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

#49MediumFrequency: 100%

Group Anagrams

Asked at Oracle

Array Hash Table String Sorting

Rank

#71MediumFrequency: 100%

Simplify Path

Asked at Oracle

Array Hash Table Two Pointers Binary Search Sorting

Rank

#532MediumFrequency: 100%

K-diff Pairs in an Array

Asked at Salesforce

Rank

#1423MediumFrequency: 100%

Maximum Number of Occurrences of a Substring

Asked at Salesforce

Rank

#286MediumFrequency: 100%

Walls and Gates

Asked at DoorDash

Rank

#1171MediumFrequency: 100%

Shortest Path in Binary Matrix

Asked at Airbnb

Hash Table Linked List Design Doubly-Linked List

#10

Rank

#146MediumFrequency: 100%

LRU Cache

Asked at Flipkart

#11

Rank

#362MediumFrequency: 100%

Design Hit Counter

Asked at Databricks

Array Binary Search Design Queue Data Stream

#12

Rank

#314MediumFrequency: 97%

Binary Tree Vertical Order Traversal

Asked at Meta

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

#13

Rank

#227MediumFrequency: 96%

Basic Calculator II

Asked at Meta

Math String Stack

#14

Rank

#658MediumFrequency: 96%

Find K Closest Elements

Asked at DoorDash

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

#15

Rank

#348MediumFrequency: 93%

Design Tic-Tac-Toe

Asked at Databricks

Array Hash Table Design Matrix Simulation

#16

Rank

#215MediumFrequency: 92%

Kth Largest Element in an Array

Asked at Meta

Array Divide and Conquer Sorting Heap (Priority Queue)Quickselect

#17

Rank

#1790MediumFrequency: 91%

Lowest Common Ancestor of a Binary Tree III

Asked at Meta

Hash Table Two Pointers Tree Binary Tree

#18

Rank

#364MediumFrequency: 88%

Nested List Weight Sum II

Asked at LinkedIn

Stack Depth-First Search Breadth-First Search

#19

Rank

#1046MediumFrequency: 88%

Max Consecutive Ones III

Asked at LinkedIn

Array Binary Search Sliding Window Prefix Sum

#20

Rank

#200MediumFrequency: 88%

Number of Islands

Asked at Salesforce

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

#21

Rank

#300MediumFrequency: 88%

Longest Increasing Subsequence

Asked at Salesforce

Array Binary Search Dynamic Programming

#22

Rank

#647MediumFrequency: 88%

Palindromic Substrings

Asked at Salesforce

Array Math Binary Search Prefix Sum Randomized

#23

Rank

#912MediumFrequency: 87%

Random Pick with Weight

Asked at Meta

#24

Rank

#238MediumFrequency: 87%

Product of Array Except Self

Asked at Oracle

Array Dynamic Programming Breadth-First Search

#25

Rank

#322MediumFrequency: 87%

Coin Change

Asked at Oracle

#26

Rank

#1478MediumFrequency: 87%

Maximum Number of Events That Can Be Attended

Asked at Oracle

Array Greedy Sorting Heap (Priority Queue)

#27

Rank

#621MediumFrequency: 85%

Task Scheduler

Asked at Amazon

Array Hash Table Greedy Sorting Heap (Priority Queue)Counting

#28

Rank

#50MediumFrequency: 85%

Pow(x, n)

Asked at Meta

Math Recursion

#29

Rank

#162MediumFrequency: 85%

Find Peak Element

Asked at Meta

#30

Rank

#3MediumFrequency: 84%

Longest Substring Without Repeating Characters

Asked at Microsoft

Depth-First Search Breadth-First Search

#31

Rank

#339MediumFrequency: 84%

Nested List Weight Sum

Asked at Meta

#32

Rank

#366MediumFrequency: 84%

Find Leaves of Binary Tree

Asked at LinkedIn

#33

Rank

#8MediumFrequency: 84%

String to Integer (atoi)

