Stage 1 · Code
Mock Interviews & Strategy
Blind 75
The curated list of 75 LeetCode questions covering every essential pattern — not a magic formula, but a structured way to eliminate coverage gaps.
What Is the Blind 75
The Blind 75 is a community-curated list of 75 LeetCode problems compiled by a Meta engineer (Tej Swaroop) that covers the highest-frequency interview topics. It is not exhaustive and it is not magic — what makes it useful is its coverage breadth: every major pattern appears at least once, so running through it reveals your weak spots.
Blind 75 covers the same patterns as the full LeetCode 300 in roughly a quarter of the problems. The goal is breadth-first learning. After completing it once, you can circle back and deepen individual patterns with targeted practice.
How to Use It
- Pick a category — start with the one you're weakest at, not your strongest.
- Solve without looking — give each problem 20–30 minutes of genuine effort before peeking.
- One problem a day minimum — consistency compounds. 75 problems ÷ 1 per day = 2.5 months.
- Keep a log — after each problem write: pattern, recurrence, time/space complexity, one thing you missed.
- Rotate categories — don't do 20 Arrays in a row; mix it up to force your brain to pattern-switch.
- Revisit after a month — spaced repetition fixes the patterns in long-term memory.
Category Breakdown
Arrays & Hashing (9) and Trees (8) are the largest categories, followed by DP (7) and Graphs (7). This matches interview frequency — expect arrays and trees in nearly every phone screen.
| Category | Problem Count | Key Patterns |
|---|---|---|
| Array & Hashing | 9 | Two Sum variants, anagram grouping, frequency maps |
| Two Pointers | 3 | Container with most water, 3Sum, trapping rain water |
| Sliding Window | 4 | Longest substring, minimum window, anagram windows |
| Stack | 3 | Valid parentheses, min stack, daily temperatures |
| Binary Search | 4 | Rotated array, search range, find peak element |
| Linked List | 5 | Reverse, merge, cycle detection, remove nth from end |
| Trees | 8 | Traversals, max depth, LCA, serialise, level-order |
| Tries | 3 | Word search, prefix tree, word break |
| Heap / Priority Queue | 3 | K largest, merge k sorted, median from stream |
| Backtracking | 4 | Subsets, permutations, combination sum, N-Queens |
| Graphs | 7 | Islands, clone graph, course schedule, word ladder |
| Dynamic Programming | 7 | Climbing stairs, coin change, LIS, edit distance |
| Intervals | 3 | Merge, insert, non-overlapping intervals |
| Greedy | 3 | Jump game, gas station, task scheduler |
| Math & Bit Manipulation | 6 | Single number, count bits, reverse bits, missing number |
Checklist
Use the table below as a progress tracker. The problems are ordered by category, not difficulty — start wherever you need the most practice.
Open the LeetCode list page at https://leetcode.com/list/xi4ci4ig/ — you can mark problems as completed there and track your progress visually.
- Array: Two Sum, Best Time to Buy/Sell Stock, Product of Array Except Self, Maximum Subarray, Contains Duplicate
- Two Pointers: Container With Most Water, 3Sum
- Sliding Window: Longest Substring Without Repeating Characters, Longest Repeating Character Replacement, Minimum Window Substring
- Stack: Valid Parentheses
- Binary Search: Search in Rotated Sorted Array, Find Minimum in Rotated Sorted Array
- Linked List: Reverse Linked List, Merge Two Sorted Lists, Linked List Cycle, Remove Nth Node, Reorder List
- Tree: Max Depth, Invert Tree, Same Tree, Subtree of Another Tree, LCA, Level Order, Serialise/Deserialise, Validate BST
- DP: Climbing Stairs, Coin Change, Longest Increasing Subsequence, Longest Common Subsequence, Word Break, Combination Sum IV, House Robber
- Graph: Number of Islands, Clone Graph, Course Schedule, Pacific Atlantic, Longest Consecutive Sequence, Alien Dictionary, Graph Valid Tree
- Backtracking: Subsets, Permutations, Combination Sum, Word Search
- Greedy: Jump Game, Jump Game II, Gas Station
- Interval: Merge Intervals, Insert Interval, Non-overlapping Intervals
- Trie: Implement Trie, Word Search II
- Bit Manipulation: Single Number, Number of 1 Bits, Counting Bits, Reverse Bits, Missing Number
- Math: Reverse Integer, Plus One, Power of Three
Mark this lesson complete to store local progress and unlock a cleaner resume path the next time you visit.