Beginner-Friendly Interview Questions

Array Hash Table

Rank

#3594MediumFrequency: 100%High Priority

Identify the Largest Outlier in an Array

Array Hash Table Counting Enumeration

Rank

#3655MediumFrequency: 100%High Priority

Digit Operations to Make Two Integers Equal

Math Graph Heap (Priority Queue)Number Theory Shortest Path

Rank

#1371MediumFrequency: 100%High Priority

Minimum Remove to Make Valid Parentheses

Array String Depth-First Search Breadth-First Search Graph

String Stack

Rank

#3613MediumFrequency: 100%High Priority

Maximize Amount After Two Days of Conversions

Asked at Uber

Rank

#49MediumFrequency: 100%High Priority

Group Anagrams

Array Hash Table String Sorting

Rank

#71MediumFrequency: 100%High Priority

Simplify Path

String Stack

Rank

#1306EasyFrequency: 100%High Priority

Minimum Absolute Difference

Array Sorting

Rank

#532MediumFrequency: 100%High Priority

K-diff Pairs in an Array

Array Hash Table Two Pointers Binary Search Sorting

Rank

#1423MediumFrequency: 100%High Priority

Maximum Number of Occurrences of a Substring

Hash Table String Sliding Window

#10

Rank

#286MediumFrequency: 100%High Priority

Walls and Gates

Array Breadth-First Search Matrix

#11

Rank

#1171MediumFrequency: 100%High Priority

Shortest Path in Binary Matrix

Asked at Airbnb

Array Breadth-First Search Matrix

#12

Rank

#146MediumFrequency: 100%High Priority

LRU Cache

Asked at Flipkart

Hash Table Linked List Design Doubly-Linked List

#13

Rank

#362MediumFrequency: 100%High Priority

Design Hit Counter

Array Binary Search Design Queue Data Stream

#14

Rank

#314MediumFrequency: 97%High Priority

Binary Tree Vertical Order Traversal

Hash Table Tree Depth-First Search Breadth-First Search Sorting+1 more

#15

Rank

#227MediumFrequency: 96%High Priority

Basic Calculator II

Math String Stack

#16

Rank

#658MediumFrequency: 96%High Priority

Find K Closest Elements

Array Two Pointers Binary Search Sliding Window Sorting+1 more

#17

Rank

#680EasyFrequency: 95%High Priority

Valid Palindrome II

Two Pointers String Greedy

#18

Rank

#348MediumFrequency: 93%High Priority

Design Tic-Tac-Toe

Array Hash Table Design Matrix Simulation

#19

Rank

#88EasyFrequency: 92%High Priority

Merge Sorted Array

Array Two Pointers Sorting

#20

Rank

#215MediumFrequency: 92%High Priority

Kth Largest Element in an Array

Array Divide and Conquer Sorting Heap (Priority Queue)Quickselect

#21

Rank

#1790MediumFrequency: 91%High Priority

Lowest Common Ancestor of a Binary Tree III

Hash Table Two Pointers Tree Binary Tree

#22

Rank

#364MediumFrequency: 88%High Priority

Nested List Weight Sum II

Stack Depth-First Search Breadth-First Search

#23

Rank

#1046MediumFrequency: 88%High Priority

Max Consecutive Ones III

Array Binary Search Sliding Window Prefix Sum

#24

Rank

#200MediumFrequency: 88%High Priority

Number of Islands

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

#25

Rank

#300MediumFrequency: 88%High Priority

Longest Increasing Subsequence

Array Binary Search Dynamic Programming

#26

Rank

#647MediumFrequency: 88%High Priority

Palindromic Substrings

Two Pointers String Dynamic Programming

#27

Rank

#408EasyFrequency: 87%High Priority

Valid Word Abbreviation

Two Pointers String

#28

Rank

#912MediumFrequency: 87%High Priority

Random Pick with Weight

Array Math Binary Search Prefix Sum Randomized

#29

Rank

#125EasyFrequency: 87%High Priority

Valid Palindrome

Two Pointers String

#30

Rank

#206EasyFrequency: 87%High Priority

Reverse Linked List

Linked List Recursion

#31

Rank

#238MediumFrequency: 87%High Priority

Product of Array Except Self

Array Prefix Sum

#32

Rank

#322MediumFrequency: 87%High Priority

Coin Change

Array Dynamic Programming Breadth-First Search

#33

Rank

#1478MediumFrequency: 87%High Priority

Maximum Number of Events That Can Be Attended

Array Greedy Sorting Heap (Priority Queue)

#34

Rank

#621MediumFrequency: 85%High Priority

Task Scheduler

Array Hash Table Greedy Sorting Heap (Priority Queue)+1 more

#35

Rank

#50MediumFrequency: 85%High Priority

Pow(x, n)

