Turing coding interview
questions, leaked.
41 problems reported across recent Turing interviews. Top patterns: array, string, hash table. The list below is what most reported candidates actually saw, plus the honest play if you can't grind all of it.
Turing's bar is arrays and strings. You're facing 23 array problems and 16 string problems across 41 total OAs, with a split that skews medium difficulty (28 of 41). That's a lot of ground. The good news: 11 are easy wins you can nail in the first five minutes. The harder news: if you freeze on a sliding-window or hash-table pattern mid-assessment, you've got seconds to recover. That's where StealthCoder steps in. When the clock is moving and your brain isn't, a real-time solution invisible to the proctor is the difference between passing and bombing.
Top problems at Turing
| # | Problem | Diff | Frequency | Pass % | Patterns |
|---|---|---|---|---|---|
| 01 | Valid Parentheses | EASY | 100.0 | 42% | String · Stack |
| 02 | Longest Substring Without Repeating Characters | MEDIUM | 91.8 | 37% | Hash Table · String · Sliding Window |
| 03 | Baseball Game | EASY | 81.2 | 79% | Array · Stack · Simulation |
| 04 | Minimum Cost For Tickets | MEDIUM | 73.8 | 67% | Array · Dynamic Programming |
| 05 | Koko Eating Bananas | MEDIUM | 71.5 | 49% | Array · Binary Search |
| 06 | Validate IP Address | MEDIUM | 65.7 | 28% | String |
| 07 | Longest Common Prefix | EASY | 65.7 | 45% | String · Trie |
| 08 | Number of Islands | MEDIUM | 65.7 | 62% | Array · Depth-First Search · Breadth-First Search |
| 09 | Minimum Length of Anagram Concatenation | MEDIUM | 62.0 | 40% | Hash Table · String · Counting |
| 10 | Find the Town Judge | EASY | 62.0 | 50% | Array · Hash Table · Graph |
| 11 | Apply Operations to Make Sum of Array Greater Than or Equal to k | MEDIUM | 57.5 | 43% | Math · Greedy · Enumeration |
| 12 | Maximum Subarray | MEDIUM | 57.5 | 52% | Array · Divide and Conquer · Dynamic Programming |
| 13 | Climbing Stairs | EASY | 57.5 | 54% | Math · Dynamic Programming · Memoization |
| 14 | Merge Intervals | MEDIUM | 57.5 | 49% | Array · Sorting |
| 15 | Regular Expression Matching | HARD | 51.8 | 29% | String · Dynamic Programming · Recursion |
| 16 | Find Duplicate File in System | MEDIUM | 51.8 | 68% | Array · Hash Table · String |
| 17 | Longest Consecutive Sequence | MEDIUM | 51.8 | 47% | Array · Hash Table · Union Find |
| 18 | Partition Array Into Three Parts With Equal Sum | EASY | 51.8 | 42% | Array · Greedy |
| 19 | Product of Array Except Self | MEDIUM | 51.8 | 68% | Array · Prefix Sum |
| 20 | Maximum Number of Vowels in a Substring of Given Length | MEDIUM | 51.8 | 60% | String · Sliding Window |
| 21 | House Robber | MEDIUM | 51.8 | 52% | Array · Dynamic Programming |
| 22 | Degree of an Array | EASY | 51.8 | 57% | Array · Hash Table |
| 23 | Race Car | HARD | 43.7 | 44% | Dynamic Programming |
| 24 | Jump Game | MEDIUM | 43.7 | 39% | Array · Dynamic Programming · Greedy |
| 25 | Sum of Digit Differences of All Pairs | MEDIUM | 43.7 | 42% | Array · Hash Table · Math |
| 26 | Number of Subsequences That Satisfy the Given Sum Condition | MEDIUM | 43.7 | 44% | Array · Two Pointers · Binary Search |
| 27 | Find All Anagrams in a String | MEDIUM | 43.7 | 52% | Hash Table · String · Sliding Window |
| 28 | Best Time to Buy and Sell Stock | EASY | 43.7 | 55% | Array · Dynamic Programming |
| 29 | Kth Largest Element in an Array | MEDIUM | 43.7 | 68% | Array · Divide and Conquer · Sorting |
| 30 | Maximum Repeating Substring | EASY | 43.7 | 40% | String · Dynamic Programming · String Matching |
| 31 | Spiral Matrix | MEDIUM | 43.7 | 54% | Array · Matrix · Simulation |
| 32 | Longest Palindromic Substring | MEDIUM | 43.7 | 36% | Two Pointers · String · Dynamic Programming |
| 33 | Consecutive Numbers | MEDIUM | 43.7 | 46% | Database |
| 34 | Valid Palindrome | EASY | 43.7 | 51% | Two Pointers · String |
