Learning Roadmap
A structured path from beginner to interview-ready. Each topic links directly to filtered problems.
Most common interview topic. Learn the mental model of indexing and iteration.
Turn O(n²) brute force into O(n) with a map. Critical pattern.
Substring, reversal, and pattern matching — appears in ~30% of problems.
Builds the modular arithmetic and base conversion intuition you'll need.
- –Read the problem twice before touching code
- –Always clarify constraints (negative numbers? duplicates? sorted?)
- –Brute force first — then optimize
- –Write test cases before coding
Reduce nested loops. Essential for sorted array and palindrome problems.
Optimal for subarray/substring problems. Learn fixed vs variable window.
Goes beyond sorted arrays — learn to binary search on the answer space.
Pointer manipulation and the classic fast/slow pointer trick.
Monotonic stack pattern unlocks dozens of problems instantly.
Tree traversal is the foundation of graph algorithms and recursion.
Learn the decision tree model — essential for combinations/permutations.
- –After solving, look at the 'most votes' discussion solution
- –Re-solve problems you struggled with 3 days later
- –For trees: always think about what info each node needs to return
- –Draw out examples on paper — don't start with code
The hardest and most important topic. Start with 1D, then 2D, then intervals.
Matrix traversal, connected components, topological sort.
Top-K patterns, median of stream, scheduling problems.
Recognize when local optimal = global optimal. Hard to learn, easy to apply.
Prefix matching, autocomplete, word search — fast string lookup structure.
Connected components and cycle detection in one elegant structure.
- –For DP: define the state clearly before writing recurrence
- –For graphs: always track visited nodes to avoid infinite loops
- –Practice explaining your approach out loud (mock interview habit)
- –Time yourself — aim for 25 mins per Medium problem
XOR tricks, bit masking — comes up in FAANG interviews.
Range query problems — advanced but impressive.
Next greater element, histogram problems, stock spans.
Knapsack variants, bitmask DP, digit DP — for senior roles.
- –Do 2–3 mock interviews per week on Pramp or with friends
- –Review your notes on each problem after finishing it
- –Focus on the companies you're targeting (check their Blind posts)
- –Don't chase a perfect streak — consistency beats perfection
Study Strategies
Stop trying to memorize solutions. Instead, learn to map problem characteristics to patterns: sorted array → binary search or two pointers; subarray/substring → sliding window; tree/graph traversal → DFS/BFS; optimize a value → DP or greedy. With ~15 core patterns, you can tackle 90% of problems.
Don't grind 2000+ random problems. The Neetcode 150 (subset of Blind 75 + extras) covers every core pattern with the most representative problems. Quality over quantity — solve 150 problems deeply rather than 500 problems shallowly.
Spend max 25 minutes on a problem. If you're stuck, look at the hint or solution. Understand it completely, implement it yourself without looking, then come back and re-solve it from scratch in 3 days. Struggling past 25 minutes has diminishing returns.
Use the review system in this app. After solving a problem, rate it Hard/Good/Easy. The SM-2 algorithm schedules re-reviews at optimal intervals. This is how you retain what you learn instead of forgetting it within a week.
Practice narrating your thought process as you code. Interviewers care about how you think, not just whether you get the answer. Say things like 'I'm noticing the array is sorted, so I could use binary search...' — it shows analytical thinking even when you're stuck.
Pass 1: understand the problem and draw examples. Pass 2: think of the brute force approach and its complexity. Pass 3: optimize by identifying the bottleneck. Never skip to Pass 3 — the brute force pass often reveals the pattern.