Apple

300 LeetCode interview questions

Difficulty Distribution

Easy
76
25%
Medium
178
59%
Hard
46
15%

Top Topics

All Questions

TitleDifficulty
LRU CacheMedium
Two SumEasy
Number of IslandsMedium
Merge IntervalsMedium
Best Time to Buy and Sell StockEasy
Design Hit CounterMedium
Longest Common PrefixEasy
Rotate ArrayMedium
Reverse Linked ListEasy
Valid SudokuMedium
Group AnagramsMedium
Top K Frequent ElementsMedium
Course Schedule IIMedium
Course ScheduleMedium
Valid ParenthesesEasy
Longest Substring Without Repeating CharactersMedium
Product of Array Except SelfMedium
Valid PalindromeEasy
Rotate ImageMedium
Reverse Words in a StringMedium
Kth Largest Element in an ArrayMedium
Spiral MatrixMedium
Best Time to Buy and Sell Stock IIMedium
Maximum SubarrayMedium
Reverse IntegerMedium
Merge k Sorted ListsHard
Meeting Rooms IIMedium
Trapping Rain WaterHard
Time Based Key-Value StoreMedium
Lowest Common Ancestor of a Binary TreeMedium
Subarray Sum Equals KMedium
Subarray Product Less Than KMedium
Median of Two Sorted ArraysHard
Reverse BitsEasy
Find First and Last Position of Element in Sorted ArrayMedium
Snapshot ArrayMedium
Design Circular QueueMedium
Number of 1 BitsEasy
Merge Two Sorted ListsEasy
Find Median from Data StreamHard
Move ZeroesEasy
Word LadderHard
Insert Delete GetRandom O(1)Medium
Basic Calculator IIMedium
Min StackMedium
Climbing StairsEasy
Compare Version NumbersMedium
Search a 2D Matrix IIMedium
Merge Sorted ArrayEasy
Word BreakMedium
String CompressionMedium
Find the Index of the First Occurrence in a StringEasy
Peeking IteratorMedium
3SumMedium
Implement Trie (Prefix Tree)Medium
Design Tic-Tac-ToeMedium
Binary Tree Level Order TraversalMedium
Pascal's TriangleEasy
Ransom NoteEasy
Sqrt(x)Easy
Max Points on a LineHard
Delete Node in a Linked ListMedium
Number of Squareful ArraysHard
Number of Pairs of Strings With Concatenation Equal to TargetMedium
Longest Consecutive SequenceMedium
First Unique Character in a StringEasy
Calculate Score After Performing InstructionsMedium
Find Servers That Handled Most Number of RequestsHard
Regular Expression MatchingHard
Remove Duplicates from Sorted ArrayEasy
Design HashMapEasy
Best Time to Buy and Sell Stock with Transaction FeeMedium
Maximum Depth of Binary TreeEasy
Maximal SquareMedium
Binary Tree PathsEasy
Find the Grid of Region AverageMedium
Count the Number of Incremovable Subarrays IIHard
Maximum Rows Covered by ColumnsMedium
Count the Number of Incremovable Subarrays IEasy
Array NestingMedium
Flatten Nested List IteratorMedium
Remove Nth Node From End of ListMedium
Two Sum II - Input Array Is SortedMedium
Serialize and Deserialize Binary TreeHard
Task SchedulerMedium
Longest Palindromic SubstringMedium
Container With Most WaterMedium
Letter Combinations of a Phone NumberMedium
Generate ParenthesesMedium
Decode StringMedium
Find K Closest ElementsMedium
Find Winner on a Tic Tac Toe GameEasy
Remove All Adjacent Duplicates In StringEasy
Search in Rotated Sorted ArrayMedium
Implement Queue using StacksEasy
Fibonacci NumberEasy
Meeting RoomsEasy
Integer to English WordsHard
Text JustificationHard
Jump GameMedium
Reverse StringEasy
Flood FillEasy
Insert IntervalMedium
Sliding Window MaximumHard
String to Integer (atoi)Medium
Roman to IntegerEasy
PermutationsMedium
Coin ChangeMedium
Total Hamming DistanceMedium
Edit DistanceMedium
Serialize and Deserialize N-ary TreeHard
Find All Lonely Numbers in the ArrayMedium
Best Time to Buy and Sell Stock with CooldownMedium
Path SumEasy
Fizz BuzzEasy
Gas StationMedium
Add Two NumbersMedium
Cheapest Flights Within K StopsMedium
Keys and RoomsMedium
Interleaving StringMedium
Valid AnagramEasy
Missing NumberEasy
LFU CacheHard
Middle of the Linked ListEasy
Set Matrix ZeroesMedium
Word SearchMedium
Rotting OrangesMedium
Maximum Frequency StackHard
Lowest Common Ancestor of a Binary Tree IIIMedium
Distribute Money to Maximum ChildrenEasy
Design Memory AllocatorMedium
Brace ExpansionMedium
Odd Even Linked ListMedium
Binary Tree Vertical Order TraversalMedium
Design Log Storage SystemMedium
Sort ColorsMedium
Combination SumMedium
Simplify PathMedium
Reverse Linked List IIMedium
Binary Tree Maximum Path SumHard
House RobberMedium
Apple Redistribution into BoxesEasy
Kth Smallest Element in a Sorted MatrixMedium
Exam RoomMedium
Best Time to Buy and Sell Stock IVHard
Alien DictionaryHard
Design Add and Search Words Data StructureMedium
Maximum Path Quality of a GraphHard
Convert Sorted Array to Binary Search TreeEasy
Find Peak ElementMedium
