Recent interview Questions for Amazon

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  1. Number of Ways to Reorder Array to Get Same BST
  2. Minimum Cost For Tickets
  3. Merge Two 2D Arrays by Summing Values
  4. Watering Plants II
  5. Rotated Digits
  6. Peak Index in a Mountain Array
  7. Subarray Sums Divisible by K
  8. Encode String with Shortest Length
  9. Shortest Path to Get Food
  10. The Maze III
  11. Redundant Connection
  12. Compare Strings by Frequency of the Smallest Character
  13. 01 Matrix
  14. Check if the Sentence Is Pangram
  15. Reordered Power of 2
  16. Minimum Cost to Connect Sticks
  17. Sum of Mutated Array Closest to Target
  18. Longest Repeating Substring
  19. Swap Adjacent in LR String
  20. All Paths from Source Lead to Destination
  21. Running Sum of 1d Array
  22. Distinct Subsequences II
  23. Minimum Flips in Binary Tree to Get Result
  24. Evaluate Division
  25. Unique Paths
  26. Permutations II
  27. Network Delay Time
  28. Binary Tree Longest Consecutive Sequence II
  29. Number of Recent Calls
  30. Avoid Flood in The City
  31. Escape the Spreading Fire
  32. Maximum Non Negative Product in a Matrix
  33. Find Median from Data Stream
  34. Longest Word in Dictionary through Deleting
  35. Minimize Max Distance to Gas Station
  36. Missing Number
  37. Contains Duplicate
  38. Push Dominoes
  39. Rotate Image
  40. Erect the Fence
  41. Longest Absolute File Path
  42. Serialize and Deserialize Binary Tree
  43. Linked List Random Node
  44. Permutation Sequence
  45. N-Queens II
  46. Minimum Number of Operations to Move All Balls to Each Box
  47. Range Sum of BST
  48. My Calendar I
  49. Create Binary Tree From Descriptions
  50. Build a Matrix With Conditions
  51. Recover Binary Search Tree
  52. Recyclable and Low Fat Products
  53. Exam Room
  54. All People Report to the Given Manager
  55. Maximum Beauty of an Array After Applying Operation
  56. Rising Temperature
  57. N-ary Tree Preorder Traversal
  58. Random Pick with Weight
  59. Map of Highest Peak
  60. Largest Time for Given Digits
  61. Remove All Adjacent Duplicates In String
  62. Maximum Score After Splitting a String
  63. Find if Path Exists in Graph
  64. Degree of an Array
  65. Daily Temperatures
  66. Odd Even Linked List
  67. Remove Element
  68. Richest Customer Wealth
  69. Super Ugly Number
  70. K-diff Pairs in an Array
  71. Minimum Area Rectangle
  72. Valid Phone Numbers
  73. Find the Most Competitive Subsequence
  74. Count of Smaller Numbers After Self
  75. Find Duplicate File in System
  76. Game of Life
  77. Insert Interval
  78. Create Hello World Function
  79. Maximum XOR With an Element From Array
  80. Group Shifted Strings
  81. Build Binary Expression Tree From Infix Expression
  82. Number of Digit One
  83. Product of Array Except Self
  84. Shuffle an Array
  85. Encode and Decode TinyURL
  86. Minimum Increment Operations to Make Array Beautiful
  87. Trapping Rain Water II
  88. Recover the Original Array
  89. Best Time to Buy and Sell Stock with Cooldown
  90. Minimum Path Sum
  91. Group Anagrams
  92. Number of Longest Increasing Subsequence
  93. Find All Possible Recipes from Given Supplies
  94. Partition Equal Subset Sum
  95. Count Number of Distinct Integers After Reverse Operations
  96. Letter Tile Possibilities
  97. K Inverse Pairs Array
  98. Minimum Absolute Difference Between Elements With Constraint
  99. Maximum Length of Semi-Decreasing Subarrays
  100. Regular Expression Matching
  101. Average Time of Process per Machine
  102. Strong Password Checker
  103. Find Words That Can Be Formed by Characters
  104. Merge Sorted Array
  105. Robot Return to Origin
