TikTok coding interview
questions, leaked.
180 problems reported across recent TikTok interviews. Top patterns: array, string, dynamic programming. The list below is what most candidates actually saw, plus the honest play if you can't grind all of it.
TikTok's coding interview is array-heavy and medium-tier brutal. Out of 180 reported problems, 120 are medium difficulty, and arrays dominate at 100 problems, followed by strings at 50. You're walking into LRU Cache, Merge Intervals, Course Schedule, and Trapping Rain Water. These aren't one-liners. If you hit a wall on a hard problem mid-assessment, StealthCoder runs invisible during screen share and surfaces a working solution in seconds, no proctor visibility. That safety net matters when you're burned out halfway through.
Top problems at TikTok
| # | Problem | Diff | Frequency | Pass % | Patterns |
|---|---|---|---|---|---|
| 01 | LRU Cache | MEDIUM | 96.0 | 45% | Hash Table · Linked List · Design |
| 02 | Merge Intervals | MEDIUM | 89.6 | 49% | Array · Sorting |
| 03 | Course Schedule | MEDIUM | 0.0 | 49% | Depth-First Search · Breadth-First Search · Graph |
| 04 | Longest Increasing Subsequence | MEDIUM | 0.0 | 58% | Array · Binary Search · Dynamic Programming |
| 05 | Making A Large Island | HARD | 0.0 | 55% | Array · Depth-First Search · Breadth-First Search |
| 06 | Longest Substring Without Repeating Characters | MEDIUM | 84.8 | 37% | Hash Table · String · Sliding Window |
| 07 | Trapping Rain Water | HARD | 82.2 | 65% | Array · Two Pointers · Dynamic Programming |
| 08 | Minimum Window Substring | HARD | 76.9 | 45% | Hash Table · String · Sliding Window |
| 09 | Merge k Sorted Lists | HARD | 76.9 | 57% | Linked List · Divide and Conquer · Heap (Priority Queue) |
| 10 | Word Search | MEDIUM | 76.0 | 45% | Array · String · Backtracking |
| 11 | Search in Rotated Sorted Array | MEDIUM | 75.1 | 43% | Array · Binary Search |
| 12 | Number of Islands | MEDIUM | 0.0 | 62% | Array · Depth-First Search · Breadth-First Search |
| 13 | Meeting Rooms II | MEDIUM | 0.0 | 52% | Array · Two Pointers · Greedy |
| 14 | Valid Parenthesis String | MEDIUM | 0.0 | 39% | String · Dynamic Programming · Stack |
| 15 | Top K Frequent Elements | MEDIUM | 0.0 | 65% | Array · Hash Table · Divide and Conquer |
| 16 | Kth Missing Positive Number | EASY | 0.0 | 62% | Array · Binary Search |
| 17 | Split Message Based on Limit | HARD | 0.0 | 43% | String · Binary Search · Enumeration |
| 18 | Max Area of Island | MEDIUM | 0.0 | 73% | Array · Depth-First Search · Breadth-First Search |
| 19 | N-Queens | HARD | 73.1 | 73% | Array · Backtracking |
| 20 | Longest Palindromic Substring | MEDIUM | 73.1 | 36% | Two Pointers · String · Dynamic Programming |
| 21 | Restore IP Addresses | MEDIUM | 72.1 | 53% | String · Backtracking |
| 22 | 3Sum | MEDIUM | 71.0 | 37% | Array · Two Pointers · Sorting |
| 23 | Combination Sum | MEDIUM | 71.0 | 75% | Array · Backtracking |
| 24 | Word Ladder | HARD | 69.8 | 43% | Hash Table · String · Breadth-First Search |
| 25 | Sqrt(x) | EASY | 68.6 | 40% | Math · Binary Search |
| 26 | Text Justification | HARD | 67.4 | 48% | Array · String · Simulation |
| 27 | Best Time to Buy and Sell Stock | EASY | 67.4 | 55% | Array · Dynamic Programming |
| 28 | Valid Parentheses | EASY | 66.0 | 42% | String · Stack |
| 29 | Spiral Matrix | MEDIUM | 64.6 | 54% | Array · Matrix · Simulation |
| 30 | Find Peak Element | MEDIUM | 64.6 | 47% | Array · Binary Search |
| 31 | Two Sum | EASY | 64.6 | 56% | Array · Hash Table |
| 32 | Binary Tree Maximum Path Sum | HARD | 64.6 | 41% | Dynamic Programming · Tree · Depth-First Search |
| 33 | Sort Colors | MEDIUM | 64.6 | 68% | Array · Two Pointers · Sorting |
| 34 | Construct Binary Tree from Preorder and Inorder Traversal | MEDIUM | 63.0 | 67% | Array · Hash Table · Divide and Conquer |
| 35 | Word Break II | HARD | 63.0 | 54% | Array · Hash Table · String |
| 36 | Maximum Subarray | MEDIUM | 61.4 | 52% | Array · Divide and Conquer · Dynamic Programming |
| 37 | Permutations | MEDIUM | 61.4 | 81% | Array · Backtracking |
| 38 | Edit Distance | MEDIUM | 61.4 | 59% | String · Dynamic Programming |
| 39 | Generate Parentheses | MEDIUM | 61.4 | 77% | String · Dynamic Programming · Backtracking |