Math Recursion

#36

Rank

#162MediumFrequency: 85%High Priority

Find Peak Element

Array Binary Search

#37

Rank

#3MediumFrequency: 84%High Priority

Longest Substring Without Repeating Characters

Hash Table String Sliding Window

#38

Rank

#339MediumFrequency: 84%High Priority

Nested List Weight Sum

Depth-First Search Breadth-First Search

#39

Rank

#366MediumFrequency: 84%High Priority

Find Leaves of Binary Tree

Tree Depth-First Search Binary Tree

#40

Rank

#8MediumFrequency: 84%High Priority

String to Integer (atoi)

String

#41

Rank

#198MediumFrequency: 84%High Priority

House Robber

#42

Rank

#213MediumFrequency: 84%High Priority

House Robber II

#43

Rank

#752MediumFrequency: 84%High Priority

IP to CIDR

String Bit Manipulation

#44

Rank

#560MediumFrequency: 81%High Priority

Subarray Sum Equals K

Array Hash Table Prefix Sum

#45

Rank

#1894EasyFrequency: 80%High Priority

Merge Strings Alternately

Two Pointers String

#46

Rank

#14EasyFrequency: 80%High Priority

Longest Common Prefix

Asked at Apple

String Trie

#47

Rank

#53MediumFrequency: 79%High Priority

Maximum Subarray

Array Divide and Conquer Dynamic Programming

#48

Rank

#70EasyFrequency: 79%High Priority

Climbing Stairs

Math Dynamic Programming Memoization

#49

Rank

#1908EasyFrequency: 79%High Priority

Recyclable and Low Fat Products

Database

#50

Rank

#236MediumFrequency: 79%High Priority

Lowest Common Ancestor of a Binary Tree

Tree Depth-First Search Binary Tree

#51

Rank

#2809EasyFrequency: 77%High Priority

Create Hello World Function

#52

Rank

#199MediumFrequency: 76%High Priority

Binary Tree Right Side View

Tree Depth-First Search Breadth-First Search Binary Tree

#53

Rank

#347MediumFrequency: 76%High Priority

Top K Frequent Elements

Array Hash Table Divide and Conquer Sorting Heap (Priority Queue)+3 more

#54

Rank

#1713MediumFrequency: 76%High Priority

Dot Product of Two Sparse Vectors

Array Hash Table Two Pointers Design

#55

Rank

#3654MediumFrequency: 74%High Priority

Minimum Array Sum

#56

Rank

#543EasyFrequency: 74%High Priority

Diameter of Binary Tree

Tree Depth-First Search Binary Tree

#57

Rank

#27EasyFrequency: 73%High Priority

Remove Element

Array Two Pointers

#58

Rank

#2383EasyFrequency: 73%High Priority

Add Two Integers

Math

#59

Rank

#975EasyFrequency: 73%High Priority

Range Sum of BST

Tree Depth-First Search Binary Search Tree Binary Tree

#60

Rank

#907MediumFrequency: 73%High Priority

Koko Eating Bananas

Array Binary Search

#61

Rank

#1397MediumFrequency: 73%High Priority

Search Suggestions System

Array String Binary Search Trie Sorting+1 more

#62

Rank

#1783MediumFrequency: 73%High Priority

Ways to Make a Fair Array

Array Prefix Sum

#63

Rank

#1915EasyFrequency: 73%High Priority

Check if One String Swap Can Make Strings Equal

Hash Table String Counting

#64

Rank

#778MediumFrequency: 72%High Priority

Reorganize String

Hash Table String Greedy Sorting Heap (Priority Queue)+1 more

#65

Rank

#56MediumFrequency: 72%High Priority

Merge Intervals

Array Sorting

#66

Rank

#39MediumFrequency: 72%High Priority

Combination Sum

Asked at TikTok

Array Backtracking

#67

Rank

#139MediumFrequency: 72%High Priority

Word Break

Asked at TikTok

Array Hash Table String Dynamic Programming Trie+1 more

#68

Rank

#1929MediumFrequency: 72%High Priority

Maximum Value at a Given Index in a Bounded Array

Asked at TikTok

Binary Search Greedy

#69

Rank

#235MediumFrequency: 72%High Priority

Lowest Common Ancestor of a Binary Search Tree

Tree Depth-First Search Binary Search Tree Binary Tree

#70

Rank

#277MediumFrequency: 72%High Priority

Find the Celebrity

Two Pointers Graph Interactive

#71

Rank

#605EasyFrequency: 72%High Priority

Can Place Flowers

Array Greedy

#72

Rank

#2MediumFrequency: 71%High Priority

Add Two Numbers

Linked List Math Recursion

#73

Rank

#20EasyFrequency: 71%High Priority

Valid Parentheses

Asked at Apple

String Stack

#74

Rank

#121EasyFrequency: 69%High Priority

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