  106. Shuffle the Array
  107. Sort an Array
  108. Frog Jump II
  109. Smallest Good Base
  110. Pacific Atlantic Water Flow
  111. Maximum Font to Fit a Sentence in a Screen
  112. Campus Bikes
  113. Employee Importance
  114. Correct a Binary Tree
  115. The Earliest and Latest Rounds Where Players Compete
  116. Create Maximum Number
  117. Flood Fill
  118. Design HashMap
  119. Lonely Pixel I
  120. Find All Duplicates in an Array
  121. Basic Calculator III
  122. Clone Graph
  123. Path Sum
  124. Maximum Employees to Be Invited to a Meeting
  125. Last Day Where You Can Still Cross
  126. Largest Submatrix With Rearrangements
  127. Number of Islands II
  128. Valid Palindrome II
  129. Shortest Path with Alternating Colors
  130. Maximum Score Words Formed by Letters
  131. Find Winner on a Tic Tac Toe Game
  132. Find Distance in a Binary Tree
  133. Longest Arithmetic Subsequence
  134. Reorganize String
  135. Heaters
  136. Subsets
  137. Minimum Time to Build Blocks
  138. Binary Tree Right Side View
  139. Optimal Account Balancing
  140. All Possible Full Binary Trees
  141. Two Sum II - Input Array Is Sorted
  142. Find K-th Smallest Pair Distance
  143. Checking Existence of Edge Length Limited Paths II
  144. Relative Sort Array
  145. Bricks Falling When Hit
  146. Reverse String
  147. Pizza With 3n Slices
  148. Count Good Numbers
  149. Complete Binary Tree Inserter
  150. Tiling a Rectangle with the Fewest Squares
  151. Flatten a Multilevel Doubly Linked List
  152. Longest Common Subsequence Between Sorted Arrays
  153. Palindrome Linked List
  154. Design an Expression Tree With Evaluate Function
  155. Reverse Nodes in k-Group
  156. Single Number
  157. Largest Triangle Area
  158. Longest Palindromic Subsequence
  159. Path Sum III
  160. Freedom Trail
  161. Queries on Number of Points Inside a Circle
  162. Validate Binary Search Tree
  163. Lowest Common Ancestor of a Binary Search Tree
  164. Consecutive Characters
  165. Longest Mountain in Array
  166. Battleships in a Board
  167. Defanging an IP Address
  168. Increasing Order Search Tree
  169. Closest Binary Search Tree Value II
  170. Shopping Offers
  171. Minimum Operations to Reduce X to Zero
  172. Number of Flowers in Full Bloom
  173. Check if Number Has Equal Digit Count and Digit Value
  174. Sum of Distances in Tree
  175. Largest Substring Between Two Equal Characters
  176. Minimum Insertion Steps to Make a String Palindrome
  177. Dungeon Game
  178. Super Egg Drop
  179. Number of Matching Subsequences
  180. People Whose List of Favorite Companies Is Not a Subset of Another List
  181. Maximum Swap
  182. Rotate Array
  183. Longest Arithmetic Subsequence of Given Difference
  184. Maximum Number of K-Divisible Components
  185. Shortest Subarray with Sum at Least K
  186. Maximum Side Length of a Square with Sum Less than or Equal to Threshold
  187. Rank Transform of an Array
  188. Split Two Strings to Make Palindrome
  189. Grumpy Bookstore Owner
  190. Sqrt(x)
  191. Check if Word Can Be Placed In Crossword
  192. Validate Stack Sequences
  193. Next Greater Element III
  194. Symmetric Tree
  195. All O`one Data Structure
  196. Count Pairs in Two Arrays
  197. Unique Email Addresses
  198. Minimize Product Sum of Two Arrays
  199. Fibonacci Number
  200. Binary Tree Inorder Traversal
  201. Minimum Number of Operations to Reinitialize a Permutation
  202. Smallest Subsequence of Distinct Characters
  203. Word Subsets
  204. Water and Jug Problem
  205. Design Linked List
  206. Number of Ways to Form a Target String Given a Dictionary
  207. Delete Leaves With a Given Value
  208. Trapping Rain Water
