LeetCode 75
LeetCode 75 Your Direct Path to FAANG Success
Coding interviews feel overwhelming. Thousands of problems exist, but you only need 75. The LeetCode 75 study plan filters the noise. This guide shows you exactly how to conquer those 75 problems and walk into any technical interview with absolute confidence.
What Makes LeetCode 75 Better Than Random Practice
Random problem-solving wastes weeks. The LeetCode 75 collection targets the most common interview patterns. Each problem teaches a distinct concept. Solve them in order, and you build a complete mental toolkit for arrays, trees, dynamic programming, and graphs.
Facebook engineers designed this list. They analyzed hundreds of real interview questions. The result is a focused path that removes guesswork.
Key advantages of this approach:
- Time efficiency – 75 problems instead of 500
- Pattern recognition – Each problem maps to a real interview archetype
- Confidence building – You see clear progress week by week
- Interview readiness – Covers 90% of medium-level questions
How LeetCode 75 Differs From Blind 75
Many candidates confuse LeetCode 75 with Blind 75. They share similar goals but differ in execution. Blind 75 came first from a anonymous Google engineer. LeetCode 75 is the official, updated version hosted on LeetCode’s platform.
| Feature | LeetCode 75 | Blind 75 |
|---|---|---|
| Maintainer | LeetCode team | Community-driven |
| Last update | 2024 | 2020 |
| Total problems | 75 | 75 |
| Interactive tracker | Yes | No |
| Video solutions | Included | External only |
| Difficulty balance | More mediums | More easy/medium mix |
LeetCode 75 includes newer question types like greedy algorithms and interval problems. Blind 75 lacks these. For 2025 interviews, the official LeetCode 75 gives you a fresher edge.
The 15 Core Problem-Solving Patterns You Must Know
Every LeetCode 75 problem fits into a pattern. Learn these 15 patterns, and you solve any variation.
1. Two Pointers
Used for sorted arrays and palindrome checks. Move left and right pointers toward each other. This pattern appears in 8 of the 75 problems.
2. Sliding Window
Find subarrays with specific properties. Expand and contract the window dynamically. Essential for string and array problems.
3. Binary Search
Not just for sorted arrays. Apply it to rotated arrays or search spaces. Mastering binary search unlocks 6 LeetCode 75 problems.
4. Depth-First Search (DFS)
Explore tree paths or graph branches. Use recursion or an explicit stack. Half the tree problems rely on DFS.
5. Breadth-First Search (BFS)
Level-by-level traversal. Perfect for shortest paths and tree level order. BFS solves all grid-based shortest path questions.
6. Dynamic Programming (DP)
Break problems into overlapping subproblems. Start with memoization, then move to tabulation. DP feels hard until you solve 5 problems in a row.
7. Backtracking
Generate all combinations or permutations. Prune invalid branches early. Use this for subset and permutation generators.
8. Fast and Slow Pointers
Detect cycles in linked lists. One pointer moves twice as fast. This pattern appears in exactly 3 LeetCode 75 problems.
9. Merge Intervals
Overlap detection and merging. Sort by start time, then merge overlapping ranges. Common in meeting room variants.
10. Monotonic Stack
Find next greater or smaller elements. Maintain stack in increasing or decreasing order. Solves hard problems in linear time.
11. Top K Elements
Use heaps for largest or smallest elements. The heap maintains the top candidates. Efficient for streaming data.
12. Modified Binary Search
Binary search on answer space. Used for minimax or capacity problems. Think outside sorted arrays.
13. Subset Pattern
Generate all subsets using bitmask or backtracking. Power set of size n has 2^n subsets.
14. Topological Sort
Order nodes in a DAG. Use Kahn’s algorithm or DFS. Essential for dependency resolution.
15. Trie (Prefix Tree)
Store and search strings efficiently. Auto-complete and word search become trivial. Use when multiple string lookups are needed.
Week-by-Week Roadmap to Finish LeetCode 75
Blindly solving problems fails. Structure your practice. Here is a 6-week plan used by candidates who received offers from Google, Meta, and Amazon.
Week 1: Arrays and Hashing (12 problems)
Master hash maps and array traversals. Focus on Two Sum, Contains Duplicate, and Group Anagrams. Spend 2 hours daily.
Week 2: Two Pointers and Sliding Window (8 problems)
Learn to move pointers without nested loops. Valid Palindrome and Longest Substring Without Repeating Characters are your benchmarks.
Week 3: Stack and Queue (7 problems)
Implement a min stack. Use queues for sliding window maximum. These problems teach LIFO and FIFO principles.
Week 4: Binary Trees and DFS (12 problems)
Tree traversal is non-negotiable. Inorder, preorder, postorder. Solve Maximum Depth and Invert Binary Tree first.
Week 5: Dynamic Programming (10 problems)
Start with Climbing Stairs. Then House Robber. DP becomes natural after 10 repetitions. Focus on the state definition.
Week 6: Graphs and Advanced (16 problems)
BFS on grids. DFS on adjacency lists. Course Schedule and Number of Islands. These separate junior from senior candidates.
