01 · OPEN A PROBLEM
A tab appears on the page
When there’s a lesson for the problem you’re on, a small “Interactive lesson” tab shows at the edge of the page. One click opens the panel.
CHROME EXTENSION · FREE TO INSTALL
Stuck on a LeetCode problem? Learn the idea right next to it.
An interactive lesson opens in Chrome’s side panel, beside the problem you’re on. Short screens, pictures you can tap and one small question at a time, in the language you code in.
✓ All of Blind 75 and NeetCode 150✓ 3 lessons free, no account✓ 11 languages
HOW IT WORKS.
Understand it.
Then write it.
A lesson doesn’t hand you the code. It gets you to the idea with small examples, so the solution you write on LeetCode is your own.
02 · LEARN THE IDEA
One question per screen
Tap the picture, type a number or pick an answer. Each one is checked right away, and a wrong answer tells you why.
03 · IN YOUR LANGUAGE
It follows the editor
Choose C++ on LeetCode and the lesson’s code is C++. Python, JavaScript, Java, C#, TypeScript, Go, Kotlin, Scala, Swift and Rust too.
WHAT’S COVERED.
213 problems,
and counting.
Every problem of Blind 75 and NeetCode 150 has a lesson, plus the classics around them. Many have a lesson per approach, from brute force to the best one. Each name opens its lesson on AlgoCademy.
Loops - Challenges
Helper Functions
Two Pointers
Hash Table
Sliding Window
Bit Manipulation
Binary Search
- Kth Largest Element in an Array
- Search Insert Position
- Find First and Last Position of Element in Sorted Array
- Search a 2D Matrix
- Find Peak Element
- Minimum Time to Complete Trips
- Koko Eating Bananas
- Search in Rotated Sorted Array
- Find Minimum in Rotated Sorted Array
- Median of Two Sorted Arrays
- Time Based Key-Value Store
Partial Sums #1
Partial Sums #2
Matrix
Recursion
Divide And Conquer
Greedy
Backtracking
Linked Lists
- Reverse Linked List
- Remove Linked List Elements
- Remove Nth Node From End of List
- Remove Duplicates from Sorted List II
- Linked List Cycle
- Find the Duplicate Number
- Palindrome Linked List
- Intersection of Two Linked Lists
- Add Two Numbers
- Copy List with Random Pointer
- Merge Two Sorted Lists
- Reorder List
- Reverse Nodes in k-Group
- Merge k Sorted Lists
Heap
Stack
Binary Trees
- Binary Tree Postorder Traversal
- Binary Tree Zigzag Level Order Traversal
- Symmetric Tree
- Lowest Common Ancestor of a Binary Search Tree
- Diameter of Binary Tree
- Binary Tree Maximum Path Sum
- Kth Smallest Element in a BST
- Validate Binary Search Tree
- Count Good Nodes in Binary Tree
- Maximum Sum BST in Binary Tree
- Maximum Depth of Binary Tree
- Balanced Binary Tree
- Invert Binary Tree
- Same Tree
- Subtree of Another Tree
- Recover a Tree From Preorder Traversal
- Construct Binary Tree from Preorder and Inorder Traversal
- Serialize and Deserialize Binary Tree
- Binary Tree Inorder Traversal
- Binary Tree Level Order Traversal
- Binary Tree Right Side View
- Flatten Binary Tree to Linked List
- Convert Sorted Array to Binary Search Tree
Tries
Dynamic Programming
- Trapping Rain Water
- Unique Paths
- Climbing Stairs
- Min Cost Climbing Stairs
- House Robber
- House Robber II
- Decode Ways
- Maximum Product Subarray
- Best Time to Buy and Sell Stock with Cooldown
- Coin Change
- Coin Change II
- Partition Equal Subset Sum
- Word Break
- Longest Common Subsequence
- Edit Distance
- Distinct Subsequences
- Regular Expression Matching
- Longest Increasing Subsequence
- Longest Palindromic Substring
- Burst Balloons
Intervals
Graphs
- Find if Path Exists in Graph
- Number of Islands
- Max Area of Island
- Number of Connected Components in an Undirected Graph
- Graph Valid Tree
- Redundant Connection
- 01 Matrix
- Rotting Oranges
- Walls and Gates
- Shortest Path with Alternating Colors
- Course Schedule
- Course Schedule II
- Alien Dictionary
- Reconstruct Itinerary
- Clone Graph
- Pacific Atlantic Water Flow
- Surrounded Regions
- Network Delay Time
- Cheapest Flights Within K Stops
- Swim in Rising Water
- Min Cost to Connect All Points
- Word Ladder
WHAT’S FREE.
Start without
an account.
Pick any three lessons and play them to the end. After that, the first three screens of every lesson stay free.
FREE
3lessons of your choice in full, then the first three screens of every other lessonPRO
213problems’ lessons, all of them, along with step-by-step coding practice for each on AlgoCademyPRO starts with a 7-day free trial.
See pricingIs it free?
Installing it is free. Three lessons of your choice play in full without an account, and the first three screens of every other lesson are free too. AlgoCademy PRO opens all of them, here and on AlgoCademy.
Which problems does it cover?
213 LeetCode problems so far: every problem of Blind 75 and NeetCode 150, and more. The list is below, and the panel has it too, with a search box.
Does it work in my language?
The lesson’s code follows the language you choose in LeetCode’s editor: Python, JavaScript, Java, C++, C#, TypeScript, Go, Kotlin, Scala, Swift or Rust. You can also change it in the panel.
Does it give me the solution?
No. A lesson builds the idea with small questions and pictures, then leaves the code to you. If you want to write it one checked step at a time, the panel links to the same problem on AlgoCademy.
What does it read on LeetCode?
Two things, and both stay in your browser: which problem you’re on, from the page’s address, and the language chosen in the editor. It never reads your code. AlgoCademy only receives the lesson you open.
Where does it work?
On leetcode.com, in Chrome on a computer (version 116 or newer). It is not for phones.
FREE TO INSTALL.
Next time you’re stuck,
open the lesson.
It takes a minute to add, and nothing to set up.