  209. Combination Sum
  210. Find the Celebrity
  211. Decode Ways
  212. Maximum Level Sum of a Binary Tree
  213. Removing Minimum Number of Magic Beans
  214. Power of Three
  215. 4 Keys Keyboard
  216. Construct Binary Tree from Preorder and Postorder Traversal
  217. Maximum Depth of Binary Tree
  218. Design Skiplist
  219. Minimize Malware Spread
  220. My Calendar III
  221. Search in Rotated Sorted Array
  222. Maximum Value of K Coins From Piles
  223. LRU Cache
  224. Letter Combinations of a Phone Number
  225. Score of Parentheses
  226. Continuous Subarray Sum
  227. Count Numbers with Unique Digits
  228. Lonely Pixel II
  229. Count Words Obtained After Adding a Letter
  230. Remove Duplicates from Sorted Array
  231. Maximum Width Ramp
  232. Delete Duplicate Folders in System
  233. Longest Line of Consecutive One in Matrix
  234. Max Points on a Line
  235. Top K Frequent Words
  236. Moving Average from Data Stream
  237. Maximum Profit in Job Scheduling
  238. Snapshot Array
  239. Strange Printer
  240. Longest Valid Parentheses
  241. Boats to Save People
  242. Rotting Oranges
  243. Escape a Large Maze
  244. Binary String With Substrings Representing 1 To N
  245. Circle and Rectangle Overlapping
  246. Find Target Indices After Sorting Array
  247. Number of Ways to Divide a Long Corridor
  248. Number of Visible People in a Queue
  249. Longest Substring with At Most Two Distinct Characters
  250. Remove Duplicates from Sorted List
  251. Single Number II
  252. Matchsticks to Square
  253. Maximum Population Year
  254. Special Array With X Elements Greater Than or Equal X
  255. Alphabet Board Path
  256. Best Time to Buy and Sell Stock II
  257. Minimum Distance Between BST Nodes
  258. Jump Game II
  259. Find Champion I
  260. Erect the Fence II
  261. Fair Distribution of Cookies
  262. Binary Tree Level Order Traversal
  263. Valid Square
  264. Maximum Strictly Increasing Cells in a Matrix
  265. Confusing Number II
  266. Maximum Vacation Days
  267. Same Tree
  268. Number of Good Leaf Nodes Pairs
  269. Backspace String Compare
  270. Roman to Integer
  271. Count Submatrices With All Ones
  272. Maximum Average Subarray II
  273. Bold Words in String
  274. Course Schedule
  275. Convex Polygon
  276. Remove Comments
  277. Subarray With Elements Greater Than Varying Threshold
  278. Destroying Asteroids
  279. Maximum Number of Points with Cost
  280. Vertical Order Traversal of a Binary Tree
  281. Student Attendance Record I
  282. Number of Zero-Filled Subarrays
  283. Target Sum
  284. Interval List Intersections
  285. Stickers to Spell Word
  286. All Elements in Two Binary Search Trees
  287. Remove Outermost Parentheses
  288. Design Circular Queue
  289. Random Point in Non-overlapping Rectangles
  290. Number of Valid Clock Times
  291. Check if a Parentheses String Can Be Valid
  292. Delete Columns to Make Sorted II
  293. Minimum Replacements to Sort the Array
  294. Flower Planting With No Adjacent
  295. Binary Subarrays With Sum
  296. Sliding Window Median
  297. Task Scheduler
  298. Interleaving String
  299. Guess Number Higher or Lower II
  300. Buddy Strings
  301. Merge Similar Items
  302. Number of Beautiful Partitions
  303. Longest Continuous Increasing Subsequence
  304. Minimize Hamming Distance After Swap Operations
  305. Where Will the Ball Fall
  306. Stream of Characters
  307. Find the Winner of the Circular Game
  308. Department Highest Salary
  309. Sort List
  310. Nim Game
  311. Array Prototype Last
  312. Palindrome Permutation
  313. New 21 Game
  314. Count Fertile Pyramids in a Land
  315. 24 Game
  316. Find All Anagrams in a String