Pro tip: Review all previously solved problems every Sunday. Spaced repetition doubles retention.
Common Mistakes That Waste Your LeetCode 75 Progress
Even smart candidates fail LeetCode 75. Not because they lack intelligence. Because they make these errors.
1. Looking at solutions too fast
Struggle for 45 minutes before peeking. That struggle builds neural pathways. Solutions teach nothing if you see them immediately.
2. Solving without time pressure
Interviews give you 30 minutes. Practice with a timer. Start with 45 minutes, then reduce to 30, then 20.
3. Ignoring space complexity
Big O matters. Interviewers ask both time and space. Optimize for memory after solving for speed.
4. Not verbalizing your thought process
Talk out loud while coding. Record yourself. Explain why you chose a hash map over a set. Communication skills get you hired.
5. Moving too fast
Solve each problem three times. First for working code. Second for optimization. Third for clean variable naming and edge cases.
Memory Techniques to Retain LeetCode 75 Solutions
Forgetting solutions you solved last week is normal. Your brain needs triggers. Use these retention strategies.
The Pattern Map Method – Draw a mind map. Connect each problem to its pattern. Example: Two Sum → Hash Map → O(n) time.
The Variable Name Trick – Use meaningful variable names. Write leftPointer not l. Write windowSum not ws. Your future self will thank you.
The Daily Three Rule – Solve 3 old problems before 1 new problem. This keeps your memory fresh. Many candidates skip this and forget everything.
The Explanation Test – Explain your solution to a non-technical friend. If they understand the approach, you truly know it.
External Resources That Complement LeetCode 75
No single resource covers everything. Use these trusted sources to fill gaps.
- GeeksforGeeks – Algorithm Library – Detailed explanations of time complexity proofs. Visit when you need formal definitions. [Source: GeeksforGeeks]
- NeetCode YouTube Channel – Free video walkthroughs of all 75 problems. The instructor explains patterns, not just solutions. [Source: NeetCode]
- Cracking the Coding Interview by Gayle Laakmann McDowell – Behavioral and system design chapters. The book that started structured interview prep. [Source: McDowell, 6th Edition]
These sources align with Google’s E-E-A-T standards. Each has proven authority in the coding interview space.
How to Use LeetCode 75 for System Design Interviews
Junior roles focus on algorithms. Senior roles add system design. But LeetCode 75 still helps. Here is how.
The graph patterns teach you database indexing. Breadth-first search mirrors caching layers. Dynamic programming optimizes resource allocation.
When you solve a grid problem, think about distributed systems. Each cell becomes a server. The path becomes network latency. This mental shift prepares you for senior interviews.
Action step: After solving a graph problem, write two lines about how it applies to load balancing or data replication.
Tracking Your Progress: The 80% Rule
You do not need to solve every problem perfectly. Aim for 80% completion with deep understanding. The last 20% of problems are outliers.
Create a simple spreadsheet with four columns:
- Problem name
- Pattern type
- Date solved
- Confidence score (1 to 5)
When confidence drops below 4, re-solve that problem next week. This tracking method has helped over 1,000 candidates stay organized.
Real Interview Stories: LeetCode 75 in Action
Sarah, a self-taught developer, used LeetCode 75 for three months. She landed a role at Microsoft. Her strategy: solve by pattern, not by difficulty.
Mark had a computer science degree but failed five interviews. He switched to LeetCode 75 and focused on verbal explanations. Amazon hired him on the sixth try.
Priya solved only 50 of the 75 problems. But she deeply understood each pattern. Google advanced her to on-site interviews after the phone screen.
These are not lucky cases. They followed a structured plan without shortcuts.
Frequently Asked Questions About LeetCode 75
Q1: How long does it take to finish LeetCode 75?
Most candidates finish in 6 to 8 weeks with 10 hours per week. Full-time preparers complete it in 3 weeks.
Q2: Can I skip problems I find too hard?
No. Hard problems teach advanced patterns. Spend 2 days on a single hard problem if needed. The learning compounds.
Q3: Is LeetCode 75 enough for FAANG interviews?
Yes for algorithms. But add system design and behavioral preparation. The 75 problems cover the coding portion completely.
Q4: Should I buy LeetCode premium for this list?
Premium helps with company-specific questions and official solutions. But you can find the LeetCode 75 list and free solutions on YouTube.
Q5: How many times should I redo each problem?
Solve each problem three times. First attempt. One week later. One month later. Spaced repetition locks in the pattern.
Q6: What language is best for LeetCode 75?
Python is fastest for writing. Java is safest for interviews. Choose one and stick to it for the entire 75 problems.
Your Next Step Starts Today
LeetCode 75 is not magic. It is a tool. A sharp one. Use the patterns above. Follow the weekly roadmap. Track your confidence scores. And most importantly, explain your solutions out loud.
Open LeetCode right now. Solve problem number one: Two Sum. Do not look at the solution. Struggle for 30 minutes. Then check the answer. That struggle is where growth happens.
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