Asked at Databricks

#34

Rank

#198MediumFrequency: 84%

House Robber

Asked at Databricks

#35

Rank

#213MediumFrequency: 84%

House Robber II

Asked at Databricks

#36

Rank

#752MediumFrequency: 84%

IP to CIDR

Asked at Databricks

String Bit Manipulation

#37

Rank

#560MediumFrequency: 81%

Subarray Sum Equals K

Asked at Meta

Array Divide and Conquer Dynamic Programming

#38

Rank

#53MediumFrequency: 79%

Maximum Subarray

Asked at Microsoft

#39

Rank

#236MediumFrequency: 79%

Lowest Common Ancestor of a Binary Tree

Asked at Meta

Tree Depth-First Search Breadth-First Search Binary Tree

#40

Rank

#199MediumFrequency: 76%

Binary Tree Right Side View

Asked at Meta

#41

Rank

#347MediumFrequency: 76%

Top K Frequent Elements

Asked at Meta

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

#42

Rank

#1713MediumFrequency: 76%

Dot Product of Two Sparse Vectors

Asked at Meta

Array Hash Table Two Pointers Design

#43

Rank

#3654MediumFrequency: 74%

Minimum Array Sum

Asked at Amazon

#44

Rank

#907MediumFrequency: 73%

Koko Eating Bananas

Asked at DoorDash

Array String Binary Search Trie Sorting Heap (Priority Queue)

