Hash Table Interview Questions

Rank

#146MediumFrequency: 100%

LRU Cache

Rank

#833HardFrequency: 100%

Bus Routes

Rank

#432HardFrequency: 93.8%

All O`one Data Structure

Rank

#348MediumFrequency: 93.6%

Design Tic-Tac-Toe

Array Hash Table Design Matrix Simulation

Rank

#314MediumFrequency: 93.4%

Binary Tree Vertical Order Traversal

Hash Table Tree Depth-First Search Breadth-First Search Sorting Binary Tree

Rank

#3MediumFrequency: 92.8%

Longest Substring Without Repeating Characters

Rank

#305HardFrequency: 89.9%

Number of Islands II

Array Hash Table Union-Find

Rank

#1790MediumFrequency: 88.5%

Lowest Common Ancestor of a Binary Tree III

Hash Table Two Pointers Tree Binary Tree Binary Lifting Lowest Common Ancestor

Rank

#560MediumFrequency: 87.2%

Subarray Sum Equals K

#10

Rank

#694MediumFrequency: 86.6%

Number of Distinct Islands

Array Hash Table Depth-First Search Breadth-First Search Union-Find Sorting Matrix Hash Function

#11

Rank

#438MediumFrequency: 84.4%

Find All Anagrams in a String

#12

Rank

#1366MediumFrequency: 83.2%

First Unique Number

Array Hash Table Design Queue Data Stream

#13

Rank

#1112EasyFrequency: 82.7%

Find Words That Can Be Formed by Characters

#14

Rank

#1190MediumFrequency: 82.4%

Smallest Common Region

Array Hash Table String Tree Depth-First Search Breadth-First Search Binary Lifting Lowest Common Ancestor

#15

Rank

#244MediumFrequency: 82.3%

Shortest Word Distance II

Array Hash Table Two Pointers String Design

#16

Rank

#49MediumFrequency: 81.6%

Group Anagrams

#17

Rank

#347MediumFrequency: 81.3%

Top K Frequent Elements

Array Hash Table Divide and Conquer Sorting Heap (Priority Queue)Bucket Sort Counting Quickselect

#18

Rank

#1023MediumFrequency: 79.9%

Time Based Key-Value Store

Hash Table String Binary Search Design

#19

Rank

#1713MediumFrequency: 79.6%

Dot Product of Two Sparse Vectors

Array Hash Table Two Pointers Design Linear Algebra

#20

Rank

#2023HardFrequency: 79.4%

Design Movie Rental System

Array Hash Table Design Heap (Priority Queue)Ordered Set

#21

Rank

#127HardFrequency: 79%

Word Ladder

Hash Table String Breadth-First Search Bidirectional Search

#22

Rank

#460HardFrequency: 78.9%

LFU Cache

#23

Rank

#336HardFrequency: 78.6%

Palindrome Pairs

Array Hash Table String Trie Hash Function

#24

Rank

#631HardFrequency: 78.6%

Design Excel Sum Formula

Array Hash Table String Graph Theory Design Topological Sort Matrix

#25

Rank

#778MediumFrequency: 78.3%

Reorganize String

Hash Table String Greedy Sorting Heap (Priority Queue)Counting

#26

Rank

#138MediumFrequency: 78.1%

Copy List with Random Pointer

Hash Table Linked List

#27

Rank

#2147HardFrequency: 76.6%

The Score of Students Solving Math Expression

Array Hash Table Math String Dynamic Programming Stack Memoization

#28

Rank

#1024HardFrequency: 76.6%

Triples with Bitwise AND Equal To Zero

#29

Rank

#3994EasyFrequency: 76.6%

Find The Least Frequent Digit

#30

Rank

#380MediumFrequency: 76.2%

Insert Delete GetRandom O(1)

Array Hash Table Math Design Randomized

#31

Rank

#2640MediumFrequency: 76%

Maximum Number of Integers to Choose From a Range I

Array Hash Table Binary Search Greedy Sorting

#32

Rank

#2667HardFrequency: 76%

Maximum Frequency Score of a Subarray

Array Hash Table Math Stack Sliding Window

#33

Rank

#36MediumFrequency: 75.8%

Valid Sudoku

#34

Rank

#3750MediumFrequency: 75.5%

Closest Equal Element Queries

Array Hash Table Binary Search

#35

Rank

#76HardFrequency: 74.7%

Minimum Window Substring

#36

Rank

#160EasyFrequency: 73.9%

Intersection of Two Linked Lists

Hash Table Linked List Two Pointers

#37

Rank

#17MediumFrequency: 73.6%

Letter Combinations of a Phone Number

Hash Table String Backtracking

#38

Rank

#2301HardFrequency: 73.2%

Count Array Pairs Divisible by K

Array Hash Table Math Counting Number Theory Euclidean Algorithm Greatest Common Divisor

#39

Rank

#807MediumFrequency: 72.8%

Custom Sort String

#40

Rank

#1125MediumFrequency: 72.7%

Design File System

#41

Rank

#2169MediumFrequency: 72.1%

Simple Bank System

Array Hash Table Design Simulation

#42

Rank

#2905HardFrequency: 71.9%

Count Paths That Can Form a Palindrome in a Tree

Hash Table Bit Manipulation Tree Depth-First Search

#43

Rank

#128MediumFrequency: 70.7%

Longest Consecutive Sequence

Array Hash Table Union-Find

#44

Rank

#133MediumFrequency: 70.5%

Clone Graph

Hash Table Depth-First Search Breadth-First Search Graph Theory

#45

Rank

#169EasyFrequency: 70.4%

Majority Element

Array Hash Table Divide and Conquer Sorting Counting Boyer–Moore Majority Vote Algorithm

#46

Rank

#219EasyFrequency: 70.1%

Contains Duplicate II

#47

Rank

#242EasyFrequency: 69.8%

Valid Anagram

#48

Rank

#13EasyFrequency: 69.2%

Roman to Integer

#49

Rank

#1029HardFrequency: 69.1%

Vertical Order Traversal of a Binary Tree

Hash Table Tree Depth-First Search Breadth-First Search Sorting Binary Tree

#50

Rank

#3356MediumFrequency: 67.9%

Shortest Uncommon Substring in an Array

#51

Rank

#1249MediumFrequency: 66.8%

Snapshot Array

Array Hash Table Binary Search Design Persistent Data Structure

#52

Rank

#960HardFrequency: 66.4%

Minimize Malware Spread

Array Hash Table Depth-First Search Breadth-First Search Union-Find Graph Theory

#53

Rank

#1423MediumFrequency: 66.4%

Maximum Number of Occurrences of a Substring

#54

Rank

#3317MediumFrequency: 66.4%

Maximum Palindromes After Operations

Array Hash Table String Greedy Sorting Counting

#55

Rank

#893MediumFrequency: 65.7%

All Nodes Distance K in Binary Tree

Hash Table Tree Depth-First Search Breadth-First Search Binary Tree

#56

Rank

#588HardFrequency: 65.6%

Design In-Memory File System

Hash Table String Design Trie Sorting

#57

Rank

#889EasyFrequency: 65.6%

Buddy Strings

#58

Rank

#202EasyFrequency: 65.5%

Happy Number

Hash Table Math Two Pointers Floyd's Cycle Finding Algorithm

#59

Rank

#217EasyFrequency: 65.5%

Contains Duplicate

#60

Rank

#1409HardFrequency: 65.5%

Minimum Number of Flips to Convert Binary Matrix to Zero Matrix

Array Hash Table Bit Manipulation Breadth-First Search Matrix

#61

Rank

#1697MediumFrequency: 65.5%

Strings Differ by One Character

Hash Table String Rolling Hash Hash Function

#62

Rank

#757MediumFrequency: 65.5%

Pyramid Transition Matrix

Hash Table String Backtracking Bit Manipulation

#63

Rank

#2726HardFrequency: 65.2%

Minimum Reverse Operations

Array Hash Table Breadth-First Search Union-Find Ordered Set

#64

Rank

#3863MediumFrequency: 64.9%

Power Grid Maintenance

Array Hash Table Depth-First Search Breadth-First Search Union-Find Graph Theory Heap (Priority Queue)Ordered Set

#65

Rank

#1915EasyFrequency: 64.6%

Check if One String Swap Can Make Strings Equal

#66

Rank

#940MediumFrequency: 63.6%

Fruit Into Baskets

#67

Rank

#1469MediumFrequency: 63.5%

Minimum Number of Steps to Make Two Strings Anagram

#68

Rank

#621MediumFrequency: 63.1%

Task Scheduler

Array Hash Table Greedy Sorting Heap (Priority Queue)Counting

#69

Rank

#1108MediumFrequency: 62.6%

Analyze User Website Visit Pattern

#70

Rank

#205EasyFrequency: 62.6%

Isomorphic Strings

#71

Rank

#1219MediumFrequency: 62.5%

Longest Well-Performing Interval

Array Hash Table Stack Monotonic Stack Prefix Sum

#72

Rank

#2502EasyFrequency: 62.5%

Sort the People

#73

Rank

#1647MediumFrequency: 62.5%

Can Convert String in K Moves

#74

Rank

#2696MediumFrequency: 62.5%

The Number of Beautiful Subsets

Array Hash Table Math Dynamic Programming Backtracking Sorting Combinatorics

#75

Rank

#1055MediumFrequency: 62.2%

Pairs of Songs With Total Durations Divisible by 60

#76

Rank

#41HardFrequency: 61.4%

First Missing Positive

#77

Rank

#249MediumFrequency: 61.4%

Group Shifted Strings

#78

Rank

#721MediumFrequency: 61.4%

Accounts Merge

Array Hash Table String Depth-First Search Breadth-First Search Union-Find Sorting

