Oracle

314 LeetCode interview questions

Difficulty Distribution

Easy
61
19%
Medium
194
62%
Hard
59
19%

Top Topics

All Questions

TitleDifficulty
LRU CacheMedium
Longest Substring Without Repeating CharactersMedium
Number of IslandsMedium
Two SumEasy
Group AnagramsMedium
Top K Frequent ElementsMedium
Sliding Window MaximumHard
Valid ParenthesesEasy
Merge k Sorted ListsHard
Merge IntervalsMedium
Meeting Rooms IIMedium
Longest Palindromic SubstringMedium
Spiral MatrixMedium
Minimum One Bit Operations to Make Integers ZeroHard
LFU CacheHard
Search in Rotated Sorted ArrayMedium
Asteroid CollisionMedium
Remove All Adjacent Duplicates in String IIMedium
Container With Most WaterMedium
3SumMedium
Reverse Linked ListEasy
Trapping Rain WaterHard
Longest Consecutive SequenceMedium
Min StackMedium
Minimum Absolute DifferenceEasy
Valid AnagramEasy
Rotting OrangesMedium
Find Valid Pair of Adjacent Digits in StringEasy
Maximum SubarrayMedium
Roman to IntegerEasy
Count Pairs Of Similar StringsEasy
Maximize Value of Function in a Ball Passing GameHard
Koko Eating BananasMedium
Best Time to Buy and Sell StockEasy
Binary Tree Right Side ViewMedium
Design Authentication ManagerMedium
Lowest Common Ancestor of a Binary TreeMedium
Generate ParenthesesMedium
Decode StringMedium
All Ancestors of a Node in a Directed Acyclic GraphMedium
Lucky Numbers in a MatrixEasy
Count Ways To Build Good StringsMedium
Count the Number of Houses at a Certain Distance IMedium
Minimize Length of Array Using OperationsMedium
Count the Number of Houses at a Certain Distance IIHard
HTML Entity ParserMedium
Count Distinct Numbers on BoardEasy
Count Ways to Group Overlapping RangesMedium
Course ScheduleMedium
Longest Common PrefixEasy
Binary Tree Zigzag Level Order TraversalMedium
Find Median from Data StreamHard
Sort ColorsMedium
Maximum Number of Events That Can Be AttendedMedium
Median of Two Sorted ArraysHard
Word Squares IIMedium
Diameter of Binary TreeEasy
Coin ChangeMedium
Zigzag ConversionMedium
First Missing PositiveHard
Kth Largest Element in an ArrayMedium
Delete Node in a BSTMedium
Contiguous ArrayMedium
Unique Binary Search TreesMedium
Simplify PathMedium
Restore IP AddressesMedium
Implement Trie (Prefix Tree)Medium
Time Based Key-Value StoreMedium
Copy List with Random PointerMedium
Majority ElementEasy
Insert Delete GetRandom O(1)Medium
Binary Tree Level Order TraversalMedium
Degree of an ArrayEasy
Kth Smallest Element in a BSTMedium
Binary Tree Maximum Path SumHard
Task SchedulerMedium
Count the Number of Infection SequencesHard
Product of Array Except SelfMedium
Logger Rate LimiterEasy
Vertical Order Traversal of a Binary TreeHard
Word LadderHard
Minimum Window SubstringHard
Longest Mountain in ArrayMedium
Merge In Between Linked ListsMedium
Diagonal TraverseMedium
Letter Combinations of a Phone NumberMedium
Find First and Last Position of Element in Sorted ArrayMedium
Search a 2D MatrixMedium
Gas StationMedium
Word Break IIHard
Move ZeroesEasy
Longest Increasing SubsequenceMedium
String CompressionMedium
Subarray Sum Equals KMedium
Design In-Memory File SystemHard
Integer to RomanMedium
Maximum Profit From Trading StocksMedium
N-QueensHard
Valid PalindromeEasy
Palindromic SubstringsMedium
Pour WaterMedium