#45

Rank

#1397MediumFrequency: 73%

Search Suggestions System

Asked at DoorDash

#46

Rank

#1783MediumFrequency: 73%

Ways to Make a Fair Array

Asked at DoorDash

Hash Table String Greedy Sorting Heap (Priority Queue)Counting

#47

Rank

#778MediumFrequency: 72%

Reorganize String

Asked at Amazon

#48

Rank

#56MediumFrequency: 72%

Merge Intervals

Asked at Meta

Array Sorting

#49

Rank

#39MediumFrequency: 72%

Combination Sum

Asked at TikTok

Array Hash Table String Dynamic Programming Trie Memoization

#50

Rank

#139MediumFrequency: 72%

Word Break

Asked at TikTok

#51

Rank

#1929MediumFrequency: 72%

Maximum Value at a Given Index in a Bounded Array

Asked at TikTok

Binary Search Greedy

#52

Rank

#235MediumFrequency: 72%

Lowest Common Ancestor of a Binary Search Tree

Asked at LinkedIn

Tree Depth-First Search Binary Search Tree Binary Tree

#53

Rank

#277MediumFrequency: 72%

Find the Celebrity

Asked at LinkedIn

Two Pointers Graph Interactive

#54

Rank

#2MediumFrequency: 71%

Add Two Numbers

Asked at Google

Linked List Math Recursion

#55

Rank

#1108MediumFrequency: 69%

Analyze User Website Visit Pattern

Asked at Amazon

Array Hash Table Sorting

#56

Rank

#1028MediumFrequency: 69%

Interval List Intersections

Asked at Meta

#57

Rank

#129MediumFrequency: 68%

Sum Root to Leaf Numbers

Asked at Meta

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

#58

Rank

#1014MediumFrequency: 68%

K Closest Points to Origin

Asked at Meta

#59

Rank

#1085MediumFrequency: 67%

The Earliest Moment When Everyone Become Friends

Asked at Google

Array Union Find Sorting

#60

Rank

#3639MediumFrequency: 67%

Zero Array Transformation I

Asked at Google

Array Greedy Sorting Heap (Priority Queue)Prefix Sum

#61

Rank

#3647MediumFrequency: 67%

Zero Array Transformation III

Asked at Google

#62

Rank

#138MediumFrequency: 67%

Copy List with Random Pointer

Asked at Amazon

Hash Table Linked List

#63

Rank

#2089MediumFrequency: 66%

Maximum Matrix Sum

Asked at Microsoft

Array Greedy Matrix

#64

Rank

#957MediumFrequency: 66%

Minimum Add to Make Parentheses Valid

Asked at Meta

String Stack Greedy

#65

Rank

#78MediumFrequency: 64%

Subsets

Asked at Meta

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

#66

Rank

#758MediumFrequency: 64%

Convert Binary Search Tree to Sorted Doubly Linked List

Asked at Meta

#67

Rank

#893MediumFrequency: 64%

All Nodes Distance K in Binary Tree

Asked at Meta

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

#68

Rank

#1909MediumFrequency: 64%

Buildings With an Ocean View

Asked at Meta

#69

Rank

#54MediumFrequency: 63%

Spiral Matrix

Asked at Uber

Array String Backtracking Matrix

#70

Rank

#79MediumFrequency: 63%

Word Search

Asked at Uber

#71

Rank

#399MediumFrequency: 63%

Evaluate Division

Asked at Uber

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

#72

Rank

#772MediumFrequency: 63%

Construct Quad Tree

Asked at Uber

Array Divide and Conquer Tree Matrix

#73

Rank

#1549MediumFrequency: 63%

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

Asked at Uber

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

#74

Rank

#34MediumFrequency: 63%

Find First and Last Position of Element in Sorted Array

Asked at LinkedIn

#75

Rank

#40MediumFrequency: 63%

Combination Sum II

Asked at LinkedIn

#76

Rank

#152MediumFrequency: 63%

Maximum Product Subarray

Asked at LinkedIn

Array Hash Table Two Pointers String Design

#77

Rank

#244MediumFrequency: 63%

Shortest Word Distance II

Asked at LinkedIn

#78

Rank

#31MediumFrequency: 62%

Next Permutation

Asked at Meta

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

#79

Rank

#721MediumFrequency: 62%

Accounts Merge

Asked at Meta

#80

Rank

#253MediumFrequency: 62%

Meeting Rooms II

Asked at TikTok

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

#81

Rank

#694MediumFrequency: 62%

Number of Distinct Islands

Asked at TikTok

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

#82

Rank

#2414MediumFrequency: 60%

Move Pieces to Obtain a String

Asked at Google

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

#83

Rank

#2868MediumFrequency: 60%

Continuous Subarrays

Asked at Google

#84

Rank

#2891MediumFrequency: 60%

Maximum Beauty of an Array After Applying Operation

Asked at Google

Array Binary Search Sliding Window Sorting

#85

Rank

#15MediumFrequency: 60%

3Sum

Asked at Amazon

#86

Rank

#55MediumFrequency: 60%

Jump Game

Asked at Amazon

#87

Rank

#3018MediumFrequency: 60%

Make String a Subsequence Using Cyclic Increments

Asked at Amazon

Hash Table Depth-First Search Breadth-First Search Graph

#88

Rank

#133MediumFrequency: 60%

Clone Graph

Asked at Meta

#89

Rank

#807MediumFrequency: 60%

Custom Sort String

Asked at Meta

Hash Table String Sorting

#90

Rank

#850MediumFrequency: 57%

Insert into a Sorted Circular Linked List

Asked at Meta

Linked List

#91

Rank

#998MediumFrequency: 57%

Check Completeness of a Binary Tree

Asked at Meta

Depth-First Search Breadth-First Search Graph Topological Sort

#92

Rank

#207MediumFrequency: 56%

Course Schedule

Asked at Google

#93

Rank

#2164MediumFrequency: 56%

Two Best Non-Overlapping Events

Asked at Google

Array Binary Search Dynamic Programming Sorting Heap (Priority Queue)