  317. Longest Chunked Palindrome Decomposition
  318. Longest Uncommon Subsequence II
  319. Fancy Sequence
  320. Sentence Similarity
  321. Minimum White Tiles After Covering With Carpets
  322. Best Time to Buy and Sell Stock III
  323. Unique Binary Search Trees
  324. Median of Two Sorted Arrays
  325. Find And Replace in String
  326. Partition List
  327. Most Stones Removed with Same Row or Column
  328. Nth Magical Number
  329. Bomb Enemy
  330. Find and Replace Pattern
  331. Summary Ranges
  332. Guess the Word
  333. Subtree of Another Tree
  334. Majority Element II
  335. Shortest Bridge
  336. Combinations
  337. Single Element in a Sorted Array
  338. Longest Univalue Path
  339. Duplicate Zeros
  340. Wiggle Sort II
  341. Queue Reconstruction by Height
  342. Substring with Concatenation of All Words
  343. Minimum Space Wasted From Packaging
  344. Count Positions on Street With Required Brightness
  345. Max Consecutive Ones III
  346. Valid Mountain Array
  347. Minimum Lines to Represent a Line Chart
  348. Path with Maximum Probability
  349. Distance Between Bus Stops
  350. Island Perimeter
  351. Binary Tree Zigzag Level Order Traversal
  352. Largest Color Value in a Directed Graph
  353. Rings and Rods
  354. Design HashSet
  355. Count Houses in a Circular Street
  356. Longest Continuous Subarray With Absolute Diff Less Than or Equal to Limit
  357. Continuous Subarrays
  358. Find Two Non-overlapping Sub-arrays Each With Target Sum
  359. Maximal Square
  360. Maximum Distance Between a Pair of Values
  361. Search a 2D Matrix II
  362. Champagne Tower
  363. Counting Words With a Given Prefix
  364. Univalued Binary Tree
  365. Stamping the Grid
  366. Department Top Three Salaries
  367. Parallel Courses III
  368. Minimum Operations to Make a Subsequence
  369. Minimum Interval to Include Each Query
  370. Course Schedule III
  371. Minimum Absolute Difference in BST
  372. Integer Replacement
  373. Integer to English Words
  374. Redundant Connection II
  375. Knight Dialer
  376. Find a Peak Element II
  377. Minimum Operations to Convert Number
  378. Remove Max Number of Edges to Keep Graph Fully Traversable
  379. The Maze II
  380. Minimum Number of Flips to Make the Binary String Alternating
  381. Maximum Number of Visible Points
  382. Process Tasks Using Servers
  383. Divide Chocolate
  384. Construct Binary Tree from Preorder and Inorder Traversal
  385. Reverse Linked List II
  386. Search in a Binary Search Tree
  387. Range Module
  388. Number of Provinces
  389. Max Chunks To Make Sorted
  390. Jump Game III
  391. Find Unique Binary String
  392. Remove Duplicates from Sorted Array II
  393. Poor Pigs
  394. Longest Substring Without Repeating Characters
  395. Find Original Array From Doubled Array
  396. Largest Values From Labels
  397. Minimum Adjacent Swaps to Reach the Kth Smallest Number
  398. Repeated DNA Sequences
  399. Implement Stack using Queues
  400. Bulls and Cows
  401. Satisfiability of Equality Equations
  402. Reconstruct Itinerary
  403. Maximize Distance to Closest Person
  404. K Empty Slots
  405. Most Frequent Number Following Key In an Array
  406. Path with Maximum Gold
  407. Different Ways to Add Parentheses
  408. Change Minimum Characters to Satisfy One of Three Conditions
  409. Find All Lonely Numbers in the Array
  410. Find the Minimum Number of Fibonacci Numbers Whose Sum Is K
  411. Maximum Sum Circular Subarray
  412. Top K Frequent Elements
  413. Permutation in String
  414. Monotonic Array
  415. Implement Magic Dictionary
  416. Sort Characters By Frequency
  417. Guess Number Higher or Lower
  418. Check if There is a Path With Equal Number of 0's And 1's
