Amazon

Explore Card

• Arrays and Strings
  Two Sum
  Longest Substring Without Repeating Characters
  String to Integer (atoi)
  Container With Most Water
  Integer to Roman
  Roman to Integer
  3Sum
  3Sum Closest
  Implement strStr()
  Rotate Image
  Group Anagrams
  Minimum Window Substring
  Compare Version Numbers
  Product of Array Except Self
  Missing Number
  Integer to English Words
  First Unique Character in a String
  Valid Parentheses
  Most Common Word
  Reorder Log Files
  Trapping Rain Water
• Linked Lists
  Add Two Numbers
  Merge Two Sorted Lists
  Reverse Nodes in k-Group
  Copy List with Random Pointer
  Reverse Linked List
  Merge k Sorted Lists
• Trees and Graphs
  Validate Binary Search Tree
  Symmetric Tree
  Binary Tree Level Order Traversal
  Binary Tree Zigzag Level Order Traversal
  Binary Tree Maximum Path Sum
  Word Ladder II
  Word Ladder
  Number of Islands
  Course Schedule
  Lowest Common Ancestor of a Binary Tree
  Diameter of Binary Tree
  Cut Off Trees for Golf Event
  Flood Fill
• Recursion
  Letter Combinations of a Phone Number
  Generate Parentheses
  Word Search
  Word Search II
• Sorting and Searching
  Median of Two Sorted Arrays
  Search in Rotated Sorted Array
  Merge Intervals
  Two Sum II – Input array is sorted
  Kth Largest Element in an Array
  Meeting Rooms II
  Top K Frequent Elements
  K Closest Points to Origin
• Dynamic Programming
  Longest Palindromic Substring
  Maximum Subarray
  Best Time to Buy and Sell Stock
  Word Break
  Coin Change
• Design
  LRU Cache
  Min Stack
  Find Median from Data Stream
  Serialize and Deserialize Binary Tree
  Design Tic-Tac-Toe
  Design Search Autocomplete System
  Maximum Frequency Stack
• Others
  Reverse Integer
  Second Highest Salary
  Partition Labels
  Prison Cells After N Days

ProblemSet

• Two Sum
• LRU Cache
• Number of Islands
• Trapping Rain Water
• Substring With Largest Variance
• Integer to English Words
• Meeting Rooms II
• Design In-Memory File System
• Group Anagrams
• Word Ladder
• Merge k Sorted Lists
• Analyze User Website Visit Pattern
• Word Search II
• Sum of Total Strength of Wizards
• Count Unique Characters of All Substrings of a Given String
• Sliding Window Maximum
• K Closest Points to Origin
• Search Suggestions System
• Copy List with Random Pointer
• Maximum Units on a Truck
• Reorder Data in Log Files
• Concatenated Words
• Sum of Subarray Ranges
• Course Schedule II
• Word Break II
• All Nodes Distance K in Binary Tree
• Course Schedule
• Rotting Oranges
• Reorganize String
• Boundary of Binary Tree
• Longest Duplicate Substring
• Minimum Health to Beat Game
• Sum of Subarray Minimums
• Design Tic-Tac-Toe
• Minimum Number of Moves to Make Palindrome
• Maximum Length of Subarray With Positive Product
• Build Binary Expression Tree From Infix Expression
• Plates Between Candles
• Shortest Path to Get Food
• Maximum Twin Sum of a Linked List
• Total Appeal of A String
• Find K-th Smallest Pair Distance
• Design Parking System
• Find Triangular Sum of an Array
• Sequentially Ordinal Rank Tracker
• Minimum Number of Swaps to Make the Binary String Alternating
• Number of Ways to Select Buildings
• Design an Expression Tree With Evaluate Function
• Minimum Number of Keypresses
• Maximum Number of Books You Can Take