#94

Rank

#6MediumFrequency: 56%

Zigzag Conversion

Asked at Amazon

#95

Rank

#17MediumFrequency: 56%

Letter Combinations of a Phone Number

Asked at Amazon

#96

Rank

#5MediumFrequency: 55%

Longest Palindromic Substring

Asked at Microsoft

#97

Rank

#12MediumFrequency: 55%

Integer to Roman

Asked at Microsoft

Hash Table Math String

#98

Rank

#18MediumFrequency: 55%

4Sum

Asked at Microsoft

#99

Rank

#33MediumFrequency: 55%

Search in Rotated Sorted Array

Asked at Microsoft

#100

Rank

#90MediumFrequency: 55%

Subsets II

Asked at Microsoft

Array Hash Table Union Find

#101

Rank

#128MediumFrequency: 55%

Longest Consecutive Sequence

Asked at Microsoft

#102

Rank

#155MediumFrequency: 55%

Min Stack

Asked at Microsoft

Stack Design

#103

Rank

#167MediumFrequency: 55%

Two Sum II - Input Array Is Sorted

Asked at Microsoft

Array Two Pointers Binary Search

#104

Rank

#291MediumFrequency: 55%

Word Pattern II

Asked at Microsoft

Hash Table Two Pointers String Sliding Window

#105

Rank

#567MediumFrequency: 55%

Permutation in String

Asked at Microsoft

#106

Rank

#1036MediumFrequency: 55%

Rotting Oranges

Asked at Microsoft

#107

Rank

#1147MediumFrequency: 55%

Flip Columns For Maximum Number of Equal Rows

Asked at Microsoft

String Dynamic Programming Backtracking

#108

Rank

#22MediumFrequency: 53%

Generate Parentheses

Asked at Google

#109

Rank

#114MediumFrequency: 53%

Flatten Binary Tree to Linked List

Asked at Google

Linked List Stack Tree Depth-First Search Binary Tree

#110

Rank

#2300MediumFrequency: 53%

Construct String With Repeat Limit

Asked at Google

Hash Table String Greedy Heap (Priority Queue)Counting

#111

Rank

#380MediumFrequency: 51%

Insert Delete GetRandom O(1)

Asked at Amazon

Array Hash Table Math Design Randomized

#112

Rank

#1056MediumFrequency: 51%

Capacity To Ship Packages Within D Days

Asked at Amazon

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

#113

Rank

#116MediumFrequency: 51%

Populating Next Right Pointers in Each Node

Asked at Meta

#114

Rank

#173MediumFrequency: 51%

Binary Search Tree Iterator

Asked at Meta

Stack Tree Design Binary Search Tree Binary Tree Iterator

#115

Rank

#398MediumFrequency: 51%

Random Pick Index

Asked at Meta

Hash Table Math Reservoir Sampling Randomized

#116

Rank

#7MediumFrequency: 48%

Reverse Integer

Asked at Google

Math

#117

Rank

#976MediumFrequency: 48%

Minimum Area Rectangle

Asked at Google

Array Hash Table Math Geometry Sorting

#118

Rank

#1886MediumFrequency: 48%

Minimum Limit of Balls in a Bag

Asked at Google

Array Two Pointers String Simulation

#119

Rank

#2232MediumFrequency: 48%

Adding Spaces to a String

Asked at Google

#120

Rank

#3643MediumFrequency: 48%

Zero Array Transformation II

Asked at Google

Array Binary Search Prefix Sum

#121

Rank

#48MediumFrequency: 47%

Rotate Image

Asked at Meta

Array Math Matrix

#122

Rank

#545MediumFrequency: 47%

Boundary of Binary Tree

Asked at Meta

#123

Rank

#122MediumFrequency: 45%

Best Time to Buy and Sell Stock II

Asked at Amazon

#124

Rank

#151MediumFrequency: 45%

Reverse Words in a String

Asked at Amazon

Array Heap (Priority Queue)

