Cisco vs Citadel Interview Questions
Cisco lists 87 LeetCode interview questions while Citadel lists 101. They share 19 problems — 22% of Cisco's bank and 19% of Citadel's. Focus on the overlap first, then drill into 68 Cisco-only and 82 Citadel-only questions.
Overview
Preparation Strategy
Step 1 — Shared core: Solve the 19 overlapping problems first. These are the highest-yield questions for candidates interviewing at both Cisco and Citadel.
Step 2 — Company-specific depth: Add Cisco-specific problems like Longest Palindromic Substring, Predict the Winner, Lucky Numbers in a Matrix 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
19 Shared Questions
High-priority problems to practice for both Cisco and Citadel.
| Problem | Difficulty |
|---|---|
| House Robber | Medium |
| Fizz Buzz | Easy |
| LRU Cache | Medium |
| Merge Intervals | Medium |
| Max Points on a Line | Hard |
| Trapping Rain Water | Hard |
| Best Time to Buy and Sell Stock | Easy |
| Letter Combinations of a Phone Number | Medium |
| Number of Islands | Medium |
| 3Sum | Medium |
| Word Search | Medium |
| Group Anagrams | Medium |
| Find Servers That Handled Most Number of Requests | Hard |
| Insert Delete GetRandom O(1) | Medium |
| Merge k Sorted Lists | Hard |
| Palindromic Substrings | Medium |
| Climbing Stairs | Easy |
| Permutations | Medium |
| Sliding Window Maximum | Hard |
Unique to Cisco (68)
Problems in Cisco's list that do not appear at Citadel.
| Problem | Difficulty |
|---|---|
| Longest Palindromic Substring | Medium |
| Predict the Winner | Medium |
| Lucky Numbers in a Matrix | Easy |
| Rotate Image | Medium |
| Spiral Matrix | Medium |
| Snakes and Ladders | Medium |
| Number of Valid Words in a Sentence | Easy |
| Maximum Difference Between Increasing Elements | Easy |
| Find Third Transaction | Medium |
| Implement Router | Medium |
| Word Search II | Hard |
| Maximum Subarray | Medium |
Unique to Citadel (82)
Problems in Citadel's list that do not appear at Cisco.
Frequently Asked Questions
How many LeetCode questions do Cisco and Citadel share?
Cisco and Citadel share 19 LeetCode interview questions. 68 problems appear only in Cisco's list and 82 appear only in Citadel's list.
What topics overlap most between Cisco and Citadel?
The most common shared topics between Cisco and Citadel are Array (13 shared questions), Dynamic Programming (5 shared questions), String (5 shared questions), Hash Table (5 shared questions), Math (4 shared questions). Mastering these areas prepares you for both companies.
Which company asks harder LeetCode questions: Cisco or Citadel?
Cisco has 24 Easy, 50 Medium, and 13 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 Cisco and Citadel?
Start with the 19 shared problems since they cover what both companies ask most often. Then add 20 Cisco-specific and 20 Citadel-specific questions to round out your prep.