| 35 | Longest Repeating Character Replacement | MEDIUM | 43.7 | 57% | Hash Table · String · Sliding Window |
| 36 | Group Anagrams | MEDIUM | 43.7 | 71% | Array · Hash Table · String |
| 37 | Reverse Only Letters | EASY | 43.7 | 67% | Two Pointers · String |
| 38 | 3Sum | MEDIUM | 43.7 | 37% | Array · Two Pointers · Sorting |
| 39 | Minimum Number of Operations to Make Word K-Periodic | MEDIUM | 43.7 | 60% | Hash Table · String · Counting |
| 40 | Find First and Last Position of Element in Sorted Array | MEDIUM | 43.7 | 47% | Array · Binary Search |
| 41 | Minimum Number of Operations to Satisfy Conditions | MEDIUM | 43.7 | 41% | Array · Dynamic Programming · Matrix |
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 Turing OA. The proctor cannot see it. Screen share cannot detect it. Made for the engineer who has done the work but might still blank with a webcam pointed at him.
Get StealthCoder- array23 · 56%
- string16 · 39%
- hash table11 · 27%
- dynamic programming11 · 27%
- sorting5 · 12%
- two pointers5 · 12%
- sliding window4 · 10%
- math3 · 7%
- greedy3 · 7%
- counting3 · 7%
Array and string problems dominate the prep list, but don't sleep on hash tables and dynamic programming, each appearing in 11 problems. Most candidates grind arrays, miss the hash-table angle, then hit a subproblem they didn't see coming. The medium-heavy distribution (68 percent of the test) means you'll see problems like 'Longest Substring Without Repeating Characters' and 'Maximum Subarray' that require you to spot the right data structure or algorithmic trick fast. Sorting and two-pointers are lower-frequency but still in rotation. If you blank on a medium-difficulty array or string problem during your live assessment, StealthCoder reads the problem, surfaces a working solution in seconds, and you stay invisible to the proctor.
Companies with similar patterns
If you prepped for Turing, these companies recycle ~60% of the same topics.
You've seen the list.
Now make sure you pass Turing.
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. Made for the engineer who has done the work but might still blank with a webcam pointed at him. Works on HackerRank, CodeSignal, CoderPad, and Karat.
Turing interview FAQ
How many array problems should I solve before Turing's OA?+
Array problems make up 56 percent of the test (23 of 41). Aim to solve at least 15 to 20 array problems cold, mixing easy and medium difficulty. Focus on sliding-window and two-pointer patterns since those show up repeatedly and are quick wins if you spot them early.
Should I study dynamic programming or strings first for Turing?+
Strings first. Sixteen string problems appear in their list, and many are easier to drill than DP. Valid Parentheses, Longest Palindromic Substring, and Validate IP Address are common gates. Dynamic programming (11 problems) is harder and slower to solve, so tackle it after you're comfortable with string manipulation.
Are hash tables really necessary for Turing's assessment?+
Yes. Hash tables appear in 11 problems, often paired with arrays or strings. Problems like 'Longest Substring Without Repeating Characters' and 'Find the Town Judge' depend on hash-table intuition to run efficiently. If you skip hash tables, you'll timeout or brute-force your way to a rejection.
What's the difficulty spread I should expect?+
Sixty-eight percent medium, 27 percent easy, 5 percent hard. Most of your time will be on medium problems like 'Merge Intervals' and 'Number of Islands'. Nail the easy problems in the first few minutes, then pace yourself on the medium ones. Hard problems are rare and often time-killers; skip them if stuck.
Is 'Regular Expression Matching' a dealbreaker if I haven't seen it?+
It's hard and rare, so don't panic if you don't know it. But if it appears in your OA and you blank, that's exactly what StealthCoder is for. It runs invisibly during your screen share and solves it while you stay composed and on the proctor's good side.