Medium LeetCode Interview Questions

Array String Depth-First Search Breadth-First Search Graph

Rank

#3613MediumFrequency: 100%

Maximize Amount After Two Days of Conversions

Asked at Uber

Rank

#1085MediumFrequency: 100%

The Earliest Moment When Everyone Become Friends

Asked at Oracle

Array Union Find Sorting

Rank

#64MediumFrequency: 100%

Minimum Path Sum

Asked at Salesforce

Array Dynamic Programming Breadth-First Search

Rank

#322MediumFrequency: 100%

Coin Change

Asked at Airbnb

Rank

#3681MediumFrequency: 100%

Maximum Area Rectangle With Point Constraints I

Asked at Infosys

Array Math Binary Indexed Tree Segment Tree Geometry Sorting Enumeration

Rank

#1056MediumFrequency: 100%

Capacity To Ship Packages Within D Days

Asked at Databricks

Hash Table Depth-First Search Breadth-First Search Union Find Hash Function

Rank

#694MediumFrequency: 98%

Number of Distinct Islands

Asked at Flipkart

#10

Rank

#314MediumFrequency: 97%

Binary Tree Vertical Order Traversal

Asked at Meta

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

#11

Rank

#227MediumFrequency: 96%

Basic Calculator II

Asked at Meta

Math String Stack

#12

Rank

#739MediumFrequency: 94%

Daily Temperatures

Asked at TikTok

Array Binary Search Sliding Window Sorting

#13

Rank

#957MediumFrequency: 94%

Minimum Add to Make Parentheses Valid

Asked at PayPal

String Stack Greedy

#14

Rank

#2891MediumFrequency: 93%

Maximum Beauty of an Array After Applying Operation

Asked at Salesforce

#15

Rank

#152MediumFrequency: 93%

Maximum Product Subarray

Asked at Salesforce

Linked List Math Recursion

#16

Rank

#2MediumFrequency: 93%

Add Two Numbers

Asked at Infosys

#17

Rank

#3639MediumFrequency: 93%

Zero Array Transformation I

Asked at Databricks

Array Divide and Conquer Sorting Heap (Priority Queue)Quickselect

#18

Rank

#215MediumFrequency: 92%

Kth Largest Element in an Array

Asked at Meta

#19

Rank

#19MediumFrequency: 92%

Remove Nth Node From End of List

Asked at Salesforce

Linked List Two Pointers

#20

Rank

#1790MediumFrequency: 91%

Lowest Common Ancestor of a Binary Tree III

Asked at Meta

Hash Table Two Pointers Tree Binary Tree

#21

Rank

#129MediumFrequency: 91%

Sum Root to Leaf Numbers

Asked at Apple

Array Binary Search Sliding Window Prefix Sum

#22

Rank

#1046MediumFrequency: 91%

Max Consecutive Ones III

Asked at Oracle

#23

Rank

#1423MediumFrequency: 91%

Maximum Number of Occurrences of a Substring

Asked at Infosys

#24

Rank

#122MediumFrequency: 90%

Best Time to Buy and Sell Stock II

Asked at Oracle

Array Two Pointers Binary Search Sorting

#25

Rank

#852MediumFrequency: 89%

Friends Of Appropriate Ages

Asked at Infosys

#26

Rank

#146MediumFrequency: 88%

LRU Cache

Asked at Microsoft

Hash Table Linked List Design Doubly-Linked List

#27

Rank

#364MediumFrequency: 88%

Nested List Weight Sum II

Asked at LinkedIn

Stack Depth-First Search Breadth-First Search

#28

Rank

#7MediumFrequency: 88%

Reverse Integer

Asked at Salesforce

Math

#29

Rank

#6MediumFrequency: 88%

Zigzag Conversion

Asked at Flipkart

String

#30

Rank

#912MediumFrequency: 87%

Random Pick with Weight

Asked at Meta

Array Math Binary Search Prefix Sum Randomized

#31

Rank

#998MediumFrequency: 87%

Check Completeness of a Binary Tree

Asked at Apple

Array Hash Table Greedy Sorting Heap (Priority Queue)Counting

#32

Rank

#394MediumFrequency: 87%

Decode String

Asked at Oracle

String Stack Recursion

#33

Rank

#621MediumFrequency: 85%

Task Scheduler

Asked at Amazon

#34

Rank

#50MediumFrequency: 85%

Pow(x, n)