  419. Count Pairs of Equal Substrings With Minimum Difference
  420. String to Integer (atoi)
  421. Counting Bits
  422. Occurrences After Bigram
  423. Last Moment Before All Ants Fall Out of a Plank
  424. Maximum AND Sum of Array
  425. Minimum Speed to Arrive on Time
  426. Pairs of Songs With Total Durations Divisible by 60
  427. Maximum Product Subarray
  428. Arithmetic Slices
  429. Number of Atoms
  430. Removing Minimum and Maximum From Array
  431. Robot Room Cleaner
  432. Reverse Integer
  433. Minimum Window Substring
  434. Read N Characters Given read4 II - Call Multiple Times
  435. Count Subarrays With More Ones Than Zeros
  436. Evaluate Boolean Binary Tree
  437. Find Customers With Positive Revenue this Year
  438. Repeated Substring Pattern
  439. Detect Squares
  440. Minimum Moves to Move a Box to Their Target Location
  441. Merge Two Sorted Lists
  442. Minimum Obstacle Removal to Reach Corner
  443. Word Break
  444. Merge k Sorted Lists
  445. Split BST
  446. All Paths From Source to Target
  447. Jump Game
  448. Number of Subsequences That Satisfy the Given Sum Condition
  449. Plus One Linked List
  450. Partition Labels
  451. Diameter of Binary Tree
  452. Minimum Knight Moves
  453. Lowest Common Ancestor of a Binary Tree III
  454. Sliding Window Maximum
  455. Matrix Block Sum
  456. Watering Plants
  457. Excel Sheet Column Title
  458. Parallel Courses II
  459. Number of Submatrices That Sum to Target
  460. The k Strongest Values in an Array
  461. Maximum Number of Words Found in Sentences
  462. Bag of Tokens
  463. Subsets II
  464. Min Cost Climbing Stairs
  465. Count and Say
  466. Construct Binary Tree from Inorder and Postorder Traversal
  467. Edit Distance
  468. Number of Days Between Two Dates
  469. Valid Perfect Square
  470. Minimum Remove to Make Valid Parentheses
  471. Arithmetic Subarrays
  472. Patching Array
  473. Concatenation of Array
  474. Maximum Points You Can Obtain from Cards
  475. Remove Invalid Parentheses
  476. K-Similar Strings
  477. Coin Path
  478. Path With Maximum Minimum Value
  479. Minimum Time to Finish the Race
  480. Coin Change II
  481. Next Greater Element II
  482. Similar RGB Color
  483. Copy List with Random Pointer
  484. Flatten Nested List Iterator
  485. Flip String to Monotone Increasing
  486. Number of Good Pairs
  487. Rank Scores
  488. Number Complement
  489. Graph Valid Tree
  490. Replace All Digits with Characters
  491. Container With Most Water
  492. Find the Subtasks That Did Not Execute
  493. Longest Palindrome by Concatenating Two Letter Words
  494. Maximum Candies Allocated to K Children
  495. Longest Uploaded Prefix
  496. Smallest Rectangle Enclosing Black Pixels
  497. Paint House III
  498. Happy Number
  499. All Nodes Distance K in Binary Tree
  500. Expression Add Operators
  501. Number of Restricted Paths From First to Last Node
  502. Valid Tic-Tac-Toe State
  503. Largest Rectangle in Histogram
  504. Longest Binary Subsequence Less Than or Equal to K
  505. Minimum Distance to Type a Word Using Two Fingers
  506. Minimum Absolute Difference
  507. Next Closest Time
  508. Additive Number
  509. Smallest Index With Equal Value
  510. Closest Binary Search Tree Value
  511. Minimum Cost to Hire K Workers
  512. X of a Kind in a Deck of Cards
  513. Is Subsequence
  514. Sentence Screen Fitting
  515. Largest Divisible Subset
  516. Shortest Path Visiting All Nodes
  517. Special Positions in a Binary Matrix
  518. Online Stock Span
  519. Make The String Great
  520. Set Matrix Zeroes
  521. Count Ways to Distribute Candies
  522. Reverse Bits
  523. Longest String Chain
