Blind 75 LeetCode: The Complete Guide

The Blind 75 is a curated list of 75 LeetCode problems, originally posted on the Blind forum by a Facebook engineer, designed so that solving them teaches you essentially every pattern that shows up in coding interviews. It's the single highest-leverage list in interview prep: if your time is limited, drill these 75 and you'll recognize the structure of most real interview questions.

Below is the full list organized by pattern, a study method that beats grinding randomly, and an honest comparison with the larger NeetCode 150.

How to use this list

1. Go by pattern, not by number. Solve all the Arrays & Hashing problems together, then Two Pointers, and so on — you internalize the pattern faster in a batch than scattered.
2. Spaced repetition. Re-solve each problem a few days later from scratch. Recognition, not memorization, is the goal — you want to see a new problem and recall the pattern.
3. Time-box. Give a medium ~25 minutes; if you're stuck, read the solution, understand it, and re-solve it the next day. Staring for two hours teaches less than understanding and repeating.
4. Narrate. Say the approach and Big-O out loud as you code — that's the interview skill, and it's how our 15-patterns guide frames each one.

Arrays & Hashing

Problem	Difficulty	Pattern
Two Sum	Easy	Hash map
Contains Duplicate	Easy	Hash set
Valid Anagram	Easy	Counting
Group Anagrams	Medium	Hash map
Top K Frequent Elements	Medium	Heap / bucket
Product of Array Except Self	Medium	Prefix/suffix
Encode and Decode Strings	Medium	Design
Longest Consecutive Sequence	Medium	Hash set

Two Pointers

Problem	Difficulty	Pattern
Valid Palindrome	Easy	Two pointers
Two Sum II (sorted)	Medium	Two pointers
3Sum	Medium	Sort + two pointers
Container With Most Water	Medium	Two pointers

Sliding Window

Problem	Difficulty	Pattern
Best Time to Buy/Sell Stock	Easy	Sliding window
Longest Substring Without Repeating	Medium	Sliding window
Longest Repeating Char Replacement	Medium	Sliding window
Minimum Window Substring	Hard	Sliding window

Stack

Problem	Difficulty	Pattern
Valid Parentheses	Easy	Stack

Binary Search

Problem	Difficulty	Pattern
Search in Rotated Sorted Array	Medium	Binary search
Find Minimum in Rotated Sorted Array	Medium	Binary search

Linked List

Problem	Difficulty	Pattern
Reverse Linked List	Easy	Pointers
Merge Two Sorted Lists	Easy	Pointers
Reorder List	Medium	Two pointers
Remove Nth Node From End	Medium	Two pointers
Linked List Cycle	Easy	Fast/slow
Merge K Sorted Lists	Hard	Heap

Trees

Problem	Difficulty	Pattern
Invert Binary Tree	Easy	DFS
Maximum Depth of Binary Tree	Easy	DFS
Same Tree	Easy	DFS
Subtree of Another Tree	Easy	DFS
Lowest Common Ancestor (BST)	Medium	BST
Binary Tree Level Order Traversal	Medium	BFS
Validate BST	Medium	DFS
Kth Smallest in BST	Medium	Inorder
Construct Tree from Pre/Inorder	Medium	Recursion
Binary Tree Max Path Sum	Hard	DFS
Serialize/Deserialize Tree	Hard	BFS/DFS

Tries

Problem	Difficulty	Pattern
Implement Trie	Medium	Trie
Word Search II	Hard	Trie + backtracking

Heap / Priority Queue

Problem	Difficulty	Pattern
Find Median from Data Stream	Hard	Two heaps

Backtracking

Problem	Difficulty	Pattern
Combination Sum	Medium	Backtracking
Word Search	Medium	Backtracking

Graphs

Problem	Difficulty	Pattern
Number of Islands	Medium	BFS/DFS
Clone Graph	Medium	BFS/DFS
Pacific Atlantic Water Flow	Medium	DFS
Course Schedule	Medium	Topo sort
Number of Connected Components	Medium	Union-find
Graph Valid Tree	Medium	Union-find

Dynamic Programming

Problem	Difficulty	Pattern
Climbing Stairs	Easy	1-D DP
House Robber	Medium	1-D DP
House Robber II	Medium	1-D DP
Coin Change	Medium	Unbounded DP
Longest Increasing Subsequence	Medium	DP
Word Break	Medium	DP
Combination Sum IV	Medium	DP
Decode Ways	Medium	1-D DP
Unique Paths	Medium	2-D DP
Longest Common Subsequence	Medium	2-D DP

Intervals

Problem	Difficulty	Pattern
Insert Interval	Medium	Intervals
Merge Intervals	Medium	Sort + sweep
Non-overlapping Intervals	Medium	Greedy
Meeting Rooms II	Medium	Heap

FAQ

What is the Blind 75?

The Blind 75 is a curated list of 75 LeetCode problems, originally shared on the Blind forum, chosen so that solving them covers nearly every pattern asked in coding interviews. It's the highest-leverage list for limited prep time.

Is the Blind 75 enough to pass FAANG interviews?

For many candidates, yes - it teaches the core patterns. If you have more time, follow it with NeetCode 150 or company-tagged problems for extra coverage of harder variants, but the Blind 75 builds the foundation.

Blind 75 vs NeetCode 150 - which should I do?

Blind 75 is the efficient core; NeetCode 150 is a superset that adds ~75 more problems for deeper coverage and includes excellent video explanations. Start with Blind 75; graduate to NeetCode 150 if you have weeks rather than days.

How long does it take to finish the Blind 75?

At a sustainable pace of 5 problems a day with spaced re-solves, about 3-4 weeks. Cramming all 75 once in a week builds familiarity but not the recall that spaced repetition gives.

Should I solve the Blind 75 by number or by pattern?

By pattern. Solving all the sliding-window problems together, then all the DP problems, internalizes each pattern far faster than working through a random order.