Curated List
Essential 75 — Highest-Frequency LeetCode Problems 2026
The 75 highest-frequency coding interview problems, curated from our full catalog and organized by pattern. If you only have time for one list, make it this one.
✓ Solutions Available
Python • JS • Java • C++
Practice Mode Enabled
17
Easy
51
Medium
7
Hard
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Sliding Window 2 problems
| Problem | Difficulty | Solution | Link | |
|---|---|---|---|---|
| Longest Substring Without Repeating Characters
#String
#Hash Map
#Sliding Window | Medium | Solution | ||
| Minimum Window Substring
#String
#Hash Map
#Sliding Window | Hard | Solution |
Two Pointers 8 problems
| Problem | Difficulty | Solution | Link | |
|---|---|---|---|---|
| Two Sum II - Input Array Is Sorted
#Array
#Two Pointers
#Binary Search | Medium | Solution | ||
| 3Sum
#Array
#Two Pointers
#Sorting | Medium | Solution | ||
| Container With Most Water
#Array
#Two Pointers
#Greedy | Medium | Solution | ||
| Trapping Rain Water
#Array
#Two Pointers
#Stack | Hard | Solution | ||
| Valid Palindrome
#String
#Two Pointers | Easy | Solution | ||
| Remove Duplicates from Sorted Array
#Array
#Two Pointers | Easy | Solution | ||
| Sort Colors
#Array
#Sorting
#Two Pointers | Medium | Solution | ||
| Squares of a Sorted Array
#Array
#Two Pointers
#Sorting | Easy | Solution |
Binary Search 6 problems
| Problem | Difficulty | Solution | Link | |
|---|---|---|---|---|
| Binary Search
#Array
#Binary Search | Easy | Solution | ||
| Search in Rotated Sorted Array
#Array
#Binary Search | Medium | Solution | ||
| Find Minimum in Rotated Sorted Array
#Array
#Binary Search | Medium | Solution | ||
| Search a 2D Matrix
#Array
#Binary Search
#Matrix | Medium | Solution | ||
| Capacity to Ship Packages Within D Days
#Array
#Binary Search | Medium | Solution | ||
| Median of Two Sorted Arrays
#Array
#Binary Search
#Divide and Conquer | Hard | Solution |
Prefix Sum 2 problems
| Problem | Difficulty | Solution | Link | |
|---|---|---|---|---|
| Subarray Sum Equals K
#Array
#Hash Map
#Prefix Sum | Medium | Solution | ||
| Product of Array Except Self
#Array
#Prefix Product | Medium | Solution |
Hash Map / Set 7 problems
| Problem | Difficulty | Solution | Link | |
|---|---|---|---|---|
| Two Sum
#Array
#Hash Map | Easy | Solution | ||
| Group Anagrams
#String
#Hash Map
#Sorting | Medium | Solution | ||
| Top K Frequent Elements
#Array
#Hash Map
#Heap | Medium | Solution | ||
| Valid Anagram
#String
#Hash Map
#Sorting | Easy | Solution | ||
| Longest Consecutive Sequence
#Array
#Hash Set | Medium | Solution | ||
| Contains Duplicate
#Array
#Hash Table
#Sorting | Easy | Solution | ||
| LRU Cache
#Hash Table
#Linked List
#Design | Medium | Solution |
Stack 3 problems
| Problem | Difficulty | Solution | Link | |
|---|---|---|---|---|
| Valid Parentheses
#String
#Stack | Easy | Solution | ||
| Min Stack
#Stack
#Design | Medium | Solution | ||
| Daily Temperatures
#Array
#Stack
#Monotonic Stack | Medium | Solution |
Queue / BFS 4 problems
| Problem | Difficulty | Solution | Link | |
|---|---|---|---|---|
| Number of Islands
#Array
#DFS
#BFS | Medium | Solution | ||
| Rotting Oranges
#Array
#BFS
#Matrix | Medium | Solution | ||
| Binary Tree Level Order Traversal
#Tree
#BFS | Medium | Solution | ||
| 01 Matrix
#Array
#BFS
#Matrix | Medium | Solution |
Heap / Priority Queue 4 problems
| Problem | Difficulty | Solution | Link | |
|---|---|---|---|---|
| Kth Largest Element in an Array
#Array
#Heap
#Sorting | Medium | Solution | ||
| Find Median from Data Stream
#Two Heaps
#Design
#Sorting | Hard | Solution | ||
| Merge K Sorted Lists
#Linked List
#Heap
#Divide and Conquer | Hard | Solution | ||
| K Closest Points to Origin
#Array
#Math
#Divide and Conquer | Medium | Solution |
Linked List 6 problems
| Problem | Difficulty | Solution | Link | |
|---|---|---|---|---|
| Reverse Linked List
#Linked List
#Recursion | Easy | Solution | ||
| Linked List Cycle
#Linked List
#Two Pointers
#Hash Table | Easy | Solution | ||
| Merge Two Sorted Lists
#Linked List
#Recursion | Easy | Solution | ||
| Add Two Numbers
