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Amazon Master DSA Sheet

This compilation contains exclusive, previously asked data structure and algorithm questions from real Amazon interviews. Focus on these core problem patterns to confidently tackle even the hardest interview challenges.

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0
1938
Kth Smallest Element in a Sorted Matrix
Medium
Find Servers That Handled Most Number of Requests
Hard
Dota2 Senate
Medium
Minimum Additions to Make Valid String
Medium
Double Modular Exponentiation
Medium
Inorder Successor in BST
Medium
Subarray Product Less Than K6 Months
Medium
Word Ladder II6 Months
Hard
N-Queens II6 Months
Hard
Knight Probability in Chessboard
Medium
Insert Delete GetRandom O(1) - Duplicates allowed6 Months
Hard
Minimum Penalty for a Shop3 Months
Medium
Maximize Area of Square Hole in Grid3 Months
Medium
Number of Connected Components in an Undirected Graph6 Months
Medium
Asteroid Collision30 Days
Medium
Grumpy Bookstore Owner
Medium
Active Users
Medium
Open the Lock30 Days
Medium
Snapshot Array6 Months
Medium
Validate IP Address
Medium
Find the Length of the Longest Common Prefix
Medium
Escape a Large Maze
Hard
Design HashMap6 Months
Easy
Permutation Sequence30 Days
Hard
K-th Smallest Prime Fraction
Medium
Majority Element II6 Months
Medium
String Compression II
Hard
Count Number of Ways to Place Houses6 Months
Medium
Divide an Array Into Subarrays With Minimum Cost II30 Days
Hard
Length of Longest V-Shaped Diagonal Segment6 Months
Hard
Jump Game II3 Months
Medium
Rotating the Box
Medium
Find the Closest Palindrome
Hard
Walking Robot Simulation
Medium
Difference Between Element Sum and Digit Sum of an Array
Easy
Longest Univalue Path
Medium
Reverse Prefix of Word
Easy
Minimized Maximum of Products Distributed to Any Store
Medium
Determine if Two Strings Are Close
Medium
Minimum Number of Steps to Make Two Strings Anagram
Medium
Minimum Score of a Path Between Two Cities
Medium
Sort Integers by The Number of 1 Bits
Easy
Count Good Triplets
Easy
Find Greatest Common Divisor of Array
Easy
Maximum XOR After Operations
Medium
Design A Leaderboard
Medium
Longest Subarray of 1's After Deleting One Element
Medium
Longest Happy String
Medium
Score After Flipping Matrix
Medium
Number of People Aware of a Secret6 Months
Medium
Furthest Building You Can Reach6 Months
Medium
Operations on Tree
Medium
Market Analysis I
Medium
Non-negative Integers without Consecutive Ones
Hard
Reverse Linked List3 Months
Easy
Design Tic-Tac-Toe6 Months
Medium
String Without AAA or BBB
Medium
Minimum Height Trees6 Months
Medium
Find a Peak Element II6 Months
Medium
Best Sightseeing Pair
Medium
Print Binary Tree
Medium
Distribute Elements Into Two Arrays I
Easy
Count Unguarded Cells in the Grid
Medium
Day of the Year
Easy
User Activity for the Past 30 Days I
Easy
Max Stack
Hard
Max Difference You Can Get From Changing an Integer
Medium
Longest Nice Subarray3 Months
Medium
Minimum ASCII Delete Sum for Two Strings
Medium
Minimum Number of Operations to Sort a Binary Tree by Level
Medium
Sort Matrix by Diagonals
Medium
Finding the Users Active Minutes
Medium
Reachable Nodes In Subdivided Graph
Hard
Minimum Operations to Make Array Equal
Medium
Special Array II
Medium
Most Beautiful Item for Each Query6 Months
Medium
Minimum Index Sum of Two Lists3 Months
Easy
Process Tasks Using Servers
Medium
Pseudo-Palindromic Paths in a Binary Tree
Medium
Partitioning Into Minimum Number Of Deci-Binary Numbers
Medium
Jump Game III
Medium
Maximum Side Length of a Square with Sum Less than or Equal to Threshold3 Months
Medium
Maximum Fruits Harvested After at Most K Steps
Hard
Minimum Subsequence in Non-Increasing Order
Easy
Game Play Analysis II
Easy
Minimum Difficulty of a Job Schedule
Hard
Shortest Uncommon Substring in an Array
Medium
Min Stack3 Months
Medium
Meeting Rooms II3 Months
Medium
Minimum Genetic Mutation
Medium
Product's Price for Each Store
Easy
Largest Magic Square3 Months
Medium
Minimize Maximum of Array
Medium
Maximum Tastiness of Candy Basket
Medium
Special Binary String
Hard
Paint House IV
Medium
Minimum Distance to the Target Element
Easy
Shortest Subarray With OR at Least K II
Medium
Count Operations to Obtain Zero6 Months
Easy
Number of Valid Subarrays
Hard
Valid Parentheses30 Days
Easy
Check If a Word Occurs As a Prefix of Any Word in a Sentence
Easy
Destination City
Easy
Find Followers Count3 Months
Easy
Range Addition II
Easy
Fruits Into Baskets II
Easy
Best Meeting Point
Hard
Minimum Moves to Reach Target Score
Medium
Second Highest Salary30 Days
Medium
Using a Robot to Print the Lexicographically Smallest String
Medium
Longest Substring Of All Vowels in Order
Medium
Design SQL
Medium
Maximum Length of Subarray With Positive Product
Medium
Minimum Value to Get Positive Step by Step Sum
Easy
Maximum Subarray Sum with One Deletion
Medium
Vowel Spellchecker6 Months
Medium
Spiral Matrix30 Days
Medium
Minimum Number of Swaps to Make the Binary String Alternating
Medium
Graph Valid Tree
Medium
Linked List in Binary Tree
Medium
Minimum Bit Flips to Convert Number
Easy
Count the Number of Arrays with K Matching Adjacent Elements
Hard
Top K Frequent Words3 Months
Medium
Brick Wall
Medium
Avoid Flood in The City6 Months
Medium
Minimum Deletions to Make String Balanced
Medium
Shortest Distance from All Buildings
Hard
Alternating Groups I
Easy
Letter Case Permutation
Medium
Find Resultant Array After Removing Anagrams
Easy
Delete Characters to Make Fancy String
Easy
Customer Placing the Largest Number of Orders
Easy
Convert Sorted List to Binary Search Tree
Medium
Monthly Transactions I3 Months
Medium
Special Array I
Easy
Find Closest Number to Zero
Easy
Count Visited Nodes in a Directed Graph
Hard
Maximum Number of Balloons
Easy
Invalid Tweets
Easy
Smallest Range Covering Elements from K Lists6 Months
Hard
Unique Binary Search Trees30 Days
Medium
Course Schedule III6 Months
Hard
Investments in 2016
Medium
Course Schedule II6 Months
Medium
Find Common Characters
Easy
Zigzag Conversion30 Days
Medium
Customer Who Visited but Did Not Make Any Transactions3 Months
Easy
Pacific Atlantic Water Flow6 Months
Medium
Trapping Rain Water30 Days
Hard
Subarray With Elements Greater Than Varying Threshold
Hard
Compare Version Numbers3 Months
Medium
Get Maximum in Generated Array
Easy
Unique Email Addresses
Easy
Remove Sub-Folders from the Filesystem
Medium
The Number of Employees Which Report to Each Employee6 Months
Easy
Two Out of Three
Easy
Shortest Word Distance
Easy
Sum of Perfect Square Ancestors6 Months
Hard
Number of Days Between Two Dates
Easy
Merge Intervals30 Days
Medium
Path Sum III
Medium
Product of Array Except Self3 Months
Medium
Sort the Students by Their Kth Score
Medium
Maximum Sum Circular Subarray
Medium
Koko Eating Bananas30 Days
Medium
Unique Morse Code Words3 Months
Easy
Count the Hidden Sequences
Medium
Find K Closest Elements3 Months
Medium
Minimum Number of Days to Make m Bouquets30 Days
Medium
Find Original Array From Doubled Array6 Months
Medium
Binary Number with Alternating Bits3 Months
Easy
Kth Smallest Element in a BST6 Months
Medium
Shopping Offers
Medium
Divide Intervals Into Minimum Number of Groups
Medium
Design Spreadsheet
Medium
Event Emitter
Medium
Climbing Stairs30 Days
Easy
Maximize Distance to Closest Person
Medium
Alien Dictionary30 Days
Hard
Non-decreasing Subsequences
Medium
Partition Array Into Two Arrays to Minimize Sum Difference6 Months
Hard
Encode and Decode Strings
Medium
Power of Four
Easy
Serialize and Deserialize Binary Tree3 Months
Hard
Maximum Number of Words You Can Type
Easy
Pow(x, n)3 Months
Medium
Minimum Number of Coins to be Added
Medium
Minimum Operations to Write the Letter Y on a Grid
Medium
Palindrome Pairs
Hard
Design HashSet
Easy
Design a Stack With Increment Operation3 Months
Medium
Find Maximum Value in a Constrained Sequence3 Months
Medium
Longest Substring Without Repeating Characters30 Days
Medium
3Sum With Multiplicity
Medium
Copy List with Random Pointer3 Months
Medium
All Nodes Distance K in Binary Tree3 Months
Medium
Maximum Depth of N-ary Tree
Easy
Transpose Matrix6 Months
Easy
Distribute Candies Among Children II
Medium
Maximum Product Subarray3 Months
Medium
Generate Parentheses30 Days
Medium
Monotone Increasing Digits
Medium
Two City Scheduling
Medium
Minimum Deletions to Make Character Frequencies Unique
Medium
Split Array Largest Sum30 Days
Hard
Next Permutation30 Days
Medium
Get Watched Videos by Your Friends
Medium
Invalid Transactions
Medium
Split BST
Medium
Maximize Greatness of an Array
Medium
Time Based Key-Value Store30 Days
Medium
Battleships in a Board30 Days
Medium
Number of Paths with Max Score
Hard
Movie Rating6 Months
Medium
Maximum Height by Stacking Cuboids
Hard
Count Subarrays With Score Less Than K
Hard
Minimum Distance Between BST Nodes
Easy
Building H2O
Medium
Clone Graph3 Months
Medium
Count Zero Request Servers6 Months
Medium
Construct Quad Tree
Medium
Find Numbers with Even Number of Digits
Easy
Find the Longest Balanced Substring of a Binary String
Easy
Managers with at Least 5 Direct Reports30 Days
Medium
Substring with Concatenation of All Words
Hard
Minimum Cost For Tickets
Medium
Finding Pairs With a Certain Sum
Medium
Maximum Depth of Binary Tree6 Months
Easy
Find Closest Node to Given Two Nodes
Medium
Optimal Account Balancing
Hard
Create Target Array in the Given Order
Easy
Maximum Distance in Arrays
Medium
Describe the Painting
Medium
Maximum Score of Non-overlapping Intervals
Hard
Baseball Game
Easy
