Programming Interviews Exposed
Part 1 — Data Structures That Decide Your Result
I’m rereading Programming Interviews Exposed (3rd Edition) — and it’s a strong reminder that interviews are rarely about “clever tricks”.
They’re about:
- Fundamentals
- Clear thinking
- How you explain your logic under pressure
This is Part 1 of a short series where I’m sharing what actually matters in Data Structures — without overcomplicating it.
1️⃣ Arrays & Strings
Simple… until they’re not
Most interview problems secretly revolve around:
- Two pointers
- Sliding window
- In-place updates
If you truly master strings and arrays, interviews start to feel lighter.
Key reminders:
- O(1) access time
- Off-by-one errors are common traps
- Think about boundaries first
2️⃣ Linked Lists
Where pointers expose weak thinking
Classic interview traps:
- Reverse a list
- Detect a cycle
- Remove k-th node from end
It’s never about syntax.
It’s about pointer rewiring safely and intentionally.
Important mindset shifts:
- No indexing
- Only references
- Singly vs Doubly linked lists matter
3️⃣ Stacks & Queues
Hidden everywhere
Many problems don’t explicitly say “use a stack” — they expect you to recognize the pattern.
Stack → LIFO
Used in:
- Recursion
- Undo operations
- Expression parsing
Queue → FIFO
Used in:
- BFS
- Scheduling
- Streams
- Task processing
4️⃣ Trees
Where recursion finally makes sense
Interview favorites include:
- Height & depth
- Tree traversal
- Lowest Common Ancestor (LCA)
If trees scare you, recursion is usually the real issue.
Mindset matters:
- Binary Tree ≠ Binary Search Tree
- DFS vs BFS is a strategic choice
5️⃣ Hash Tables
The ultimate shortcut
Used for:
- Frequency counting
- Deduplication
- Caching
- Turning nested loops into clean logic
Average lookup: O(1)
When stuck in an interview, ask yourself:
“Can a hash map simplify this?”
Interview Truth
Data structures don’t fail you — preparation does.
Interviews test:
- Thinking patterns
- Communication
- Pattern recognition
Patterns repeat more than problems.
Explain your logic out loud.
That matters more than memorizing solutions.
This is Part 1 of the series.
👉 Part 2 — Algorithms — coming next.