#125

Rank

#373MediumFrequency: 45%

Find K Pairs with Smallest Sums

Asked at Amazon

#126

Rank

#19MediumFrequency: 43%

Remove Nth Node From End of List

Asked at Meta

Linked List Two Pointers

#127

Rank

#249MediumFrequency: 43%

Group Shifted Strings

Asked at Meta

Array Hash Table String

#128

Rank

#325MediumFrequency: 43%

Maximum Size Subarray Sum Equals k

Asked at Meta

#129

Rank

#498MediumFrequency: 43%

Diagonal Traverse

Asked at Meta

Array Hash Table Math Prefix Sum

#130

Rank

#523MediumFrequency: 43%

Continuous Subarray Sum

Asked at Meta

#131

Rank

#670MediumFrequency: 43%

Maximum Swap

Asked at Meta

Math Greedy

#132

Rank

#11MediumFrequency: 42%

Container With Most Water

Asked at Google

Array Two Pointers Greedy

#133

Rank

#46MediumFrequency: 42%

Permutations

Asked at Google

Math Dynamic Programming Combinatorics

#134

Rank

#62MediumFrequency: 42%

Unique Paths

Asked at Google

#135

Rank

#63MediumFrequency: 42%

Unique Paths II

Asked at Google

#136

Rank

#75MediumFrequency: 42%

Sort Colors

Asked at Google

#137

Rank

#179MediumFrequency: 42%

Largest Number

Asked at Google

Array String Greedy Sorting

#138

Rank

#394MediumFrequency: 42%

Decode String

Asked at Google

String Stack Recursion

#139

Rank

#424MediumFrequency: 42%

Longest Repeating Character Replacement

Asked at Google

#140

Rank

#518MediumFrequency: 42%

Coin Change II

Asked at Google

#141

Rank

#739MediumFrequency: 42%

Daily Temperatures

Asked at Google

Array Queue Sorting Simulation

#142

Rank

#987MediumFrequency: 42%

Reveal Cards In Increasing Order

Asked at Google

#143

Rank

#1330MediumFrequency: 42%

Longest Arithmetic Subsequence of Given Difference

Asked at Google

Array Hash Table Dynamic Programming

#144

Rank

#1585MediumFrequency: 42%

The kth Factor of n

Asked at Google

Math Number Theory

#145

Rank

#1966MediumFrequency: 42%

Frequency of the Most Frequent Element

Asked at Google

Array Binary Search Greedy Sliding Window Sorting Prefix Sum

#146

Rank

#3681MediumFrequency: 42%

Maximum Area Rectangle With Point Constraints I

Asked at Google

Array Math Binary Indexed Tree Segment Tree Geometry Sorting Enumeration

#147

Rank

#109MediumFrequency: 37%

Convert Sorted List to Binary Search Tree

Asked at Meta

Linked List Divide and Conquer Tree Binary Search Tree Binary Tree

#148

Rank

#230MediumFrequency: 37%

Kth Smallest Element in a BST

Asked at Meta

Tree Depth-First Search Binary Search Tree Binary Tree

#149

Rank

#378MediumFrequency: 37%

Kth Smallest Element in a Sorted Matrix

Asked at Meta

Array Binary Search Sorting Heap (Priority Queue)Matrix

#150

Rank

#735MediumFrequency: 37%

Asteroid Collision

Asked at Meta

Array Stack Simulation

#151

Rank

#852MediumFrequency: 37%

Friends Of Appropriate Ages

Asked at Meta

Array Two Pointers Binary Search Sorting

#152

Rank

#36MediumFrequency: 36%

Valid Sudoku

Asked at Amazon

#153

Rank

#64MediumFrequency: 36%

Minimum Path Sum

Asked at Amazon

#154

Rank

#80MediumFrequency: 36%

Remove Duplicates from Sorted Array II

Asked at Amazon

#155

Rank

#103MediumFrequency: 36%

Binary Tree Zigzag Level Order Traversal

Asked at Amazon

#156

Rank

#134MediumFrequency: 36%

Gas Station

Asked at Amazon

Array Greedy

#157

Rank

#45MediumFrequency: 33%

Jump Game II

Asked at Google

Start Free TrialNo credit card required View Pricing

#158

Rank

View All Companies

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Medium LeetCode Interview Questions

Master 158 medium difficulty coding problems frequently asked in technical interviews at top tech companies. Perfect for building confidence and fundamental problem-solving skills.

Easy (110)Medium (260)Hard (67)

