Intel coding interview
questions, leaked.
25 problems reported across recent Intel interviews. Top patterns: array, hash table, string. The list below is what most reported candidates actually saw, plus the honest play if you can't grind all of it.
Intel's assessment hits you with 25 problems weighted heavily toward arrays, hash tables, and strings. You're looking at 10 easy problems to build momentum, 14 medium to drain your time, and one hard problem that'll probably be Trapping Rain Water or a graph traversal. The difficulty curve is forgiving on paper but brutal in execution. If you've done Two Sum and Valid Parentheses a hundred times, you'll move fast. If you blank on sliding-window logic or how to build an LRU Cache under pressure, StealthCoder runs invisibly during your screen share and surfaces a working solution in seconds.
Top problems at Intel
| # | Problem | Diff | Frequency | Pass % | Patterns |
|---|---|---|---|---|---|
| 01 | Trapping Rain Water | HARD | 100.0 | 65% | Array · Two Pointers · Dynamic Programming |
| 02 | Find Consecutive Integers from a Data Stream | MEDIUM | 100.0 | 49% | Hash Table · Design · Queue |
| 03 | Maximum Nesting Depth of the Parentheses | EASY | 100.0 | 84% | String · Stack |
| 04 | Valid Parentheses | EASY | 94.4 | 42% | String · Stack |
| 05 | Number of Islands | MEDIUM | 94.4 | 62% | Array · Depth-First Search · Breadth-First Search |
| 06 | Copy List with Random Pointer | MEDIUM | 87.1 | 61% | Hash Table · Linked List |
| 07 | Two Sum | EASY | 82.5 | 56% | Array · Hash Table |
| 08 | Count Primes | MEDIUM | 76.9 | 35% | Array · Math · Enumeration |
| 09 | Longest Substring Without Repeating Characters | MEDIUM | 76.9 | 37% | Hash Table · String · Sliding Window |
| 10 | Best Time to Buy and Sell Stock II | MEDIUM | 69.6 | 70% | Array · Dynamic Programming · Greedy |
| 11 | LRU Cache | MEDIUM | 69.6 | 45% | Hash Table · Linked List · Design |
| 12 | Reverse Integer | MEDIUM | 69.6 | 30% | Math |
| 13 | Maximum Subarray | MEDIUM | 59.5 | 52% | Array · Divide and Conquer · Dynamic Programming |
| 14 | Climbing Stairs | EASY | 59.5 | 54% | Math · Dynamic Programming · Memoization |
| 15 | Merge Two Sorted Lists | EASY | 59.5 | 67% | Linked List · Recursion |
| 16 | Reverse Words in a String | MEDIUM | 59.5 | 52% | Two Pointers · String |
| 17 | Add Two Numbers | MEDIUM | 59.5 | 46% | Linked List · Math · Recursion |
| 18 | Best Time to Buy and Sell Stock | EASY | 59.5 | 55% | Array · Dynamic Programming |
| 19 | Palindrome Number | EASY | 59.5 | 59% | Math |
| 20 | Container With Most Water | MEDIUM | 59.5 | 58% | Array · Two Pointers · Greedy |
| 21 | Merge Sorted Array | EASY | 59.5 | 53% | Array · Two Pointers · Sorting |
| 22 | Rotate Image | MEDIUM | 59.5 | 78% | Array · Math · Matrix |
| 23 | Linked List Cycle | EASY | 59.5 | 53% | Hash Table · Linked List · Two Pointers |
| 24 | Valid Palindrome | EASY | 59.5 | 51% | Two Pointers · String |
| 25 | Top K Frequent Words | MEDIUM | 59.5 | 59% | Array · Hash Table · String |
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 Intel 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- array11 · 44%
- hash table7 · 28%
- string6 · 24%
- two pointers6 · 24%
- math6 · 24%
- dynamic programming5 · 20%
- linked list5 · 20%
- stack3 · 12%
- matrix2 · 8%
- greedy2 · 8%
Arrays dominate the interview (11 out of 25 problems), so your first week should be maximum subarray patterns, sliding windows, and two-pointer techniques. Hash tables are the second wall (7 problems), mostly appearing alongside strings and linked lists for design questions like LRU Cache and Copy List with Random Pointer. The good news: 40 percent of Intel's problems are easy, meaning a solid two-week grind on array iteration, hash-table lookups, and string manipulation will get you past the filter. The hard problem is a single outlier; don't spend four days on it. Spend one day on Trapping Rain Water to understand monotonic stacks, then shift to the medium problems that actually appear in volume. If you hit a wall on a linked-list plus hash-table hybrid or a dynamic-programming array problem during the live assessment, StealthCoder is your hedge for whatever didn't stick during prep.
Companies with similar patterns
If you prepped for Intel, these companies recycle ~60% of the same topics.
You've seen the list.
Now make sure you pass Intel.
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.
Intel interview FAQ
Should I drill arrays first for Intel, or start with hash tables?+
Arrays first. 11 out of 25 problems touch array logic, and most of those are medium difficulty. Hash tables appear in 7 problems, but they usually combine with arrays or linked lists. Master sliding window and two pointers on arrays, then layer in hash tables for deduplication and caching patterns.
Is one hard problem enough to prepare for, or will Intel ask multiple hard questions?+
One hard problem is typical for Intel's assessment. Trapping Rain Water is the reported outlier. Don't chase hard problems for four days. Spend one focused session on monotonic-stack logic, then shift to the 14 medium problems that actually drive your score.
How many string problems should I expect, and what type?+
Six string problems are in the dataset, but most combine with other patterns like stacks (Valid Parentheses, Maximum Nesting Depth) or hash tables (Longest Substring Without Repeating Characters). Drill sliding window plus hash table as a paired skill, not string manipulation in isolation.
Is LRU Cache a must-know for Intel, or is it nice-to-have?+
LRU Cache is a must-know. It's a medium-difficulty design problem that appears in the top 10 and requires fluency with doubly-linked lists, hash tables, and Python's OrderedDict or manual node manipulation. Get it production-ready.
What if I run out of time during the assessment and hit a problem I haven't drilled?+
That's where the math and dynamic-programming problems become a risk. You'll see 6 math problems (Reverse Integer, Count Primes, Climbing Stairs) and 5 DP problems scattered across arrays and linked lists. If a DP or number-theory hybrid surprises you live, you need a backup; that's the real value of prep safety nets.