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Learn Code
Introduction
Overview
Container With Most Water
Two Sum (Sorted Array)
3-Sum
Triangle Numbers
Move Zeroes
Sort Colors
Trapping Rain Water
Overview
Maximum Sum of Subarrays of Size K
Max Points You Can Obtain From Cards
Max Sum of Distinct Subarrays Length k
Overview
Longest Substring Without Repeating Characters
Longest Repeating Character Replacement
Overview
Can Attend Meetings
Insert Interval
Non-Overlapping Intervals
Merge Intervals
Employee Free Time
Overview
Valid Parentheses
Decode String
Longest Valid Parentheses
Monotonic Stack
Daily Temperatures
Largest Rectangle in Histogram
Overview
Linked List Cycle
Palindrome Linked List
Remove Nth Node From End of List
Reorder List
Swap Nodes in Pairs
Overview
Apple Harvest (Koko Eating Bananas)
Search in Rotated Sorted Array
Split Array Largest Sum
Kth Smallest Element in a Sorted Matrix
Minimum Shipping Capacity
Overview
Kth Largest Element in an Array
K Closest Points to Origin
Find K Closest Elements
Merge K Sorted Lists
Median from Data Stream
Introduction
Fundamentals
Return Values
Maximum Depth of Binary Tree
Path Sum
Passing Values Down and Helper Functions
Validate Binary Search Tree
Calculate Tilt
Diameter of a Binary Tree
Path Sum II
Longest Univalue Path
Graphs Overview
Adjacency List
Copy Graph
Graph Valid Tree
Matrices
Flood Fill
Number of Islands
Surrounded Regions
Pacific Atlantic Water Flow
Introduction
Overview
Level Order Sum
Rightmost Node
Zigzag Level Order
Maximum Width of Binary Tree
Graphs Overview
Minimum Knight Moves
Rotting Oranges
01-Matrix
Bus Routes
Overview
Word Search
Solution Space Trees
Subsets
Generate Parentheses
Combination Sum
Palindrome Partitioning
N-Queens
Overview
Course Schedule
Course Schedule II
Shortest Path Algorithms
Network Delay Time
Cheapest Flights Within K Stops
Path With Minimum Effort
Find City with Fewest Reachable
Fundamentals
Solving a Question with Dynamic Programming
Counting Bits
Decode Ways
Unique Paths
Maximal Square
Longest Increasing Subsequence
Word Break
Maximum Profit in Job Scheduling
Paint House
Paint House II
Minimum Window Subsequence
Overview
Best Time to Buy and Sell Stock
Gas Station
Jump Game
Jump Game II
Partition Labels
Overview
Implement Trie Methods
Prefix Matching
Overview
Count Vowels in Substrings
Subarray Sum Equals K
Spiral Matrix
Rotate Image
Set Matrix Zeroes
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Tutor

Learn DSA Through Visualizations

A visual guide to the most important patterns and approaches for the coding interview.


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This guide uses interactive visualizations to teach you the most important algorithm patterns for the coding interview.

Done
Problem / Lesson
Difficulty
Two Pointers (7 problems)

0%

Lesson

Container With Most Water

Medium

Two Sum (Sorted Array)

Medium

3-Sum

Medium

Triangle Numbers

Medium

Move Zeroes

Easy

Sort Colors

Medium

Trapping Rain Water

Hard
Sliding Window (5 problems)

0%

Lesson

Maximum Sum of Subarrays of Size K

Easy

Max Points You Can Obtain From Cards

Medium

Max Sum of Distinct Subarrays Length k

Medium

Longest Substring Without Repeating Characters

Medium

Longest Repeating Character Replacement

Medium
Intervals (5 problems)

0%

Lesson

Can Attend Meetings

Easy

Insert Interval

Medium

Non-Overlapping Intervals

Medium

Merge Intervals

Medium

Employee Free Time

Hard
Stack (5 problems)

0%

Lesson

Valid Parentheses

Easy

Decode String

Medium

Longest Valid Parentheses

Hard

Daily Temperatures

Medium

Largest Rectangle in Histogram

Hard
Linked List (5 problems)

0%

Lesson

Linked List Cycle

Easy

Palindrome Linked List

Easy

Remove Nth Node From End of List

Medium

Reorder List

Medium

Swap Nodes in Pairs

Medium
Binary Search (2 problems)

0%

Lesson

Apple Harvest (Koko Eating Bananas)

Medium

Search in Rotated Sorted Array

Medium
Heap (4 problems)

0%

Lesson

Kth Largest Element in an Array

Medium

K Closest Points to Origin

Medium

Find K Closest Elements

Medium

Merge K Sorted Lists

Hard
Depth-First Search (13 problems)

0%

Lesson

Maximum Depth of Binary Tree

Easy

Path Sum

Easy

Validate Binary Search Tree

Medium

Calculate Tilt

Easy

Diameter of a Binary Tree

Easy

Path Sum II

Medium

Longest Univalue Path

Medium

Copy Graph

Easy

Graph Valid Tree

Medium

Flood Fill

Easy

Number of Islands

Medium

Surrounded Regions

Medium

Pacific Atlantic Water Flow

Medium
Breadth-First Search (8 problems)

0%

Lesson

Level Order Sum

Easy

Rightmost Node

Medium

Zigzag Level Order

Medium

Maximum Width of Binary Tree

Medium

Minimum Knight Moves

Medium

Rotting Oranges

Medium

01-Matrix

Medium

Bus Routes

Hard
Backtracking (4 problems)

0%

Lesson

Word Search

Medium

Subsets

Medium

Generate Parentheses

Medium

Combination Sum

Medium
Graphs (2 problems)

0%

Lesson

Course Schedule

Medium

Course Schedule II

Medium
Dynamic Programming (7 problems)

0%

Lesson

Counting Bits

Easy

Decode Ways

Medium

Unique Paths

Medium

Maximal Square

Medium

Longest Increasing Subsequence

Medium

Word Break

Medium

Maximum Profit in Job Scheduling

Medium
Greedy Algorithms (3 problems)

0%

Lesson

Best Time to Buy and Sell Stock

Easy

Gas Station

Medium

Jump Game

Medium
Trie (2 problems)

0%

Lesson

Implement Trie Methods

Medium

Prefix Matching

Medium
Prefix Sum (2 problems)

0%

Lesson

Count Vowels in Substrings

Medium

Subarray Sum Equals K

Medium
Matrices (3 problems)

0%

Lesson

Spiral Matrix

Medium

Rotate Image

Medium

Set Matrix Zeroes

Medium
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