Amazon vs Citadel Interview Questions
Amazon lists 1,968 LeetCode interview questions while Citadel lists 101. They share 91 problems — 5% of Amazon's bank and 90% of Citadel's. Focus on the overlap first, then drill into 1,877 Amazon-only and 10 Citadel-only questions.
Overview
Preparation Strategy
Step 1 — Shared core: Solve the 91 overlapping problems first. These are the highest-yield questions for candidates interviewing at both Amazon and Citadel.
Step 2 — Company-specific depth: Add Amazon-specific problems like Two Sum, Longest Substring Without Repeating Characters, Add Two Numbers and Citadel-specific problems from the exclusive lists below.
Step 3 — Difficulty tuning: Citadel skews harder in our data. Budget extra time for Hard problems if you are targeting that company.
Difficulty Comparison
Top Shared Topics
91 Shared Questions
High-priority problems to practice for both Amazon and Citadel.
| Problem | Difficulty |
|---|---|
| LRU Cache | Medium |
| Trapping Rain Water | Hard |
| Number of Islands | Medium |
| Best Time to Buy and Sell Stock | Easy |
| Group Anagrams | Medium |
| Reorganize String | Medium |
| 3Sum | Medium |
| Merge Intervals | Medium |
| Container With Most Water | Medium |
| Median of Two Sorted Arrays | Hard |
| Koko Eating Bananas | Medium |
| Course Schedule | Medium |
| Merge k Sorted Lists | Hard |
| Rotting Oranges | Medium |
| Climbing Stairs | Easy |
| House Robber | Medium |
| Letter Combinations of a Phone Number | Medium |
| Course Schedule II | Medium |
| Word Search | Medium |
| Sliding Window Maximum | Hard |
| Find Median from Data Stream | Hard |
| Insert Delete GetRandom O(1) | Medium |
| Asteroid Collision | Medium |
| N-Queens | Hard |
| Best Time to Buy and Sell Stock II | Medium |
| Binary Tree Maximum Path Sum | Hard |
| Serialize and Deserialize Binary Tree | Hard |
| Sqrt(x) | Easy |
| Binary Tree Zigzag Level Order Traversal | Medium |
| LFU Cache | Hard |
Showing top 30 of 91 shared problems.
Unique to Amazon (1,877)
Problems in Amazon's list that do not appear at Citadel.
| Problem | Difficulty |
|---|---|
| Two Sum | Easy |
| Longest Substring Without Repeating Characters | Medium |
| Add Two Numbers | Medium |
| Longest Palindromic Substring | Medium |
| Valid Parentheses | Easy |
| Longest Common Prefix | Easy |
| Subarray Sum Equals K | Medium |
| Merge Sorted Array | Easy |
| Search in Rotated Sorted Array | Medium |
| Top K Frequent Elements | Medium |
| Maximum Subarray | Medium |
| Longest Consecutive Sequence | Medium |
Unique to Citadel (10)
Problems in Citadel's list that do not appear at Amazon.
Frequently Asked Questions
How many LeetCode questions do Amazon and Citadel share?
Amazon and Citadel share 91 LeetCode interview questions. 1877 problems appear only in Amazon's list and 10 appear only in Citadel's list.
What topics overlap most between Amazon and Citadel?
The most common shared topics between Amazon and Citadel are Array (17 shared questions), Hash Table (6 shared questions), Dynamic Programming (6 shared questions), Depth-First Search (6 shared questions), Breadth-First Search (6 shared questions). Mastering these areas prepares you for both companies.
Which company asks harder LeetCode questions: Amazon or Citadel?
Amazon has 527 Easy, 1074 Medium, and 367 Hard questions. Citadel has 5 Easy, 60 Medium, and 36 Hard questions. Citadel has a higher proportion of Hard problems in its interview set.
How should I prepare if interviewing at both Amazon and Citadel?
Start with the 91 shared problems since they cover what both companies ask most often. Then add 20 Amazon-specific and 10 Citadel-specific questions to round out your prep.