Happy NumberEasy
H-IndexMedium
Find All Anagrams in a StringMedium
Palindromic SubstringsMedium
Valid Palindrome IIEasy
Capacity To Ship Packages Within D DaysMedium
Knight Probability in ChessboardMedium
Validate IP AddressMedium
Best Time to Buy and Sell Stock IIIHard
Find the CelebrityMedium
Minimum Knight MovesMedium
Remove ElementEasy
Add BinaryEasy
Search a 2D MatrixMedium
Largest Rectangle in HistogramHard
Validate Binary Search TreeMedium
Reorder ListMedium
Find Minimum in Rotated Sorted ArrayMedium
The Skyline ProblemHard
Intersection of Two ArraysEasy
Island PerimeterEasy
Next Greater Element IIMedium
Maximum Product of Three NumbersEasy
Random Pick with WeightMedium
Sum of Subarray MinimumsMedium
House Robber IIMedium
Permutations IIMedium
Determine if Two Strings Are CloseMedium
String Compression IIIMedium
Employee Free TimeHard
Robot Bounded In CircleMedium
Intersection of Two Linked ListsEasy
Same TreeEasy
Word Ladder IIHard
Longest Substring with At Most K Distinct CharactersMedium
Read N Characters Given read4 II - Call Multiple TimesHard
Shortest Path in Binary MatrixMedium
Short Encoding of WordsMedium
Sudoku SolverHard
Convert Sorted List to Binary Search TreeMedium
Contains DuplicateEasy
Evaluate Reverse Polish NotationMedium
Basic CalculatorHard
K Closest Points to OriginMedium
Reconstruct ItineraryHard
Best Poker HandEasy
Find Largest Value in Each Tree RowMedium
Logger Rate LimiterEasy
Continuous Subarray SumMedium
Binary Tree Right Side ViewMedium
Design Browser HistoryMedium
Find Pivot IndexEasy
Top K Frequent WordsMedium
Interval List IntersectionsMedium
My Calendar IIMedium
4SumMedium
Longest Increasing Path in a MatrixHard
Paths in Matrix Whose Sum Is Divisible by KHard
Construct Binary Tree from Preorder and Postorder TraversalMedium
Convert Object to JSON StringMedium
All Nodes Distance K in Binary TreeMedium
Design Task ManagerMedium
Minimum Falling Path SumMedium
Permutation in StringMedium
Maximum Sum Circular SubarrayMedium
All O`one Data StructureHard
Parse Lisp ExpressionHard
Find Distance in a Binary TreeMedium
Koko Eating BananasMedium
First Missing PositiveHard
Jump Game IIMedium
Minimum Window SubstringHard
Decode WaysMedium
Symmetric TreeEasy
Copy List with Random PointerMedium
Implement Stack using QueuesEasy
Lowest Common Ancestor of a Binary Search TreeMedium
First Bad VersionEasy
Max Consecutive OnesEasy
Reverse PairsHard
01 MatrixMedium
Diameter of Binary TreeEasy
Can Place FlowersEasy
Asteroid CollisionMedium
Similar String GroupsHard
Transpose MatrixEasy
Snakes and LaddersMedium
Product of the Last K NumbersMedium
Minimum Remove to Make Valid ParenthesesMedium
Verifying an Alien DictionaryEasy
Goat LatinEasy
Shortest Distance from All BuildingsHard
Web Crawler MultithreadedMedium
Sum of Subarray RangesMedium
Word Pattern IIMedium
Clone GraphMedium
Split Strings by SeparatorEasy
Walking Robot SimulationMedium
First Letter to Appear TwiceEasy
Guess the WordHard
Sliding Window MedianHard
Max Chunks To Make SortedMedium
Intersection of Three Sorted ArraysEasy
Optimize Water Distribution in a VillageHard
Binary Tree Zigzag Level Order TraversalMedium
Max Area of IslandMedium
Number of Changing KeysEasy
Minimize Maximum Component CostMedium
Second Highest SalaryMedium
Maximize Distance to Closest PersonMedium
Spiral Matrix IIIMedium
Binary Search Tree IteratorMedium
Shortest Word DistanceEasy
Subsets IIMedium
Read N Characters Given Read4Easy
Minimum Speed to Arrive on TimeMedium
Count PrimesMedium
Reverse Nodes in k-GroupHard
Image SmootherEasy
Longest Common SubsequenceMedium
Zigzag ConversionMedium
Counting BitsEasy
Reverse Vowels of a StringEasy
Remove Linked List ElementsEasy
Contains Duplicate IIEasy
Maximum Population YearEasy
Water and Jug ProblemMedium
Design TwitterMedium
Longest Repeating Character ReplacementMedium
Dot Product of Two Sparse VectorsMedium
Substring with Concatenation of All WordsHard
Sentence Similarity IIMedium
Design Linked ListMedium
Encode and Decode TinyURLMedium
Minimum Size Subarray SumMedium
Non-overlapping IntervalsMedium
The MazeMedium
Number of Recent CallsEasy
Evaluate DivisionMedium
Sort an ArrayMedium
Assign CookiesEasy
Word Search IIHard
Meeting SchedulerMedium
One Edit DistanceMedium
Exclusive Time of FunctionsMedium
Remove Duplicates from Sorted List IIMedium
Moving Average from Data StreamEasy
Longest Happy PrefixHard
Balanced Binary TreeEasy
Valid Parenthesis StringMedium

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