Asked at Meta

Math Recursion

#35

Rank

#162MediumFrequency: 85%

Find Peak Element

Asked at Meta

#36

Rank

#134MediumFrequency: 85%

Gas Station

Asked at Infosys

Array Greedy

#37

Rank

#3MediumFrequency: 84%

Longest Substring Without Repeating Characters

Asked at Microsoft

Depth-First Search Breadth-First Search

#38

Rank

#339MediumFrequency: 84%

Nested List Weight Sum

Asked at Meta

#39

Rank

#366MediumFrequency: 84%

Find Leaves of Binary Tree

Asked at LinkedIn

Array Hash Table Dynamic Programming

#40

Rank

#1330MediumFrequency: 83%

Longest Arithmetic Subsequence of Given Difference

Asked at Airbnb

#41

Rank

#1108MediumFrequency: 83%

Analyze User Website Visit Pattern

Asked at PayPal

Array Hash Table Sorting

#42

Rank

#772MediumFrequency: 83%

Construct Quad Tree

Asked at Infosys

Array Divide and Conquer Tree Matrix

#43

Rank

#3654MediumFrequency: 83%

Minimum Array Sum

Asked at Databricks

Array Depth-First Search Breadth-First Search Union Find Matrix

#44

Rank

#200MediumFrequency: 82%

Number of Islands

Asked at Amazon

#45

Rank

#424MediumFrequency: 82%

Longest Repeating Character Replacement

Asked at Apple

Hash Table Math Reservoir Sampling Randomized

#46

Rank

#398MediumFrequency: 82%

Random Pick Index

Asked at Oracle

#47

Rank

#1014MediumFrequency: 82%

K Closest Points to Origin

Asked at Salesforce

Array Math Divide and Conquer Geometry Sorting Heap (Priority Queue)Quickselect

#48

Rank

#560MediumFrequency: 81%

Subarray Sum Equals K

Asked at Meta

Array Hash Table Design Matrix Simulation

#49

Rank

#348MediumFrequency: 81%

Design Tic-Tac-Toe

Asked at PayPal

#50

Rank

#151MediumFrequency: 80%

Reverse Words in a String

Asked at Airbnb

Array Divide and Conquer Dynamic Programming

#51

Rank

#53MediumFrequency: 79%

Maximum Subarray

Asked at Microsoft

#52

Rank

#236MediumFrequency: 79%

Lowest Common Ancestor of a Binary Tree

Asked at Meta

Array Binary Search Design Queue Data Stream

#53

Rank

#362MediumFrequency: 79%

Design Hit Counter

Asked at Uber

#54

Rank

#380MediumFrequency: 79%

Insert Delete GetRandom O(1)

Asked at Oracle

Array Hash Table Math Design Randomized

#55

Rank

#1966MediumFrequency: 79%

Frequency of the Most Frequent Element

Asked at Salesforce

Array Binary Search Greedy Sliding Window Sorting Prefix Sum

#56

Rank

#109MediumFrequency: 79%

Convert Sorted List to Binary Search Tree

Asked at Flipkart

Linked List Divide and Conquer Tree Binary Search Tree Binary Tree

#57

Rank

#166MediumFrequency: 79%

Fraction to Recurring Decimal

Asked at Databricks

Array Binary Search Matrix

#58

Rank

#74MediumFrequency: 78%

Search a 2D Matrix

Asked at Apple

#59

Rank

#356MediumFrequency: 77%

Line Reflection

Asked at PayPal

Array Hash Table Math

#60

Rank

#199MediumFrequency: 76%

Binary Tree Right Side View

Asked at Meta

Tree Depth-First Search Breadth-First Search Binary Tree

#61

Rank

#347MediumFrequency: 76%

Top K Frequent Elements

Asked at Meta

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

#62

Rank

#1713MediumFrequency: 76%

Dot Product of Two Sparse Vectors

Asked at Meta

Array Hash Table Two Pointers Design

#63

Rank

#2232MediumFrequency: 76%

Adding Spaces to a String

Asked at Oracle

Array Two Pointers String Simulation

#64

Rank

#1478MediumFrequency: 76%

Maximum Number of Events That Can Be Attended

Asked at Salesforce

Array Greedy Sorting Heap (Priority Queue)

#65

Rank

#249MediumFrequency: 76%

Group Shifted Strings

Asked at Infosys

Array Hash Table String

#66

Rank

#1488MediumFrequency: 76%

Sort Integers by The Power Value

Asked at Databricks

Dynamic Programming Memoization Sorting

#67

Rank

#173MediumFrequency: 75%

Binary Search Tree Iterator

Asked at Salesforce

Stack Tree Design Binary Search Tree Binary Tree Iterator

#68

Rank

#39MediumFrequency: 74%

Combination Sum

Asked at PayPal

#69

Rank

#71MediumFrequency: 73%

Simplify Path

Asked at Meta

#70

Rank

#1585MediumFrequency: 73%

The kth Factor of n

Asked at TikTok

Math Number Theory

#71

Rank

#55MediumFrequency: 73%

Jump Game

Asked at DoorDash

Array Hash Table String Sorting

#72

Rank

#2089MediumFrequency: 73%

Maximum Matrix Sum

Asked at Airbnb

Array Greedy Matrix

#73

Rank

#49MediumFrequency: 72%

Group Anagrams

Asked at Amazon

#74

Rank

#778MediumFrequency: 72%

Reorganize String

Asked at Amazon

Hash Table String Greedy Sorting Heap (Priority Queue)Counting

#75

Rank

#56MediumFrequency: 72%

Merge Intervals

Asked at Meta

Array Sorting

#76

Rank

#235MediumFrequency: 72%

Lowest Common Ancestor of a Binary Search Tree

Asked at LinkedIn

Tree Depth-First Search Binary Search Tree Binary Tree

#77

Rank

#277MediumFrequency: 72%

Find the Celebrity

Asked at LinkedIn

Two Pointers Graph Interactive

#78

Rank

#658MediumFrequency: 72%

Find K Closest Elements

Asked at Infosys

Array Two Pointers Binary Search Sliding Window Sorting Heap (Priority Queue)