Button with Longest Push Time
Easy
Count Salary Categories3 Months
Medium
Longest Harmonious Subsequence6 Months
Easy
Longest Palindromic Substring30 Days
Medium
Search Suggestions System6 Months
Medium
Binary Tree Paths
Easy
Maximum Product of Two Elements in an Array
Easy
Car Pooling
Medium
The Number of the Smallest Unoccupied Chair
Medium
Largest 1-Bordered Square
Medium
Two Sum IV - Input is a BST3 Months
Easy
K Closest Points to Origin6 Months
Medium
Verifying an Alien Dictionary
Easy
Longest String Chain6 Months
Medium
Diameter of Binary Tree3 Months
Easy
Minimum Cost to Move Chips to The Same Position
Easy
Painting the Walls
Hard
Nth Highest Salary6 Months
Medium
Count Vowel Strings in Ranges
Medium
Number of 1 Bits3 Months
Easy
Largest Number3 Months
Medium
Remove Boxes
Hard
The Number of Beautiful Subsets
Medium
Maximum Good Subarray Sum
Medium
Find the Distance Value Between Two Arrays
Easy
Minimum Non-Zero Product of the Array Elements
Medium
Minimum Number of K Consecutive Bit Flips
Hard
Rabbits in Forest
Medium
Swim in Rising Water6 Months
Hard
Design Excel Sum Formula6 Months
Hard
Longest Repeating Character Replacement30 Days
Medium
Longest Word in Dictionary
Medium
Valid Word
Easy
Longest Increasing Path in a Matrix3 Months
Hard
Regular Expression Matching6 Months
Hard
Capacity To Ship Packages Within D Days30 Days
Medium
Reverse Nodes in Even Length Groups
Medium
Basic Calculator III
Hard
Maximum Number of Visible Points
Hard
High-Access Employees
Medium
Remove All Occurrences of a Substring
Medium
Game of Life6 Months
Medium
First Unique Number
Medium
Check if All the Integers in a Range Are Covered
Easy
Wildcard Matching
Hard
Maximum Profit in Job Scheduling6 Months
Hard
Number of Ways to Form a Target String Given a Dictionary
Hard
Maximum Swap
Medium
Number of Visible People in a Queue
Hard
Count Nodes With the Highest Score
Medium
Number of Adjacent Elements With the Same Color
Medium
Count Elements With Maximum Frequency6 Months
Easy
My Calendar I
Medium
Longest Non-decreasing Subarray From Two Arrays
Medium
Exchange Seats3 Months
Medium
Unique Paths II3 Months
Medium
Maximum Length Substring With Two Occurrences
Easy
Minimum String Length After Removing Substrings
Easy
High Five
Easy
Minimum Reverse Operations
Hard
Count Ways To Build Good Strings
Medium
Collecting Chocolates
Medium
Average Time of Process per Machine3 Months
Easy
Make Lexicographically Smallest Array by Swapping Elements
Medium
Middle of the Linked List3 Months
Easy
Maximum Number of Integers to Choose From a Range I
Medium
Manhattan Distances of All Arrangements of Pieces
Hard
Queue Reconstruction by Height6 Months
Medium
Reverse Bits30 Days
Easy
Maximize the Minimum Game Score
Hard
Number of Ways to Separate Numbers
Hard
Find All Anagrams in a String6 Months
Medium
Reverse Odd Levels of Binary Tree
Medium
Maximum Sum BST in Binary Tree6 Months
Hard
Basic Calculator II6 Months
Medium
Longest Strictly Increasing or Strictly Decreasing Subarray
Easy
Random Pick with Weight30 Days
Medium
House Robber III3 Months
Medium
Maximum Strength of K Disjoint Subarrays
Hard
Parallel Courses III
Hard
Stock Price Fluctuation
Medium
Find the Array Concatenation Value
Easy
Permutation in String30 Days
Medium
Minimum Knight Moves
Medium
IPO
Hard
Minimum Window Substring30 Days
Hard
Rotate Image30 Days
Medium
Max Chunks To Make Sorted
Medium
Group the People Given the Group Size They Belong To
Medium
Find Winner on a Tic Tac Toe Game
Easy
Find All Numbers Disappeared in an Array6 Months
Easy
Count Sub Islands
Medium
Sqrt(x)30 Days
Easy
Minimum Difference Between Highest and Lowest of K Scores
Easy
Merge Two Binary Trees6 Months
Easy
Valid Palindrome II30 Days
Easy
Maximum Number of Consecutive Values You Can Make
Medium
Maximum Number of Tasks You Can Assign6 Months
Hard
Task Scheduler30 Days
Medium
Find Words That Can Be Formed by Characters
Easy
Convert Binary Number in a Linked List to Integer
Easy
Students and Examinations6 Months
Easy
Divisor Game
Easy
Lexicographically Smallest String After Applying Operations6 Months
Medium
Analyze User Website Visit Pattern30 Days
Medium
Count Subarrays With Median K30 Days
Hard
Minimum Length of String After Operations
Medium
Maximum Width Ramp
Medium
Daily Temperatures3 Months
Medium
Valid Sudoku30 Days
Medium
Palindrome Partitioning II6 Months
Hard
Decoded String at Index
Medium
First Missing Positive30 Days
Hard
Minimum Number of Operations to Make Arrays Similar
Hard
Find the Prefix Common Array of Two Arrays
Medium
String Compression30 Days
Medium
Max Points on a Line30 Days
Hard
The Skyline Problem
Hard
Backspace String Compare
Easy
Minimum Absolute Difference Between Elements With Constraint
Medium
Search in Rotated Sorted Array30 Days
Medium
Angle Between Hands of a Clock
Medium
Kth Largest Element in a Stream6 Months
Easy
Check If It Is a Straight Line
Easy
Two Sum II - Input Array Is Sorted3 Months
Medium
Max Sum of a Pair With Equal Sum of Digits
Medium
Escape the Spreading Fire
Hard
Minimum Operations to Make All Array Elements Equal
Medium
As Far from Land as Possible
Medium
Alice and Bob Playing Flower Game
Medium
Combination Sum30 Days
Medium
Count Subarrays With Fixed Bounds
Hard
Lemonade Change6 Months
Easy
Two Sum30 Days
Easy
Exclusive Time of Functions30 Days
Medium
Roman to Integer3 Months
Easy
Palindromic Substrings6 Months
Medium
Rotting Oranges30 Days
Medium
Rearrange String k Distance Apart
Hard
LFU Cache6 Months
Hard
Insert Delete GetRandom O(1)6 Months
Medium
Count Binary Substrings30 Days
Easy
Minimum Number of Refueling Stops6 Months
Hard
Longest Common Prefix30 Days
Easy
Distribute Candies Among Children III
Hard
Restaurant Growth6 Months
Medium
Number of Islands30 Days
Medium
Average Waiting Time
Medium
Valid Number6 Months
Hard
Word Search II6 Months
Hard
Find the Index of the First Occurrence in a String30 Days
Easy
Length of the Longest Alphabetical Continuous Substring
Medium
Time Needed to Rearrange a Binary String
Medium
Interval List Intersections3 Months
Medium
Valid Perfect Square
Easy
Sliding Window Median
Hard
Count Square Submatrices with All Ones30 Days
Medium
Maximal Square3 Months
Medium
Logger Rate Limiter3 Months
Easy
Guess the Word
Hard
Height Checker
Easy
Find and Replace Pattern
Medium
Find the Minimum Area to Cover All Ones II
Hard
Design Parking System3 Months
Easy
Split Array into Consecutive Subsequences
Medium
Reverse Words in a String30 Days
Medium
Detect Cycles in 2D Grid
Medium
Check if a Parentheses String Can Be Valid
Medium
Maximum Sum of Distinct Subarrays With Length K6 Months
Medium
Split Message Based on Limit
Hard
Count the Number of Inversions
Hard
Successful Pairs of Spells and Potions6 Months
Medium
Minimum Cost Path with Edge Reversals30 Days
Medium
Partition Array Into Three Parts With Equal Sum
Easy
Taking Maximum Energy From the Mystic Dungeon6 Months
Medium
Find the Smallest Divisor Given a Threshold3 Months
Medium
Linked List Cycle II3 Months
Medium
Binary Tree Cameras6 Months
Hard
Burst Balloons6 Months
Hard
Distribute Candies Among Children I
Easy
Merge Sorted Array30 Days
Easy
Permutations30 Days
Medium
Walls and Gates
Medium
Insert Interval3 Months
Medium
Shortest Path in Binary Matrix3 Months
Medium
Heaters
Medium
Web Crawler
Medium
Maximum Total Damage With Spell Casting6 Months
Medium
Add Binary3 Months
Easy
Single Number III
Medium
LRU Cache30 Days
Medium
Product of the Last K Numbers
Medium
Remove K Digits6 Months
Medium
Reaching Points
Hard
Trapping Rain Water II3 Months
Hard
Populating Next Right Pointers in Each Node II
Medium
Minimum Rounds to Complete All Tasks
Medium
Bus Routes6 Months
Hard
Set Matrix Zeroes3 Months
Medium
Minimum Edge Reversals So Every Node Is Reachable
Hard
Design In-Memory File System
Hard
Isomorphic Strings3 Months
Easy
Closest Prime Numbers in Range
Medium
Pascal's Triangle30 Days
Easy
Count and Say3 Months
Medium
Find All Possible Recipes from Given Supplies6 Months
Medium
Range Sum Query 2D - Immutable3 Months
Medium
Partition to K Equal Sum Subsets3 Months
Medium
Bitwise ORs of Subarrays
Medium
Longest Arithmetic Subsequence3 Months
Medium
Shortest Bridge6 Months
Medium
Design Circular Queue6 Months
Medium
Closest Binary Search Tree Value II
Hard
All O`one Data Structure6 Months
Hard
Robot Bounded In Circle6 Months
Medium
Container With Most Water30 Days
Medium
Power Grid Maintenance6 Months
Medium
Find The Original Array of Prefix Xor
Medium
Fair Candy Swap
Easy
Rank Teams by Votes
Medium
Design Snake Game
Medium
Basic Calculator3 Months
Hard
Minimum Space Wasted From Packaging
Hard
Longest Valid Parentheses3 Months
Hard
Find Distance in a Binary Tree
Medium
Single Element in a Sorted Array30 Days
Medium
Restore IP Addresses3 Months
Medium
Last Person to Fit in the Bus
Medium
Count the Digits That Divide a Number
Easy
Move Zeroes30 Days
Easy
Search a 2D Matrix II30 Days
Medium
Course Schedule30 Days
Medium
Making A Large Island3 Months
Hard
Longest Common Subsequence6 Months
Medium
Excel Sheet Column Number
Easy
Serialize and Deserialize BST6 Months
Medium
Number of Ways to Select Buildings
Medium
Snakes and Ladders
Medium
Maximum Number of Robots Within Budget
Hard
Frog Jump6 Months
Hard
Maximum Number of Vowels in a Substring of Given Length3 Months
Medium
Non-overlapping Intervals3 Months
Medium
Find Valid Pair of Adjacent Digits in String
Easy
Range Product Queries of Powers
Medium
Divide Nodes Into the Maximum Number of Groups
Hard
Loud and Rich6 Months
Medium
Edit Distance6 Months
Medium
