Weekend Sprint

32 Problems. 6 Tiers. 1 Weekend. Focused DSA prep based on real SDE interview reports (2024-2025).

Start with Graphs | View Schedule | Interview Day

Icon	Tier	Problems	Description	Link
🔴	Tier 1: Graphs	8 problems	Highest frequency. BFS/DFS, topo sort, Dijkstra's. Appeared in nearly every SDE onsite.	Study Graphs
🟠	Tier 2: Trees	6 problems	Tree DP, LCA, serialize/deserialize. Second highest frequency in SDE interviews.	Study Trees
🟡	Tier 3: Sliding Window	4 problems	Phone screen favorites. Master the expand/shrink template and you're golden.	Study Sliding Window
🟢	Tier 4: DP	5 problems	1 DP question per loop typical. Cover 1D, 2D, and DFS+memo patterns.	Study DP
🔵	Tier 5: HashMap/Heap/BS	6 problems	Pattern matching and optimization. Group anagrams, top-K, binary search variants.	Study Data Structures
🟣	Tier 6: Strings	3 problems	Tries, two-pointer string matching, and backtracking.	Study Strings

The Reality Check

You have an interview this week. No time for a 3-month grind. This site is your battle plan.

YOUR SITUATION

This is not a "learn DSA from scratch" resource. This is a focused, prioritized list of 32 problems that actually show up in SDE interviews, based on real interview reports from 2024-2025.

Here is what your interview looks like:

• 2 coding rounds, 45 minutes each, conducted virtually
• Plain text editor (no IDE) -- you cannot run your code, no syntax highlighting, no autocomplete
• Based on actual SDE interview reports collected from candidates who interviewed in 2024-2025
• Expect 1 main problem per round, possibly with a follow-up or extension

NO CODE EXECUTION

You will write code in a plain text editor (no IDE). Practice writing syntactically correct solutions without an IDE. Every character matters when you cannot hit "Run".

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What Interviews Test

Area	Focus	Weight
Data Structures & Algorithms	Graphs, Trees, DP, Sliding Window, HashMap/Heap, Strings	~70%
System Design	High-level architecture, trade-offs, scalability	~25%
Behavioral	Collaboration, ambiguity, leadership	~5%

DSA IS THE GATE

Your coding rounds are the make-or-break. System design matters, but you will not reach the hiring committee if you bomb the coding rounds. Prioritize DSA above everything else this week.

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How to Use This Site

Step-by-step guide (click to expand)

1. Start with Tier 1 (Graphs) -- This is the highest-frequency category. If you only have a few hours, spend them here. Work through all 8 problems.

2. Work through each tier in order -- The tiers are ranked by frequency of appearance in real SDE interviews. Tier 1 first, Tier 6 last.

3. Use the Templates page for quick reference -- Memorize the BFS template, the sliding window template, and the topo sort template. These cover at least 60% of problems.

4. Follow the Schedule for a structured plan -- If you have a full weekend, the schedule breaks the 32 problems across Saturday and Sunday with morning/afternoon/evening blocks.

5. Review the Interview Day checklist before your rounds -- Communication phrases, time allocation per section, and tips from candidates who received offers.

The fastest path if you are short on time

Time Available	What to Cover
2 hours	Graphs (#1-4): Islands, Course Schedule I/II, Word Ladder
4 hours	Add Trees (#9-11): Max Path Sum, LCA (BST + BT)
8 hours	Add Sliding Window (#15-18) and DP (#19-21)
Full weekend	All 32 problems + 2 timed mocks in a plain text editor

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Problem Distribution at a Glance

Tier	Category	Count	Priority
🔴 T1	Graphs	8	Critical
🟠 T2	Trees	6	High
🟡 T3	Sliding Window	4	High
🟢 T4	DP	5	Medium
🔵 T5	HashMap / Heap / BS	6	Medium
🟣 T6	Strings	3	Lower
	Total	32

DIMINISHING RETURNS

Going from 0 to 20 problems is massive. Going from 20 to 32 is incremental. If you are running out of time, stop at Tier 4 and spend the remaining hours doing timed mock rounds in a plain text editor instead.

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Interview Day at a Glance

INTERVIEW FORMAT

Your rounds: 2 coding rounds, 45 min each, in a plain text editor (no code execution). Start with brute force, optimize, dry-run your code, communicate constantly.

Time allocation per 45-minute round

Phase	Time	What to Do
Clarify	2-3 min	Restate the problem, confirm inputs/outputs, ask about edge cases
Brute Force	1 min	State the naive approach and its complexity
Optimal Approach	3-5 min	Explain your optimized solution before writing any code
Code	15-20 min	Write clean, well-named code in a plain text editor
Dry Run	3-5 min	Walk through an example step by step -- do this without being asked
Complexity	1 min	State time and space complexity
Follow-up	Remaining	Handle extensions or optimizations

Communication phrases that work

"This looks like a [pattern] problem because..."

"The brute force would be O(n^2), but we can optimize with..."

"Let me verify with a quick dry run..."

"The trade-off here is memory vs time -- I'll go with..."

MAX 1 HINT

Needing more than 1 hint from your interviewer pushes you toward "Lean Hire" or worse. If you are stuck, talk through your thought process out loud rather than sitting in silence.

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Tips from Candidates Who Got Offers

1. Start with brute force -- One candidate was explicitly told: "start brute force before diving into optimal."

2. Dry-run your code -- A candidate received a "Hire" rating despite having a bug, because they caught it during their dry run.

3. Never go silent -- Communicate even when stuck: "I'm considering whether BFS or DFS fits better here because..."

4. Write production-ready code -- The grading criteria is tight. The expectation is production-ready code that handles every corner case.

5. You cannot run your code -- Practice writing correct solutions in a plain text editor. Syntax errors in a plain text editor look bad.

YOU GOT THIS

32 problems. 6 tiers. A clear plan. You are more prepared than most candidates who spend months grinding random problems. Focus beats volume. Now go start with Graphs.