#79

Rank

#2479HardFrequency: 61.4%

Meeting Rooms III

Array Hash Table Sorting Heap (Priority Queue)Simulation

#80

Rank

#817EasyFrequency: 61.4%

Design HashMap

Array Hash Table Linked List Design Hash Function

#81

Rank

#2237MediumFrequency: 61.1%

Longest Palindrome by Concatenating Two Letter Words

Array Hash Table String Greedy Counting

#82

Rank

#139MediumFrequency: 60.5%

Word Break

Array Hash Table String Dynamic Programming Trie Memoization Brute-Force Search

#83

Rank

#3736EasyFrequency: 60%

Find Valid Pair of Adjacent Digits in String

#84

Rank

#424MediumFrequency: 59.8%

Longest Repeating Character Replacement

#85

Rank

#523MediumFrequency: 59.8%

Continuous Subarray Sum

Array Hash Table Math Prefix Sum Pigeonhole Principle

#86

Rank

#381HardFrequency: 59.7%

Insert Delete GetRandom O(1) - Duplicates allowed

Array Hash Table Math Design Randomized

#87

Rank

#105MediumFrequency: 59.3%

Construct Binary Tree from Preorder and Inorder Traversal

Array Hash Table Divide and Conquer Tree Binary Tree

#88

Rank

#140HardFrequency: 59.3%

Word Break II

Array Hash Table String Dynamic Programming Backtracking Trie Memoization

#89

Rank

#3638HardFrequency: 59.3%

Minimum Operations to Make Character Frequencies Equal

Hash Table String Dynamic Programming Counting Enumeration

#90

Rank

#398MediumFrequency: 59.1%

Random Pick Index

Hash Table Math Reservoir Sampling Randomized

#91

Rank

#692MediumFrequency: 59.1%

Top K Frequent Words

Array Hash Table String Trie Sorting Heap (Priority Queue)Bucket Sort Counting

#92

Rank

#3594MediumFrequency: 58.8%

Identify the Largest Outlier in an Array

Array Hash Table Counting Enumeration

#93

Rank

#1905MediumFrequency: 58%

Design Authentication Manager

#94

Rank

#480HardFrequency: 57.6%

Sliding Window Median

Array Hash Table Sliding Window Heap (Priority Queue)Treap

#95

Rank

#187MediumFrequency: 57.5%

Repeated DNA Sequences

Hash Table String Bit Manipulation Sliding Window Rolling Hash Hash Function Z Algorithm Boyer–Moore String-Search Algorithm

#96

Rank

#931HardFrequency: 57.5%

Maximum Frequency Stack

Hash Table Stack Design Ordered Set

#97

Rank

#740MediumFrequency: 57.5%

Delete and Earn

#98

Rank

#1016MediumFrequency: 57%

Subarray Sums Divisible by K

#99

Rank

#1308MediumFrequency: 57%

Smallest String With Swaps

Array Hash Table String Depth-First Search Breadth-First Search Union-Find Sorting

#100

Rank

#73MediumFrequency: 56.6%

Set Matrix Zeroes

#101

Rank

#149HardFrequency: 56.3%

Max Points on a Line

Array Hash Table Math Geometry Euclidean Algorithm Greatest Common Divisor

#102

Rank

#2594EasyFrequency: 55.8%

Count Pairs Of Similar Strings

Array Hash Table String Bit Manipulation Counting

#103

Rank

#387EasyFrequency: 55.2%

First Unique Character in a String

Hash Table String Queue Counting

#104

Rank

#2177EasyFrequency: 55.1%

Check Whether Two Strings are Almost Equivalent

#105

Rank

#208MediumFrequency: 55%

Implement Trie (Prefix Tree)

#106

Rank

#383EasyFrequency: 55%

Ransom Note

#107

Rank

#496EasyFrequency: 54.7%

Next Greater Element I

Array Hash Table Stack Monotonic Stack

#108

Rank

#268EasyFrequency: 54.4%

Missing Number

Array Hash Table Math Binary Search Bit Manipulation Sorting

#109

Rank

#2543MediumFrequency: 54.4%

Most Popular Video Creator

Array Hash Table String Sorting Heap (Priority Queue)

#110

Rank

#2856MediumFrequency: 54.4%

Count Complete Subarrays in an Array

#111

Rank

#2119HardFrequency: 54.1%

Minimum Number of Operations to Make Array Continuous

Array Hash Table Binary Search Sliding Window

#112

Rank

#525MediumFrequency: 53.4%

Contiguous Array

#113

Rank

#2679EasyFrequency: 53.4%

Count Distinct Numbers on Board

Array Hash Table Math Simulation

#114

Rank

#1526MediumFrequency: 53.4%

HTML Entity Parser

#115

Rank

#3732MediumFrequency: 53.1%

Calculate Score After Performing Instructions

Array Hash Table String Simulation

#116

Rank

#2461MediumFrequency: 52.9%

Amount of Time for Binary Tree to Be Infected

Hash Table Tree Depth-First Search Breadth-First Search Binary Tree

#117

Rank

#632HardFrequency: 52.9%

Smallest Range Covering Elements from K Lists

Array Hash Table Greedy Sliding Window Sorting Heap (Priority Queue)

#118

Rank

#976MediumFrequency: 52.9%

Minimum Area Rectangle

Array Hash Table Math Geometry Sorting

#119

Rank

#12MediumFrequency: 52.8%

Integer to Roman

#120

Rank

#141EasyFrequency: 52.8%

Linked List Cycle

Hash Table Linked List Two Pointers Floyd's Cycle Finding Algorithm

#121

Rank

#567MediumFrequency: 52.8%

Permutation in String

Hash Table Two Pointers String Sliding Window

#122

Rank

#3254MediumFrequency: 52.4%

Number of Divisible Triplet Sums

#123

Rank

#532MediumFrequency: 52.4%

K-diff Pairs in an Array

Array Hash Table Two Pointers Binary Search Sorting

#124

Rank

#2574HardFrequency: 52.4%

Count Subarrays With Median K

#125

Rank

#359EasyFrequency: 52.3%

Logger Rate Limiter

Hash Table Design Data Stream

#126

Rank

#37HardFrequency: 52.1%

Sudoku Solver

Array Hash Table Backtracking Matrix Algorithm X Dancing Links

#127

Rank

#648MediumFrequency: 52.1%

Replace Words

#128

Rank

#395MediumFrequency: 51.4%

Longest Substring with At Least K Repeating Characters

Hash Table String Divide and Conquer Sliding Window

#129

Rank

#349EasyFrequency: 51.1%

Intersection of Two Arrays

Array Hash Table Two Pointers Binary Search Sorting

#130

Rank

#1038HardFrequency: 51%

Number of Squareful Arrays

Array Hash Table Math Dynamic Programming Backtracking Bit Manipulation Bitmask

#131

Rank

#697EasyFrequency: 50.6%

Degree of an Array

#132

Rank

#246EasyFrequency: 50.5%

Strobogrammatic Number

Hash Table Two Pointers String

#133

Rank

#2186EasyFrequency: 50.3%

Count Vowel Substrings of a String

#134

Rank

#535MediumFrequency: 49.9%

Encode and Decode TinyURL

Hash Table String Design Hash Function

#135

Rank

#753MediumFrequency: 49.9%

Open the Lock

Array Hash Table String Breadth-First Search Bidirectional Search

#136

Rank

#999MediumFrequency: 49.9%

Regions Cut By Slashes

Array Hash Table Depth-First Search Breadth-First Search Union-Find Matrix Planar Graph