#79

Rank

#325MediumFrequency: 71%

Maximum Size Subarray Sum Equals k

Asked at Apple

#80

Rank

#1028MediumFrequency: 69%

Interval List Intersections

Asked at Meta

#81

Rank

#1171MediumFrequency: 69%

Shortest Path in Binary Matrix

Asked at Meta

Array Hash Table String Breadth-First Search

#82

Rank

#753MediumFrequency: 69%

Open the Lock

Asked at Apple

#83

Rank

#518MediumFrequency: 69%

Coin Change II

Asked at Airbnb

Hash Table String Sorting

#84

Rank

#807MediumFrequency: 68%

Custom Sort String

Asked at Oracle

#85

Rank

#62MediumFrequency: 68%

Unique Paths

Asked at Infosys

Math Dynamic Programming Combinatorics

#86

Rank

#90MediumFrequency: 68%

Subsets II

Asked at Infosys

#87

Rank

#1036MediumFrequency: 68%

Rotting Oranges

Asked at Databricks

Array Greedy Sorting Heap (Priority Queue)Prefix Sum

#88

Rank

#3647MediumFrequency: 67%

Zero Array Transformation III

Asked at Google

#89

Rank

#138MediumFrequency: 67%

Copy List with Random Pointer

Asked at Amazon

Hash Table Linked List

#90

Rank

#353MediumFrequency: 67%

Design Snake Game

Asked at Apple

Array Hash Table Design Queue Simulation

#91

Rank

#1549MediumFrequency: 67%

Longest Continuous Subarray With Absolute Diff Less Than or Equal to Limit

Asked at Salesforce

Array Queue Sliding Window Heap (Priority Queue)Ordered Set Monotonic Queue

#92

Rank

#907MediumFrequency: 66%

Koko Eating Bananas

Asked at Microsoft

Array Greedy Heap (Priority Queue)

#93

Rank

#2094MediumFrequency: 66%

Remove Stones to Minimize the Total

Asked at Apple

#94

Rank

#128MediumFrequency: 66%

Longest Consecutive Sequence

Asked at DoorDash

Array Hash Table Union Find

#95

Rank

#5MediumFrequency: 65%

Longest Palindromic Substring

Asked at Databricks

#96

Rank

#78MediumFrequency: 64%

Subsets

Asked at Meta

Linked List Stack Tree Depth-First Search Binary Search Tree Binary Tree Doubly-Linked List

#97

Rank

#758MediumFrequency: 64%

Convert Binary Search Tree to Sorted Doubly Linked List

Asked at Meta

#98

Rank

#893MediumFrequency: 64%

All Nodes Distance K in Binary Tree

Asked at Meta

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

#99

Rank

#1909MediumFrequency: 64%

Buildings With an Ocean View

Asked at Meta

#100

Rank

#2414MediumFrequency: 64%

Move Pieces to Obtain a String

Asked at PayPal

#101

Rank

#54MediumFrequency: 63%

Spiral Matrix

Asked at Uber

Array String Backtracking Matrix

#102

Rank

#79MediumFrequency: 63%

Word Search

Asked at Uber

#103

Rank

#399MediumFrequency: 63%

Evaluate Division

Asked at Uber

Array String Depth-First Search Breadth-First Search Union Find Graph Shortest Path

#104

Rank

#34MediumFrequency: 63%

Find First and Last Position of Element in Sorted Array

Asked at LinkedIn

#105

Rank

#40MediumFrequency: 63%

Combination Sum II

Asked at LinkedIn

Array Hash Table Two Pointers String Design

#106

Rank

#244MediumFrequency: 63%

Shortest Word Distance II

Asked at LinkedIn

#107

Rank

#987MediumFrequency: 63%

Reveal Cards In Increasing Order

Asked at DoorDash

Array Queue Sorting Simulation

#108

Rank

#2695MediumFrequency: 63%

Find Score of an Array After Marking All Elements

Asked at Flipkart

Array Hash Table Sorting Heap (Priority Queue)Simulation

#109

Rank

#12MediumFrequency: 63%

Integer to Roman

Asked at PayPal

#110

Rank

#46MediumFrequency: 63%

Permutations

Asked at PayPal

#111

Rank

#31MediumFrequency: 62%

Next Permutation

Asked at Meta

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

#112

Rank

#721MediumFrequency: 62%

Accounts Merge

Asked at Meta

#113

Rank

#2868MediumFrequency: 60%

Continuous Subarrays

Asked at Google

Array Queue Sliding Window Heap (Priority Queue)Ordered Set Monotonic Queue

#114

Rank

#15MediumFrequency: 60%

3Sum

Asked at Amazon

#115

Rank

#3018MediumFrequency: 60%

Make String a Subsequence Using Cyclic Increments

Asked at Amazon

Hash Table Depth-First Search Breadth-First Search Graph

#116

Rank

#133MediumFrequency: 60%

Clone Graph

Asked at Meta

#117

Rank

#1586MediumFrequency: 60%

Longest Subarray of 1's After Deleting One Element

Asked at Infosys

Array Dynamic Programming Sliding Window

#118

Rank

#2300MediumFrequency: 59%

Construct String With Repeat Limit

Asked at Flipkart

Hash Table String Greedy Heap (Priority Queue)Counting

#119

Rank

#48MediumFrequency: 59%

Rotate Image

Asked at Infosys

Array Math Matrix

#120

Rank

#1705MediumFrequency: 58%

Count Unhappy Friends

Asked at TikTok

Array Simulation

#121

Rank

#253MediumFrequency: 58%

Meeting Rooms II

Asked at Salesforce

Array Two Pointers Greedy Sorting Heap (Priority Queue)Prefix Sum

#122

Rank

#11MediumFrequency: 58%

Container With Most Water

Asked at Salesforce

Array Two Pointers Greedy

#123

Rank

#139MediumFrequency: 57%

Word Break

Asked at Meta

Array Hash Table String Dynamic Programming Trie Memoization

#124

Rank

#850MediumFrequency: 57%

Insert into a Sorted Circular Linked List

Asked at Meta

Linked List

#125

Rank

#523MediumFrequency: 57%

Continuous Subarray Sum

Asked at TikTok

Array Hash Table Math Prefix Sum

#126

Rank

#33MediumFrequency: 57%

Search in Rotated Sorted Array

Asked at Oracle

Depth-First Search Breadth-First Search Graph Topological Sort

#127

Rank

#207MediumFrequency: 56%

Course Schedule

Asked at Google

#128

Rank

#2164MediumFrequency: 56%

Two Best Non-Overlapping Events

Asked at Google

Array Binary Search Dynamic Programming Sorting Heap (Priority Queue)

