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Oracle
Previous Year Questions
Word Squares
Hard
LRU Cache
Medium
Data Stream as Disjoint Intervals
Hard
Delete Node in a BST
Medium
Design Hit Counter
Medium
Two Sum
Easy
Brick Wall
Medium
Merge k Sorted Lists
Hard
Meeting Rooms II
Medium
Frog Jump
Hard
Number of Islands
Medium
Serialize and Deserialize Binary Tree
Hard
Merge Intervals
Medium
Decode String
Medium
Basic Calculator II
Medium
Add Strings
Easy
Letter Combinations of a Phone Number
Medium
Set Matrix Zeroes
Medium
Search in Rotated Sorted Array
Medium
Spiral Matrix
Medium
Maximum Subarray
Easy
Web Crawler Multithreaded
Medium
Design HashMap
Easy
Exclusive Time of Functions
Medium
Top K Frequent Words
Medium
Minimum Index Sum of Two Lists
Easy
Binary Search Tree Iterator
Medium
Valid Parentheses
Easy
Word Ladder
Medium
Word Ladder II
Hard
Sort Colors
Medium
Encode and Decode TinyURL
Medium
Boundary of Binary Tree
Medium
Design Bounded Blocking Queue
Medium
Remove Comments
Medium
Reverse Substrings Between Each Pair of Parentheses
Medium
Lowest Common Ancestor of a Binary Tree
Medium
Implement Queue using Stacks
Easy
Sudoku Solver
Hard
Copy List with Random Pointer
Medium
Convert Binary Search Tree to Sorted Doubly Linked List
Medium
Trapping Rain Water
Hard
Reverse Linked List
Easy
Permutations
Medium
Find All Anagrams in a String
Medium
Insert Delete GetRandom O(1)
Medium
Team Scores in Football Tournament
Medium
Product of Array Except Self
Medium
Kth Smallest Element in a BST
Medium
Add Two Numbers
Medium
Multiply Strings
Medium
Find Duplicate File in System
Medium
Intersection of Two Arrays
Easy
Range Module
Hard
Best Time to Buy and Sell Stock
Easy
Linked List Cycle
Easy
Word Break
Medium
Binary Tree Vertical Order Traversal
Medium
Merge Two Sorted Lists
Easy
All Nodes Distance K in Binary Tree
Medium
Find First and Last Position of Element in Sorted Array
Medium
Implement Trie (Prefix Tree)
Medium
Regular Expression Matching
Hard
Longest Palindromic Substring
Medium
Longest Duplicate Substring
Hard
Tenth Line
Easy
Median of Two Sorted Arrays
Hard
Longest Substring Without Repeating Characters
Medium
Shortest Palindrome
Hard
Check Completeness of a Binary Tree
Medium
Number of Distinct Islands
Medium
Missing Ranges
Medium
Course Schedule
Medium
Intersection of Two Linked Lists
Easy
Symmetric Tree
Easy
Next Greater Element II
Medium
Reverse String
Easy
Univalued Binary Tree
Easy
Fizz Buzz
Easy
Count Primes
Easy
Find Median from Data Stream
Hard
Integer to English Words
Hard
Pacific Atlantic Water Flow
Medium
Integer to Roman
Medium
Roman to Integer
Easy
Simplify Path
Medium
Web Crawler
Medium
Kth Largest Element in an Array
Medium
Valid Tic-Tac-Toe State
Medium
Shortest Word Distance
Easy
Find Duplicate Subtrees
Medium
Convert Sorted List to Binary Search Tree
Medium
Serialize and Deserialize BST
Medium
Populating Next Right Pointers in Each Node
Medium
Flatten Binary Tree to Linked List
Medium
Valid Anagram
Easy
Divide Two Integers
Medium
Insert Interval
Hard
Flatten Nested List Iterator
Medium
Group Anagrams
Medium
Accounts Merge
Medium
Min Stack
Easy
The Maze II
Medium
Isomorphic Strings
Easy
Single Number
Easy
Peeking Iterator