Validate Binary Search TreeMedium
Maximal SquareMedium
Search a 2D Matrix IIMedium
Reverse Vowels of a StringEasy
Max Area of IslandMedium
Add Two NumbersMedium
Set Matrix ZeroesMedium
Word SearchMedium
Meeting RoomsEasy
Top K Frequent WordsMedium
Number of Distinct IslandsMedium
Largest NumberMedium
Reverse Words in a StringMedium
Palindrome NumberEasy
Next PermutationMedium
Count Vowel Substrings of a StringEasy
Number of Visible People in a QueueHard
Rotate ImageMedium
Jump GameMedium
Course Schedule IIMedium
Reorganize StringMedium
Design HashMapEasy
Pairs of Songs With Total Durations Divisible by 60Medium
Maximum Profit in Job SchedulingHard
Search Suggestions SystemMedium
Second Highest SalaryMedium
Single Element in a Sorted ArrayMedium
Consecutive Numbers SumHard
Find Leaves of Binary TreeMedium
Kth Smallest Element in a Sorted MatrixMedium
Merge Two Sorted ListsEasy
Remove Duplicates from Sorted ArrayEasy
PermutationsMedium
Linked List CycleEasy
Capacity To Ship Packages Within D DaysMedium
Combination Sum IIMedium
Rotate ListMedium
Sort an ArrayMedium
Maximum Good People Based on StatementsHard
Find the Smallest Divisor Given a ThresholdMedium
House RobberMedium
Find the Winner of the Circular GameMedium
Permutation in StringMedium
Divide Two IntegersMedium
Surrounded RegionsMedium
Delete Node in a Linked ListMedium
Kill ProcessMedium
Subarray Product Less Than KMedium
Reverse IntegerMedium
Minimum Array SumMedium
Maximum Number of Non-overlapping Palindrome SubstringsHard
Open the LockMedium
Sum Root to Leaf NumbersMedium
Invalid TransactionsMedium
Distance to a Cycle in Undirected GraphHard
Two Sum II - Input Array Is SortedMedium
Find K Pairs with Smallest SumsMedium
Pow(x, n)Medium
Merge Sorted ArrayEasy
Populating Next Right Pointers in Each NodeMedium
Minimum Size Subarray SumMedium
Basic CalculatorHard
Integer to English WordsHard
First Unique Character in a StringEasy
Island PerimeterEasy
Rearranging FruitsHard
Word BreakMedium
Isomorphic StringsEasy
Remove Duplicates from Sorted ListEasy
Contains DuplicateEasy
Distinct SubsequencesHard
Flatten Binary Tree to Linked ListMedium
Next Greater Element IEasy
Reformat DateEasy
Daily TemperaturesMedium
Remove All Adjacent Duplicates In StringEasy
Longest Substring with At Most K Distinct CharactersMedium
Calculate Amount Paid in TaxesEasy
Non-overlapping IntervalsMedium
Regular Expression MatchingHard
TriangleMedium
All Nodes Distance K in Binary TreeMedium
Minimum Cost to Make Array EqualHard
Clone GraphMedium
Basic Calculator IIMedium
CandyHard
Maximum Earnings From TaxiMedium
Keys and RoomsMedium
Rotate StringEasy
Reverse Substrings Between Each Pair of ParenthesesMedium
Valid SudokuMedium
Frog JumpHard
Climbing StairsEasy
Sort ListMedium
Reverse Linked List IIMedium
Count Binary SubstringsEasy
Meeting Rooms IIIHard
Sqrt(x)Easy
Minimum Remove to Make Valid ParenthesesMedium
Number of Music PlaylistsHard
Add StringsEasy
Find Minimum in Rotated Sorted ArrayMedium
Palindrome Linked ListEasy
Decrypt String from Alphabet to Integer MappingEasy
Number of Closed IslandsMedium
Convert Binary Number in a Linked List to IntegerEasy
Binary Tree Level Order Traversal IIMedium
Minimum Cost Path with Edge ReversalsMedium