#129

Rank

#17MediumFrequency: 56%

Letter Combinations of a Phone Number

Asked at Amazon

#130

Rank

#18MediumFrequency: 55%

4Sum

Asked at Microsoft

Array Two Pointers Binary Search

#131

Rank

#155MediumFrequency: 55%

Min Stack

Asked at Microsoft

Stack Design

#132

Rank

#167MediumFrequency: 55%

Two Sum II - Input Array Is Sorted

Asked at Microsoft

#133

Rank

#198MediumFrequency: 55%

House Robber

Asked at Microsoft

#134

Rank

#213MediumFrequency: 55%

House Robber II

Asked at Microsoft

#135

Rank

#291MediumFrequency: 55%

Word Pattern II

Asked at Microsoft

Hash Table Two Pointers String Sliding Window

#136

Rank

#567MediumFrequency: 55%

Permutation in String

Asked at Microsoft

#137

Rank

#1147MediumFrequency: 55%

Flip Columns For Maximum Number of Equal Rows

Asked at Microsoft

#138

Rank

#1886MediumFrequency: 54%

Minimum Limit of Balls in a Bag

Asked at Apple

Array Binary Search Prefix Sum

#139

Rank

#1095MediumFrequency: 54%

Two City Scheduling

Asked at Flipkart

Array Greedy Sorting

#140

Rank

#3643MediumFrequency: 54%

Zero Array Transformation II

Asked at PayPal

#141

Rank

#22MediumFrequency: 53%

Generate Parentheses

Asked at Google

String Dynamic Programming Backtracking

#142

Rank

#114MediumFrequency: 53%

Flatten Binary Tree to Linked List

Asked at Google

Linked List Stack Tree Depth-First Search Binary Tree

#143

Rank

#116MediumFrequency: 51%

Populating Next Right Pointers in Each Node

Asked at Meta

Linked List Tree Depth-First Search Breadth-First Search Binary Tree

#144

Rank

#954MediumFrequency: 50%

Maximum Sum Circular Subarray

Asked at Flipkart

Array Divide and Conquer Dynamic Programming Queue Monotonic Queue

#145

Rank

#976MediumFrequency: 48%

Minimum Area Rectangle

Asked at Google

Array Hash Table Math Geometry Sorting

#146

Rank

#63MediumFrequency: 48%

Unique Paths II

Asked at Infosys

#147

Rank

#545MediumFrequency: 47%

Boundary of Binary Tree

Asked at Meta

#148

Rank

#238MediumFrequency: 45%

Product of Array Except Self

Asked at Amazon

Array Heap (Priority Queue)

#149

Rank

#373MediumFrequency: 45%

Find K Pairs with Smallest Sums

Asked at Amazon

#150

Rank

#498MediumFrequency: 43%

Diagonal Traverse

Asked at Meta

#151

Rank

#647MediumFrequency: 43%

Palindromic Substrings

Asked at Meta

#152

Rank

#670MediumFrequency: 43%

Maximum Swap

Asked at Meta

Math Greedy

#153

Rank

#2021MediumFrequency: 43%

Remove All Occurrences of a Substring

Asked at PayPal

String Stack Simulation

#154

Rank

#75MediumFrequency: 42%

Sort Colors

Asked at Google

Array Binary Search Dynamic Programming

#155

Rank

#179MediumFrequency: 42%

Largest Number

Asked at Google

Array String Greedy Sorting

#156

Rank

#300MediumFrequency: 42%

Longest Increasing Subsequence

Asked at Google

#157

Rank

#1783MediumFrequency: 42%

Ways to Make a Fair Array

Asked at Infosys

Array Hash Table Two Pointers Binary Search Sorting

#158

Rank

#532MediumFrequency: 40%

K-diff Pairs in an Array

Asked at PayPal

#159

Rank

#230MediumFrequency: 37%

Kth Smallest Element in a BST

Asked at Meta

Tree Depth-First Search Binary Search Tree Binary Tree

#160

Rank

#378MediumFrequency: 37%

Kth Smallest Element in a Sorted Matrix

Asked at Meta

Array Binary Search Sorting Heap (Priority Queue)Matrix

#161

Rank

#735MediumFrequency: 37%

Asteroid Collision

Asked at Meta

Array Stack Simulation

#162

Rank

#752MediumFrequency: 37%

IP to CIDR

Asked at Infosys

String Bit Manipulation

#163

Rank

#36MediumFrequency: 36%

Valid Sudoku

Asked at Amazon

#164

Rank

#80MediumFrequency: 36%

Remove Duplicates from Sorted Array II

Asked at Amazon

#165

Rank

#103MediumFrequency: 36%

Binary Tree Zigzag Level Order Traversal

Asked at Amazon

#166

Rank

#45MediumFrequency: 33%

Jump Game II

Asked at Google

Array String Binary Search Trie Sorting Heap (Priority Queue)

#167

Rank

#1397MediumFrequency: 33%

Search Suggestions System

Asked at Oracle

#168

Rank

#2552MediumFrequency: 21%

Maximum Sum of Distinct Subarrays With Length K

Asked at DoorDash

Array Hash Table Sliding Window

#169

Rank

View All Companies

Need help during your interview?

Get AI-powered real-time assistance with Interview Solver—live hints, solutions, and explanations during your actual coding interviews.