#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

#49MediumFrequency: 100%

Group Anagrams

Asked at Oracle

Array Hash Table String Sorting

Rank

#71MediumFrequency: 100%

Simplify Path

Asked at Oracle

Array Hash Table Two Pointers Binary Search Sorting

Rank

#532MediumFrequency: 100%

K-diff Pairs in an Array

Asked at Salesforce

Rank

#1423MediumFrequency: 100%

Maximum Number of Occurrences of a Substring

Asked at Salesforce

Rank

#286MediumFrequency: 100%

Walls and Gates

Asked at DoorDash

Rank

#1171MediumFrequency: 100%

Shortest Path in Binary Matrix

Asked at Airbnb

Hash Table Linked List Design Doubly-Linked List

#10

Rank

#146MediumFrequency: 100%

LRU Cache

Asked at Flipkart

#11

Rank

#362MediumFrequency: 100%

Design Hit Counter

Asked at Databricks

Array Binary Search Design Queue Data Stream

#12

Rank

#314MediumFrequency: 97%

Binary Tree Vertical Order Traversal

Asked at Meta

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

#13

Rank

#227MediumFrequency: 96%

Basic Calculator II

Asked at Meta

Math String Stack

#14

Rank

#658MediumFrequency: 96%

Find K Closest Elements

Asked at DoorDash

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

#15

Rank

#348MediumFrequency: 93%

Design Tic-Tac-Toe

Asked at Databricks

Array Hash Table Design Matrix Simulation

#16

Rank

#215MediumFrequency: 92%

Kth Largest Element in an Array

Asked at Meta

Array Divide and Conquer Sorting Heap (Priority Queue)Quickselect

#17

Rank

#1790MediumFrequency: 91%

Lowest Common Ancestor of a Binary Tree III

Asked at Meta

Hash Table Two Pointers Tree Binary Tree

#18

Rank

#364MediumFrequency: 88%

Nested List Weight Sum II

Asked at LinkedIn

Stack Depth-First Search Breadth-First Search

#19

Rank

#1046MediumFrequency: 88%

Max Consecutive Ones III

Asked at LinkedIn

Array Binary Search Sliding Window Prefix Sum

#20

Rank

#200MediumFrequency: 88%

Number of Islands

Asked at Salesforce

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

#21

Rank

#300MediumFrequency: 88%

Longest Increasing Subsequence

Asked at Salesforce

Array Binary Search Dynamic Programming

#22

Rank

#647MediumFrequency: 88%

Palindromic Substrings

Asked at Salesforce

Array Math Binary Search Prefix Sum Randomized

#23

Rank

#912MediumFrequency: 87%

Random Pick with Weight

Asked at Meta

#24

Rank

#238MediumFrequency: 87%

Product of Array Except Self

Asked at Oracle

Array Dynamic Programming Breadth-First Search

#25

Rank

#322MediumFrequency: 87%

Coin Change

Asked at Oracle

#26

Rank

#1478MediumFrequency: 87%

Maximum Number of Events That Can Be Attended

Asked at Oracle

Array Greedy Sorting Heap (Priority Queue)

#27

Rank

#621MediumFrequency: 85%

Task Scheduler

Asked at Amazon

Array Hash Table Greedy Sorting Heap (Priority Queue)Counting

#28

Rank

#50MediumFrequency: 85%

Pow(x, n)

Asked at Meta

Math Recursion

#29

Rank

#162MediumFrequency: 85%

Find Peak Element

Asked at Meta

#30

Rank

#3MediumFrequency: 84%

Longest Substring Without Repeating Characters

Asked at Microsoft

Depth-First Search Breadth-First Search

#31

Rank

#339MediumFrequency: 84%

Nested List Weight Sum

Asked at Meta

#32

Rank

#366MediumFrequency: 84%

Find Leaves of Binary Tree

Asked at LinkedIn

#33

Rank

#8MediumFrequency: 84%

String to Integer (atoi)

Asked at Databricks

#34

Rank

#198MediumFrequency: 84%

House Robber

Asked at Databricks

#35

Rank

#213MediumFrequency: 84%

House Robber II

Asked at Databricks

#36

Rank

#752MediumFrequency: 84%

IP to CIDR

Asked at Databricks

String Bit Manipulation

#37

Rank

#560MediumFrequency: 81%

Subarray Sum Equals K

Asked at Meta

Array Divide and Conquer Dynamic Programming

#38

Rank

#53MediumFrequency: 79%

Maximum Subarray

Asked at Microsoft

#39

Rank

#236MediumFrequency: 79%

Lowest Common Ancestor of a Binary Tree

Asked at Meta

Tree Depth-First Search Breadth-First Search Binary Tree

#40

Rank

#199MediumFrequency: 76%

Binary Tree Right Side View

Asked at Meta

#41

Rank

#347MediumFrequency: 76%

Top K Frequent Elements

Asked at Meta

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

#42

Rank

#1713MediumFrequency: 76%

Dot Product of Two Sparse Vectors

Asked at Meta

Array Hash Table Two Pointers Design

#43

Rank

#3654MediumFrequency: 74%

Minimum Array Sum

Asked at Amazon

#44

Rank

#907MediumFrequency: 73%

Koko Eating Bananas

Asked at DoorDash

Array String Binary Search Trie Sorting Heap (Priority Queue)