Minimum Time to Collect All Apples in a Tree
Medium
Minimum Degree of a Connected Trio in a Graph
Hard
Minimize the Maximum Difference of Pairs
Medium
Path With Minimum Effort
Medium
Cut Off Trees for Golf Event
Hard
Lexicographically Smallest String After Substring Operation
Medium
Decode String3 Months
Medium
Intersection of Two Linked Lists30 Days
Easy
Count Complete Subarrays in an Array
Medium
Department Highest Salary3 Months
Medium
Count Vowel Substrings of a String
Easy
Sort the Matrix Diagonally
Medium
Word Ladder30 Days
Hard
Beautiful Arrangement
Medium
Find the Minimum Area to Cover All Ones I
Medium
Count Univalue Subtrees
Medium
Find the Substring With Maximum Cost
Medium
Maximum Subarray30 Days
Medium
Minimum Equal Sum of Two Arrays After Replacing Zeros
Medium
Shifting Letters II
Medium
Minimum Number of Keypresses
Medium
Shuffle an Array
Medium
Distribute Coins in Binary Tree6 Months
Medium
Bulls and Cows
Medium
Beautiful Towers II
Medium
Split a String in Balanced Strings
Easy
Minimum Increment to Make Array Unique6 Months
Medium
Maximum Ascending Subarray Sum
Easy
Contains Duplicate30 Days
Easy
Rectangle Overlap
Easy
Rearrange Array to Maximize Prefix Score
Medium
Fraction Addition and Subtraction
Medium
Squares of a Sorted Array3 Months
Easy
Cherry Pickup
Hard
Minimum Absolute Difference
Easy
Replace Words
Medium
Check If Array Pairs Are Divisible by k6 Months
Medium
Critical Connections in a Network6 Months
Hard
Number of Digit One6 Months
Hard
Word Pattern II
Medium
Maximum Length of Pair Chain6 Months
Medium
Parallel Courses
Medium
Number of Changing Keys
Easy
Sort Colors3 Months
Medium
Merge Two Sorted Lists30 Days
Easy
Diagonal Traverse II
Medium
Flood Fill3 Months
Easy
Validate Stack Sequences
Medium
Binary Search Tree to Greater Sum Tree
Medium
Greatest Common Divisor of Strings6 Months
Easy
Pairs of Songs With Total Durations Divisible by 60
Medium
Number of Matching Subsequences
Medium
Top K Frequent Elements30 Days
Medium
Find All Duplicates in an Array
Medium
Image Smoother
Easy
Number of Sub-arrays of Size K and Average Greater than or Equal to Threshold
Medium
Decode the Slanted Ciphertext
Medium
Minimum Cost to Connect Sticks
Medium
Median of Two Sorted Arrays30 Days
Hard
Falling Squares
Hard
3Sum30 Days
Medium
Add to Array-Form of Integer
Easy
Regions Cut By Slashes
Medium
Largest Rectangle in Histogram3 Months
Hard
HTML Entity Parser
Medium
Maximum Median Sum of Subsequences of Size 3
Medium
Reverse Nodes in k-Group3 Months
Hard
Replace Elements with Greatest Element on Right Side
Easy
Shortest Path with Alternating Colors
Medium
Construct Binary Tree from String
Medium
Minimum Adjacent Swaps to Make a Valid Array
Medium
Decode Ways3 Months
Medium
Binary Tree Right Side View3 Months
Medium
Two Sum III - Data structure design
Easy
Minimum Number of Chairs in a Waiting Room
Easy
Count Days Without Meetings
Medium
Minimum Operations to Reduce X to Zero
Medium
Erect the Fence
Hard
The Maze II
Medium
Online Stock Span30 Days
Medium
Reverse Words in a String II
Medium
Average Selling Price3 Months
Easy
Trips and Users
Hard
Minimum Sum of Squared Difference3 Months
Medium
Minimum Health to Beat Game
Medium
Design Front Middle Back Queue
Medium
Minimum Path Sum6 Months
Medium
Uncrossed Lines
Medium
Maximum Number of Occurrences of a Substring6 Months
Medium
Minimum Suffix Flips
Medium
Group Anagrams30 Days
Medium
Find the Duplicate Number3 Months
Medium
Find Minimum Time to Reach Last Room II
Medium
Minimum Time for K Connected Components
Medium
Implement Trie (Prefix Tree)3 Months
Medium
Remove Linked List Elements30 Days
Easy
Shortest Palindrome3 Months
Hard
Lucky Numbers in a Matrix
Easy
Find Minimum Time to Finish All Jobs
Hard
Design Log Storage System
Medium
Encode and Decode TinyURL
Medium
Remove Stones to Minimize the Total
Medium
Jump Game30 Days
Medium
Find Users With Valid E-Mails
Easy
Number of Recent Calls3 Months
Easy
All Ancestors of a Node in a Directed Acyclic Graph
Medium
Decode the Message
Easy
Palindrome Partitioning3 Months
Medium
Consecutive Numbers6 Months
Medium
Delete Nodes And Return Forest
Medium
Integer to Roman3 Months
Medium
Find Duplicate Subtrees
Medium
Construct Binary Tree from Inorder and Postorder Traversal6 Months
Medium
Palindrome Number30 Days
Easy
Robot Collisions
Hard
Minimum Substring Partition of Equal Character Frequency
Medium
Same Tree6 Months
Easy
Reconstruct Itinerary
Hard
Shortest Common Supersequence6 Months
Hard
Sum of Two Integers3 Months
Medium
Concatenation of Array30 Days
Easy
Minimum Operations to Make Binary Array Elements Equal to One I
Medium
Merge k Sorted Lists30 Days
Hard
Valid Anagram30 Days
Easy
Make The String Great
Easy
Minimum Operations to Exceed Threshold Value II
Medium
Rotate Array30 Days
Medium
Random Pick with Blacklist
Hard
K Divisible Elements Subarrays
Medium
Reverse String3 Months
Easy
Maximum XOR for Each Query
Medium
Word Break II3 Months
Hard
Minimum Score Triangulation of Polygon
Medium
The Maze
Medium
Maximum Units on a Truck6 Months
Easy
Check if a String Is an Acronym of Words
Easy
Divide Array Into Arrays With Max Difference
Medium
Valid Palindrome30 Days
Easy
Best Time to Buy and Sell Stock II3 Months
Medium
Majority Element30 Days
Easy
Number of Students Unable to Eat Lunch6 Months
Easy
Design Underground System
Medium
Remove Invalid Parentheses
Hard
Longest Substring with At Most Two Distinct Characters
Medium
Convert Binary Search Tree to Sorted Doubly Linked List
Medium
Check for Contradictions in Equations
Hard
Advantage Shuffle
Medium
Sell Diminishing-Valued Colored Balls30 Days
Medium
Immediate Food Delivery II3 Months
Medium
Contiguous Array3 Months
Medium
Fibonacci Number3 Months
Easy
Odd Even Jump
Hard
Island Perimeter6 Months
Easy
Remove All Adjacent Duplicates in String II30 Days
Medium
Longest Substring with At Most K Distinct Characters
Medium
Rectangle Area
Medium
Maximize Score of Numbers in Ranges
Medium
Add Two Numbers30 Days
Medium
Sentence Similarity II
Medium
Minimum Remove to Make Valid Parentheses
Medium
Minimum Cuts to Divide a Circle
Easy
Partition Equal Subset Sum3 Months
Medium
Dungeon Game3 Months
Hard
Last Substring in Lexicographical Order
Hard
Max Consecutive Ones III30 Days
Medium
Minimum Time to Complete Trips6 Months
Medium
Longest Cycle in a Graph
Hard
Finding MK Average
Hard
Make Sum Divisible by P
Medium
Construct K Palindrome Strings
Medium
Subarrays with K Different Integers30 Days
Hard
Word Search30 Days
Medium
Simplify Path3 Months
Medium
Count Unreachable Pairs of Nodes in an Undirected Graph6 Months
Medium
Race Car
Hard
Maximum Profit From Trading Stocks
Medium
Delete Duplicate Folders in System
Hard
Subsets II6 Months
Medium
Maximum Repeating Substring
Easy
Leaf-Similar Trees
Easy
Find the City With the Smallest Number of Neighbors at a Threshold Distance
Medium
Maximum Subarray Min-Product
Medium
Recyclable and Low Fat Products3 Months
Easy
Course Schedule IV
Medium
Design Hit Counter6 Months
Medium
Evaluate Division6 Months
Medium
Letter Combinations of a Phone Number30 Days
Medium
Permutations II3 Months
Medium
Monotonic Array3 Months
Easy
Reorder List30 Days
Medium
Sum of Nodes with Even-Valued Grandparent
Medium
Sum of Subarray Minimums30 Days
Medium
Create Binary Tree From Descriptions
Medium
Design Add and Search Words Data Structure3 Months
Medium
Find Duplicate File in System
Medium
Minimum Cost Path with Teleportations3 Months
Hard
Find the Town Judge
Easy
Find the K-Sum of an Array6 Months
Hard
Sum of Square Numbers6 Months
Medium
Moving Average from Data Stream
Easy
Implement Stack using Queues3 Months
Easy
Symmetric Tree6 Months
Easy
Final Prices With a Special Discount in a Shop3 Months
Easy
Minimum Number of Work Sessions to Finish the Tasks
Medium
Longest Balanced Subarray I3 Months
Medium
Employee Importance
Medium
Combine Two Tables30 Days
Easy
Maximum Score From Removing Substrings
Medium
Super Egg Drop
Hard
Triangle3 Months
Medium
Remove Zero Sum Consecutive Nodes from Linked List
Medium
Delete Node in a BST6 Months
Medium
Subarray Sum Equals K30 Days
Medium
Network Delay Time6 Months
Medium
3Sum Closest30 Days
Medium
N-Queens3 Months
Hard
All Paths From Source to Target
Medium
Binary Tree Maximum Path Sum3 Months
Hard
Sum of All Odd Length Subarrays
Easy
Largest Local Values in a Matrix
Easy
Diagonal Traverse6 Months
Medium
Lowest Common Ancestor of a Binary Tree30 Days
Medium
Multiply Strings3 Months
Medium
Best Time to Buy and Sell Stock30 Days
Easy
Maximal Rectangle3 Months
Hard
Gas Station30 Days
Medium
How Many Numbers Are Smaller Than the Current Number3 Months
Easy
Longest Mountain in Array
Medium
Longest Palindromic Subsequence6 Months
Medium
Keys and Rooms6 Months
Medium
Valid Word Abbreviation
Easy
Find N Unique Integers Sum up to Zero6 Months
Easy
Soup Servings
Medium
Sort an Array6 Months
Medium
Delete Duplicate Emails6 Months
Easy
Find Lucky Integer in an Array
Easy
Find Bottom Left Tree Value
Medium
Most Expensive Item That Can Not Be Bought
Medium
Best Time to Buy and Sell Stock III
Hard
Minimum Moves to Spread Stones Over Grid
Medium
Count Number of Nice Subarrays6 Months
Medium
Optimal Partition of String
Medium
Largest Triangle Area6 Months
Easy
Remove Duplicates from Sorted Array3 Months
Easy
Random Pick Index
Medium
Number of Subarrays That Match a Pattern I
Medium
Coin Change II3 Months
Medium
Concatenated Words
Hard
Design Browser History3 Months
Medium
Cousins in Binary Tree
Easy
Best Time to Buy and Sell Stock IV
Hard
Department Top Three Salaries3 Months