#Linked List
#Math
#Recursion | Medium | Solution | ||
| Remove Nth Node From End of List
#Linked List
#Two Pointers | Medium | Solution | ||
| Copy List with Random Pointer
#Hash Table
#Linked List | Medium | Solution |
Trees / DFS 5 problems
| Problem | Difficulty | Solution | Link | |
|---|---|---|---|---|
| Invert Binary Tree
#Tree
#DFS
#BFS | Easy | Solution | ||
| Maximum Depth of Binary Tree
#Tree
#DFS
#BFS | Easy | Solution | ||
| Validate Binary Search Tree
#Tree
#DFS
#BST | Medium | Solution | ||
| Lowest Common Ancestor of a BST
#Tree
#DFS
#BST | Medium | Solution | ||
| Binary Tree Maximum Path Sum
#Tree
#DFS
#DP | Hard | Solution |
Graphs 1 problems
| Problem | Difficulty | Solution | Link | |
|---|---|---|---|---|
| Clone Graph
#Graph
#DFS
#BFS | Medium | Solution |
Dynamic Programming 9 problems
| Problem | Difficulty | Solution | Link | |
|---|---|---|---|---|
| Climbing Stairs
#DP
#Math
#Memoization | Easy | Solution | ||
| House Robber
#Array
#DP | Medium | Solution | ||
| Coin Change
#Array
#DP
#BFS | Medium | Solution | ||
| Longest Increasing Subsequence
#Array
#DP
#Binary Search | Medium | Solution | ||
| Longest Common Subsequence
#String
#DP | Medium | Solution | ||
| Word Break
#String
#DP
#Hash Set | Medium | Solution | ||
| Unique Paths
#Math
#DP
#Combinatorics | Medium | Solution | ||
| Maximum Subarray
#Array
#DP
#Divide and Conquer | Medium | Solution | ||
| Decode Ways
#String
#DP | Medium | Solution |
Greedy 2 problems
| Problem | Difficulty | Solution | Link | |
|---|---|---|---|---|
| Jump Game
#Array
#Greedy
#DP | Medium | Solution | ||
| Jump Game II
#Array
#Greedy
#DP | Medium | Solution |
Backtracking 4 problems
| Problem | Difficulty | Solution | Link | |
|---|---|---|---|---|
| Permutations
#Array
#Backtracking | Medium | Solution | ||
| Subsets
#Array
#Backtracking
#Bit Manipulation | Medium | Solution | ||
| Combination Sum
#Array
#Backtracking | Medium | Solution | ||
| Word Search
#Array
#Matrix
#Backtracking | Medium | Solution |
Trie 1 problems
| Problem | Difficulty | Solution | Link | |
|---|---|---|---|---|
| Implement Trie (Prefix Tree)
#Design
#Trie | Medium | Solution |
Monotonic Stack 1 problems
| Problem | Difficulty | Solution | Link | |
|---|---|---|---|---|
| Largest Rectangle in Histogram
#Array
#Stack
#Monotonic Stack | Hard | Solution |
Topological Sort 2 problems
| Problem | Difficulty | Solution | Link | |
|---|---|---|---|---|
| Course Schedule
#Graph
#DFS
#BFS | Medium | Solution | ||
| Course Schedule II
#Graph
#DFS
#BFS | Medium | Solution |
Bit Manipulation 3 problems
| Problem | Difficulty | Solution | Link | |
|---|---|---|---|---|
| Single Number
#Array
#Bit Manipulation | Easy | Solution | ||
| Missing Number
#Array
#Math
#Bit Manipulation | Easy | Solution | ||
| Counting Bits
#DP
#Bit Manipulation | Easy | Solution |
Intervals 2 problems
| Problem | Difficulty | Solution | Link | |
|---|---|---|---|---|
| Merge Intervals
#Array
#Sorting | Medium | Solution | ||
| Insert Interval
#Array | Medium | Solution |
Matrix 3 problems
| Problem | Difficulty | Solution | Link | |
|---|---|---|---|---|
| Rotate Image
#Array
#Matrix
#Math | Medium | Solution | ||
| Spiral Matrix
#Array
#Matrix
#Simulation | Medium | Solution | ||
| Set Matrix Zeroes
#Array
#Matrix | Medium | Solution |
Want more problems?
The full catalog has 321+ problems with pattern filters, difficulty filters, and company tags.
Essential 75 vs. Blind 75 — What's the difference?
Essential 75
- • Filtered by interview frequency from 200+ real problems
- • Organized by coding pattern (Sliding Window, Two Pointers…)
- • Teaches you to recognize pattern types on sight
- • Best for pattern-first learners and structured prep
Blind 75
- • Original list curated on Blind by an ex-Facebook engineer
- • Organized by data structure (Array, Graph, DP…)
- • The industry-standard reference — broadly cited in FAANG prep
- • Good complement once you've built your pattern intuition
Start here for a structured, pattern-based approach. Then cross-check your coverage against the Blind 75 to make sure you haven't missed anything.