  524. Decrease Elements To Make Array Zigzag
  525. Remove Nth Node From End of List
  526. Coin Change
  527. Decode String
  528. Count Primes
  529. Binary Tree Cameras
  530. Number of Ways to Build Sturdy Brick Wall
  531. Distinct Subsequences
  532. Reverse Words in a String
  533. Minimum Cost to Cut a Stick
  534. Shortest Path in a Grid with Obstacles Elimination
  535. Minimum Absolute Difference Queries
  536. Largest Number At Least Twice of Others
  537. Alien Dictionary
  538. Cinema Seat Allocation
  539. Logger Rate Limiter
  540. Minimum Add to Make Parentheses Valid
  541. Regions Cut By Slashes
  542. Word Ladder II
  543. Flatten Binary Tree to Linked List
  544. Kth Largest Element in an Array
  545. Couples Holding Hands
  546. Valid Number
  547. Minimum Depth of Binary Tree
  548. Minimum Number of Days to Make m Bouquets
  549. Sender With Largest Word Count
  550. Longest Uncommon Subsequence I
  551. Implement Trie (Prefix Tree)
  552. Combination Sum IV
  553. Count Binary Substrings
  554. Random Flip Matrix
  555. Lowest Common Ancestor of a Binary Tree
  556. Count Subarrays With Median K
  557. 4Sum
  558. Restore IP Addresses
  559. Maximal Rectangle
  560. Single-Row Keyboard
  561. Plus One
  562. Minimum Time Difference
  563. Design Most Recently Used Queue
  564. Cat and Mouse
  565. Number of Dice Rolls With Target Sum
  566. Delete Columns to Make Sorted
  567. Booking Concert Tickets in Groups
  568. Single-Threaded CPU
  569. Two Sum
  570. Minimum Number of Arrows to Burst Balloons
  571. Race Car
  572. Minimum Falling Path Sum II
  573. Fraction to Recurring Decimal
  574. Shortest Path in Binary Matrix
  575. As Far from Land as Possible
  576. Range Sum Query - Mutable
  577. Shortest Word Distance II
  578. Max Consecutive Ones
  579. Valid Word Square
  580. Ugly Number II
  581. Minimum Unique Word Abbreviation
  582. Find Latest Group of Size M
  583. Find the Duplicate Number
  584. Word Ladder
  585. Capacity To Ship Packages Within D Days
  586. Longest Substring with At Most K Distinct Characters
  587. Determine if Two Strings Are Close
  588. House Robber
  589. Intersection of Two Arrays
  590. Random Pick with Blacklist
  591. Find Anagram Mappings
  592. Domino and Tromino Tiling
  593. Simplified Fractions
  594. Insert Delete GetRandom O(1)
  595. License Key Formatting
  596. Longest Nice Substring
  597. Camelcase Matching
  598. Isomorphic Strings
  599. Non-overlapping Intervals
  600. Minimum Path Cost in a Grid
  601. Maximum Width of Binary Tree
  602. Maximum Score After Applying Operations on a Tree
  603. First Bad Version
  604. Minimum Time to Complete Trips
  605. Implement Queue using Stacks
  606. Find Positive Integer Solution for a Given Equation
  607. Meeting Rooms II
  608. Best Sightseeing Pair
  609. Partition to K Equal Sum Subsets
  610. Max Area of Island
  611. Remove Sub-Folders from the Filesystem
  612. Car Fleet
  613. Divide Array in Sets of K Consecutive Numbers
  614. Walls and Gates
  615. Binary Search Tree Iterator
  616. Form Largest Integer With Digits That Add up to Target
  617. Design Add and Search Words Data Structure
  618. Swim in Rising Water
  619. Arranging Coins
  620. Matrix Diagonal Sum
  621. Shortest Distance to Target Color
  622. Hand of Straights
  623. Integer Break
  624. Perfect Rectangle
  625. N-Queens
  626. Minimum Number of Vertices to Reach All Nodes
  627. Multiply Strings
  628. Search a 2D Matrix
  629. Cherry Pickup
  630. Binary Tree Vertical Order Traversal
  631. Car Pooling
  632. Combine Two Tables
  633. Count Unique Characters of All Substrings of a Given String
  634. Parallel Courses
  635. Unique Paths II