Hard
Text Justification6 Months
Hard
House Robber II6 Months
Medium
Number of Submatrices That Sum to Target
Hard
Minimum Obstacle Removal to Reach Corner
Hard
Convert Sorted Array to Binary Search Tree6 Months
Easy
Delete Node in a Linked List3 Months
Medium
Reorder Routes to Make All Paths Lead to the City Zero
Medium
Count Good Nodes in Binary Tree
Medium
Fizz Buzz6 Months
Easy
Balanced Binary Tree30 Days
Easy
Defanging an IP Address
Easy
N-th Tribonacci Number6 Months
Easy
Minimum Fuel Cost to Report to the Capital6 Months
Medium
Maximum Product of Splitted Binary Tree3 Months
Medium
Find Score of an Array After Marking All Elements
Medium
Find the Highest Altitude
Easy
Candy30 Days
Hard
Sum Root to Leaf Numbers
Medium
Champagne Tower30 Days
Medium
Flatten Binary Tree to Linked List6 Months
Medium
Length of Last Word30 Days
Easy
Number of Distinct Islands
Medium
Design Linked List6 Months
Medium
Smallest Subtree with all the Deepest Nodes6 Months
Medium
Lowest Common Ancestor of Deepest Leaves
Medium
Minimum Time Difference
Medium
Maximum Number of Groups With Increasing Length
Hard
Find Triangular Sum of an Array6 Months
Medium
Insert into a Binary Search Tree
Medium
Lowest Common Ancestor of a Binary Search Tree6 Months
Medium
Reverse Vowels of a String6 Months
Easy
Assign Cookies30 Days
Easy
Delete the Middle Node of a Linked List
Medium
Next Greater Node In Linked List3 Months
Medium
Article Views I3 Months
Easy
Ugly Number3 Months
Easy
Reverse Substrings Between Each Pair of Parentheses
Medium
Scramble String6 Months
Hard
Remove Digit From Number to Maximize Result
Easy
132 Pattern30 Days
Medium
Binary Tree Longest Consecutive Sequence
Medium
Summary Ranges3 Months
Easy
Minimum Interval to Include Each Query
Hard
Number of Closed Islands
Medium
Time Taken to Cross the Door
Hard
Find Center of Star Graph
Easy
Add Strings6 Months
Easy
Excel Sheet Column Title3 Months
Easy
Divide Players Into Teams of Equal Skill
Medium
Dot Product of Two Sparse Vectors
Medium
Reverse Integer30 Days
Medium
Max Consecutive Ones30 Days
Easy
K-diff Pairs in an Array
Medium
Combination Sum II6 Months
Medium
Tree Diameter
Medium
Palindrome Linked List3 Months
Easy
Check If Two String Arrays are Equivalent
Easy
Maximum Population Year3 Months
Easy
Remove Element3 Months
Easy
Sliding Puzzle
Hard
Ugly Number II
Medium
Maximum Number of Events That Can Be Attended6 Months
Medium
Next Greater Element II3 Months
Medium
Nearest Exit from Entrance in Maze
Medium
Apply Discount to Prices
Medium
Path Sum II6 Months
Medium
Plus One30 Days
Easy
Largest Positive Integer That Exists With Its Negative
Easy
Count Pairs Whose Sum is Less than Target6 Months
Easy
Count Good Numbers6 Months
Medium
Minimum Falling Path Sum3 Months
Medium
Kth Largest Element in an Array30 Days
Medium
01 Matrix
Medium
Count Servers that Communicate
Medium
Longest Nice Substring
Easy
Expression Add Operators
Hard
Odd Even Linked List3 Months
Medium
Reverse Linked List II6 Months
Medium
Single Number II3 Months
Medium
Max Area of Island3 Months
Medium
Interleaving String6 Months
Medium
Minimum Number of Arrows to Burst Balloons
Medium
Missing Number30 Days
Easy
Minimum Time to Make Rope Colorful
Medium
Is Subsequence3 Months
Easy
Minimum Number of Removals to Make Mountain Array
Hard
Number of Provinces3 Months
Medium
Maximum Length of Repeated Subarray
Medium
Unique Paths III
Hard
Best Time to Buy and Sell Stock with Transaction Fee
Medium
All Possible Full Binary Trees
Medium
N-Repeated Element in Size 2N Array3 Months
Easy
Count Odd Numbers in an Interval Range
Easy
Product Sales Analysis I
Easy
Implement Queue using Stacks6 Months
Easy
Find Customer Referee
Easy
Replace Non-Coprime Numbers in Array
Hard
Coin Change3 Months
Medium
Matrix Diagonal Sum
Easy
Patching Array
Hard
Find Occurrences of an Element in an Array
Medium
Sort Array by Increasing Frequency
Easy
Substrings of Size Three with Distinct Characters
Easy
Continuous Subarray Sum
Medium
Fair Distribution of Cookies
Medium
Shuffle the Array3 Months
Easy
Most Profitable Path in a Tree
Medium
Deepest Leaves Sum
Medium
Sum of Unique Elements
Easy
Search Insert Position30 Days
Easy
Number of Flowers in Full Bloom
Hard
Car Fleet3 Months
Medium
Number of Substrings Containing All Three Characters
Medium
Find Leaves of Binary Tree
Medium
Find First and Last Position of Element in Sorted Array30 Days
Medium
Lexicographically Smallest Beautiful String
Hard
Minimum Operations to Reduce an Integer to 0
Medium
Path Crossing
Easy
Word Pattern
Easy
Binary Tree Zigzag Level Order Traversal6 Months
Medium
Best Time to Buy and Sell Stock using Strategy3 Months
Medium
Sentence Similarity III
Medium
Length of Longest Subarray With at Most K Frequency
Medium
Strong Password Checker
Hard
Rising Temperature3 Months
Easy
Number of Good Pairs
Easy
Minimum Number of Primes to Sum to Target
Medium
Is Graph Bipartite?6 Months
Medium
The k-th Lexicographical String of All Happy Strings of Length n
Medium
Flip String to Monotone Increasing
Medium
Minimum Difference Between Largest and Smallest Value in Three Moves
Medium
Best Time to Buy and Sell Stock with Cooldown6 Months
Medium
Minimum Cost to Make at Least One Valid Path in a Grid
Hard
Find the Longest Substring Containing Vowels in Even Counts
Medium
Convert a Number to Hexadecimal
Easy
Sum of Beauty of All Substrings6 Months
Medium
Find Missing Observations
Medium
Fruit Into Baskets30 Days
Medium
Valid Arrangement of Pairs
Hard
Search in Rotated Sorted Array II6 Months
Medium
Add Two Numbers II3 Months
Medium
Intersection of Two Arrays6 Months
Easy
Reverse Pairs3 Months
Hard
Longest Increasing Subsequence30 Days
Medium
Maximum K to Sort a Permutation
Medium
Fraction to Recurring Decimal6 Months
Medium
Relative Sort Array
Easy
Maximum Product of Three Numbers
Easy
Make String a Subsequence Using Cyclic Increments
Medium
Find Peak Element3 Months
Medium
Remove Nth Node From End of List30 Days
Medium
Perfect Squares3 Months
Medium
Distinct Subsequences6 Months
Hard
Delete and Earn6 Months
Medium
Word Subsets
Medium
Number of Ways to Split Array
Medium
Count Nodes Equal to Average of Subtree
Medium
Arranging Coins3 Months
Easy
Jewels and Stones6 Months
Easy
Subsets30 Days
Medium
Add Digits30 Days
Easy
Cheapest Flights Within K Stops3 Months
Medium
Missing Element in Sorted Array
Medium
Count the Number of Good Subarrays
Medium
Validate Binary Search Tree30 Days
Medium
Step-By-Step Directions From a Binary Tree Node to Another
Medium
Minimum Cost to Equalize Array
Hard
Meeting Rooms III3 Months
Hard
Sudoku Solver3 Months
Hard
Function Composition
Easy
Find the Number of Possible Ways for an Event
Hard
Find Minimum in Rotated Sorted Array3 Months
Medium
Integer to English Words6 Months
Hard
Unique Paths30 Days
Medium
Brightest Position on Street
Medium
Minimum Number of Pushes to Type Word I
Easy
Lexicographically Smallest Negated Permutation that Sums to Target3 Months
Medium
Maximum Number of Removable Characters
Medium
Restore the Array From Adjacent Pairs
Medium
Remove All Adjacent Duplicates In String3 Months
Easy
Happy Number3 Months
Easy
Reverse Words in a String III3 Months
Easy
Duplicate Emails6 Months
Easy
Contains Duplicate II3 Months
Easy
Next Greater Element III6 Months
Medium
Rotate String3 Months
Easy
Divide Two Integers3 Months
Medium
Process String with Special Operations I
Medium
Minimum Number of Swaps to Make the String Balanced
Medium
Relative Ranks
Easy
Remove Duplicate Letters
Medium
Water Bottles
Easy
Stickers to Spell Word
Hard
Split Array With Same Average
Hard
Truncate Sentence
Easy
Widest Vertical Area Between Two Points Containing No Points
Easy
Target Sum3 Months
Medium
Longest Continuous Increasing Subsequence
Easy
Degree of an Array6 Months
Easy
Sliding Window Maximum3 Months
Hard
Find K Pairs with Smallest Sums3 Months
Medium
Minimum Amount of Time to Collect Garbage
Medium
Next Greater Element I30 Days
Easy
Path with Maximum Gold
Medium
Minimum Number of Moves to Make Palindrome
Hard
Maximum Beauty of an Array After Applying Operation
Medium
Vertical Order Traversal of a Binary Tree30 Days
Hard
Minimum Insertion Steps to Make a String Palindrome
Hard
Design Memory Allocator6 Months
Medium
Find Missing and Repeated Values30 Days
Easy
Intersection of Two Arrays II
Easy
Merge Strings Alternately3 Months
Easy
Minimum Size Subarray Sum3 Months
Medium
Rotated Digits
Medium
Sequence Reconstruction
Medium
Non-decreasing Array
Medium
Kill Process
Medium
Number of Substrings With Only 1s
Medium
Word Break30 Days
Medium
Find Longest Self-Contained Substring
Hard
Maximum Points You Can Obtain from Cards3 Months
Medium
Find the Winner of the Circular Game
Medium
Time Needed to Buy Tickets
Easy
Numbers At Most N Given Digit Set
Hard
Number of Islands II
Hard
Sort Characters By Frequency30 Days
Medium
Longest Consecutive Sequence30 Days
Medium
Alternating Digit Sum
Easy
Project Employees I
Easy
Find Median from Data Stream3 Months
Hard
House Robber3 Months
Medium
Reorganize String30 Days
Medium
Minimum Moves to Equal Array Elements II
Medium
Last Stone Weight30 Days
Easy
Divide Array Into Equal Pairs
Easy
Water and Jug Problem
Medium
Longest Path With Different Adjacent Characters
Hard
String to Integer (atoi)30 Days
Medium
Consecutive Numbers Sum
Hard
Remove Duplicates From an Unsorted Linked List
Medium
Range Sum of BST
Easy
Boundary of Binary Tree
Medium
Employee Bonus3 Months
Easy
First Unique Character in a String30 Days
Easy
Check if Array Is Sorted and Rotated6 Months
Easy