#137

Rank

#3034EasyFrequency: 49.9%

Points That Intersect With Cars

#138

Rank

#2889MediumFrequency: 49.9%

Number of Black Blocks

#139

Rank

#4253MediumFrequency: 49.9%

Minimum Cost to Equalize Arrays Using Swaps

#140

Rank

#3541MediumFrequency: 49.3%

Report Spam Message

#141

Rank

#3751MediumFrequency: 48.9%

Maximum Frequency After Subarray Operation

Array Hash Table Dynamic Programming Greedy Enumeration Prefix Sum

#142

Rank

#3897HardFrequency: 48.8%

Count Number of Trapezoids II

Array Hash Table Math Geometry

#143

Rank

#311MediumFrequency: 48.8%

Sparse Matrix Multiplication

Array Hash Table Matrix Linear Algebra

#144

Rank

#2133MediumFrequency: 48.7%

Number of Pairs of Strings With Concatenation Equal to Target

#145

Rank

#340MediumFrequency: 48%

Longest Substring with At Most K Distinct Characters

#146

Rank

#266EasyFrequency: 47.5%

Palindrome Permutation

Hash Table String Bit Manipulation

#147

Rank

#290EasyFrequency: 47.5%

Word Pattern

#148

Rank

#291MediumFrequency: 47.5%

Word Pattern II

Hash Table String Backtracking

#149

Rank

#690MediumFrequency: 47.5%

Employee Importance

Array Hash Table Tree Depth-First Search Breadth-First Search

#150

Rank

#894HardFrequency: 47.5%

Random Pick with Blacklist

Array Hash Table Math Binary Search Sorting Randomized

#151

Rank

#1267MediumFrequency: 47.5%

Remove Zero Sum Consecutive Nodes from Linked List

Hash Table Linked List

#152

Rank

#1502MediumFrequency: 47.5%

Construct K Palindrome Strings

Hash Table String Greedy Counting

#153

Rank

#1643MediumFrequency: 47.5%

Number of Nodes in the Sub-Tree With the Same Label

Hash Table Tree Depth-First Search Breadth-First Search Counting DP on Trees

#154

Rank

#1820HardFrequency: 47.5%

Number Of Ways To Reconstruct A Tree

Array Hash Table Tree Graph Theory Simulation

#155

Rank

#2306MediumFrequency: 47.5%

Create Binary Tree From Descriptions

Array Hash Table Tree Binary Tree

#156

Rank

#2331EasyFrequency: 47.5%

Intersection of Multiple Arrays

Array Hash Table Sorting Counting

#157

Rank

#2339MediumFrequency: 47.5%

K Divisible Elements Subarrays

Array Hash Table Trie Rolling Hash Hash Function Enumeration

#158

Rank

#3335MediumFrequency: 47.5%

Minimum Operations to Write the Letter Y on a Grid

Array Hash Table Matrix Counting

#159

Rank

#3385MediumFrequency: 47.5%

Match Alphanumerical Pattern in Matrix I

Array Hash Table String Matrix

#160

Rank

#448EasyFrequency: 47%

Find All Numbers Disappeared in an Array

#161

Rank

#2436EasyFrequency: 46.5%

Make Array Zero by Subtracting Equal Amounts

Array Hash Table Greedy Sorting Heap (Priority Queue)Simulation

#162

Rank

#1034HardFrequency: 46%

Subarrays with K Different Integers

Array Hash Table Sliding Window Counting

#163

Rank

#1400EasyFrequency: 46%

Find Winner on a Tic Tac Toe Game

Array Hash Table Matrix Simulation

#164

Rank

#142MediumFrequency: 45%

Linked List Cycle II

Hash Table Linked List Two Pointers Floyd's Cycle Finding Algorithm

#165

Rank

#170EasyFrequency: 44.7%

Two Sum III - Data structure design

Array Hash Table Two Pointers Design Data Stream

#166

Rank

#3886MediumFrequency: 44.6%

Count Number of Trapezoids I

Array Hash Table Math Geometry

#167

Rank

#126HardFrequency: 44.1%

Word Ladder II

Hash Table String Backtracking Breadth-First Search Bidirectional Search

#168

Rank

#442MediumFrequency: 44%

Find All Duplicates in an Array

#169

Rank

#1370MediumFrequency: 44%

Count Number of Nice Subarrays

Array Hash Table Math Sliding Window Prefix Sum

#170

Rank

#451MediumFrequency: 43.2%

Sort Characters By Frequency

Hash Table String Sorting Heap (Priority Queue)Bucket Sort Counting

#171

Rank

#726HardFrequency: 43.2%

Number of Atoms

Hash Table String Stack Sorting

#172

Rank

#677MediumFrequency: 43.2%

Map Sum Pairs

#173

Rank

#2270MediumFrequency: 43%

Find All Lonely Numbers in the Array

#174

Rank

#2587MediumFrequency: 43%

Design Memory Allocator

Array Hash Table Design Simulation

#175

Rank

#2334HardFrequency: 43%

Number of Flowers in Full Bloom

Array Hash Table Binary Search Sorting Prefix Sum Ordered Set

#176

Rank

#3825MediumFrequency: 42.7%

Apply Substitutions

Array Hash Table String Depth-First Search Breadth-First Search Graph Theory Topological Sort

#177

Rank

#229MediumFrequency: 42.5%

Majority Element II

Array Hash Table Sorting Counting Boyer–Moore Majority Vote Algorithm

#178

Rank

#389EasyFrequency: 42%

Find the Difference

Hash Table String Bit Manipulation Sorting

#179

Rank

#1319EasyFrequency: 41.7%

Unique Number of Occurrences

#180

Rank

#808MediumFrequency: 41.6%

Number of Matching Subsequences

Array Hash Table String Binary Search Dynamic Programming Trie Sorting

#181

Rank

#645EasyFrequency: 41.4%

Set Mismatch

Array Hash Table Bit Manipulation Sorting

#182

Rank

#768MediumFrequency: 41.4%

Partition Labels

Hash Table Two Pointers String Greedy

#183

Rank

#2547EasyFrequency: 41.2%

Odd String Difference

#184

Rank

#355MediumFrequency: 41.2%

Design Twitter

Hash Table Linked List Design Heap (Priority Queue)

#185

Rank

#2581MediumFrequency: 40.9%

Divide Players Into Teams of Equal Skill

#186

Rank

#1129MediumFrequency: 40.9%

Longest String Chain

Array Hash Table Two Pointers String Dynamic Programming Sorting

#187

Rank

#1554MediumFrequency: 40.7%

Minimum Time to Collect All Apples in a Tree

Hash Table Tree Depth-First Search Breadth-First Search DP on Trees

#188

Rank

#1207MediumFrequency: 40.2%

Delete Nodes And Return Forest

Array Hash Table Tree Depth-First Search Binary Tree

#189

Rank

#3421EasyFrequency: 40.2%

Count Pairs That Form a Complete Day I

#190

Rank

#159MediumFrequency: 39.1%

Longest Substring with At Most Two Distinct Characters

#191

Rank

#2220MediumFrequency: 39.1%

Find All Possible Recipes from Given Supplies

Array Hash Table String Graph Theory Topological Sort Directed Acyclic Graph

#192

Rank

#3329MediumFrequency: 39.1%

Find the Length of the Longest Common Prefix

#193

Rank

#582MediumFrequency: 39.1%

Kill Process

Array Hash Table Tree Depth-First Search Breadth-First Search

#194

Rank

#896MediumFrequency: 38.5%

Smallest Subtree with all the Deepest Nodes

Hash Table Tree Depth-First Search Breadth-First Search Binary Tree Binary Lifting Lowest Common Ancestor DP on Trees

#195

Rank

#3227EasyFrequency: 38.2%

Find Missing and Repeated Values

Array Hash Table Math Matrix

#196

Rank

#30HardFrequency: 38.2%

Substring with Concatenation of All Words

#197

Rank

#2552MediumFrequency: 38.2%

Maximum Sum of Distinct Subarrays With Length K

#198

Rank

#106MediumFrequency: 38.2%

Construct Binary Tree from Inorder and Postorder Traversal

Array Hash Table Divide and Conquer Tree Binary Tree

#199

Rank

#990EasyFrequency: 37.9%

Verifying an Alien Dictionary

#200

Rank

#966MediumFrequency: 36.3%

Binary Subarrays With Sum

Array Hash Table Sliding Window Prefix Sum

#201

Rank

#653EasyFrequency: 35.7%

Two Sum IV - Input is a BST

Hash Table Two Pointers Tree Depth-First Search Breadth-First Search Binary Search Tree Binary Tree

#202

Rank

#1087MediumFrequency: 35.7%

Longest Arithmetic Subsequence

Array Hash Table Binary Search Dynamic Programming

#203

Rank

#1510EasyFrequency: 35.7%

Find Lucky Integer in an Array

#204

Rank

#2520MediumFrequency: 35.6%

Using a Robot to Print the Lexicographically Smallest String

Hash Table String Stack Greedy

#205

Rank

#1995MediumFrequency: 35.5%

Finding Pairs With a Certain Sum

Array Hash Table Design

#206

Rank

#421MediumFrequency: 35.3%

Maximum XOR of Two Numbers in an Array

Array Hash Table Bit Manipulation Trie

#207

Rank

#325MediumFrequency: 35%

Maximum Size Subarray Sum Equals k

#208

Rank

#635MediumFrequency: 35%

Design Log Storage System

Hash Table String Design Ordered Set

#209

Rank

#1003MediumFrequency: 34.8%

Minimum Area Rectangle II

Array Hash Table Math Geometry

#210

Rank

#823HardFrequency: 34.3%

Split Array With Same Average

Array Hash Table Math Dynamic Programming Bit Manipulation Meet in the Middle Bitmask

#211

Rank

#1873EasyFrequency: 34.3%

Longest Nice Substring

Hash Table String Divide and Conquer Bit Manipulation Sliding Window

#212

Rank

#2308EasyFrequency: 34.3%

Divide Array Into Equal Pairs

Array Hash Table Bit Manipulation Counting

#213

Rank

#869HardFrequency: 34.2%

Similar String Groups

Array Hash Table String Depth-First Search Breadth-First Search Union-Find

#214

Rank

#1218MediumFrequency: 34%

Lowest Common Ancestor of Deepest Leaves

Hash Table Tree Depth-First Search Breadth-First Search Binary Tree Binary Lifting Lowest Common Ancestor DP on Trees

#215

Rank

#1256EasyFrequency: 33.7%

Rank Transform of an Array

#216

Rank

#862MediumFrequency: 33.7%

Find And Replace in String

#217

Rank

#1925MediumFrequency: 33.5%

Count Nice Pairs in an Array

#218

Rank

#2118MediumFrequency: 33.5%

Maximum Earnings From Taxi

Array Hash Table Binary Search Dynamic Programming Sorting

#219

Rank

#782EasyFrequency: 33.3%

Jewels and Stones

#220

Rank

#3410HardFrequency: 33.3%

Find Longest Self-Contained Substring

#221

Rank

#1272MediumFrequency: 33.3%

Invalid Transactions

#222

Rank

#3267MediumFrequency: 33.1%

Find Longest Special Substring That Occurs Thrice I

Hash Table String Binary Search Sliding Window Counting

#223

Rank

#3610EasyFrequency: 33.1%

Find X-Sum of All K-Long Subarrays I

Array Hash Table Sliding Window Heap (Priority Queue)

#224

Rank

#616MediumFrequency: 33%

Add Bold Tag in String

Array Hash Table String Trie String Matching Aho–Corasick Algorithm

#225

Rank

#1460MediumFrequency: 32.8%

Number of Substrings Containing All Three Characters

#226

Rank

#3838MediumFrequency: 32.4%

Path Existence Queries in a Graph I

Array Hash Table Binary Search Union-Find Graph Theory

#227

Rank

#1487MediumFrequency: 32.1%

Cinema Seat Allocation

Array Hash Table Greedy Bit Manipulation

#228

Rank

#3265MediumFrequency: 31.8%

Maximum Good Subarray Sum

#229

Rank

#2360HardFrequency: 31.3%

Substring With Largest Variance

Hash Table String Dynamic Programming Enumeration

#230

Rank

#870MediumFrequency: 31.3%

Magic Squares In Grid

Array Hash Table Math Matrix

#231

Rank

#2751MediumFrequency: 31.3%

Sliding Subarray Beauty

#232

Rank

#166MediumFrequency: 31.1%

Fraction to Recurring Decimal

#233

Rank

#2139MediumFrequency: 31.1%

Detect Squares

Array Hash Table Design Counting Data Stream

#234

Rank

#409EasyFrequency: 31.1%

Longest Palindrome

Hash Table String Greedy

#235

Rank

#2634EasyFrequency: 31.1%

Minimum Common Value

Array Hash Table Two Pointers Binary Search

#236

Rank

#2902EasyFrequency: 31.1%

Max Pair Sum in an Array

#237

Rank

#3236EasyFrequency: 31.1%

Smallest Missing Integer Greater Than Sequential Prefix Sum

#238

Rank

#2117MediumFrequency: 30.4%

Find Original Array From Doubled Array

#239

Rank

#2434MediumFrequency: 30.4%

Design a Number Container System

#240

Rank

#652MediumFrequency: 30.4%

Find Duplicate Subtrees

Hash Table Tree Depth-First Search Binary Tree

#241

Rank

#1694MediumFrequency: 30.2%

Make Sum Divisible by P

#242

Rank

#1890MediumFrequency: 30.2%

Sum of Beauty of All Substrings

#243

Rank

#1392EasyFrequency: 29.7%

Find the Difference of Two Arrays

#244

Rank

#1468EasyFrequency: 29.7%

Check If N and Its Double Exist

Array Hash Table Two Pointers Binary Search Sorting

#245

Rank

#2059MediumFrequency: 29.7%

Unique Length-3 Palindromic Subsequences

Hash Table String Bit Manipulation Prefix Sum

#246

Rank

#691HardFrequency: 29.5%

Stickers to Spell Word

Array Hash Table String Dynamic Programming Backtracking Bit Manipulation Memoization Bitmask