Try Interview Solver

Medium LeetCode Interview Questions

Master 169 medium difficulty coding problems frequently asked in technical interviews at top tech companies. Perfect for building confidence and fundamental problem-solving skills.

Easy (191)Medium (457)Hard (123)

#3594MediumFrequency: 100%

Identify the Largest Outlier in an Array

Asked at Amazon

Array Hash Table Counting Enumeration

Rank

#3655MediumFrequency: 100%

Digit Operations to Make Two Integers Equal

Asked at Microsoft

Math Graph Heap (Priority Queue)Number Theory Shortest Path

Rank

#1371MediumFrequency: 100%

Minimum Remove to Make Valid Parentheses

Asked at Meta

Array String Depth-First Search Breadth-First Search Graph

Rank

#3613MediumFrequency: 100%

Maximize Amount After Two Days of Conversions

Asked at Uber

Rank

#1085MediumFrequency: 100%

The Earliest Moment When Everyone Become Friends

Asked at Oracle

Array Union Find Sorting

Rank

#64MediumFrequency: 100%

Minimum Path Sum

Asked at Salesforce

Array Dynamic Programming Breadth-First Search

Rank

#322MediumFrequency: 100%

Coin Change

Asked at Airbnb

Rank

#3681MediumFrequency: 100%

Maximum Area Rectangle With Point Constraints I

Asked at Infosys

Array Math Binary Indexed Tree Segment Tree Geometry Sorting Enumeration

Rank

#1056MediumFrequency: 100%

Capacity To Ship Packages Within D Days

Asked at Databricks

Hash Table Depth-First Search Breadth-First Search Union Find Hash Function

Rank

#694MediumFrequency: 98%

Number of Distinct Islands

Asked at Flipkart

#10

Rank

#314MediumFrequency: 97%

Binary Tree Vertical Order Traversal

Asked at Meta

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

#11

Rank

#227MediumFrequency: 96%

Basic Calculator II

Asked at Meta

Math String Stack

#12

Rank

#739MediumFrequency: 94%

Daily Temperatures

Asked at TikTok

Array Binary Search Sliding Window Sorting

#13

Rank

#957MediumFrequency: 94%

Minimum Add to Make Parentheses Valid

Asked at PayPal

String Stack Greedy

#14

Rank

#2891MediumFrequency: 93%

Maximum Beauty of an Array After Applying Operation

Asked at Salesforce

#15

Rank

#152MediumFrequency: 93%

Maximum Product Subarray

Asked at Salesforce

Linked List Math Recursion

#16

Rank

#2MediumFrequency: 93%

Add Two Numbers

Asked at Infosys

#17

Rank

#3639MediumFrequency: 93%

Zero Array Transformation I

Asked at Databricks

Array Divide and Conquer Sorting Heap (Priority Queue)Quickselect

#18

Rank

#215MediumFrequency: 92%

Kth Largest Element in an Array

Asked at Meta

#19

Rank

#19MediumFrequency: 92%

Remove Nth Node From End of List

Asked at Salesforce

Linked List Two Pointers

#20

Rank

#1790MediumFrequency: 91%

Lowest Common Ancestor of a Binary Tree III

Asked at Meta

Hash Table Two Pointers Tree Binary Tree

#21

Rank

#129MediumFrequency: 91%

Sum Root to Leaf Numbers

Asked at Apple

Array Binary Search Sliding Window Prefix Sum

#22

Rank

#1046MediumFrequency: 91%

Max Consecutive Ones III

Asked at Oracle

#23

Rank

#1423MediumFrequency: 91%

Maximum Number of Occurrences of a Substring

Asked at Infosys

#24

Rank

#122MediumFrequency: 90%

Best Time to Buy and Sell Stock II

Asked at Oracle

Array Two Pointers Binary Search Sorting

#25

Rank

#852MediumFrequency: 89%

Friends Of Appropriate Ages

Asked at Infosys

#26

Rank

#146MediumFrequency: 88%

LRU Cache

Asked at Microsoft

Hash Table Linked List Design Doubly-Linked List

#27

Rank

#364MediumFrequency: 88%

Nested List Weight Sum II

Asked at LinkedIn

Stack Depth-First Search Breadth-First Search

#28

Rank

#7MediumFrequency: 88%

Reverse Integer

Asked at Salesforce

Math

#29

Rank

#6MediumFrequency: 88%

Zigzag Conversion

Asked at Flipkart

String

#30

Rank

#912MediumFrequency: 87%

Random Pick with Weight

Asked at Meta

Array Math Binary Search Prefix Sum Randomized

#31

Rank

#998MediumFrequency: 87%

Check Completeness of a Binary Tree

Asked at Apple

Array Hash Table Greedy Sorting Heap (Priority Queue)Counting

#32

Rank

#394MediumFrequency: 87%

Decode String

Asked at Oracle

String Stack Recursion

#33

Rank

#621MediumFrequency: 85%

Task Scheduler

Asked at Amazon

#34

Rank

#50MediumFrequency: 85%

Pow(x, n)