Create a DataFrame from List6 Months
Easy
Detonate the Maximum Bombs6 Months
Medium
Number of Longest Increasing Subsequence6 Months
Medium
Sort List3 Months
Medium
Allow One Function Call
Easy
Combinations
Medium
Min Cost to Connect All Points
Medium
4Sum30 Days
Medium
Power of Two6 Months
Easy
Populating Next Right Pointers in Each Node6 Months
Medium
Longest Duplicate Substring
Hard
Zuma Game
Hard
Maximum Number of Books You Can Take
Hard
Can Place Flowers
Easy
Merge Operations to Turn Array Into a Palindrome
Medium
Design File System6 Months
Medium
Shortest Unsorted Continuous Subarray
Medium
Count Different Palindromic Subsequences
Hard
Spiral Matrix II30 Days
Medium
Add Two Integers3 Months
Easy
Number of Atoms6 Months
Hard
Grand Slam Titles
Medium
Power of Three6 Months
Easy
Sort Features by Popularity
Medium
My Calendar III
Hard
Plates Between Candles6 Months
Medium
Max Sum of Rectangle No Larger Than K3 Months
Hard
Count the Number of K-Free Subsets
Medium
Maximum Linear Stock Score
Medium
Count Number of Pairs With Absolute Difference K
Easy
Perfect Number6 Months
Easy
Minimum Swaps to Avoid Forbidden Values3 Months
Hard
Swapping Nodes in a Linked List6 Months
Medium
Minimize the Difference Between Target and Chosen Elements
Medium
Valid Mountain Array
Easy
Pyramid Transition Matrix3 Months
Medium
Maximize the Beauty of the Garden
Hard
Minimum Number of Operations to Move All Balls to Each Box
Medium
Number of Enclaves
Medium
Not Boring Movies
Easy
Customers With Strictly Increasing Purchases
Hard
Find the Original Typed String I
Easy
Minimum Difference in Sums After Removal of Elements
Hard
Maximum Number of Events That Can Be Attended II
Hard
Put Marbles in Bags
Hard
Count Stepping Numbers in Range
Hard
Shortest Subarray to be Removed to Make Array Sorted
Medium
Minimum Pair Removal to Sort Array I3 Months
Easy
Maximum Width of Binary Tree3 Months
Medium
Kth Ancestor of a Tree Node
Hard
Sign of the Product of an Array3 Months
Easy
Lexicographical Numbers
Medium
Counting Bits
Easy
Binary Tree Vertical Order Traversal
Medium
Remove Palindromic Subsequences
Easy
Friendly Movies Streamed Last Month
Easy
Count the Number of K-Big Indices
Hard
Wiggle Sort
Medium
Paint House3 Months
Medium
Maximum Alternating Subarray Sum
Medium
Valid Parenthesis String6 Months
Medium
Find the Difference30 Days
Easy
Minimum Operations to Make the Array K-Increasing
Hard
Shortest Subarray with Sum at Least K6 Months
Hard
Insert into a Sorted Circular Linked List
Medium
Reverse String Prefix
Easy
Big Countries3 Months
Easy
Repeated String Match
Medium
Pascal's Triangle II
Easy
Maximum Average Subarray I6 Months
Easy
Remove Vowels from a String
Easy
Maximize the Profit as the Salesman
Medium
Find the Kth Smallest Sum of a Matrix With Sorted Rows
Hard
Minimize Max Distance to Gas Station
Hard
Maximum Number of Non-Overlapping Substrings
Hard
Number of Good Paths
Hard
Maximize Number of Subsequences in a String
Medium
Find the K-or of an Array
Easy
Count the Number of Substrings With Dominant Ones6 Months
Medium
Plus One Linked List
Medium
Sales Analysis II
Easy
Repeated DNA Sequences
Medium
Maximal Range That Each Element Is Maximum in It
Medium
Design a Text Editor
Hard
Max Pair Sum in an Array
Easy
Element Appearing More Than 25% In Sorted Array
Easy
Add Two Polynomials Represented as Linked Lists
Medium
Max Dot Product of Two Subsequences3 Months
Hard
Minimum Garden Perimeter to Collect Enough Apples
Medium
Insufficient Nodes in Root to Leaf Paths
Medium
The kth Factor of n
Medium
Check if Grid can be Cut into Sections
Medium
GCD Sort of an Array
Hard
Find the Lexicographically Largest String From the Box I
Medium
Amount of Time for Binary Tree to Be Infected3 Months
Medium
Prime Number of Set Bits in Binary Representation
Easy
Strange Printer
Hard
Partition List30 Days
Medium
Longest Subsequence Repeated k Times
Hard
Find the Maximum Achievable Number6 Months
Easy
Sum of Subarray Ranges6 Months
Medium
Partition Labels3 Months
Medium
Number of Calls Between Two Persons
Medium
Matchsticks to Square
Medium
Kth Missing Positive Number3 Months
Easy
Clone N-ary Tree
Medium
Kth Smallest Product of Two Sorted Arrays
Hard
Longest Winning Streak
Hard
Number of Operations to Make Network Connected6 Months
Medium
Number of Steps to Reduce a Number in Binary Representation to One
Medium
Split Linked List in Parts
Medium
Maximum Balanced Subsequence Sum
Hard
Maximum Score After Splitting a String
Easy
Subtree of Another Tree6 Months
Easy
Evaluate Boolean Binary Tree
Easy
Find Elements in a Contaminated Binary Tree
Medium
Single-Threaded CPU
Medium
Sum of Number and Its Reverse
Medium
Sum of Prefix Scores of Strings
Hard
Possible Bipartition
Medium
Primary Department for Each Employee
Easy
Maximum Size of a Set After Removals
Medium
Construct String from Binary Tree
Medium
Maximum Average Subtree
Medium
Product Sales Analysis V
Easy
Form Array by Concatenating Subarrays of Another Array
Medium
NPV Queries
Easy
Maximum Subsequence Score
Medium
License Key Formatting
Easy
Concatenation of Consecutive Binary Numbers
Medium
Count Palindromic Subsequences
Hard
Build Binary Expression Tree From Infix Expression
Hard
Most Stones Removed with Same Row or Column6 Months
Medium
Stone Game II
Medium
Find the Median of the Uniqueness Array
Hard
Percentage of Users Attended a Contest6 Months
Easy
Find a Corresponding Node of a Binary Tree in a Clone of That Tree
Easy
Smallest Subsequence of Distinct Characters
Medium
Minimum Right Shifts to Sort the Array
Easy
Different Ways to Add Parentheses6 Months
Medium
Strobogrammatic Number II
Medium
Maximum Matrix Sum3 Months
Medium
All People Report to the Given Manager
Medium
Range Sum of Sorted Subarray Sums
Medium
Sum of Digits in the Minimum Number
Easy
Game Play Analysis IV
Medium
Minimize the Maximum of Two Arrays
Medium
Remove One Element to Make the Array Strictly Increasing
Easy
Binary Subarrays With Sum3 Months
Medium
Longest Binary Subsequence Less Than or Equal to K
Medium
Threshold Majority Queries
Hard
Create Hello World Function30 Days
Easy
Repeated Substring Pattern6 Months
Easy
Find Smallest Common Element in All Rows
Medium
Maximum Unique Subarray Sum After Deletion
Easy
Third Maximum Number6 Months
Easy
Count Beautiful Substrings II
Hard
Construct Binary Tree from Preorder and Inorder Traversal3 Months
Medium
Replace Elements in an Array
Medium
Maximum Employees to Be Invited to a Meeting
Hard
Make Three Strings Equal
Easy
Global and Local Inversions
Medium
Minimum Number of Taps to Open to Water a Garden
Hard
Closest Binary Search Tree Value
Easy
Check if the Rectangle Corner Is Reachable
Hard
Count Primes30 Days
Medium
Find the Minimum and Maximum Number of Nodes Between Critical Points
Medium
Meeting Rooms6 Months
Easy
Maximum Sum of Almost Unique Subarray
Medium
Handshakes That Don't Cross
Hard
Rank Scores30 Days
Medium
Minimum Depth of Binary Tree
Easy
Game Play Analysis I6 Months
Easy
Balance a Binary Search Tree30 Days
Medium
Freedom Trail
Hard
Flipping an Image
Easy
Relocate Marbles
Medium
Minimum Operations to Make the Array Increasing
Easy
Remove Duplicates from Sorted List II
Medium
Find Common Elements Between Two Arrays
Easy
Richest Customer Wealth6 Months
Easy
Sum of Scores of Built Strings
Hard
Longest Substring with At Least K Repeating Characters30 Days
Medium
Single Number30 Days
Easy
Counter
Easy
Lexicographically Minimum String After Removing Stars
Medium
Smallest Integer Divisible by K
Medium
Count Negative Numbers in a Sorted Matrix3 Months
Easy
Evaluate Reverse Polish Notation30 Days
Medium
Replace Employee ID With The Unique Identifier6 Months
Easy
Maximum Frequency of an Element After Performing Operations II
Hard
Maximum Bags With Full Capacity of Rocks
Medium
Find in Mountain Array6 Months
Hard
Prison Cells After N Days
Medium
Tiling a Rectangle with the Fewest Squares
Hard
Ones and Zeroes
Medium
Shuffle String
Easy
Longest Balanced Substring II30 Days
Medium
Parsing A Boolean Expression
Hard
Teemo Attacking
Easy
Identify the Largest Outlier in an Array
Medium
Find the Missing IDs
Medium
Minimum Cost to Reach Destination in Time
Hard
Wiggle Sort II
Medium
Shift 2D Grid
Easy
Queries on a Permutation With Key
Medium
Two Sum Less Than K
Easy
DI String Match
Easy
Spiral Matrix III
Medium
Find Pivot Index
Easy
Maximal Score After Applying K Operations
Medium
Predict the Winner6 Months
Medium
Minimum Cost to Cut a Stick
Hard
Number of Steps to Reduce a Number to Zero
Easy
Path With Maximum Minimum Value
Medium
Ad-Free Sessions
Easy
Sequentially Ordinal Rank Tracker
Hard
Stable Subarrays With Equal Boundary and Interior Sum
Medium
Min Cost Climbing Stairs3 Months
Easy
Delete Columns to Make Sorted II3 Months
Medium
Range Sum Query 2D - Mutable
Medium
Range Addition
Medium
Serialize and Deserialize N-ary Tree
Hard
Minimum Time to Activate String
Medium
Unique Number of Occurrences6 Months
Easy
Check if Move is Legal
Medium
Number of Equivalent Domino Pairs
Easy
Can I Win
Medium
Find the Index of the Large Integer
Medium
Zigzag Iterator
Medium
Find All People With Secret
Hard
Employee Free Time
Hard
Minimum Swaps to Group All 1's Together II
Medium
Optimal Division
Medium
Design Search Autocomplete System
Hard
Count Complete Tree Nodes
Easy
Number of Subarrays with Bounded Maximum
Medium
Maximum Difference Between Even and Odd Frequency II
Hard
House Robber IV
Medium
Binary Tree Preorder Traversal
Easy
Construct Binary Search Tree from Preorder Traversal6 Months
Medium
Destroying Asteroids
Medium
Index Pairs of a String
