% | Hash Table · String · Sorting |
| 04 | Merge Intervals | MEDIUM | 85.7 | 49% | Array · Sorting |
| 05 | Add Two Numbers | MEDIUM | 85.7 | 46% | Linked List · Math · Recursion |
| 06 | Longest Substring Without Repeating Characters | MEDIUM | 83.9 | 37% | Hash Table · String · Sliding Window |
| 07 | Valid Parentheses | EASY | 83.1 | 42% | String · Stack |
| 08 | Merge Sorted Array | EASY | 81.4 | 53% | Array · Two Pointers · Sorting |
| 09 | Contains Duplicate | EASY | 0.0 | 63% | Array · Hash Table · Sorting |
| 10 | Flatten a Multilevel Doubly Linked List | MEDIUM | 0.0 | 61% | Linked List · Depth-First Search · Doubly-Linked List |
| 11 | Trapping Rain Water | HARD | 79.1 | 65% | Array · Two Pointers · Dynamic Programming |
| 12 | 3Sum | MEDIUM | 78.8 | 37% | Array · Two Pointers · Sorting |
| 13 | Median of Two Sorted Arrays | HARD | 77.4 | 44% | Array · Binary Search · Divide and Conquer |
| 14 | Longest Palindromic Substring | MEDIUM | 77.2 | 36% | Two Pointers · String · Dynamic Programming |
| 15 | Maximum Subarray | MEDIUM | 75.1 | 52% | Array · Divide and Conquer · Dynamic Programming |
| 16 | Remove Duplicates from Sorted Array | EASY | 75.1 | 60% | Array · Two Pointers |
| 17 | Longest Common Prefix | EASY | 74.8 | 45% | String · Trie |
| 18 | Palindrome Number | EASY | 74.5 | 59% | Math |
| 19 | Word Search | MEDIUM | 74.2 | 45% | Array · String · Backtracking |
| 20 | Roman to Integer | EASY | 73.6 | 65% | Hash Table · Math · String |
| 21 | Reverse Integer | MEDIUM | 72.7 | 30% | Math |
| 22 | Container With Most Water | MEDIUM | 72.1 | 58% | Array · Two Pointers · Greedy |
| 23 | Search in Rotated Sorted Array | MEDIUM | 70.7 | 43% | Array · Binary Search |
| 24 | Subsets | MEDIUM | 70.0 | 81% | Array · Backtracking · Bit Manipulation |
| 25 | Merge Two Sorted Lists | EASY | 69.6 | 67% | Linked List · Recursion |
| 26 | Next Permutation | MEDIUM | 68.1 | 43% | Array · Two Pointers |
| 27 | Validate Binary Search Tree | MEDIUM | 67.3 | 34% | Tree · Depth-First Search · Binary Search Tree |
| 28 | Generate Parentheses | MEDIUM | 66.9 | 77% | String · Dynamic Programming · Backtracking |
| 29 | Group Anagrams | MEDIUM | 66.9 | 71% | Array · Hash Table · String |
| 30 | Rotate Image | MEDIUM | 65.6 | 78% | Array · Math · Matrix |
| 31 | Pow(x, n) | MEDIUM | 64.6 | 37% | Math · Recursion |
| 32 | Climbing Stairs | EASY | 64.2 | 54% | Math · Dynamic Programming · Memoization |
| 33 | Remove Element | EASY | 63.7 | 60% | Array · Two Pointers |
| 34 | Jump Game | MEDIUM | 62.1 | 39% | Array · Dynamic Programming · Greedy |
| 35 | Sqrt(x) | EASY | 61.6 | 40% | Math · Binary Search |
| 36 | Divide Array Into Arrays With Max Difference | MEDIUM | 0.0 | 79% | Array · Greedy · Sorting |
| 37 | Generate Tag for Video Caption | EASY | 0.0 | 31% | String · Simulation |
| 38 | Maximum Difference Between Increasing Elements | EASY | 0.0 | 66% | Array |
| 39 | Fibonacci Number | EASY | 0.0 | 73% | Math · Dynamic Programming · Recursion |
| 40 | Max Consecutive Ones | EASY | 0.0 | 62% | Array |
| 41 | Maximum Difference Between Even and Odd Frequency II | HARD | 0.0 | 49% | String · Sliding Window · Enumeration |
| 42 | Invalid Transactions | MEDIUM | 0.0 | 31% | Array · Hash Table · String |
| 43 | Insert Delete GetRandom O(1) | MEDIUM | 0.0 | 55% | Array · Hash Table · Math |
| 44 | Students and Examinations | EASY | 0.0 | 60% | Database |
| 45 | Palindrome Partitioning | MEDIUM | 0.0 | 72% | String · Dynamic Programming · Backtracking |
| 46 | Best Time to Buy and Sell Stock | EASY | 0.0 | 55% | Array · Dynamic Programming |
| 47 | Product of Array Except Self | MEDIUM | 0.0 | 68% | Array · Prefix Sum |
| 48 | Max Area of Island | MEDIUM | 0.0 | 73% | Array · Depth-First Search · Breadth-First Search |
| 49 | Binary Tree Level Order Traversal | MEDIUM | 61.0 | 71% | Tree · Breadth-First Search · Binary Tree |
| 50 | Find First and Last Position of Element in Sorted Array | MEDIUM | 59.8 | 47% | Array · Binary Search |
Frequencies derived from public community-tagged interview reports. Click a row to view on LeetCode.
