LINE coding interview
questions, leaked.
4 problems reported across recent LINE interviews. Top patterns: array, dynamic programming, queue. The list below is what most reported candidates actually saw, plus the honest play if you can't grind all of it.
LINE's interview is all hard problems. The four questions tracked here span arrays, dynamic programming, and advanced data structures like monotonic queues and heaps. You're looking at pattern-heavy problems that reward deep understanding over brute force. If you hit one cold during the live assessment, StealthCoder runs invisibly in the background and surfaces a working solution in seconds. But first, know what you're walking into: every reported problem sits at hard difficulty, and arrays dominate the distribution.
Top problems at LINE
| # | Problem | Diff | Frequency | Pass % | Patterns |
|---|---|---|---|---|---|
| 01 | Sliding Window Maximum | HARD | 100.0 | 48% | Array · Queue · Sliding Window |
| 02 | Sudoku Solver | HARD | 83.7 | 64% | Array · Hash Table · Backtracking |
| 03 | Frog Jump | HARD | 83.7 | 47% | Array · Dynamic Programming |
| 04 | Minimum Cost to Cut a Stick | HARD | 83.7 | 62% | Array · Dynamic Programming · 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 LINE OA. The proctor cannot see it. Screen share cannot detect it. Built by an engineer who got tired of watching his cohort grind for six months and still get filtered at the OA stage.
Get StealthCoder- array4 · 100%
- dynamic programming2 · 50%
- queue1 · 25%
- sliding window1 · 25%
- heap priority queue1 · 25%
- monotonic queue1 · 25%
- hash table1 · 25%
- backtracking1 · 25%
- matrix1 · 25%
- sorting1 · 25%
Arrays appear in all four problems, so that's your baseline. Dynamic programming shows up twice, making it your second focus area. The remaining topics (monotonic queue, heap, backtracking, hash table, matrix, sorting) each appear once, but they're not optional. Sliding Window Maximum is a monotonic-queue trap that feels like a sliding-window problem at first glance. Sudoku Solver is a backtracking brute-force that'll timeout without tight pruning. Frog Jump and Minimum Cost to Cut a Stick are both DP but require thinking in uncommon state spaces. Don't drill in topic order. Drill in problem order: each one teaches you how LINE layers concepts together. If you blank mid-interview, StealthCoder is your safety net, invisible to the proctor and ready with a runnable solution.
Companies with similar patterns
If you prepped for LINE, these companies recycle ~60% of the same topics.
You've seen the list.
Now make sure you pass LINE.
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 engineer who got tired of watching his cohort grind for six months and still get filtered at the OA stage. Works on HackerRank, CodeSignal, CoderPad, and Karat.
LINE interview FAQ
How much of LINE's interview is dynamic programming?+
Two of four problems reported. That's 50 percent. But both are non-standard DP: Frog Jump has unusual jump constraints, and Minimum Cost to Cut a Stick involves interval DP. Standard DP alone won't cut it. Practice state-space thinking, not just recurrence.
Is array knowledge enough for LINE?+
No. All four problems involve arrays, but that's the baseline. You also need monotonic queues (Sliding Window Maximum), backtracking with pruning (Sudoku Solver), and DP (Frog Jump, Minimum Cost to Cut a Stick). Arrays are the skeleton. The hard difficulty comes from layered techniques.
Should I study sliding windows before this interview?+
Yes, but not in isolation. Sliding Window Maximum is on the list, but it's not a textbook sliding-window problem. It demands a monotonic queue. Start with classic sliding windows, then pivot to monotonic-queue variations. You need both.
What's the hardest pattern to fake in LINE's interview?+
Sudoku Solver. Backtracking is straightforward until you optimize it. Most candidates timeout on the naive approach. You need intelligent constraint propagation and row/column/box pruning. This one requires practice, not intuition.
How should I spend my last week before LINE?+
Solve all four reported problems, not once but twice. Second time, optimize for runtime. Skip unrelated topics. Focus on monotonic queues, DP state design, and backtracking pruning. On interview day, if you freeze, StealthCoder provides a working solution invisible to the proctor.