| 40 | Combination Sum II | MEDIUM | 61.4 | 58% | Array · Backtracking |
| 41 | Find First and Last Position of Element in Sorted Array | MEDIUM | 59.6 | 47% | Array · Binary Search |
| 42 | Regular Expression Matching | HARD | 57.6 | 29% | String · Dynamic Programming · Recursion |
| 43 | Container With Most Water | MEDIUM | 57.6 | 58% | Array · Two Pointers · Greedy |
| 44 | Word Break | MEDIUM | 57.6 | 48% | Array · Hash Table · String |
| 45 | Reverse Nodes in k-Group | HARD | 57.6 | 63% | Linked List · Recursion |
| 46 | Longest Consecutive Sequence | MEDIUM | 55.5 | 47% | Array · Hash Table · Union Find |
| 47 | Jump Game | MEDIUM | 55.5 | 39% | Array · Dynamic Programming · Greedy |
| 48 | Best Time to Buy and Sell Stock II | MEDIUM | 55.5 | 70% | Array · Dynamic Programming · Greedy |
| 49 | Group Anagrams | MEDIUM | 53.2 | 71% | Array · Hash Table · String |
| 50 | Merge Sorted Array | EASY | 53.2 | 53% | Array · Two Pointers · Sorting |
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 TikTok OA. The proctor cannot see it. Screen share cannot detect it. Made by a working Amazon engineer who got tired of watching qualified friends bomb OAs they'd solve cold in an IDE.
Get StealthCoder- array100 · 56%
- string50 · 28%
- dynamic programming38 · 21%
- hash table37 · 21%
- depth first search26 · 14%
- breadth first search24 · 13%
- math24 · 13%
- two pointers22 · 12%
- matrix20 · 11%
- binary search19 · 11%
Arrays and strings account for roughly 84 percent of the problem set. Dynamic programming hits 38 problems, hash tables 37, and graph traversal (DFS/BFS combined) sits around 50. The jump from medium to hard is steep: Trapping Rain Water needs monotonic stack thinking, Making A Large Island requires union find or optimized DFS, and Merge k Sorted Lists demands heap or merge-sort logic. Start with array and string fundamentals, move into sliding-window (Longest Substring Without Repeating, Minimum Window Substring), then hammer dynamic programming and graph patterns. If you haven't internalized two-pointers or binary search under pressure, StealthCoder is your hedge for the live OA when pattern recognition fails.
Companies with similar patterns
If you prepped for TikTok, these companies recycle ~60% of the same topics.
You've seen the list.
Now make sure you pass TikTok.
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 by a working Amazon engineer who got tired of watching qualified friends bomb OAs they'd solve cold in an IDE. Works on HackerRank, CodeSignal, CoderPad, and Karat.
TikTok interview FAQ
How much of TikTok's interview is actually arrays?+
Arrays appear in roughly 55 percent of the 180 reported problems, often paired with other patterns like sorting, two-pointers, or binary search. Strings are second at 28 percent. If you can't handle array manipulation and searching efficiently, you're starting behind. Drill those first.
Is dynamic programming optional or required?+
Dynamic programming shows up in 38 reported problems, and several of the hardest ones combine it with other patterns. Longest Increasing Subsequence, Trapping Rain Water, and Valid Parenthesis String all need DP thinking. It's not optional. Plan 40 percent of your prep time there.
What's the hardest problem category I should expect?+
41 of 180 are hard. Merge k Sorted Lists, Trapping Rain Water, and Making A Large Island are typical difficulty. They mix multiple patterns: heap work, monotonic stacks, union find, or optimized DFS. Medium problems can also require clean algorithmic thinking, so don't assume hard means novel.
Should I practice hash-table problems separately?+
Hash tables appear in 37 problems but often embedded in medium-difficulty strings and arrays. LRU Cache, Top K Frequent Elements, and Longest Substring Without Repeating all need hash-table fluency. Practice them as part of sliding-window and design problem flows, not in isolation.
How many graph problems will I see?+
DFS and BFS combined account for roughly 50 problems. Course Schedule, Number of Islands, and Making A Large Island are common. Graph traversal is core to their interview. If topological sort or union find feel unfamiliar, block dedicated time before your OA.