#45

Rank

#1397MediumFrequency: 73%

Search Suggestions System

Asked at DoorDash

#46

Rank

#1783MediumFrequency: 73%

Ways to Make a Fair Array

Asked at DoorDash

Hash Table String Greedy Sorting Heap (Priority Queue)Counting

#47

Rank

#778MediumFrequency: 72%

Reorganize String

Asked at Amazon

#48

Rank

#56MediumFrequency: 72%

Merge Intervals

Asked at Meta

Array Sorting

#49

Rank

#39MediumFrequency: 72%

Combination Sum

Asked at TikTok

Array Hash Table String Dynamic Programming Trie Memoization

#50

Rank

#139MediumFrequency: 72%

Word Break

Asked at TikTok

#51

Rank

#1929MediumFrequency: 72%

Maximum Value at a Given Index in a Bounded Array

Asked at TikTok

Binary Search Greedy

#52

Rank

#235MediumFrequency: 72%

Lowest Common Ancestor of a Binary Search Tree

Asked at LinkedIn

Tree Depth-First Search Binary Search Tree Binary Tree

#53

Rank

#277MediumFrequency: 72%

Find the Celebrity

Asked at LinkedIn

Two Pointers Graph Interactive

#54

Rank

#2MediumFrequency: 71%

Add Two Numbers

Asked at Google

Linked List Math Recursion

#55

Rank

#1108MediumFrequency: 69%

Analyze User Website Visit Pattern

Asked at Amazon

Array Hash Table Sorting

#56

Rank

#1028MediumFrequency: 69%

Interval List Intersections

Asked at Meta

#57

Rank

#129MediumFrequency: 68%

Sum Root to Leaf Numbers

Asked at Meta

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

#58

Rank

#1014MediumFrequency: 68%

K Closest Points to Origin

Asked at Meta

#59

Rank

#1085MediumFrequency: 67%

The Earliest Moment When Everyone Become Friends

Asked at Google

Array Union Find Sorting

#60

Rank

#3639MediumFrequency: 67%

Zero Array Transformation I

Asked at Google

Array Greedy Sorting Heap (Priority Queue)Prefix Sum

#61

Rank

#3647MediumFrequency: 67%

Zero Array Transformation III

Asked at Google

#62

Rank

#138MediumFrequency: 67%

Copy List with Random Pointer

Asked at Amazon

Hash Table Linked List

#63

Rank

#2089MediumFrequency: 66%

Maximum Matrix Sum

Asked at Microsoft

Array Greedy Matrix

#64

Rank

#957MediumFrequency: 66%

Minimum Add to Make Parentheses Valid

Asked at Meta

String Stack Greedy

#65

Rank

#78MediumFrequency: 64%

Subsets

Asked at Meta

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

#66

Rank

#758MediumFrequency: 64%

Convert Binary Search Tree to Sorted Doubly Linked List

Asked at Meta

#67

Rank

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#2868MediumFrequency: 60%

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#90MediumFrequency: 55%

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#1886MediumFrequency: 48%

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#62MediumFrequency: 42%

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#135

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#63MediumFrequency: 42%

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#75MediumFrequency: 42%

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#137

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#179MediumFrequency: 42%

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#394MediumFrequency: 42%

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#424MediumFrequency: 42%

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#140

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#518MediumFrequency: 42%

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#141

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#739MediumFrequency: 42%

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#987MediumFrequency: 42%

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#143

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#1330MediumFrequency: 42%

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#1585MediumFrequency: 42%

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#3681MediumFrequency: 42%

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#852MediumFrequency: 37%

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#36MediumFrequency: 36%

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#64MediumFrequency: 36%

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#103MediumFrequency: 36%

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