#247

Rank

#2433EasyFrequency: 29.5%

Best Poker Hand

#248

Rank

#839MediumFrequency: 29.5%

Short Encoding of Words

#249

Rank

#736HardFrequency: 29.5%

Parse Lisp Expression

Hash Table String Stack Recursion

#250

Rank

#3678MediumFrequency: 29.5%

Design Task Manager

#251

Rank

#1770MediumFrequency: 29.3%

Minimum Deletions to Make Character Frequencies Unique

Hash Table String Greedy Sorting

#252

Rank

#1982MediumFrequency: 29.3%

Remove Duplicates From an Unsorted Linked List

Hash Table Linked List

#253

Rank

#2247MediumFrequency: 29.3%

Number of Unique Flavors After Sharing K Candies

#254

Rank

#2475MediumFrequency: 29.3%

Largest Palindromic Number

Hash Table String Greedy Counting

#255

Rank

#2487MediumFrequency: 29.3%

Optimal Partition of String

Hash Table String Greedy

#256

Rank

#984MediumFrequency: 29.1%

Most Stones Removed with Same Row or Column

Hash Table Depth-First Search Union-Find Graph Theory Bipartite Graph

#257

Rank

#1227EasyFrequency: 29.1%

Number of Equivalent Domino Pairs

#258

Rank

#1619EasyFrequency: 29.1%

Path Crossing

#259

Rank

#2333MediumFrequency: 29.1%

Count Number of Rectangles Containing Each Point

Array Hash Table Binary Search Binary Indexed Tree Sorting

#260

Rank

#2473MediumFrequency: 29.1%

Max Sum of a Pair With Equal Sum of Digits

Array Hash Table Sorting Heap (Priority Queue)

#261

Rank

#2289MediumFrequency: 29.1%

Minimum Operations to Make the Array Alternating

#262

Rank

#4061HardFrequency: 29.1%

Minimum Swaps to Avoid Forbidden Values

#263

Rank

#3501MediumFrequency: 28.9%

Delete Nodes From Linked List Present in Array

Array Hash Table Linked List

#264

Rank

#350EasyFrequency: 28.9%

Intersection of Two Arrays II

Array Hash Table Two Pointers Binary Search Sorting

#265

Rank

#1330MediumFrequency: 28.9%

Longest Arithmetic Subsequence of Given Difference

#266

Rank

#1422MediumFrequency: 28.9%

Divide Array in Sets of K Consecutive Numbers

#267

Rank

#1482EasyFrequency: 28.9%

How Many Numbers Are Smaller Than the Current Number

Array Hash Table Sorting Counting Sort

#268

Rank

#1635EasyFrequency: 28.9%

Number of Good Pairs

#269

Rank

#2378MediumFrequency: 28.1%

Sender With Largest Word Count

#270

Rank

#3646HardFrequency: 28.1%

Sum of Good Subsequences

#271

Rank

#1813MediumFrequency: 27.8%

Maximum Erasure Value

#272

Rank

#2054MediumFrequency: 27.8%

The Number of the Smallest Unoccupied Chair

Array Hash Table Heap (Priority Queue)

#273

Rank

#2833MediumFrequency: 27.8%

Count Zero Request Servers

Array Hash Table Sliding Window Sorting

#274

Rank

#3819MediumFrequency: 27.8%

Count Covered Buildings

#275

Rank

#1176MediumFrequency: 27.8%

Design A Leaderboard

Hash Table Design Sorting

#276

Rank

#3933MediumFrequency: 27.8%

Minimum Jumps to Reach End via Prime Teleportation

Array Hash Table Math Breadth-First Search Number Theory

#277

Rank

#2135HardFrequency: 27.7%

Maximum Number of Ways to Partition an Array

Array Hash Table Counting Enumeration Prefix Sum

#278

Rank

#1604MediumFrequency: 27.7%

Least Number of Unique Integers after K Removals

Array Hash Table Greedy Sorting Counting

#279

Rank

#353MediumFrequency: 27.7%

Design Snake Game

Array Hash Table Design Queue Simulation

#280

Rank

#3445MediumFrequency: 27.7%

Lexicographically Minimum String After Removing Stars

Hash Table String Stack Greedy Heap (Priority Queue)

#281

Rank

#519MediumFrequency: 27.3%

Widest Pair of Indices With Equal Range Sum

#282

Rank

#1143MediumFrequency: 27.3%

Find Smallest Common Element in All Rows

Array Hash Table Binary Search Matrix Counting

#283

Rank

#1363EasyFrequency: 27.3%

Greatest English Letter in Upper and Lower Case

Hash Table String Enumeration

#284

Rank

#1473MediumFrequency: 27.3%

Find the Longest Substring Containing Vowels in Even Counts

Hash Table String Bit Manipulation Prefix Sum

#285

Rank

#1743MediumFrequency: 27.3%

Count Substrings That Differ by One Character

Hash Table String Dynamic Programming Enumeration

#286

Rank

#1799HardFrequency: 27.3%

Minimum Incompatibility

Array Hash Table Dynamic Programming Bit Manipulation Bitmask

#287

Rank

#2524EasyFrequency: 27.3%

Largest Positive Integer That Exists With Its Negative

#288

Rank

#3228MediumFrequency: 27.3%

Maximum Size of a Set After Removals

#289

Rank

#3315HardFrequency: 27.3%

Maximum Number of Intersections on the Chart

Array Hash Table Math Binary Indexed Tree Geometry Sweep Line Sorting

#290

Rank

#3362HardFrequency: 27.3%

Find the Median of the Uniqueness Array

Array Hash Table Binary Search Sliding Window

#291

Rank

#4083MediumFrequency: 27.3%

Stable Subarrays With Equal Boundary and Interior Sum

#292

Rank

#1064MediumFrequency: 27.2%

Smallest Integer Divisible by K

Hash Table Math Pigeonhole Principle

#293

Rank

#1776MediumFrequency: 27.2%

Minimum Operations to Reduce X to Zero

Array Hash Table Binary Search Sliding Window Prefix Sum

#294

Rank

#594EasyFrequency: 27.2%

Longest Harmonious Subsequence

Array Hash Table Sliding Window Sorting Counting

#295

Rank

#554MediumFrequency: 26.7%

Brick Wall

#296

Rank

#1149EasyFrequency: 26.7%

Intersection of Three Sorted Arrays

Array Hash Table Binary Search Counting

#297

Rank

#1848EasyFrequency: 26.7%

Sum of Unique Elements

#298

Rank

#3707MediumFrequency: 26.7%

Find the Most Common Response

#299

Rank

#508MediumFrequency: 26.5%

Most Frequent Subtree Sum

Hash Table Tree Depth-First Search Binary Tree DP on Trees

#300

Rank

#837EasyFrequency: 26.5%

Most Common Word

#301

Rank

#1044EasyFrequency: 26.5%

Find Common Characters

#302

Rank

#1624MediumFrequency: 26.5%

Clone Binary Tree With Random Pointer

Hash Table Tree Depth-First Search Breadth-First Search Binary Tree

#303

Rank

#1798MediumFrequency: 26.5%

Max Number of K-Sum Pairs

#304

Rank

#1816MediumFrequency: 26.5%

Lowest Common Ancestor of a Binary Tree IV

Hash Table Tree Depth-First Search Binary Tree Binary Lifting Lowest Common Ancestor

#305

Rank

#2116EasyFrequency: 26.5%

Count Number of Pairs With Absolute Difference K

#306

Rank

#2340HardFrequency: 26.5%

Total Appeal of A String

Hash Table String Dynamic Programming

#307

Rank

#2362MediumFrequency: 26.5%

Minimum Rounds to Complete All Tasks

#308

Rank

#2413MediumFrequency: 26.5%

Smallest Number in Infinite Set

#309

Rank

#2677MediumFrequency: 26.5%

Cousins in Binary Tree II

Hash Table Tree Depth-First Search Breadth-First Search Binary Tree

#310

Rank

#3276MediumFrequency: 26.5%

Minimum Number of Pushes to Type Word II

#311

Rank

#3408EasyFrequency: 26.5%

Count the Number of Special Characters I

#312

Rank

#3656EasyFrequency: 26.5%

Minimum Number of Operations to Make Elements in Array Distinct

#313

Rank

#1364MediumFrequency: 26.3%

Tuple with Same Product

#314

Rank

#2427EasyFrequency: 26.3%

First Letter to Appear Twice

Hash Table String Bit Manipulation Counting

#315

Rank

#3699MediumFrequency: 26.3%

Count Special Subsequences

Array Hash Table Math Enumeration

#316

Rank

#1483MediumFrequency: 25.4%

Rank Teams by Votes

Array Hash Table String Sorting Counting

#317

Rank

#2161MediumFrequency: 25.4%

Stock Price Fluctuation

Hash Table Design Heap (Priority Queue)Data Stream Ordered Set

#318

Rank

#299MediumFrequency: 25.4%

Bulls and Cows

#319

Rank

#2766MediumFrequency: 25.4%

Find the Prefix Common Array of Two Arrays

#320

Rank

#2448MediumFrequency: 25.4%

Count Number of Bad Pairs

#321

Rank

#1741EasyFrequency: 25.3%

Sort Array by Increasing Frequency

#322

Rank

#1160MediumFrequency: 25.3%

Letter Tile Possibilities

Hash Table String Backtracking Counting

#323

Rank

#1612MediumFrequency: 25.3%

Avoid Flood in The City

Array Hash Table Binary Search Greedy Heap (Priority Queue)

#324

Rank

#433MediumFrequency: 25.1%

Minimum Genetic Mutation

Hash Table String Breadth-First Search Bidirectional Search

#325

Rank

#711HardFrequency: 25.1%

Number of Distinct Islands II

Array Hash Table Depth-First Search Breadth-First Search Union-Find Sorting Matrix Hash Function

