How often are these problems asked?
Frequency scores are based on crowdsourced interview reports. A higher score means the problem has been reported more often in recent Dell interviews.
Very Likely
75-100%
Likely
50-74%
Sometimes
25-49%
Rare
0-24%
Problem database last updated: June 20, 2025
D
Dell Coding Interview Questions
7 problems · 2 Easy, 3 Medium, 2 Hard · Ranked #184 of 458
Difficulty breakdown
2 Easy
29% · avg 23%
3 Medium
43% · avg 59%
2 Hard
29% · avg 18%
Top topics
string
57.1%2x
hash-table
28.6%
database
28.6%25.5x
array
14.3%
sorting
14.3%
stack
14.3%1.7x
Interview profile
Based on 7 reported problems, Dell interviews are significantly harder than average - 29% Hard vs 18% across all companies.
Compared to the industry average, Dell puts unusual emphasis on database (28.6% of problems, 25.5x the industry average), string (57.1% of problems, 2x the industry average). If you're short on time, these are the categories to double down on.
The most common topics are string (57.1%), hash-table (28.6%), database (28.6%), array (14.3%). Problems below are sorted by frequency, the ones at the top are asked most often.
All 7 problems
| Problem | Difficulty | Frequency | Topics | |
|---|---|---|---|---|
Group Anagrams Given an array of strings strs, group the anagrams together. You can return the answer in any order. | Medium | Very Likely | arrayhash-tablestring | Solve |
Valid Parentheses Given a string s containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid. | Easy | Very Likely | stringstack | Solve |
Longest Substring Without Repeating Characters Given a string s, find the length of the longest substring without duplicate characters. | Medium | Very Likely | hash-tablestringsliding-window | Solve |
Merge k Sorted Lists You are given an array of k linked-lists lists, each linked-list is sorted in ascending order. | Hard | Very Likely | linked-listdivide-and-conquerheap-priority-queue | Solve |
Longest Palindromic Substring Given a string s, return the longest palindromic substring in s. | Medium | Very Likely | two-pointersstringdynamic-programming | Solve |
Department Top Three Salaries Table: Employee | Hard | Very Likely | database | Solve |
Delete Duplicate Emails Table: Person | Easy | Very Likely | database | Solve |
Group Anagrams
SolveGiven an array of strings strs, group the anagrams together. You can return the answer in any order.
MediumVery Likely
arrayhash-tablestring
Valid Parentheses
SolveGiven a string s containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid.
EasyVery Likely
stringstack
Longest Substring Without Repeating Characters
SolveGiven a string s, find the length of the longest substring without duplicate characters.
MediumVery Likely
hash-tablestringsliding-window
Merge k Sorted Lists
SolveYou are given an array of k linked-lists lists, each linked-list is sorted in ascending order.
HardVery Likely
linked-listdivide-and-conquerheap-priority-queue
Longest Palindromic Substring
SolveGiven a string s, return the longest palindromic substring in s.
MediumVery Likely
two-pointersstringdynamic-programming
Preparing for your Dell coding interview
Dell interviews focus heavily on string, hash-table, database problems. If you're short on time, these are the categories to prioritize. The problems on this page are sorted by frequency, so start from the top and work your way down.
Beyond solving problems, practice explaining your approach. Dell interviewers care about your thought process - how you break down a problem, consider edge cases, and evaluate tradeoffs between solutions. A clean O(n) solution you can explain clearly beats an O(log n) solution you can't articulate.
Looking for more companies? Browse all 458 companies in our directory, or sharpen your fundamentals with our free data structure visualizers and AI-powered DSA tutor.
Frequently Asked Questions
What coding problems does Dell ask in interviews?add
Dell has been reported to ask 7 distinct coding problems. The most common topics are string, hash-table, database. 2 are Easy difficulty, 3 are Medium, and 2 are Hard. Problems are sorted by frequency - the ones at the top are asked most often.
How hard are Dell coding interviews?add
Based on 7 reported problems, Dell interviews are significantly harder than average - 29% Hard vs 18% across all companies. 43% of questions are Medium difficulty. Focus on the high-frequency Medium problems first, then work through the Hard ones.
How should I prepare for a Dell coding interview?add
Start with the highest-frequency problems listed on this page. Focus on the core topics: string, hash-table, database. Practice solving them under time pressure and explaining your approach out loud. Mock interviews with AI can simulate the real experience.
Other companies to explore
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