Easy
Product Sales Analysis II
Easy
All Valid Triplets That Can Represent a Country
Easy
Maximum Candies Allocated to K Children6 Months
Medium
Linked List Cycle3 Months
Easy
Path with Maximum Probability
Medium
Longest Palindrome
Easy
Sum of Left Leaves
Easy
Super Pow
Medium
Find the Difference of Two Arrays6 Months
Easy
Map of Highest Peak
Medium
Product Price at a Given Date6 Months
Medium
Lexicographically Smallest Palindrome
Easy
Increasing Triplet Subsequence6 Months
Medium
To Be Or Not To Be6 Months
Easy
Armstrong Number
Easy
Binary Search Tree Iterator
Medium
Number of Sets of K Non-Overlapping Line Segments
Medium
Maximize Y‑Sum by Picking a Triplet of Distinct X‑Values
Medium
Equal Tree Partition
Medium
Flatten Nested List Iterator
Medium
Contains Duplicate III6 Months
Hard
Human Traffic of Stadium
Hard
Two Sum BSTs
Medium
Find the Team Size
Easy
Decompress Run-Length Encoded List
Easy
Running Sum of 1d Array3 Months
Easy
Find Target Indices After Sorting Array6 Months
Easy
Accounts Merge3 Months
Medium
Counter II
Easy
Find the Maximum Length of Valid Subsequence II
Medium
Count Hills and Valleys in an Array
Easy
Recover Binary Search Tree6 Months
Medium
K-th Smallest in Lexicographical Order
Hard
Number of Days in a Month
Easy
Find K-Length Substrings With No Repeated Characters
Medium
Replace Question Marks in String to Minimize Its Value
Medium
Sum of Beauty in the Array
Medium
Search a 2D Matrix3 Months
Medium
Students With Invalid Departments
Easy
Sum of Distances in Tree
Hard
Best Poker Hand
Easy
Task Scheduler II
Medium
Maximum of Minimum Values in All Subarrays
Medium
Guess Number Higher or Lower6 Months
Easy
Difference Between Ones and Zeros in Row and Column
Medium
Verify Preorder Serialization of a Binary Tree
Medium
Remove Outermost Parentheses3 Months
Easy
Count Triplets with Even XOR Set Bits I
Easy
Closest Room
Hard
Jump Game VII
Medium
Path Sum
Easy
Find Interview Candidates
Medium
Subarray Sums Divisible by K6 Months
Medium
Remove Duplicates from Sorted List3 Months
Easy
Maximum Element After Decreasing and Rearranging
Medium
Count Pairs Of Nodes
Hard
Rearrange Characters to Make Target String
Easy
Filling Bookcase Shelves
Medium
Find the Maximum Number of Elements in Subset
Medium
Maximum Score After Binary Swaps
Medium
Find Eventual Safe States3 Months
Medium
Integer Replacement
Medium
Remove Duplicates from Sorted Array II6 Months
Medium
Find Critical and Pseudo-Critical Edges in Minimum Spanning Tree
Hard
Max Number of K-Sum Pairs6 Months
Medium
Shortest Path in a Grid with Obstacles Elimination
Hard
Customers Who Never Order30 Days
Easy
Redundant Connection
Medium
Boats to Save People3 Months
Medium
Count Number of Special Subsequences
Hard
Maximum Score of a Good Subarray
Hard
Combination Sum IV
Medium
Minesweeper
Medium
Delete Columns to Make Sorted III3 Months
Hard
Nim Game
Easy
Sales by Day of the Week
Hard
Max Chunks To Make Sorted II
Hard
Subarrays Distinct Element Sum of Squares II
Hard
Valid Triangle Number6 Months
Medium
Maximum Average Pass Ratio
Medium
Cache With Time Limit
Medium
Maximum Calories Burnt from Jumps
Medium
Find Minimum Time to Finish All Jobs II
Medium
Merge In Between Linked Lists6 Months
Medium
Count Beautiful Substrings I
Medium
Minimum Add to Make Parentheses Valid3 Months
Medium
Invert Binary Tree3 Months
Easy
Product Sales Analysis IV
Medium
Employees Earning More Than Their Managers30 Days
Easy
Maximum Frequency Stack6 Months
Hard
Magnetic Force Between Two Balls6 Months
Medium
Simple Bank System
Medium
Find Number of Ways to Reach the K-th Stair
Hard
Continuous Subarrays
Medium
Confirmation Rate6 Months
Medium
Valid Palindrome III
Hard
Set Mismatch3 Months
Easy
Integer Break
Medium
Cherry Pickup II
Hard
Factorial Trailing Zeroes3 Months
Medium
Find Minimum Operations to Make All Elements Divisible by Three6 Months
Easy
Count Numbers With Unique Digits II
Easy
Binary Tree Level Order Traversal II
Medium
Minimum Operations to Remove Adjacent Ones in Matrix
Hard
Count Triplets with Even XOR Set Bits II
Medium
Two Best Non-Overlapping Events3 Months
Medium
Closest Divisors
Medium
Largest Values From Labels
Medium
Find if Path Exists in Graph
Easy
Count the Number of Fair Pairs
Medium
Merge Nodes in Between Zeros
Medium
String Compression III
Medium
Maximize Points After Choosing K Tasks
Medium
Connecting Cities With Minimum Cost
Medium
Maximum Consecutive Floors Without Special Floors
Medium
Hand of Straights
Medium
Maximum Bitwise AND After Increment Operations
Hard
Binary Search3 Months
Easy
Nth Digit
Medium
Number of Unique Categories
Medium
Grid Game
Medium
Find Subsequence of Length K With the Largest Sum
Easy
Range Sum Query - Immutable6 Months
Easy
Employees With Deductions
Medium
Maximum Product of Word Lengths
Medium
Shortest Matching Substring
Hard
Strange Printer II
Hard
Maximum Gap
Medium
Merge Two 2D Arrays by Summing Values
Easy
Clumsy Factorial
Medium
Linked List Components
Medium
Profitable Schemes6 Months
Hard
Find the Number of Subarrays Where Boundary Elements Are Maximum
Hard
Count the Number of Special Characters II
Medium
My Calendar II
Medium
Create Maximum Number
Hard
Minimum Cost to Merge Stones
Hard
Maximum of Absolute Value Expression
Medium
Next Palindrome Using Same Digits
Hard
Bulb Switcher30 Days
Medium
Ant on the Boundary
Easy
Keyboard Row
Easy
Longest Continuous Subarray With Absolute Diff Less Than or Equal to Limit
Medium
Russian Doll Envelopes3 Months
Hard
2 Keys Keyboard
Medium
Minimum Unique Word Abbreviation
Hard
Least Number of Unique Integers after K Removals
Medium
Find Xor-Beauty of Array
Medium
Maximum Nesting Depth of the Parentheses
Easy
Custom Sort String
Medium
Products With Three or More Orders in Two Consecutive Years
Medium
Count of Range Sum
Hard
Distinct Numbers in Each Subarray
Medium
Largest Sum of Averages
Medium
Find Maximum Non-decreasing Array Length
Hard
Minimum Money Required Before Transactions
Hard
First Bad Version3 Months
Easy
Binary Tree Coloring Game
Medium
Closest Leaf in a Binary Tree
Medium
Maximum Sum Score of Array
Medium
Arithmetic Slices6 Months
Medium
Pizza With 3n Slices
Hard
Score of a String6 Months
Easy
Design an Expression Tree With Evaluate Function6 Months
Medium
Get the Size of a DataFrame
Easy
Minimum Insertions to Balance a Parentheses String
Medium
Memoize
Medium
Kids With the Greatest Number of Candies
Easy
Customer Order Frequency
Easy
Prime Arrangements
Easy
Sparse Matrix Multiplication
Medium
Diet Plan Performance
Easy
Find the Celebrity6 Months
Medium
Largest Divisible Subset6 Months
Medium
Rotate List3 Months
Medium
Nested List Weight Sum
Medium
Meeting Scheduler
Medium
Search in a Binary Search Tree
Easy
Minimum Sensors to Cover Grid
Medium
Smallest String Starting From Leaf
Medium
Decode XORed Permutation
Medium
Surrounded Regions30 Days
Medium
Maximum Size Subarray Sum Equals k
Medium
H-Index30 Days
Medium
Longest Common Subpath
Hard
Ransom Note6 Months
Easy
Warehouse Manager
Easy
Frequency of the Most Frequent Element30 Days
Medium
Rearranging Fruits
Hard
Return Length of Arguments Passed
Easy
K Radius Subarray Averages
Medium
Peak Index in a Mountain Array3 Months
Medium
Partition Array According to Given Pivot
Medium
Separate Black and White Balls
Medium
Sales Analysis I
Easy
Maximum Performance of a Team
Hard
Number of Good Ways to Split a String
Medium
Buildings With an Ocean View
Medium
Maximum Difference Between Even and Odd Frequency I
Easy
Lowest Common Ancestor of a Binary Tree III6 Months
Medium
Minimum Number of Increments on Subarrays to Form a Target Array6 Months
Hard
Minimum Operations to Make Array Equal to Target
Hard
Number of Distinct Averages
Easy
Design an Array Statistics Tracker
Hard
Report Contiguous Dates
Hard
Longest Balanced Subarray II30 Days
Hard
Users With Two Purchases Within Seven Days
Medium
Design Twitter3 Months
Medium
Find Words Containing Character
Easy
Calculate Money in Leetcode Bank
Easy
Digit Count in Range
Hard
Largest Unique Number
Easy
Reordered Power of 26 Months
Medium
Most Profit Assigning Work
Medium
Binary Tree Level Order Traversal3 Months
Medium
Minimum Array Sum
Medium
Minimum Speed to Arrive on Time
Medium
Letter Tile Possibilities
Medium
Count Items Matching a Rule
Easy
Substring Matching Pattern
Easy
Binary Tree Inorder Traversal6 Months
Easy
Total Sum of Interaction Cost in Tree Groups
Hard
Jump Game VIII
Medium
Count Ways to Make Array With Product
Hard
Minimum Numbers of Function Calls to Make Target Array
Medium
Find Cumulative Salary of an Employee
Hard
Maximum Number of Points From Grid Queries
Hard
Maximum Number of Achievable Transfer Requests
Hard
Friend Requests II: Who Has the Most Friends
Medium
Minimize Malware Spread
Hard
Minimum Stability Factor of Array
Hard
Number of Times a Driver Was a Passenger
Medium
Swap Nodes in Pairs3 Months
Medium
Robot Room Cleaner
Hard
Valid Tic-Tac-Toe State
Medium
Unique Length-3 Palindromic Subsequences
Medium
Convert Integer to the Sum of Two No-Zero Integers6 Months
Easy
Count of Smaller Numbers After Self3 Months
Hard
Substring With Largest Variance
Hard
Complete Binary Tree Inserter
Medium
Count Partitions with Even Sum Difference3 Months
Easy
Find Number of Coins to Place in Tree Nodes
Hard
A Number After a Double Reversal
Easy
Find the Minimum Amount of Time to Brew Potions6 Months
Medium
Find Closest Person
Easy
Find All K-Distant Indices in an Array
Easy
Find Mode in Binary Search Tree
Easy
Reach a Number
Medium
Convert BST to Greater Tree
Medium
Maximum Coins From K Consecutive Bags