#326

Rank

#926MediumFrequency: 25.1%

Find and Replace Pattern

#327

Rank

#1381HardFrequency: 25.1%

Maximum Score Words Formed by Letters

Array Hash Table String Dynamic Programming Backtracking Bit Manipulation Counting Bitmask

#328

Rank

#1436MediumFrequency: 25.1%

Get Watched Videos by Your Friends

Array Hash Table Breadth-First Search Graph Theory Sorting

#329

Rank

#1620MediumFrequency: 25.1%

Check If Array Pairs Are Divisible by k

#330

Rank

#3299MediumFrequency: 25.1%

Find the Maximum Number of Elements in Subset

#331

Rank

#3710HardFrequency: 25.1%

Design an Array Statistics Tracker

Hash Table Binary Search Design Queue Heap (Priority Queue)Data Stream Ordered Set

#332

Rank

#3894MediumFrequency: 25.1%

Maximize Y‑Sum by Picking a Triplet of Distinct X‑Values

Array Hash Table Greedy Sorting Heap (Priority Queue)

#333

Rank

#4174HardFrequency: 25.1%

Lexicographically Maximum MEX Array

Array Hash Table Greedy Queue

#334

Rank

#3871EasyFrequency: 25.1%

Minimum Deletions for At Most K Distinct Characters

#335

Rank

#264MediumFrequency: 25%

Ugly Number II

Hash Table Math Dynamic Programming Heap (Priority Queue)

#336

Rank

#952MediumFrequency: 25%

Word Subsets

#337

Rank

#3788EasyFrequency: 25%

Maximum Unique Subarray Sum After Deletion

#338

Rank

#358HardFrequency: 24.6%

Rearrange String k Distance Apart

Hash Table String Greedy Sorting Heap (Priority Queue)Counting

#339

Rank

#2689HardFrequency: 24.6%

Rearranging Fruits

Array Hash Table Greedy Sort

#340

Rank

#2626MediumFrequency: 24.6%

Count the Number of Good Subarrays

#341

Rank

#3225MediumFrequency: 24.6%

Length of Longest Subarray With at Most K Frequency

#342

Rank

#925MediumFrequency: 24.4%

Construct Binary Tree from Preorder and Postorder Traversal

Array Hash Table Divide and Conquer Tree Binary Tree

#343

Rank

#950EasyFrequency: 24.4%

X of a Kind in a Deck of Cards

Array Hash Table Math Counting Number Theory Euclidean Algorithm Greatest Common Divisor

#344

Rank

#965EasyFrequency: 24.4%

Unique Email Addresses

#345

Rank

#1934MediumFrequency: 24.4%

Evaluate the Bracket Pairs of a String

#346

Rank

#2055MediumFrequency: 24.4%

Describe the Painting

Array Hash Table Sorting Prefix Sum

#347

Rank

#2707EasyFrequency: 24.4%

Merge Two 2D Arrays by Summing Values

Array Hash Table Two Pointers

#348

Rank

#3773EasyFrequency: 24.4%

Minimum Pair Removal to Sort Array I

Array Hash Table Linked List Heap (Priority Queue)Simulation Doubly-Linked List Ordered Set

#349

Rank

#1074EasyFrequency: 23.6%

High Five

Array Hash Table Sorting Heap (Priority Queue)

#350

Rank

#1140MediumFrequency: 23.6%

Distant Barcodes

Array Hash Table Greedy Sorting Heap (Priority Queue)Counting

#351

Rank

#1883MediumFrequency: 23.6%

Find Distance in a Binary Tree

Hash Table Tree Depth-First Search Breadth-First Search Binary Tree Binary Lifting Lowest Common Ancestor

#352

Rank

#2348MediumFrequency: 23.6%

Count Number of Texts

Hash Table Math String Dynamic Programming

#353

Rank

#2429MediumFrequency: 23.6%

Design a Food Rating System

Array Hash Table String Design Heap (Priority Queue)Ordered Set

#354

Rank

#2884HardFrequency: 23.6%

Length of the Longest Valid Substring

Array Hash Table String Sliding Window

#355

Rank

#2979MediumFrequency: 23.6%

Maximize the Profit as the Salesman

Array Hash Table Binary Search Dynamic Programming Sorting

#356

Rank

#3094MediumFrequency: 23.6%

Minimum Number of Operations to Make Array Empty

#357

Rank

#3210MediumFrequency: 23.6%

Count Beautiful Substrings I

Hash Table Math String Enumeration Number Theory Prefix Sum

#358

Rank

#3363MediumFrequency: 23.6%

Most Frequent IDs

Array Hash Table Heap (Priority Queue)Ordered Set

#359

Rank

#4301MediumFrequency: 23.6%

Minimize Array Sum Using Divisible Replacements

Array Hash Table Math Greedy Number Theory

#360

Rank

#746HardFrequency: 23.4%

Prefix and Suffix Search

Array Hash Table String Design Trie

#361

Rank

#1459MediumFrequency: 23.4%

Apply Discount Every n Orders

Array Hash Table Design

#362

Rank

#1960EasyFrequency: 23.4%

Check if the Sentence Is Pangram

#363

Rank

#3955HardFrequency: 23.4%

Threshold Majority Queries

Array Hash Table Binary Search Divide and Conquer Counting Prefix Sum

#364

Rank

#1557MediumFrequency: 23.3%

Check If a String Contains All Binary Codes of Size K

Hash Table String Bit Manipulation Rolling Hash Hash Function Directed Acyclic Graph

#365

Rank

#876MediumFrequency: 23.3%

Hand of Straights

#366

Rank

#3603HardFrequency: 23.3%

Check if DFS Strings Are Palindromes

Array Hash Table String Tree Depth-First Search Hash Function

#367

Rank

#4107EasyFrequency: 23.3%

Find Missing Elements

#368

Rank

#1006MediumFrequency: 22.5%

Vowel Spellchecker

#369

Rank

#676MediumFrequency: 22.1%

Implement Magic Dictionary

Hash Table String Depth-First Search Design Trie

#370

Rank

#947MediumFrequency: 22.1%

Online Election

Array Hash Table Binary Search Design

#371

Rank

#989HardFrequency: 22.1%

Largest Component Size by Common Factor

Array Hash Table Math Union-Find Number Theory Prime Factorization

#372

Rank

#1447HardFrequency: 22.1%

Jump Game IV

#373

Rank

#1632MediumFrequency: 22.1%

Number of Good Ways to Split a String

Hash Table String Dynamic Programming Bit Manipulation Prefix Sum

#374

Rank

#1715MediumFrequency: 22.1%

Split a String Into the Max Number of Unique Substrings

Hash Table String Backtracking

#375

Rank

#1752MediumFrequency: 22.1%

Arithmetic Subarrays

#376

Rank

#2505HardFrequency: 22.1%

Number of Good Paths

Array Hash Table Tree Union-Find Graph Theory Sorting

#377

Rank

#2215EasyFrequency: 22.1%

Finding 3-Digit Even Numbers

Array Hash Table Recursion Sorting Enumeration

#378

Rank

#4047HardFrequency: 22.1%

Longest Balanced Subarray II

Array Hash Table Divide and Conquer Segment Tree Prefix Sum

#379

Rank

#1777MediumFrequency: 22%

Determine if Two Strings Are Close

Hash Table String Sorting Counting

#380

Rank

#906MediumFrequency: 22%

Walking Robot Simulation

#381

Rank

#737MediumFrequency: 22%

Sentence Similarity II

Array Hash Table String Depth-First Search Breadth-First Search Union-Find

#382

Rank

#994MediumFrequency: 21.9%

Prison Cells After N Days

Array Hash Table Math Bit Manipulation Floyd's Cycle Finding Algorithm

#383

Rank

#1644HardFrequency: 21.9%

Maximum Number of Non-Overlapping Substrings

Hash Table String Greedy Sorting

#384

Rank

#2388MediumFrequency: 21.9%

Replace Elements in an Array

#385

Rank

#2405MediumFrequency: 21.9%

Minimum Number of Keypresses

#386

Rank

#2555MediumFrequency: 21.9%

Design SQL

Array Hash Table String Design

#387

Rank

#2561EasyFrequency: 21.9%

Number of Distinct Averages

#388

Rank

#2669MediumFrequency: 21.9%

Find the Substring With Maximum Cost

Array Hash Table String Dynamic Programming

#389

Rank

#3242EasyFrequency: 21.9%

Count Elements With Maximum Frequency

#390

Rank

#3354MediumFrequency: 21.9%

Replace Question Marks in String to Minimize Its Value

Hash Table String Greedy Sorting Heap (Priority Queue)Counting

#391

Rank

#3166MediumFrequency: 21.9%

Minimum Number of Groups to Create a Valid Assignment

#392

Rank

#929MediumFrequency: 21.5%

Groups of Special-Equivalent Strings

#393

Rank

#1556EasyFrequency: 21.5%

Make Two Arrays Equal by Reversing Subarrays

#394

Rank

#2140HardFrequency: 21.5%

Longest Subsequence Repeated k Times

Hash Table Two Pointers String Backtracking Counting Enumeration

#395

Rank

#2483MediumFrequency: 21.5%

Task Scheduler II

#396

Rank

#2204EasyFrequency: 21.5%

Find Subsequence of Length K With the Largest Sum

Array Hash Table Sorting Heap (Priority Queue)

#397

Rank

#4118MediumFrequency: 21.5%

Design Ride Sharing System

Hash Table Design Queue Data Stream

#398

Rank

#391HardFrequency: 20.9%

Perfect Rectangle

Array Hash Table Math Geometry Sweep Line

#399

Rank

#1986HardFrequency: 20.9%

Largest Color Value in a Directed Graph

Hash Table String Dynamic Programming Graph Theory Topological Sort Memoization Counting Directed Acyclic Graph

