Riot Games coding interview
questions, leaked.
4 problems reported across recent Riot Games interviews. Top patterns: hash table, array, matrix. The list below is what most reported candidates actually saw, plus the honest play if you can't grind all of it.
Riot Games coding interviews hit you with hash-table and array problems almost every time. You're looking at 4 reported problems across difficulty levels, with a heavy skew toward medium. The real danger: you'll see Valid Sudoku or Sudoku Solver, and if you freeze on the backtracking or constraint-checking logic, the clock moves fast. That's where StealthCoder becomes your safety net. It runs invisibly during the assessment and surfaces working solutions the moment you hit a wall, so you keep moving and don't burn time on a half-baked approach.
Top problems at Riot Games
| # | Problem | Diff | Frequency | Pass % | Patterns |
|---|---|---|---|---|---|
| 01 | Teemo Attacking | EASY | 100.0 | 57% | Array · Simulation |
| 02 | Valid Sudoku | MEDIUM | 91.8 | 62% | Array · Hash Table · Matrix |
| 03 | Sudoku Solver | HARD | 82.4 | 64% | Array · Hash Table · Backtracking |
| 04 | Better Compression of String | MEDIUM | 72.1 | 76% | Hash Table · String · 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 Riot Games OA. The proctor cannot see it. Screen share cannot detect it. Made by an Amazon engineer who watched the leaked-problem repo become an industry secret. He decided you should have it too.
Get StealthCoder- hash table3 · 75%
- array3 · 75%
- matrix2 · 50%
- string1 · 25%
- sorting1 · 25%
- counting1 · 25%
- backtracking1 · 25%
- simulation1 · 25%
Hash-table appears in 3 of 4 problems. Arrays appear just as often. Matrix comes up twice, meaning Sudoku-style constraint problems are real. Start with hash-table fundamentals and array manipulation before anything else. Valid Sudoku and Sudoku Solver are the high-risk patterns here because they combine multiple topics (hash-table, matrix, and backtracking for the hard one). Teemo Attacking is your gimme: it's easy, pure simulation and array work. String and sorting each show up once, so they're lower noise. If you haven't drilled Sudoku constraint validation yet, do that immediately. If you blank on the backtracking during the live OA, StealthCoder gives you the solution in real time, invisible to the proctor.
Companies with similar patterns
If you prepped for Riot Games, these companies recycle ~60% of the same topics.
You've seen the list.
Now make sure you pass Riot Games.
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 an Amazon engineer who watched the leaked-problem repo become an industry secret. He decided you should have it too. Works on HackerRank, CodeSignal, CoderPad, and Karat.
Riot Games interview FAQ
Should I focus on hash-table or array first for Riot Games?+
Hash-table and array are tied at 3 problems each. Start with hash-table because it's the backbone of Valid Sudoku and Sudoku Solver, both of which demand fast constraint lookups. Arrays are required too, but hash-table proficiency is the faster multiplier for this company's pattern.
Is Sudoku Solver really worth practicing if it's only 1 of 4 problems?+
Yes. It's the hardest problem on the list and bundles hash-table, matrix, and backtracking together. Mastering it teaches you constraint satisfaction patterns that cascade into string and array problems. The time investment pays off.
What's the quickest win I can drill before the assessment?+
Teemo Attacking. It's easy, pure array and simulation, and gives you a confidence point in the first few minutes of the OA. That mental momentum matters when you hit Valid Sudoku or Sudoku Solver later.
How many hash-table problems should I solve to be safe?+
At least 8 to 10 beyond Valid Sudoku, focusing on collision handling and constraint checking. Hash-table shows up in 75% of Riot's reported problems, so the pattern density is unusually high. Don't skimp.
Should I spend time on sorting or string work?+
Sorting and string each appear once in Better Compression of String. They're not the core pattern here. Master hash-table, array, and matrix first, then pick up sorting and string as secondary drills if you have extra time.