Medium
Find X-Sum of All K-Long Subarrays I6 Months
Easy
Replace the Substring for Balanced String
Medium
Count Subarrays Where Max Element Appears at Least K Times
Medium
Count Unique Characters of All Substrings of a Given String
Hard
Minimum Falling Path Sum II
Hard
Find Largest Value in Each Tree Row
Medium
Sort the People
Easy
Paths in Matrix Whose Sum Is Divisible by K6 Months
Hard
Binary Tree Postorder Traversal
Easy
Crawler Log Folder
Easy
Fix Names in a Table3 Months
Easy
Smallest Number in Infinite Set
Medium
Minimum Amount of Damage Dealt to Bob
Hard
Find Most Frequent Vowel and Consonant
Easy
Take K of Each Character From Left and Right
Medium
The K Weakest Rows in a Matrix
Easy
Minimum Operations to Convert All Elements to Zero
Medium
Trim a Binary Search Tree
Medium
Maximum Difference Between Increasing Elements
Easy
Lexicographically Smallest Equivalent String
Medium
Count Total Number of Colored Cells
Medium
Maximum Ice Cream Bars
Medium
Bag of Tokens
Medium
Count the Number of Computer Unlocking Permutations
Medium
Time Needed to Inform All Employees
Medium
Actors and Directors Who Cooperated At Least Three Times
Easy
Zero Array Transformation III
Medium
Balanced K-Factor Decomposition
Medium
Base 73 Months
Easy
Longest Square Streak in an Array
Medium
Split a String Into the Max Number of Unique Substrings
Medium
Count Number of Rectangles Containing Each Point6 Months
Medium
Longest Subarray With Maximum Bitwise AND
Medium
Find the K-th Character in String Game I
Easy
Increasing Decreasing String
Easy
Apply Transform Over Each Element in Array
Easy
Maximum 69 Number6 Months
Easy
Root Equals Sum of Children
Easy
Triangle Judgement
Easy
Maximum Frequency of an Element After Performing Operations I6 Months
Medium
Longest Happy Prefix
Hard
Reverse String II
Easy
Maximum Subarray Sum With Length Divisible by K3 Months
Medium
Longest Balanced Substring I30 Days
Medium
Reschedule Meetings for Maximum Free Time I
Medium
Append K Integers With Minimal Sum
Medium
Check If N and Its Double Exist
Easy
Jump Game IV
Hard
Finding 3-Digit Even Numbers
Easy
Count Submatrices With All Ones
Medium
Group Sold Products By The Date
Easy
Find Longest Special Substring That Occurs Thrice I
Medium
Kth Smallest Instructions
Hard
Find the Maximum Length of Valid Subsequence I3 Months
Medium
Smallest Subarrays With Maximum Bitwise OR
Medium
Maximize Happiness of Selected Children3 Months
Medium
Sum of Absolute Differences in a Sorted Array6 Months
Medium
Out of Boundary Paths
Medium
Sort Items by Groups Respecting Dependencies
Hard
Maximum Number of Distinct Elements After Operations6 Months
Medium
Insert Greatest Common Divisors in Linked List
Medium
Minimum Hours of Training to Win a Competition
Easy
Delete Nodes From Linked List Present in Array6 Months
Medium
Count Number of Teams
Medium
Count Largest Group6 Months
Easy
Trionic Array II
Hard
Find Kth Bit in Nth Binary String
Medium
Unique Binary Search Trees II6 Months
Medium
Minimum Number of Operations to Make Elements in Array Distinct
Easy
Average of Levels in Binary Tree
Easy
Minimum Number Game
Easy
Minimum Operations to Make a Subsequence
Hard
Queries Quality and Percentage
Easy
Move Pieces to Obtain a String
Medium
Maximum Running Time of N Computers3 Months
Hard
K-th Symbol in Grammar
Medium
Minimum Removals to Balance Array30 Days
Medium
Domino and Tromino Tiling6 Months
Medium
Adding Spaces to a String
Medium
Maximum Absolute Sum of Any Subarray
Medium
4Sum II
Medium
The Earliest and Latest Rounds Where Players Compete
Hard
Minimum Limit of Balls in a Bag
Medium
Find Total Time Spent by Each Employee
Easy
Maximum Score Words Formed by Letters
Hard
Mirror Reflection
Medium
Self Dividing Numbers
Easy
Minimum Operations to Make the Integer Zero6 Months
Medium
Separate Squares I3 Months
Medium
Largest Perimeter Triangle
Easy
Design Circular Deque
Medium
Maximum Sum of 3 Non-Overlapping Subarrays
Hard
New 21 Game
Medium
Check Knight Tour Configuration
Medium
Distinct Subsequences II
Hard
Solving Questions With Brainpower
Medium
Car Fleet II
Hard
Tuple with Same Product
Medium
Water Bottles II6 Months
Medium
Product Sales Analysis III6 Months
Medium
Happy Students3 Months
Medium
Minimum Score After Removals on a Tree
Hard
Sum of Total Strength of Wizards
Hard
Check If Digits Are Equal in String After Operations I
Easy
Shortest Distance After Road Addition Queries I
Medium
Numbers With Same Consecutive Differences
Medium
Delete Leaves With a Given Value
Medium
Painting a Grid With Three Different Colors
Hard
Count Partitions With Max-Min Difference at Most K6 Months
Medium
Check if Two Chessboard Squares Have the Same Color
Easy
Lexicographically Smallest Permutation Greater Than Target6 Months
Medium
Divisible and Non-divisible Sums Difference
Easy
Number of Laser Beams in a Bank
Medium
Minimum Positive Sum Subarray
Easy
Maximum Erasure Value6 Months
Medium
Determine Whether Matrix Can Be Obtained By Rotation
Easy
List the Products Ordered in a Period
Easy
Stream of Characters
Hard
Find Minimum in Rotated Sorted Array II
Hard
Find the Original Typed String II
Hard
Longest ZigZag Path in a Binary Tree
Medium
Smallest Range II6 Months
Medium
Apply Operations to Make All Array Elements Equal to Zero
Medium
Minimum Cost to Convert String I30 Days
Medium
Cat and Mouse
Hard
Reorder Data in Log Files
Medium
Maximum Value after Insertion
Medium
Binary Tree Pruning
Medium
Minimum Number of Groups to Create a Valid Assignment30 Days
Medium
Three Consecutive Odds
Easy
Design a Food Rating System
Medium
Set Intersection Size At Least Two6 Months
Hard
Minimum Seconds to Equalize a Circular Array
Medium
Greatest Sum Divisible by Three3 Months
Medium
Count Number of Texts
Medium
Number of Employees Who Met the Target
Easy
Count the Number of Complete Components
Medium
Surface Area of 3D Shapes
Easy
Total Characters in String After Transformations I
Medium
Nth Magical Number30 Days
Hard
Minimum Addition to Make Integer Beautiful
Medium
Count Subarrays of Length Three With a Condition
Easy
Construct the Lexicographically Largest Valid Sequence
Medium
Extra Characters in a String
Medium
Clear Digits
Easy
Select K Disjoint Special Substrings
Medium
Count the Number of Ideal Arrays
Hard
Convert 1D Array Into 2D Array
Easy
Smallest Missing Non-negative Integer After Operations6 Months
Medium
Array Partition3 Months
Easy
Circular Array Loop
Medium
String Matching in an Array
Easy
Longest Repeating Substring
Medium
Remove Covered Intervals
Medium
Convert the Temperature6 Months
Easy
Best Time to Buy and Sell Stock V6 Months
Medium
Sales Analysis III
Easy
Find the K-th Character in String Game II
Hard
Sales Person
Easy
Maximum and Minimum Sums of at Most Size K Subsequences
Medium
Most Frequent IDs
Medium
Reformat Department Table
Easy
Minimum Swaps To Make Sequences Increasing
Hard
Number of Pairs Satisfying Inequality
Hard
Minimum Number of Vertices to Reach All Nodes
Medium
Solve the Equation
Medium
Find the Number of Ways to Place People I6 Months
Medium
Find the Pivot Integer
Easy
Partition Array Such That Maximum Difference Is K
Medium
Minimum Cost Walk in Weighted Graph
Hard
Maximum Sum of Three Numbers Divisible by Three6 Months
Medium
Number of Distinct Islands II
Hard
Longest Common Prefix Between Adjacent Strings After Removals
Medium
Minimum Cost to Convert String II
Hard
Number of Ways to Paint N × 3 Grid3 Months
Hard
Number of Wonderful Substrings
Medium
Reducing Dishes
Hard
Append Characters to String to Make Subsequence
Medium
Distant Barcodes
Medium
Sum of Digits in Base K
Easy
Construct Smallest Number From DI String
Medium
Maximum Total Importance of Roads
Medium
Final Array State After K Multiplication Operations I
Easy
Maximum Number of Fish in a Grid
Medium
Number of Smooth Descent Periods of a Stock
Medium
Maximum Level Sum of a Binary Tree3 Months
Medium
Perfect Rectangle3 Months
Hard
Super Washing Machines
Hard
Check Balanced String
Easy
Array Nesting
Medium
Number of Subsequences That Satisfy the Given Sum Condition6 Months
Medium
Range Module
Hard
Last Stone Weight II6 Months
Medium
Removing Stars From a String
Medium
Analyze Organization Hierarchy
Hard
Minimum Operations to Make Array Sum Divisible by K6 Months
Easy
Minimum Index of a Valid Split
Medium
Maximum Difference by Remapping a Digit
Easy
Distribute Candies to People
Easy
Find Special Substring of Length K
Easy
Largest Multiple of Three
Hard
Parse Lisp Expression
Hard
Longest Turbulent Subarray
Medium
Count Symmetric Integers
Easy
Maximum Frequency After Subarray Operation30 Days
Medium
Kth Distinct String in an Array
Easy
Valid Palindrome IV
Medium
Dinner Plate Stacks
Hard
Check if Number is a Sum of Powers of Three
Medium
Count Collisions on a Road
Medium
Binary Prefix Divisible By 56 Months
Easy
Minimum Number of Operations to Make Array Empty
Medium
Check if One String Swap Can Make Strings Equal
Easy
Total Appeal of A String
Hard
Minimum Operations to Equalize Binary String6 Months
Hard
Consecutive Transactions with Increasing Amounts
Hard
Number of Pairs of Interchangeable Rectangles
Medium
Transformed Array30 Days
Easy
Strictly Palindromic Number3 Months
Medium
Customer Purchasing Behavior Analysis
Medium
Recover a Tree From Preorder Traversal
Hard
Ways to Express an Integer as Sum of Powers
Medium
Friends Of Appropriate Ages6 Months
Medium
Maximum Number of K-Divisible Components
Hard
Rearrange Products Table
Easy
First and Last Call On the Same Day
Hard
Maximum Star Sum of a Graph
Medium
Super Ugly Number