#400

Rank

#681MediumFrequency: 20.9%

Next Closest Time

Hash Table String Backtracking Enumeration

#401

Rank

#3905MediumFrequency: 20.9%

Partition String

Hash Table String Trie Simulation

#402

Rank

#900MediumFrequency: 20.9%

Reordered Power of 2

Hash Table Math Sorting Counting Enumeration

#403

Rank

#964HardFrequency: 20.3%

Minimize Malware Spread II

Array Hash Table Depth-First Search Breadth-First Search Union-Find Graph Theory

#404

Rank

#3754MediumFrequency: 20.3%

Maximum Manhattan Distance After K Changes

Hash Table Math String Counting

#405

Rank

#835MediumFrequency: 20.3%

Linked List Components

Array Hash Table Linked List

#406

Rank

#2044MediumFrequency: 20.3%

Number of Wonderful Substrings

Hash Table String Bit Manipulation Prefix Sum

#407

Rank

#1084MediumFrequency: 20%

Find K-Length Substrings With No Repeated Characters

#408

Rank

#1098EasyFrequency: 20%

Largest Unique Number

#409

Rank

#1145HardFrequency: 20%

Number of Submatrices That Sum to Target

Array Hash Table Matrix Prefix Sum

#410

Rank

#1634MediumFrequency: 20%

Clone N-ary Tree

Hash Table Tree Depth-First Search Breadth-First Search

#411

Rank

#1891HardFrequency: 20%

Count Pairs Of Nodes

Array Hash Table Two Pointers Binary Search Graph Theory Sorting Counting

#412

Rank

#1919MediumFrequency: 20%

Sort Features by Popularity

#413

Rank

#1937HardFrequency: 20%

Maximize the Beauty of the Garden

Array Hash Table Greedy Prefix Sum

#414

Rank

#2003MediumFrequency: 20%

Distinct Numbers in Each Subarray

#415

Rank

#2163EasyFrequency: 20%

Kth Distinct String in an Array

#416

Rank

#2372EasyFrequency: 20%

Rearrange Characters to Make Target String

#417

Rank

#2586MediumFrequency: 20%

Longest Square Streak in an Array

Array Hash Table Binary Search Dynamic Programming Sorting

#418

Rank

#2834MediumFrequency: 20%

Relocate Marbles

Array Hash Table Sorting Simulation

#419

Rank

#2954MediumFrequency: 20%

Maximum Sum of Almost Unique Subarray

#420

Rank

#3139HardFrequency: 20%

Subarrays Distinct Element Sum of Squares II

Array Hash Table Binary Indexed Tree Segment Tree

#421

Rank

#3182MediumFrequency: 20%

Maximum Linear Stock Score

#422

Rank

#3208HardFrequency: 20%

Count Beautiful Substrings II

Hash Table Math String Number Theory Prefix Sum

#423

Rank

#3343EasyFrequency: 20%

Count Numbers With Unique Digits II

Hash Table Math Dynamic Programming

#424

Rank

#3405MediumFrequency: 20%

Count the Number of Special Characters II

#425

Rank

#356MediumFrequency: 19.5%

Line Reflection

#426

Rank

#734EasyFrequency: 19.5%

Sentence Similarity

#427

Rank

#884HardFrequency: 19.5%

K-Similar Strings

Hash Table String Breadth-First Search

#428

Rank

#1039EasyFrequency: 19.5%

Find the Town Judge

Array Hash Table Graph Theory

#429

Rank

#1065MediumFrequency: 19.5%

Binary String With Substrings Representing 1 To N

Hash Table String Bit Manipulation Sliding Window

#430

Rank

#1123EasyFrequency: 19.5%

Single-Row Keyboard

#431

Rank

#1238MediumFrequency: 19.5%

Alphabet Board Path

#432

Rank

#2312EasyFrequency: 19.5%

Most Frequent Number Following Key In an Array

#433

Rank

#2377EasyFrequency: 19.5%

Check if Number Has Equal Digit Count and Digit Value

#434

Rank

#2512MediumFrequency: 19.5%

Longest Uploaded Prefix

Hash Table Binary Search Union-Find Design Binary Indexed Tree Segment Tree Heap (Priority Queue)Ordered Set

#435

Rank

#2525MediumFrequency: 19.5%

Count Number of Distinct Integers After Reverse Operations

#436

Rank

#3057HardFrequency: 19.5%

Count K-Subsequences of a String With Maximum Beauty

Hash Table Math String Greedy Sorting Combinatorics Fermat's Little Theorem

#437

Rank

#447MediumFrequency: 19.5%

Number of Boomerangs

#438

Rank

#522MediumFrequency: 19.5%

Longest Uncommon Subsequence II

Array Hash Table Two Pointers String Sorting

#439

Rank

#659MediumFrequency: 19.5%

Split Array into Consecutive Subsequences

Array Hash Table Greedy Heap (Priority Queue)

#440

Rank

#797MediumFrequency: 19.5%

Rabbits in Forest

Array Hash Table Math Greedy

#441

Rank

#829MediumFrequency: 19.5%

Subdomain Visit Count

#442

Rank

#4183MediumFrequency: 19.5%

Count Caesar Cipher Pairs

Array Hash Table Math String Counting

#443

Rank

#2300MediumFrequency: 19.5%

Construct String With Repeat Limit

Hash Table String Greedy Heap (Priority Queue)Counting

#444

Rank

#2107MediumFrequency: 19.5%

Find Unique Binary String

Array Hash Table String Backtracking

#445

Rank

#3753EasyFrequency: 19.5%

Maximum Difference Between Even and Odd Frequency I

#446

Rank

#1793MediumFrequency: 19.5%

Minimum Moves to Make Array Complementary

#447

Rank

#4074MediumFrequency: 19.5%

Count Subarrays With Majority Element I

Array Hash Table Divide and Conquer Segment Tree Merge Sort Counting Prefix Sum

#448

Rank

#749EasyFrequency: 18%

Shortest Completing Word

#449

Rank

#762EasyFrequency: 18%

Find Anagram Mappings

#450

Rank

#1188HardFrequency: 18%

Brace Expansion II

Hash Table String Backtracking Stack Breadth-First Search Sorting

#451

Rank

#1573MediumFrequency: 18%

Find Two Non-overlapping Sub-arrays Each With Target Sum

Array Hash Table Binary Search Dynamic Programming Sliding Window

#452

Rank

#1650MediumFrequency: 18%

Find Root of N-Ary Tree

Hash Table Bit Manipulation Tree Depth-First Search

#453

Rank

#1722MediumFrequency: 18%

Throne Inheritance

Hash Table Tree Depth-First Search Design

#454

Rank

#1758HardFrequency: 18%

Distribute Repeating Integers

Array Hash Table Dynamic Programming Backtracking Bit Manipulation Counting Bitmask

#455

Rank

#1832HardFrequency: 18%

Minimum Operations to Make a Subsequence

Array Hash Table Binary Search Greedy Longest Increasing Subsequence

#456

Rank

#2104MediumFrequency: 18%

Operations on Tree

Array Hash Table Tree Depth-First Search Breadth-First Search Design

#457

Rank

#2447EasyFrequency: 18%

Merge Similar Items

Array Hash Table Sorting Ordered Set

#458

Rank

#2615MediumFrequency: 18%

Make Number of Distinct Characters Equal

#459

Rank

#2849HardFrequency: 18%

Sum of Imbalance Numbers of All Subarrays

#460

Rank

#3266MediumFrequency: 18%

Find Longest Special Substring That Occurs Thrice II

Hash Table String Binary Search Sliding Window Counting

#461

Rank

#3384MediumFrequency: 18%

Minimum Number of Operations to Make Word K-Periodic

#462

Rank

#3416MediumFrequency: 18%

Sum of Digit Differences of All Pairs

#463

Rank

#2338MediumFrequency: 18%

Minimum Consecutive Cards to Pick Up

#464

Rank

#379MediumFrequency: 18%

Design Phone Directory

Array Hash Table Linked List Design Queue

#465

Rank

#816EasyFrequency: 18%

Design HashSet

Array Hash Table Linked List Design Hash Function

#466

Rank

#924EasyFrequency: 18%

Fair Candy Swap

Array Hash Table Binary Search Sorting

#467

Rank

#3799EasyFrequency: 18%

Unique 3-Digit Even Numbers

Array Hash Table Recursion Enumeration

#468

Rank

#3629MediumFrequency: 18%

Total Characters in String After Transformations I

Hash Table Math String Dynamic Programming Counting

#469

Rank

#4020MediumFrequency: 18%

Lexicographically Smallest Permutation Greater Than Target

Hash Table String Greedy Counting Enumeration

#470

Rank

#4055MediumFrequency: 18%

Longest Balanced Substring I

Hash Table String Counting Enumeration

#471

Rank

#609MediumFrequency: 17%

Find Duplicate File in System

#472

Rank

#3349EasyFrequency: 17%

Maximum Length Substring With Two Occurrences

#473

Rank

#288MediumFrequency: 16.4%

Unique Word Abbreviation

Array Hash Table String Design

#474

Rank

#510MediumFrequency: 16.4%

Count Subarrays With More Ones Than Zeros

Array Hash Table Binary Search Divide and Conquer Binary Indexed Tree Segment Tree Merge Sort Ordered Set