  636. Text Justification
  637. Cherry Pickup II
  638. Longest Common Prefix
  639. Print in Order
  640. Best Meeting Point
  641. Maximum Number of Ways to Partition an Array
  642. Count Number of Rectangles Containing Each Point
  643. Length of Last Word
  644. Find All Good Strings
  645. Cracking the Safe
  646. Palindrome Number
  647. Repeated String Match
  648. Find First and Last Position of Element in Sorted Array
  649. Find Servers That Handled Most Number of Requests
  650. Remove All Ones With Row and Column Flips
  651. First Unique Character in a String
  652. Remove 9
  653. Diagonal Traverse II
  654. Put Boxes Into the Warehouse II
  655. Check If a String Contains All Binary Codes of Size K
  656. Maximum Number of Accepted Invitations
  657. Checking Existence of Edge Length Limited Paths
  658. Merge Intervals
  659. Words Within Two Edits of Dictionary
  660. Design Video Sharing Platform
  661. 3Sum Smaller
  662. Populating Next Right Pointers in Each Node II
  663. Jump Game VI
  664. Brick Wall
  665. Tree Diameter
  666. Ones and Zeroes
  667. Design A Leaderboard
  668. Find the Closest Palindrome
  669. Combination Sum II
  670. Insertion Sort List
  671. Gas Station
  672. Largest Local Values in a Matrix
  673. Design Browser History
  674. The K Weakest Rows in a Matrix
  675. Distinct Echo Substrings
  676. Nth Digit
  677. Shortest Impossible Sequence of Rolls
  678. All Ancestors of a Node in a Directed Acyclic Graph
  679. Nearest Exit from Entrance in Maze
  680. Sum of Beauty of All Substrings
  681. Kth Smallest Subarray Sum
  682. Strings Differ by One Character
  683. Product of the Last K Numbers
  684. Unique Number of Occurrences
  685. Remove All Ones With Row and Column Flips II
  686. Differences Between Two Objects
  687. Longest Consecutive Sequence
  688. Split Array Largest Sum
  689. Find Pivot Index
  690. Check If N and Its Double Exist
  691. Meeting Scheduler
  692. Evaluate the Bracket Pairs of a String
  693. String Transformation
  694. Pow(x, n)
  695. Largest Component Size by Common Factor
  696. Deepest Leaves Sum
  697. Move Pieces to Obtain a String
  698. K Closest Points to Origin
  699. Minimum Number of Flips to Convert Binary Matrix to Zero Matrix
  700. Minimum Number of Work Sessions to Finish the Tasks
  701. The Earliest Moment When Everyone Become Friends
  702. Find All K-Distant Indices in an Array
  703. Non-decreasing Array
  704. Zigzag Conversion
  705. Number of Substrings With Only 1s
  706. Minimum Number of Operations to Convert Time
  707. Time Needed to Inform All Employees
  708. Scramble String
  709. Flipping an Image
  710. Ambiguous Coordinates
  711. Average Salary Excluding the Minimum and Maximum Salary
  712. Minimum Area Rectangle II
  713. Longest Substring with At Least K Repeating Characters
  714. Unique Word Abbreviation
  715. Range Sum Query 2D - Mutable
  716. Number of Unique Good Subsequences
  717. Finding MK Average
  718. Largest Sum of Averages
  719. Finding the Number of Visible Mountains
  720. Find Kth Largest XOR Coordinate Value
  721. Lexicographically Smallest Beautiful String
  722. Remove K Digits
  723. Check If String Is Transformable With Substring Sort Operations
  724. Count Square Submatrices with All Ones
  725. Single Number III
  726. Most Profitable Path in a Tree
  727. Replace Words
  728. Invert Binary Tree
  729. Minimum Difference Between Largest and Smallest Value in Three Moves
  730. Delete Operation for Two Strings
  731. Smallest Number in Infinite Set
  732. Delete Columns to Make Sorted III
  733. Minimum Size Subarray Sum
  734. Process Restricted Friend Requests
  735. K-th Symbol in Grammar