Medium
Implement Trie II (Prefix Tree)
Medium
Complex Number Multiplication
Medium
Vowels Game in a String
Medium
Trionic Array I30 Days
Easy
Detect Squares6 Months
Medium
Neighboring Bitwise XOR
Medium
Minimum Cost to Make Arrays Identical
Medium
Count Collisions of Monkeys on a Polygon
Medium
Count the Number of Special Characters I
Easy
Adjacent Increasing Subarrays Detection I
Easy
The Two Sneaky Numbers of Digitville
Easy
Frog Jump II
Medium
Minimize the Maximum Adjacent Element Difference
Hard
Valid Phone Numbers
Easy
Take Gifts From the Richest Pile
Easy
Two-Letter Card Game
Medium
Maximum Sum With at Most K Elements
Medium
Maximum Odd Binary Number
Easy
Employees Whose Manager Left the Company
Easy
Separate Squares II3 Months
Hard
Maximum Balanced Shipments6 Months
Medium
Minimum Time to Repair Cars
Medium
Longest Absolute File Path
Medium
Number of Common Factors
Easy
Filter Elements from Array
Easy
Modify Columns
Easy
Second Minimum Node In a Binary Tree
Easy
Maximum Number of Coins You Can Get
Medium
Uncommon Words from Two Sentences
Easy
Maximum Total from Optimal Activation Order
Medium
Find The K-th Lucky Number
Medium
Maximize Cyclic Partition Score6 Months
Hard
Removing Minimum and Maximum From Array
Medium
Longest Ideal Subsequence
Medium
Minimum Cost to Hire K Workers
Hard
Gray Code6 Months
Medium
Shortest Path Visiting All Nodes
Hard
Construct Product Matrix
Medium
Buy Two Chocolates
Easy
Minimum Domino Rotations For Equal Row
Medium
Check if Matrix Is X-Matrix
Easy
Find Smallest Letter Greater Than Target
Easy
Maximum Matching of Players With Trainers
Medium
Special Array With X Elements Greater Than or Equal X
Easy
Minimum Time to Visit a Cell In a Grid
Hard
Maximum Difference Between Node and Ancestor
Medium
Minimum Time Visiting All Points
Easy
All Elements in Two Binary Search Trees
Medium
XOR Queries of a Subarray
Medium
Maximum Value of an Ordered Triplet I
Easy
Lowest Common Ancestor of a Binary Tree IV
Medium
Sort Array By Parity II6 Months
Easy
Find the Power of K-Size Subarrays I
Medium
Patients With a Condition
Easy
Minimum Pair Removal to Sort Array II3 Months
Hard
Length of the Longest Subsequence That Sums to Target
Medium
Promise Time Limit
Medium
Maximum Capacity Within Budget6 Months
Medium
Maximum Value of an Ordered Triplet II
Medium
Row With Maximum Ones
Easy
Delete Greatest Value in Each Row
Easy
Make Array Zero by Subtracting Equal Amounts
Easy
Maximize the Minimum Powered City6 Months
Hard
Prime Subtraction Operation
Medium
Minimum Number of Operations to Make All Array Elements Equal to 16 Months
Medium
Maximum Possible Number by Binary Concatenation
Medium
Find Nearest Point That Has the Same X or Y Coordinate
Easy
N-ary Tree Preorder Traversal
Easy
Allocate Mailboxes
Hard
Maximum Twin Sum of a Linked List6 Months
Medium
Find Building Where Alice and Bob Can Meet
Hard
Count Bowl Subarrays6 Months
Medium
Zero Array Transformation II
Medium
Find the Number of Good Pairs I
Easy
Data Stream as Disjoint Intervals
Hard
Number of Zero-Filled Subarrays
Medium
Find the Middle Index in Array
Easy
Minimum Time to Complete All Deliveries3 Months
Medium
Biggest Single Number
Easy
Minimum Number of Moves to Seat Everyone
Easy
Count Number of Maximum Bitwise-OR Subsets
Medium
Reveal Cards In Increasing Order6 Months
Medium
Find the Number of Distinct Colors Among the Balls
Medium
Flatten a Multilevel Doubly Linked List3 Months
Medium
Sort the Jumbled Numbers
Medium
Sleep6 Months
Easy
Find Right Interval
Medium
Count of Matches in Tournament
Easy
Number of Unique Subjects Taught by Each Teacher6 Months
Easy
Maximum Number of Words Found in Sentences3 Months
Easy
Rearrange Array Elements by Sign30 Days
Medium
Encrypt and Decrypt Strings
Hard
Kth Largest Sum in a Binary Tree
Medium
Maximum Number of Points with Cost
Medium
Knight Dialer
Medium
Equal Row and Column Pairs
Medium
Flip Columns For Maximum Number of Equal Rows
Medium
Sum of All Subset XOR Totals3 Months
Easy
Reschedule Meetings for Maximum Free Time II
Medium
Smallest Even Multiple6 Months
Easy
Magic Squares In Grid3 Months
Medium
Shortest Distance to a Character
Easy
Maximum Difference Between Adjacent Elements in a Circular Array
Easy
Design Task Manager6 Months
Medium
Delete Operation for Two Strings
Medium
Smallest Palindromic Rearrangement I
Medium
N-ary Tree Level Order Traversal
Medium
Generate Binary Strings Without Adjacent Zeros
Medium
Array Reduce Transformation
Easy
Minimum Number of People to Teach6 Months
Medium
Construct the Rectangle
Easy
Bitwise AND of Numbers Range
Medium
Minimum Absolute Difference in BST3 Months
Easy
Construct Binary Tree from Preorder and Postorder Traversal
Medium
The Latest Time to Catch a Bus
Medium
Build Array from Permutation
Easy
Minimize Manhattan Distances
Hard
Minimum Recolors to Get K Consecutive Black Blocks
Easy
Make Array Elements Equal to Zero6 Months
Easy
Partition Array for Maximum Sum3 Months
Medium
Hamming Distance
Easy
Elimination Game30 Days
Medium
Longest Subsequence With Limited Sum6 Months
Easy
Maximum Number of Operations to Move Ones to the End6 Months
Medium
Length of Longest Fibonacci Subsequence
Medium
Construct the Minimum Bitwise Array I3 Months
Easy
Zero Array Transformation I
Medium
Largest Element in an Array after Merge Operations
Medium
Minimum Division Operations to Make Array Non Decreasing
Medium
Smallest Good Base
Hard
Pizza Toppings Cost Analysis
Medium
Split With Minimum Sum
Easy
Four Divisors
Medium
Final Value of Variable After Performing Operations6 Months
Easy
Duplicate Zeros
Easy
Maximize Subarrays After Removing One Conflicting Pair
Hard
Count Beautiful Splits in an Array
Medium
Sort By
Easy
Minimize XOR
Medium
Find Good Days to Rob the Bank
Medium
Fruits Into Baskets III
Medium
Minimum Number of Days to Disconnect Island
Hard
Check if All Characters Have Equal Number of Occurrences
Easy
Minimum Average of Smallest and Largest Elements
Easy
Find K-th Smallest Pair Distance
Hard
Split Array into Fibonacci Sequence
Medium
Array Prototype Last
Easy
X of a Kind in a Deck of Cards
Easy
Rank Transform of an Array
Easy
Unique 3-Digit Even Numbers3 Months
Easy
Prime Palindrome
Medium
Maximum XOR of Two Numbers in an Array
Medium
Apply Operations to an Array
Easy
Defuse the Bomb
Easy
Minimum Sum of Four Digit Number After Splitting Digits6 Months
Easy
Minimum Array End
Medium
N-ary Tree Postorder Traversal
Easy
Smallest Number With All Set Bits
Easy
Minimum Length of String After Deleting Similar Ends
Medium
Mini Parser
Medium
Ugly Number III6 Months
Medium
Rotate Function
Medium
Count of Substrings Containing Every Vowel and K Consonants II
Medium
Remove Nodes From Linked List
Medium
Most Common Word
Easy
Sorting the Sentence
Easy
Double a Number Represented as a Linked List
Medium
Maximum Sum of Two Non-Overlapping Subarrays
Medium
Minimize Maximum Pair Sum in Array
Medium
Implement Router6 Months
Medium
Delete Columns to Make Sorted
Easy
Minimum Number of Operations to Make Array XOR Equal to K
Medium
Customers Who Bought All Products6 Months
Medium
Last Day Where You Can Still Cross6 Months
Hard
Display the First Three Rows
Easy
Insertion Sort List6 Months
Medium
Sliding Subarray Beauty
Medium
Reshape the Matrix
Easy
Sort Array By Parity6 Months
Easy
Number of Dice Rolls With Target Sum
Medium
Check Completeness of a Binary Tree
Medium
Length of the Longest Valid Substring
Hard
Even Odd Tree6 Months
Medium
Sum of Root To Leaf Binary Numbers
Easy
Reshape Data: Concatenate
Easy
Largest Odd Number in String
Easy
Year on Year Growth Rate
Hard
Most Frequent Subtree Sum
Medium
Push Dominoes
Medium
Find the Number of Good Pairs II
Medium
Nested List Weight Sum II
Medium
Robot Return to Origin
Easy
Maximum Sum With Exactly K Elements
Easy
Similar String Groups6 Months
Hard
Clone Binary Tree With Random Pointer
Medium
Largest Combination With Bitwise AND Greater Than Zero
Medium
Construct the Minimum Bitwise Array II3 Months
Medium
Binary Tree Tilt
Easy
Count Number of Bad Pairs
Medium
Orderly Queue6 Months
Hard
Increasing Order Search Tree
Easy
Minimum Number of Pushes to Type Word II
Medium
Cousins in Binary Tree II
Medium
Binary Watch
Easy
Flip Equivalent Binary Trees
Medium
Number of Segments in a String
Easy
Count Covered Buildings6 Months
Medium
The Most Recent Orders for Each Product
Medium
Find if Array Can Be Sorted
Medium
Check if the Sentence Is Pangram
Easy
Minimum Average Difference
Medium
Maximum Number of Moves in a Grid
Medium
Minimum Jumps to Reach Home
Medium
Divide an Array Into Subarrays With Minimum Cost I30 Days
Easy
Swap Sex of Employees
Easy
Find the Punishment Number of an Integer
Medium
Traffic Light Controlled Intersection
Easy
Number of Ways to Arrive at Destination
Medium
Magical String
Medium
Find the Largest Palindrome Divisible by K
Hard
Beautiful Array
Medium
Circular Sentence
Easy
Reshape Data: Pivot
Easy
Make Two Arrays Equal by Reversing Subarrays
Easy
Minimum Operations to Make the Array Alternating
Medium
Number of Even and Odd Bits
Easy
The Most Frequently Ordered Products for Each Customer
Medium
Count Substrings That Can Be Rearranged to Contain a String I
Medium
Determine if String Halves Are Alike
Easy
Combination Sum III6 Months
Medium
Number of Sub-arrays With Odd Sum
Medium
Reshape Data: Melt
Easy
Arithmetic Slices II - Subsequence
Hard
Consecutive Characters
Easy
Corporate Flight Bookings
Medium
Find the Divisibility Array of a String
Medium
Minimum Moves to Equal Array Elements
Medium
Can Make Arithmetic Progression From Sequence
Easy