#475

Rank

#531MediumFrequency: 16.4%

Lonely Pixel I

#476

Rank

#533MediumFrequency: 16.4%

Lonely Pixel II

#477

Rank

#760MediumFrequency: 16.4%

Bold Words in String

Array Hash Table String Trie String Matching Aho–Corasick Algorithm

#478

Rank

#913MediumFrequency: 16.4%

Random Flip Matrix

Hash Table Math Reservoir Sampling Randomized

#479

Rank

#991MediumFrequency: 16.4%

Array of Doubled Pairs

#480

Rank

#1124HardFrequency: 16.4%

String Transforms Into Another String

Hash Table String Graph Theory

#481

Rank

#1169MediumFrequency: 16.4%

Largest Values From Labels

Array Hash Table Greedy Sorting Counting

#482

Rank

#1273MediumFrequency: 16.4%

Compare Strings by Frequency of the Smallest Character

Array Hash Table String Binary Search Sorting

#483

Rank

#1387MediumFrequency: 16.4%

Find Elements in a Contaminated Binary Tree

Hash Table Tree Depth-First Search Breadth-First Search Design Binary Tree

#484

Rank

#1562MediumFrequency: 16.4%

People Whose List of Favorite Companies Is Not a Subset of Another List

#485

Rank

#1649MediumFrequency: 16.4%

Maximum Number of Non-Overlapping Subarrays With Sum Equals Target

Array Hash Table Greedy Prefix Sum

#486

Rank

#1684MediumFrequency: 16.4%

Find Latest Group of Size M

Array Hash Table Binary Search Simulation

#487

Rank

#1750MediumFrequency: 16.4%

Check If Two Expression Trees are Equivalent

Hash Table Tree Depth-First Search Binary Tree Counting

#488

Rank

#1796MediumFrequency: 16.4%

Correct a Binary Tree

Hash Table Tree Depth-First Search Breadth-First Search Binary Tree

#489

Rank

#1859MediumFrequency: 16.4%

Change Minimum Characters to Satisfy One of Three Conditions

Hash Table String Counting Prefix Sum

#490

Rank

#1943MediumFrequency: 16.4%

Count Pairs of Equal Substrings With Minimum Difference

Hash Table String Greedy

#491

Rank

#2071MediumFrequency: 16.4%

Longest Common Subsequence Between Sorted Arrays

#492

Rank

#2241HardFrequency: 16.4%

Recover the Original Array

Array Hash Table Two Pointers Sorting Enumeration

#493

Rank

#2256MediumFrequency: 16.4%

Count Words Obtained After Adding a Letter

Array Hash Table String Bit Manipulation Sorting

#494

Rank

#2396HardFrequency: 16.4%

Design Video Sharing Platform

Hash Table Design Heap (Priority Queue)

#495

Rank

#2435HardFrequency: 16.4%

Shortest Impossible Sequence of Rolls

#496

Rank

#2489HardFrequency: 16.4%

Sort Array by Moving Items to Empty Space

#497

Rank

#2953MediumFrequency: 16.4%

Count Pairs of Points With Distance k

#498

Rank

#3212HardFrequency: 16.4%

Count the Number of Good Partitions

Array Hash Table Math Combinatorics

#499

Rank

#3314MediumFrequency: 16.4%

Most Frequent Prime

Array Hash Table Math Matrix Counting Enumeration Number Theory Primality Test Sieve Theory Prime Number Sieve

#500

Rank

#2226EasyFrequency: 16.4%

Rings and Rods

#501

Rank

#500EasyFrequency: 16.4%

Keyboard Row

#502

Rank

#1217EasyFrequency: 16.4%

Relative Sort Array

Array Hash Table Sorting Counting Sort Quicksort Bubble Sort

#503

Rank

#3583HardFrequency: 16.4%

Sorted GCD Pair Queries

Array Hash Table Math Binary Search Combinatorics Counting Number Theory Prefix Sum Euclidean Algorithm Greatest Common Divisor

#504

Rank

#1001EasyFrequency: 16.4%

N-Repeated Element in Size 2N Array

Array Hash Table Pigeonhole Principle

#505

Rank

#2174MediumFrequency: 16.4%

Next Greater Numerically Balanced Number

Hash Table Math Backtracking Counting Enumeration

#506

Rank

#3970MediumFrequency: 16.4%

Power Update After K-th Largest Insertion I

Array Hash Table Math Segment Tree Sorting Heap (Priority Queue)

#507

Rank

#1297EasyFrequency: 16.1%

Maximum Number of Balloons

#508

Rank

#1353EasyFrequency: 15.7%

Find Resultant Array After Removing Anagrams

#509

Rank

#905MediumFrequency: 15.7%

Length of Longest Fibonacci Subsequence

#510

Rank

#3437MediumFrequency: 15.7%

Maximum Total Damage With Spell Casting

Array Hash Table Two Pointers Binary Search Dynamic Programming Sorting Counting

#511

Rank

#3653MediumFrequency: 15.7%

Maximum Subarray Sum With Length Divisible by K

#512

Rank

#3772HardFrequency: 15.7%

Minimum Pair Removal to Sort Array II

Array Hash Table Linked List Heap (Priority Queue)Simulation Doubly-Linked List Ordered Set

#513

Rank

#2755MediumFrequency: 14.6%

Extra Characters in a String

Array Hash Table String Dynamic Programming Trie

#514

Rank

#1786EasyFrequency: 14.6%

Count the Number of Consistent Strings

Array Hash Table String Bit Manipulation Counting

#515

Rank

#1500EasyFrequency: 14.6%

Count Largest Group

Hash Table Math Counting

#516

Rank

#3548HardFrequency: 14.4%

Find the Count of Good Integers

Hash Table Math Combinatorics Enumeration

#517

Rank

#3872EasyFrequency: 14.4%

Find Most Frequent Vowel and Consonant

#518

Rank

#599EasyFrequency: 13.2%

Minimum Index Sum of Two Lists

#519

Rank

#2599MediumFrequency: 13.2%

Take K of Each Character From Left and Right

#520

Rank

#2661MediumFrequency: 13.2%

Smallest Missing Non-negative Integer After Operations

Array Hash Table Math Greedy

#521

Rank

#4045MediumFrequency: 13.2%

Longest Balanced Subarray I

Array Hash Table Divide and Conquer Segment Tree Prefix Sum

#522

Rank

#4056MediumFrequency: 13.2%

Longest Balanced Substring II

Hash Table String Prefix Sum

#523

Rank

#2685MediumFrequency: 13.2%

First Completely Painted Row or Column

#524

Rank

#3434MediumFrequency: 12.6%

Find the Number of Distinct Colors Among the Balls

#525

Rank

#3581EasyFrequency: 12.6%

The Two Sneaky Numbers of Digitville

#526

Rank

#2274EasyFrequency: 12.6%

Keep Multiplying Found Values by Two

Array Hash Table Sorting Simulation

#527

Rank

#2428MediumFrequency: 12%

Equal Row and Column Pairs

Array Hash Table Matrix Simulation

#528

Rank

#2060HardFrequency: 12%

Merge BSTs to Create Single BST

Array Hash Table Tree Depth-First Search Binary Search Tree Binary Tree

#529

Rank

#1147MediumFrequency: 12%

Flip Columns For Maximum Number of Equal Rows

#530

Rank

#3621EasyFrequency: 12%

Minimum Operations to Make Array Values Equal to K

#531

Rank

#1264EasyFrequency: 12%

Maximum Number of Words You Can Type

#532

Rank

#1987EasyFrequency: 12%

Substrings of Size Three with Distinct Characters

Hash Table String Sliding Window Counting

#533

Rank

#4139MediumFrequency: 12%

Minimum Absolute Distance Between Mirror Pairs

#534

Rank

#3777HardFrequency: 12%

Maximum Product of Subsequences With an Alternating Sum Equal to K

#535

Rank

#3428EasyFrequency: 11.4%

Find the XOR of Numbers Which Appear Twice

#536

Rank

#454MediumFrequency: 11.4%

4Sum II

#537

Rank

#1866MediumFrequency: 11.4%

Restore the Array From Adjacent Pairs

Array Hash Table Depth-First Search

#538

Rank

#3885MediumFrequency: 11.4%

Count Special Triplets

#539

Rank

#2532EasyFrequency: 10.5%

Remove Letter To Equalize Frequency

#540

Rank

#920EasyFrequency: 10.5%

Uncommon Words from Two Sentences

#541

Rank

#423MediumFrequency: 10.5%

Reconstruct Original Digits from English

#542

Rank

#3688HardFrequency: 10.5%

Maximize Subarray Sum After Removing All Occurrences of One Element

Array Hash Table Divide and Conquer Dynamic Programming Segment Tree Prefix Sum

#543

Rank

#2721MediumFrequency: 10.5%

Sum of Distances

#544

Rank

#3206EasyFrequency: 10.5%

Find Common Elements Between Two Arrays

#545

Rank

#1834MediumFrequency: 10.5%

Minimum Number of People to Teach

#546

Rank

#3834MediumFrequency: 10.5%

Minimum Operations to Convert All Elements to Zero

Array Hash Table Stack Greedy Monotonic Stack

#547

Rank

#3250MediumFrequency: 10.5%

Maximum Square Area by Removing Fences From a Field

#548

Rank

#1354MediumFrequency: 10.5%

Find Players With Zero or One Losses

Array Hash Table Sorting Counting

#549

Rank

#2892EasyFrequency: 10.5%

Check if Array is Good

#550

Rank

#3813HardFrequency: 10.5%

Smallest Palindromic Rearrangement II

Hash Table Math String Combinatorics Counting

#551

Rank

#1512MediumFrequency: 10.3%

Design Underground System

Hash Table String Design

#552

Rank

#1547EasyFrequency: 10.3%

Destination City

#553

Rank

#2695MediumFrequency: 10.3%

Find Score of an Array After Marking All Elements

Array Hash Table Sorting Heap (Priority Queue)Simulation

#554

Rank

#2129MediumFrequency: 10.3%

Number of Pairs of Interchangeable Rectangles

Array Hash Table Math Counting Number Theory

#555

Rank

#352HardFrequency: 8.1%

Data Stream as Disjoint Intervals

Hash Table Binary Search Union-Find Design Data Stream Ordered Set

#556

Rank

#2079HardFrequency: 8.1%

Delete Duplicate Folders in System

Array Hash Table String Depth-First Search Trie Sorting Hash Function

#557

Rank

#2486EasyFrequency: 8.1%

Most Frequent Even Element

#558

Rank

#781HardFrequency: 8.1%

Basic Calculator IV

Hash Table Math String Stack Recursion

#559

Rank

#1470MediumFrequency: 8.1%

Tweet Counts Per Frequency

Hash Table String Binary Search Design Sorting Ordered Set

#560

Rank

#3630HardFrequency: 8.1%

Total Characters in String After Transformations II

Hash Table Math String Dynamic Programming Counting

#561

Rank

#2356MediumFrequency: 8.1%

Largest Combination With Bitwise AND Greater Than Zero

Array Hash Table Bit Manipulation Counting

#562

Rank

#2915MediumFrequency: 8.1%

Count of Interesting Subarrays

#563

Rank

#2888MediumFrequency: 8.1%

Minimum Index of a Valid Split

#564

Rank

#3847MediumFrequency: 8.1%

Minimum Swaps to Sort by Digit Sum

#565

Rank

#959MediumFrequency: 8.1%

3Sum With Multiplicity

Array Hash Table Two Pointers Sorting Counting

#566

Rank

#2406EasyFrequency: 8.1%

Decode the Message

#567

Rank

#3797MediumFrequency: 8.1%

Design Spreadsheet

Array Hash Table String Design Matrix

#568

Rank

#3592HardFrequency: 8.1%

Find X-Sum of All K-Long Subarrays II

Array Hash Table Sliding Window Heap (Priority Queue)