Asked at Meta

Math Recursion

#35

Rank

#162MediumFrequency: 85%

Find Peak Element

Asked at Meta

#36

Rank

#134MediumFrequency: 85%

Gas Station

Asked at Infosys

Array Greedy

#37

Rank

#3MediumFrequency: 84%

Longest Substring Without Repeating Characters

Asked at Microsoft

Depth-First Search Breadth-First Search

#38

Rank

#339MediumFrequency: 84%

Nested List Weight Sum

Asked at Meta

#39

Rank

#366MediumFrequency: 84%

Find Leaves of Binary Tree

Asked at LinkedIn

Array Hash Table Dynamic Programming

#40

Rank

#1330MediumFrequency: 83%

Longest Arithmetic Subsequence of Given Difference

Asked at Airbnb

#41

Rank

#1108MediumFrequency: 83%

Analyze User Website Visit Pattern

Asked at PayPal

Array Hash Table Sorting

#42

Rank

#772MediumFrequency: 83%

Construct Quad Tree

Asked at Infosys

Array Divide and Conquer Tree Matrix

#43

Rank

#3654MediumFrequency: 83%

Minimum Array Sum

Asked at Databricks

Array Depth-First Search Breadth-First Search Union Find Matrix

#44

Rank

#200MediumFrequency: 82%

Number of Islands

Asked at Amazon

#45

Rank

#424MediumFrequency: 82%

Longest Repeating Character Replacement

Asked at Apple

Hash Table Math Reservoir Sampling Randomized

#46

Rank

#398MediumFrequency: 82%

Random Pick Index

Asked at Oracle

#47

Rank

#1014MediumFrequency: 82%

K Closest Points to Origin

Asked at Salesforce

Array Math Divide and Conquer Geometry Sorting Heap (Priority Queue)Quickselect

#48

Rank

#560MediumFrequency: 81%

Subarray Sum Equals K

Asked at Meta

Array Hash Table Design Matrix Simulation

#49

Rank

#348MediumFrequency: 81%

Design Tic-Tac-Toe

Asked at PayPal

#50

Rank

#151MediumFrequency: 80%

Reverse Words in a String

Asked at Airbnb

Array Divide and Conquer Dynamic Programming

#51

Rank

#53MediumFrequency: 79%

Maximum Subarray

Asked at Microsoft

#52

Rank

#236MediumFrequency: 79%

Lowest Common Ancestor of a Binary Tree

Asked at Meta

Array Binary Search Design Queue Data Stream

#53

Rank

#362MediumFrequency: 79%

Design Hit Counter

Asked at Uber

#54

Rank

#380MediumFrequency: 79%

Insert Delete GetRandom O(1)

Asked at Oracle

Array Hash Table Math Design Randomized

#55

Rank

#1966MediumFrequency: 79%

Frequency of the Most Frequent Element

Asked at Salesforce

Array Binary Search Greedy Sliding Window Sorting Prefix Sum

#56

Rank

#109MediumFrequency: 79%

Convert Sorted List to Binary Search Tree

Asked at Flipkart

Linked List Divide and Conquer Tree Binary Search Tree Binary Tree

#57

Rank

#166MediumFrequency: 79%

Fraction to Recurring Decimal

Asked at Databricks

Array Binary Search Matrix

#58

Rank

#74MediumFrequency: 78%

Search a 2D Matrix

Asked at Apple

#59

Rank

#356MediumFrequency: 77%

Line Reflection

Asked at PayPal

Array Hash Table Math

#60

Rank

#199MediumFrequency: 76%

Binary Tree Right Side View

Asked at Meta

Tree Depth-First Search Breadth-First Search Binary Tree

#61

Rank

#347MediumFrequency: 76%

Top K Frequent Elements

Asked at Meta

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

#62

Rank

#1713MediumFrequency: 76%

Dot Product of Two Sparse Vectors

Asked at Meta

Array Hash Table Two Pointers Design

#63

Rank

#2232MediumFrequency: 76%

Adding Spaces to a String

Asked at Oracle

Array Two Pointers String Simulation

#64

Rank

#1478MediumFrequency: 76%

Maximum Number of Events That Can Be Attended

Asked at Salesforce

Array Greedy Sorting Heap (Priority Queue)

#65

Rank

#249MediumFrequency: 76%

Group Shifted Strings

Asked at Infosys

Array Hash Table String

#66

Rank

#1488MediumFrequency: 76%

Sort Integers by The Power Value

Asked at Databricks

Dynamic Programming Memoization Sorting

#67

Rank

#173MediumFrequency: 75%

Binary Search Tree Iterator

Asked at Salesforce

Stack Tree Design Binary Search Tree Binary Tree Iterator

#68

Rank

#39MediumFrequency: 74%

Combination Sum

Asked at PayPal

#69

Rank

#71MediumFrequency: 73%

Simplify Path

Asked at Meta

#70

Rank

#1585MediumFrequency: 73%

The kth Factor of n

Asked at TikTok

Math Number Theory

#71

Rank

#55MediumFrequency: 73%

Jump Game

Asked at DoorDash

Array Hash Table String Sorting

#72

Rank

#2089MediumFrequency: 73%

Maximum Matrix Sum

Asked at Airbnb

Array Greedy Matrix

#73

Rank

#49MediumFrequency: 72%

Group Anagrams

Asked at Amazon

#74

Rank

#778MediumFrequency: 72%

Reorganize String

Asked at Amazon

Hash Table String Greedy Sorting Heap (Priority Queue)Counting

#75

Rank

#56MediumFrequency: 72%

Merge Intervals

Asked at Meta

Array Sorting

#76

Rank

#235MediumFrequency: 72%

Lowest Common Ancestor of a Binary Search Tree

Asked at LinkedIn

Tree Depth-First Search Binary Search Tree Binary Tree

#77

Rank

#277MediumFrequency: 72%

Find the Celebrity

Asked at LinkedIn

Two Pointers Graph Interactive

#78

Rank

#658MediumFrequency: 72%

Find K Closest Elements

Asked at Infosys

Array Two Pointers Binary Search Sliding Window Sorting Heap (Priority Queue)