Medium
Game of Life
Medium
Binary Tree Right Side View
Medium
Subarray Sum Equals K
Medium
Minimum Knight Moves
Medium
3Sum
Medium
N-Queens
Hard
Compare Strings by Frequency of the Smallest Character
Easy
Number of Islands II
Hard
Design Twitter
Medium
Jump Game II
Hard
Cherry Pickup
Hard
First Missing Positive
Hard
Longest Valid Parentheses
Hard
Longest Consecutive Sequence
Hard
Reverse Integer
Easy
Minimum Window Substring
Hard
Rectangle Overlap
Easy
All Possible Full Binary Trees
Medium
Binary Tree Inorder Traversal
Medium
Reorganize String
Medium
Longest Common Prefix
Easy
Minimum Size Subarray Sum
Medium
Lowest Common Ancestor of a Binary Search Tree
Easy
Max Area of Island
Medium
Coin Change 2
Medium
Add Two Numbers II
Medium
Valid Palindrome
Easy
Middle of the Linked List
Easy
Search a 2D Matrix II
Medium
Move Zeroes
Easy
Valid Sudoku
Medium
Minesweeper
Medium
Missing Number
Easy
Department Highest Salary
Medium
K-diff Pairs in an Array
Easy
Reverse Linked List II
Medium
Construct Binary Search Tree from Preorder Traversal
Medium
Word Search
Medium
Word Search II
Hard
Path Sum II
Medium
Swap Nodes in Pairs
Medium
Remove Nth Node From End of List
Medium
Coin Change
Medium
K Closest Points to Origin
Medium
Spiral Matrix II
Medium
Construct Binary Tree from Preorder and Inorder Traversal
Medium
Diameter of Binary Tree
Easy
Intersection of Two Arrays II
Easy
Evaluate Reverse Polish Notation
Medium
Jump Game
Medium
Count and Say
Easy
Largest Number
Medium
Reverse Words in a String
Medium
Top K Frequent Elements
Medium
Next Greater Element I
Easy
132 Pattern
Medium
Majority Element
Easy
Unique Paths
Medium
Range Sum of BST
Easy
Path Sum III
Medium
Rotate String
Easy
Binary Tree Zigzag Level Order Traversal
Medium
All Elements in Two Binary Search Trees
Medium
Validate Binary Search Tree
Medium
Decode Ways
Medium
Remove Duplicates from Sorted Array
Easy
Backspace String Compare
Easy
Design Circular Queue
Medium
Time Based Key-Value Store
Medium
Maximum Product Subarray
Medium
Maximal Square
Medium
Path Sum
Easy
Longest Increasing Subsequence
Medium
Palindrome Number
Easy
Merge Sorted Array
Easy
Merge Two Binary Trees
Easy
Sliding Window Maximum
Hard
Pow(x;n)
Medium
Remove K Digits
Medium
Longest Substring with At Most K Distinct Characters
Hard
Contains Duplicate
Easy
Design Linked List
Medium
Binary Tree Level Order Traversal
Medium
Binary Tree Level Order Traversal II
Easy
Count of Smaller Numbers After Self
Hard
Wildcard Matching
Hard
Climbing Stairs
Easy
Best Time to Buy and Sell Stock II
Easy
Remove All Adjacent Duplicates In String
Easy
Convert Sorted Array to Binary Search Tree
Easy
Find the Duplicate Number
Medium
Container With Most Water
Medium
Interval List Intersections
Medium
Pascal's Triangle II
Easy
Course Schedule II
Medium
Ugly Number II
Medium
Populating Next Right Pointers in Each Node II
Medium
Most Common Word
Easy
Sort Array By Parity
Easy
Task Scheduler
Medium
Implement strStr()
Easy
String to Integer (atoi)
Medium
Find Minimum in Rotated Sorted Array
Medium
Squares of a Sorted Array
Easy
Add Binary
Easy
Word Break II
Hard
Lucky Numbers in a Matrix
Easy
HTML Entity Parser
Medium
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