#569

Rank

#3850HardFrequency: 8.1%

Equal Sum Grid Partition II

Array Hash Table Matrix Enumeration Prefix Sum

#570

Rank

#457MediumFrequency: 8.1%

Circular Array Loop

Array Hash Table Two Pointers Floyd's Cycle Finding Algorithm

#571

Rank

#1757MediumFrequency: 7.3%

Minimum Jumps to Reach Home

#572

Rank

#3403MediumFrequency: 7.3%

Minimum Substring Partition of Equal Character Frequency

Hash Table String Dynamic Programming Counting

#573

Rank

#3827MediumFrequency: 7.3%

Implement Router

Array Hash Table Binary Search Design Queue Ordered Set

#574

Rank

#2122EasyFrequency: 7.3%

Count Special Quadruplets

#575

Rank

#2444MediumFrequency: 7.3%

Longest Ideal Subsequence

Hash Table String Dynamic Programming

#576

Rank

#3569MediumFrequency: 7.3%

Count of Substrings Containing Every Vowel and K Consonants II

#577

Rank

#4186EasyFrequency: 7.3%

Count Residue Prefixes

#578

Rank

#1746EasyFrequency: 7.3%

Largest Substring Between Two Equal Characters

#579

Rank

#2832MediumFrequency: 7.3%

Find the Longest Equal Subarray

Array Hash Table Binary Search Sliding Window

#580

Rank

#2978MediumFrequency: 7.3%

Check if Strings Can be Made Equal With Operations II

#581

Rank

#4119MediumFrequency: 7.3%

Minimum Distance Between Three Equal Elements II

#582

Rank

#1294MediumFrequency: 7.3%

Range Frequency Queries

Array Hash Table Binary Search Design Segment Tree

#583

Rank

#1904EasyFrequency: 7.3%

Second Largest Digit in a String

#584

Rank

#4008EasyFrequency: 7.3%

Restore Finishing Order

#585

Rank

#1106HardFrequency: 7.3%

Escape a Large Maze

Array Hash Table Depth-First Search Breadth-First Search Bidirectional Search

#586

Rank

#4075HardFrequency: 7.3%

Count Subarrays With Majority Element II

Array Hash Table Divide and Conquer Segment Tree Merge Sort Prefix Sum

#587

Rank

#4318MediumFrequency: 7.3%

Valid Subarrays With Matching Sum Digits I

Array Hash Table Sliding Window Enumeration Prefix Sum

#588

Rank

#2777EasyFrequency: 7.3%

Find the Distinct Difference Array

#589

Rank

#1407MediumFrequency: 7.3%

Group the People Given the Group Size They Belong To

#590

Rank

#491MediumFrequency: 7.3%

Non-decreasing Subsequences

Array Hash Table Backtracking Bit Manipulation

#591

Rank

#720MediumFrequency: 7.3%

Longest Word in Dictionary

Array Hash Table String Trie Sorting

#592

Rank

#855HardFrequency: 7.2%

Count Unique Characters of All Substrings of a Given String

Hash Table String Dynamic Programming

#593

Rank

#1270HardFrequency: 7.2%

Dinner Plate Stacks

Hash Table Stack Design Heap (Priority Queue)

#594

Rank

#1945MediumFrequency: 7.2%

Finding the Users Active Minutes

#595

Rank

#2053EasyFrequency: 7.2%

Check if All Characters Have Equal Number of Occurrences

#596

Rank

#2005EasyFrequency: 7.2%

Check if All the Integers in a Range Are Covered

#597

Rank

#3260HardFrequency: 7.2%

Divide an Array Into Subarrays With Minimum Cost II

Array Hash Table Sliding Window Heap (Priority Queue)

#598

Rank

#3837MediumFrequency: 7.2%

Grid Teleportation Traversal

Array Hash Table Breadth-First Search Matrix

#599

Rank

#1261MediumFrequency: 5.5%

Swap For Longest Repeated Character Substring

#600

Rank

#3798HardFrequency: 5.5%

Longest Special Path II

Array Hash Table Tree Depth-First Search Prefix Sum

#601

Rank

#1913HardFrequency: 5.5%

Make the XOR of All Segments Equal to Zero

Array Hash Table Dynamic Programming Bit Manipulation Counting

#602

Rank

#842MediumFrequency: 5.5%

Card Flipping Game

#603

Rank

#3519EasyFrequency: 5.5%

Find the Number of Winning Players

#604

Rank

#2825EasyFrequency: 5.5%

Minimize String Length

#605

Rank

#3934EasyFrequency: 5.5%

Coupon Code Validator

#606

Rank

#3877MediumFrequency: 5.5%

Two-Letter Card Game

Array Hash Table String Counting Enumeration

#607

Rank

#4067MediumFrequency: 5.5%

Design Auction System

#608

Rank

#822EasyFrequency: 5.5%

Unique Morse Code Words

#609

Rank

#843MediumFrequency: 5%

Binary Trees With Factors

Array Hash Table Dynamic Programming Sorting

#610

Rank

#2724MediumFrequency: 5%

Convert an Array Into a 2D Array With Conditions

#611

Rank

#2442EasyFrequency: 5%

Number of Arithmetic Triplets

Array Hash Table Two Pointers Enumeration

#612

Rank

#1553MediumFrequency: 5%

Count Triplets That Can Form Two Arrays of Equal XOR

Array Hash Table Math Bit Manipulation Prefix Sum

#613

Rank

#3247MediumFrequency: 5%

Number of Same-End Substrings

Array Hash Table String Counting Prefix Sum

#614

Rank

#2609MediumFrequency: 5%

Distinct Prime Factors of Product of Array

Array Hash Table Math Number Theory Prime Factorization Euclidean Algorithm Primality Test Greatest Common Divisor Sieve Theory Prime Number Sieve

#615

Rank

#3502MediumFrequency: 5%

Count Substrings With K-Frequency Characters I

#616

Rank

#3487MediumFrequency: 5%

Find Maximum Removals From Source String

Array Hash Table Two Pointers String Dynamic Programming

#617

Rank

#3418MediumFrequency: 5%

Count Pairs That Form a Complete Day II

#618

Rank

#1433HardFrequency: 5%

Encrypt and Decrypt Strings

Array Hash Table String Design Trie

#619

Rank

#3360MediumFrequency: 5%

Minimum Deletions to Make String K-Special

#620

Rank

#3868MediumFrequency: 5%

Find Maximum Area of a Triangle

Array Hash Table Math Greedy Geometry Enumeration

#621

Rank

#575EasyFrequency: 5%

Distribute Candies

#622

Rank

#3324EasyFrequency: 5%

Split the Array

#623

Rank

#1472EasyFrequency: 5%

Increasing Decreasing String

#624

Rank

#3979MediumFrequency: 5%

Partition Array Into K-Distinct Groups

#625

Rank

#3634MediumFrequency: 5%

Find Mirror Score of a String

Hash Table String Stack Simulation

#626

Rank

#3957HardFrequency: 5%

Sum of Perfect Square Ancestors

Array Hash Table Math Tree Depth-First Search Counting Number Theory

#627

Rank

#3705EasyFrequency: 5%

Find the Largest Almost Missing Integer

#628

Rank

#2445MediumFrequency: 5%

Reachable Nodes With Restrictions

Array Hash Table Tree Depth-First Search Breadth-First Search Union-Find Graph Theory

#629

Rank

#4115EasyFrequency: 5%

Minimum Distance Between Three Equal Elements I

#630

Rank

#4265MediumFrequency: 5%

Longest Balanced Substring After One Swap

Hash Table String Prefix Sum

#631

Rank

#3878HardFrequency: 5%

Maximize Count of Distinct Primes After Split

Array Hash Table Math Segment Tree Number Theory Ordered Set

#632

Rank

#2480EasyFrequency: 5%

Find Subarrays With Equal Sum

#633

Rank

#1830MediumFrequency: 5%

Count Good Meals

#634

Rank

#3163EasyFrequency: 5%

Subarrays Distinct Element Sum of Squares I

Array Hash Table Segment Tree

#635

Rank

#3570MediumFrequency: 5%

Count of Substrings Containing Every Vowel and K Consonants I

#636

Rank

#4140HardFrequency: 5%

Evaluate Valid Expressions

Hash Table Math String Divide and Conquer Stack

#637

Rank

#3444MediumFrequency: 5%

Find the Number of Good Pairs II

#638

Rank

#3771MediumFrequency: 5%

Select K Disjoint Special Substrings

Hash Table String Dynamic Programming Greedy Sorting

#639

Rank

#3573MediumFrequency: 5%

Count Substrings That Can Be Rearranged to Contain a String I

#640

Rank

#1949MediumFrequency: 5%

Implement Trie II (Prefix Tree)

#641

Rank

#2920MediumFrequency: 5%

Minimum Seconds to Equalize a Circular Array

#642

Rank

#4152MediumFrequency: 5%

Minimum Subarray Length With Distinct Sum At Least K

#643

Rank

#3809MediumFrequency: 5%

Properties Graph

Array Hash Table Depth-First Search Breadth-First Search Union-Find Graph Theory

#644

Rank

#2476EasyFrequency: 5%

Check Distances Between Same Letters

#645

Rank

#2592HardFrequency: 5%

Minimum Total Cost to Make Arrays Unequal

#646

Rank

#4087MediumFrequency: 5%

Maximum Substrings With Distinct Start

#647

Rank

#2605HardFrequency: 5%

Count Anagrams

Hash Table Math String Combinatorics Counting Fermat's Little Theorem

#648

Rank

#1775EasyFrequency: 5%

Design an Ordered Stream

Array Hash Table Design Data Stream

#649

Rank

#3928MediumFrequency: 5%

Split and Merge Array Transformation

#650

Rank

#4086HardFrequency: 5%

Lexicographically Smallest String After Deleting Duplicate Characters

Hash Table String Stack Greedy Monotonic Stack

#651

Rank

#4002HardFrequency: 5%

Count Subarrays With K Distinct Integers