You have a week, maybe less. You can't out-grind the list above. StealthCoder runs invisibly during the actual Bloomberg OA. The proctor cannot see it. Screen share cannot detect it. Built by an Amazon engineer who used it to pass JPMorgan's OA and system design loop.
Get StealthCoder- array96 · 50%
- string47 · 25%
- hash table40 · 21%
- two pointers31 · 16%
- dynamic programming28 · 15%
- sorting24 · 13%
- math23 · 12%
- linked list20 · 10%
- backtracking18 · 9%
- tree17 · 9%
Arrays dominate the Bloomberg dataset (96 count), so your first week goes there. Two-pointers (31 problems) and sorting (24 problems) are the mechanics you'll see repeatedly in harder array work like Merge Intervals and Trapping Rain Water. Hash-table (40 problems) is your second pillar, especially paired with strings and sliding window (Longest Substring Without Repeating Characters is a real ask). Dynamic programming (28 problems) shows up in medium and hard tiers, so don't skip Maximum Subarray or Longest Palindromic Substring. The hard problems (21 total) cluster around arrays, binary search, and DP. You can't afford gaps in two-pointers or DP logic mid-OA. That's where StealthCoder becomes your hedge: even if you froze on a DP recurrence, the solution appears invisible to the proctor.
Companies with similar patterns
If you prepped for Bloomberg, these companies recycle ~60% of the same topics.
You've seen the list.
Now make sure you pass Bloomberg.
Memorizing every problem above in a week is a fantasy. StealthCoder is the hedge: an AI overlay that's invisible during screen share. It reads the problem on screen and surfaces a working solution in under 2 seconds. Built by an Amazon engineer who used it to pass JPMorgan's OA and system design loop. Works on HackerRank, CodeSignal, CoderPad, and Karat.
Bloomberg interview FAQ
How many array problems should I drill before my Bloomberg OA?+
At least 20 to 25. Arrays account for over half the reported problems. Start with easy ones (Two Sum, Contains Duplicate, Merge Sorted Array), then move to medium (Merge Intervals, 3Sum, Maximum Subarray). That covers the core mechanics you'll see most.
Is dynamic programming required for Bloomberg?+
Yes. 28 problems involve DP, and several hard ones (Trapping Rain Water, Longest Palindromic Substring, Median of Two Sorted Arrays) expect it. You need to recognize when to use DP and code it under pressure. Skip this at your peril.
Should I study hash-table and string separately or together?+
Together. 40 hash-table problems and 47 string problems overlap heavily in Bloomberg's dataset (Longest Substring Without Repeating Characters, Valid Anagram, Decode String). Study them as one system. Hash-table solves the sliding-window constraint; string problems test your speed.
What's the difficulty split and should I worry about hard problems?+
56 easy, 114 medium, 21 hard. The hard ones (Trapping Rain Water, Median of Two Sorted Arrays) are real and they're on the test. Don't ignore them. If you hit one live and blank, that's where StealthCoder matters most.
Which topic should I study first if I have one week?+
Arrays and two-pointers. They appear in 96 and 31 problems respectively, and they're foundational to everything else (sorting, merging, sliding window). Master those two, then add hash-table and string work.