#79

Rank

#325MediumFrequency: 71%

Maximum Size Subarray Sum Equals k

Asked at Apple

#80

Rank

#1028MediumFrequency: 69%

Interval List Intersections

Asked at Meta

#81

Rank

#1171MediumFrequency: 69%

Shortest Path in Binary Matrix

Asked at Meta

Array Hash Table String Breadth-First Search

#82

Rank

#753MediumFrequency: 69%

Open the Lock

Asked at Apple

#83

Rank

#518MediumFrequency: 69%

Coin Change II

Asked at Airbnb

Hash Table String Sorting

#84

Rank

#807MediumFrequency: 68%

Custom Sort String

Asked at Oracle

#85

Rank

#62MediumFrequency: 68%

Unique Paths

Asked at Infosys

Math Dynamic Programming Combinatorics

#86

Rank

#90MediumFrequency: 68%

Subsets II

Asked at Infosys

#87

Rank

#1036MediumFrequency: 68%

Rotting Oranges

Asked at Databricks

Array Greedy Sorting Heap (Priority Queue)Prefix Sum

#88

Rank

#3647MediumFrequency: 67%

Zero Array Transformation III

Asked at Google

#89

Rank

#138MediumFrequency: 67%

Copy List with Random Pointer

Asked at Amazon

Hash Table Linked List

#90

Rank

#353MediumFrequency: 67%

Design Snake Game

Asked at Apple

Array Hash Table Design Queue Simulation

#91

Rank

#1549MediumFrequency: 67%

Longest Continuous Subarray With Absolute Diff Less Than or Equal to Limit

Asked at Salesforce

Array Queue Sliding Window Heap (Priority Queue)Ordered Set Monotonic Queue

#92

Rank

#907MediumFrequency: 66%

Koko Eating Bananas

Asked at Microsoft

Array Greedy Heap (Priority Queue)

#93

Rank

#2094MediumFrequency: 66%

Remove Stones to Minimize the Total

Asked at Apple

#94

Rank

#128MediumFrequency: 66%

Longest Consecutive Sequence

Asked at DoorDash

Array Hash Table Union Find

#95

Rank

#5MediumFrequency: 65%

Longest Palindromic Substring

Asked at Databricks

#96

Rank

#78MediumFrequency: 64%

Subsets

Asked at Meta

Linked List Stack Tree Depth-First Search Binary Search Tree Binary Tree Doubly-Linked List

#97

Rank

#758MediumFrequency: 64%

Convert Binary Search Tree to Sorted Doubly Linked List

Asked at Meta

#98

Rank

#893MediumFrequency: 64%

All Nodes Distance K in Binary Tree

Asked at Meta

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

#99

Rank

#1909MediumFrequency: 64%

Buildings With an Ocean View

Asked at Meta

#100

Rank

#2414MediumFrequency: 64%

Move Pieces to Obtain a String

Asked at PayPal

#101

Rank

#54MediumFrequency: 63%

Spiral Matrix

Asked at Uber

Array String Backtracking Matrix

#102

Rank

#79MediumFrequency: 63%

Word Search

Asked at Uber

#103

Rank

#399MediumFrequency: 63%

Evaluate Division

Asked at Uber

Array String Depth-First Search Breadth-First Search Union Find Graph Shortest Path