Avoid Flood in The CityMedium
Jump Game IIMedium
Insert IntervalMedium
Find the Duplicate NumberMedium
Backspace String CompareEasy
Max Consecutive Ones IIIMedium
Rotate ArrayMedium
Text JustificationHard
Sort Array by Increasing FrequencyEasy
Find Peak ElementMedium
Path Sum IIMedium
Edit DistanceMedium
Count Servers that CommunicateMedium
Last Stone WeightEasy
Minimum Cost to Cut a StickHard
Swapping Nodes in a Linked ListMedium
Max StackHard
Split Array Largest SumHard
Minimum Operations to Halve Array SumMedium
Remove Linked List ElementsEasy
Binary SearchEasy
Remove Duplicates from Sorted List IIMedium
Linked List Cycle IIMedium
Fraction to Recurring DecimalMedium
Count of Range SumHard
My Calendar IMedium
Invert Binary TreeEasy
Letter Tile PossibilitiesMedium
Swap Nodes in PairsMedium
Maximize Greatness of an ArrayMedium
Maximum Candies Allocated to K ChildrenMedium
Find All Duplicates in an ArrayMedium
Merge Nodes in Between ZerosMedium
Basic Calculator IIIHard
Cache With Time LimitMedium
Maximum Employees to Be Invited to a MeetingHard
Plates Between CandlesMedium
Create Maximum NumberHard
The kth Factor of nMedium
Nested List Weight SumMedium
Count and SayMedium
Remove K DigitsMedium
SubsetsMedium
Minimum Sideway JumpsMedium
Serialize and Deserialize Binary TreeHard
Encode and Decode StringsMedium
Largest Divisible SubsetMedium
Word Search IIHard
Multiply StringsMedium
Sparse Matrix MultiplicationMedium
Next Greater Element IIIMedium
Remove Nth Node From End of ListMedium
Greatest Common Divisor of StringsEasy
Decode WaysMedium
Minimize Maximum of ArrayMedium
3Sum SmallerMedium
Generate ScheduleMedium
Merge Strings AlternatelyEasy
Count Number of Nice SubarraysMedium
Minimum Cost Homecoming of a Robot in a GridMedium
Missing NumberEasy
Evaluate Reverse Polish NotationMedium
Boundary of Binary TreeMedium
Design Add and Search Words Data StructureMedium
Minimum Number of Steps to Make Two Strings AnagramMedium
Design Circular QueueMedium
Water and Jug ProblemMedium
Number of Valid Words in a SentenceEasy
Minimum Number of Increments on Subarrays to Form a Target ArrayHard
Collect Coins in a TreeHard
K Closest Points to OriginMedium
Subarrays with K Different IntegersHard
Add Two Numbers IIMedium
Kth Missing Positive NumberEasy
Maximum Size Subarray Sum Equals kMedium
Minimum Insertion Steps to Make a String PalindromeHard
Trapping Rain Water IIHard
Find in Mountain ArrayHard
Single Number IIIMedium
Largest Rectangle in HistogramHard
Can Place FlowersEasy
Counting BitsEasy
Merge Operations to Turn Array Into a PalindromeMedium
Minimum Edge Reversals So Every Node Is ReachableHard
Wildcard MatchingHard
Sudoku SolverHard
Maximum Depth of Binary TreeEasy
Remove Invalid ParenthesesHard
Least Number of Unique Integers after K RemovalsMedium
Longest Valid ParenthesesHard
Combination SumMedium
Validate IP AddressMedium
Design File SystemMedium
Redundant ConnectionMedium
Minimum Knight MovesMedium
Bus RoutesHard
Happy NumberEasy
Flood FillEasy
Percentage of Users Attended a ContestEasy
Reverse Nodes in k-GroupHard
Design Hit CounterMedium
Simple Bank SystemMedium
Find Minimum Diameter After Merging Two TreesHard
Path Sum IIIMedium
Monthly Transactions IMedium

Showing 314 of 314 questions