#104

Rank

#34MediumFrequency: 63%

Find First and Last Position of Element in Sorted Array

Asked at LinkedIn

#105

Rank

#40MediumFrequency: 63%

Combination Sum II

Asked at LinkedIn

Array Hash Table Two Pointers String Design

#106

Rank

#244MediumFrequency: 63%

Shortest Word Distance II

Asked at LinkedIn

#107

Rank

#987MediumFrequency: 63%

Reveal Cards In Increasing Order

Asked at DoorDash

Array Queue Sorting Simulation

#108

Rank

#2695MediumFrequency: 63%

Find Score of an Array After Marking All Elements

Asked at Flipkart

Array Hash Table Sorting Heap (Priority Queue)Simulation

#109

Rank

#12MediumFrequency: 63%

Integer to Roman

Asked at PayPal

#110

Rank

#46MediumFrequency: 63%

Permutations

Asked at PayPal

#111

Rank

#31MediumFrequency: 62%

Next Permutation

Asked at Meta

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

#112

Rank

#721MediumFrequency: 62%

Accounts Merge

Asked at Meta

#113

Rank

#2868MediumFrequency: 60%

Continuous Subarrays

Asked at Google

Array Queue Sliding Window Heap (Priority Queue)Ordered Set Monotonic Queue

#114

Rank

#15MediumFrequency: 60%

3Sum

Asked at Amazon

#115

Rank

#3018MediumFrequency: 60%

Make String a Subsequence Using Cyclic Increments

Asked at Amazon

Hash Table Depth-First Search Breadth-First Search Graph

#116

Rank

#133MediumFrequency: 60%

Clone Graph

Asked at Meta

#117

Rank

#1586MediumFrequency: 60%

Longest Subarray of 1's After Deleting One Element

Asked at Infosys

Array Dynamic Programming Sliding Window

#118

Rank

#2300MediumFrequency: 59%

Construct String With Repeat Limit

Asked at Flipkart

Hash Table String Greedy Heap (Priority Queue)Counting

#119

Rank

#48MediumFrequency: 59%

Rotate Image

Asked at Infosys

Array Math Matrix

#120

Rank

#1705MediumFrequency: 58%

Count Unhappy Friends

Asked at TikTok

Array Simulation

#121

Rank

#253MediumFrequency: 58%

Meeting Rooms II

Asked at Salesforce

Array Two Pointers Greedy Sorting Heap (Priority Queue)Prefix Sum

#122

Rank

#11MediumFrequency: 58%

Container With Most Water

Asked at Salesforce

Array Two Pointers Greedy

#123

Rank

#139MediumFrequency: 57%

Word Break

Asked at Meta

Array Hash Table String Dynamic Programming Trie Memoization

#124

Rank

#850MediumFrequency: 57%

Insert into a Sorted Circular Linked List

Asked at Meta

Linked List

#125

Rank

#523MediumFrequency: 57%

Continuous Subarray Sum

Asked at TikTok

Array Hash Table Math Prefix Sum

#126

Rank

#33MediumFrequency: 57%

Search in Rotated Sorted Array

Asked at Oracle

Depth-First Search Breadth-First Search Graph Topological Sort

#127

Rank

#207MediumFrequency: 56%

Course Schedule

Asked at Google

#128

Rank

#2164MediumFrequency: 56%

Two Best Non-Overlapping Events

Asked at Google

Array Binary Search Dynamic Programming Sorting Heap (Priority Queue)

#129

Rank

#17MediumFrequency: 56%

Letter Combinations of a Phone Number

Asked at Amazon

#130

Rank

#18MediumFrequency: 55%

4Sum

Asked at Microsoft

Array Two Pointers Binary Search

#131

Rank

#155MediumFrequency: 55%

Min Stack

Asked at Microsoft

Stack Design

#132

Rank

#167MediumFrequency: 55%

Two Sum II - Input Array Is Sorted

Asked at Microsoft

#133

Rank

#198MediumFrequency: 55%

House Robber

Asked at Microsoft

#134

Rank

#213MediumFrequency: 55%

House Robber II

Asked at Microsoft

#135

Rank

#291MediumFrequency: 55%

Word Pattern II

Asked at Microsoft

Hash Table Two Pointers String Sliding Window

#136

Rank

#567MediumFrequency: 55%

Permutation in String

Asked at Microsoft

#137

Rank

#1147MediumFrequency: 55%

Flip Columns For Maximum Number of Equal Rows

Asked at Microsoft

#138

Rank

#1886MediumFrequency: 54%

Minimum Limit of Balls in a Bag

Asked at Apple

Array Binary Search Prefix Sum

#139

Rank

#1095MediumFrequency: 54%

Two City Scheduling

Asked at Flipkart

Array Greedy Sorting

#140

Rank

#3643MediumFrequency: 54%

Zero Array Transformation II

Asked at PayPal

#141

Rank

#22MediumFrequency: 53%

Generate Parentheses

Asked at Google

String Dynamic Programming Backtracking

#142

Rank

#114MediumFrequency: 53%

Flatten Binary Tree to Linked List

Asked at Google

Linked List Stack Tree Depth-First Search Binary Tree

#143

Rank

#116MediumFrequency: 51%

Populating Next Right Pointers in Each Node

Asked at Meta

Linked List Tree Depth-First Search Breadth-First Search Binary Tree

#144

Rank

#954MediumFrequency: 50%

Maximum Sum Circular Subarray

Asked at Flipkart

Array Divide and Conquer Dynamic Programming Queue Monotonic Queue

#145

Rank

#976MediumFrequency: 48%

Minimum Area Rectangle

Asked at Google

Array Hash Table Math Geometry Sorting

#146

Rank

#63MediumFrequency: 48%

Unique Paths II

Asked at Infosys

#147

Rank

#545MediumFrequency: 47%

Boundary of Binary Tree

Asked at Meta

#148

Rank

#238MediumFrequency: 45%

Product of Array Except Self

Asked at Amazon

Array Heap (Priority Queue)

#149

Rank

#373MediumFrequency: 45%

Find K Pairs with Smallest Sums

Asked at Amazon

#150

Rank

#498MediumFrequency: 43%

Diagonal Traverse

Asked at Meta

#151

Rank

#647MediumFrequency: 43%

Palindromic Substrings

Asked at Meta

#152

Rank

#670MediumFrequency: 43%

Maximum Swap

Asked at Meta

Math Greedy

#153

Rank

#2021MediumFrequency: 43%

Remove All Occurrences of a Substring

Asked at PayPal

String Stack Simulation

#154

Rank

#75MediumFrequency: 42%

Sort Colors

Asked at Google

Array Binary Search Dynamic Programming

#155

Rank

#179MediumFrequency: 42%

Largest Number

Asked at Google

Array String Greedy Sorting

#156

Rank

#300MediumFrequency: 42%

Longest Increasing Subsequence

Asked at Google

#157

Rank

#1783MediumFrequency: 42%

Ways to Make a Fair Array

Asked at Infosys

Array Hash Table Two Pointers Binary Search Sorting

#158

Rank

#532MediumFrequency: 40%

K-diff Pairs in an Array

Asked at PayPal

#159

Rank

#230MediumFrequency: 37%

Kth Smallest Element in a BST

Asked at Meta

Tree Depth-First Search Binary Search Tree Binary Tree

#160

Rank

#378MediumFrequency: 37%

Kth Smallest Element in a Sorted Matrix

Asked at Meta

Array Binary Search Sorting Heap (Priority Queue)Matrix

#161

Rank

#735MediumFrequency: 37%

Asteroid Collision

Asked at Meta

Array Stack Simulation

#162

Rank

#752MediumFrequency: 37%

IP to CIDR

Asked at Infosys

String Bit Manipulation

#163

Rank

#36MediumFrequency: 36%

Valid Sudoku

Asked at Amazon

#164

Rank

#80MediumFrequency: 36%

Remove Duplicates from Sorted Array II

Asked at Amazon

#165

Rank

#103MediumFrequency: 36%

Binary Tree Zigzag Level Order Traversal

Asked at Amazon

#166

Rank

#45MediumFrequency: 33%

Jump Game II

Asked at Google