  736. Subarrays with K Different Integers
  737. Shortest Palindrome
  738. Design an ATM Machine
  739. Shortest Completing Word
  740. Count Unreachable Pairs of Nodes in an Undirected Graph
  741. Russian Doll Envelopes
  742. Serialize and Deserialize N-ary Tree
  743. Max Number of K-Sum Pairs
  744. Parsing A Boolean Expression
  745. Range Sum of Sorted Subarray Sums
  746. Can Place Flowers
  747. Super Palindromes
  748. Amount of New Area Painted Each Day
  749. Find the Difference
  750. Design In-Memory File System
  751. Two Sum IV - Input is a BST
  752. Count K-Subsequences of a String With Maximum Beauty
  753. Mean of Array After Removing Some Elements
  754. Fizz Buzz
  755. Word Search
  756. Minimum Jumps to Reach Home
  757. Max Sum of Rectangle No Larger Than K
  758. Count Servers that Communicate
  759. Sort Colors
  760. Minimum Falling Path Sum
  761. Move Zeroes
  762. Longest Happy Prefix
  763. Filling Bookcase Shelves
  764. Car Fleet II
  765. Next Permutation
  766. Find Champion II
  767. Minimum Number of Increments on Subarrays to Form a Target Array
  768. Odd Even Jump
  769. Reverse Words in a String III
  770. Add Strings
  771. Fruit Into Baskets
  772. Largest Number
  773. Expressive Words
  774. The Maze
  775. Substrings That Begin and End With the Same Letter
  776. Merge Triplets to Form Target Triplet
  777. Excel Sheet Column Number
  778. Linked List Cycle
  779. Decode XORed Array
  780. Count Asterisks
  781. Number of Music Playlists
  782. Max Increase to Keep City Skyline
  783. Beautiful Array
  784. Missing Ranges
  785. Median Employee Salary
  786. Inorder Successor in BST
  787. Time Based Key-Value Store
  788. Longest Word in Dictionary
  789. Jump Game IV
  790. Numbers With Repeated Digits
  791. Frog Jump
  792. Strange Printer II
  793. Delete Node in a Linked List
  794. Distribute Coins in Binary Tree
  795. Add Bold Tag in String
  796. All Divisions With the Highest Score of a Binary Array
  797. Path With Minimum Effort
  798. Maximum Length of Repeated Subarray
  799. Merge Strings Alternately
  800. Remove Duplicate Letters
  801. Perfect Number
  802. Height of Binary Tree After Subtree Removal Queries
  803. Line Reflection
  804. Minimum Cost to Change the Final Value of Expression
  805. Big Countries
  806. Design Snake Game
  807. Minimum Cost to Make Array Equal
  808. Closest Node to Path in Tree
  809. Change the Root of a Binary Tree
  810. Sudoku Solver
  811. Online Election
  812. Eliminate Maximum Number of Monsters
  813. Palindrome Partitioning
  814. Kth Smallest Element in a BST
  815. Find the Difference of Two Arrays
  816. UTF-8 Validation
  817. 4Sum II
  818. Paths in Maze That Lead to Same Room
  819. Convert Sorted List to Binary Search Tree
  820. Build an Array With Stack Operations
  821. Search Suggestions System
  822. Minimum Cost to Set Cooking Time
  823. Custom Sort String
  824. LFU Cache
  825. Shortest Unsorted Continuous Subarray
  826. Strobogrammatic Number II
  827. Cat and Mouse II
  828. Pascal's Triangle
  829. Is Graph Bipartite?
  830. Longest Word With All Prefixes
  831. Word Search II
  832. 3Sum Closest
  833. Sort Transformed Array
  834. Count Prefixes of a Given String
  835. Number of Boomerangs
  836. Image Overlap
  837. Describe the Painting
  838. Closest Nodes Queries in a Binary Search Tree
  839. Divide Two Integers
  840. Binary Tree Preorder Traversal
  841. Find Peak Element
  842. Confusing Number
  843. Valid Parentheses
  844. Array of Doubled Pairs
  845. Kids With the Greatest Number of Candies
  846. Reverse String II
  847. Design Compressed String Iterator
  848. Move Sub-Tree of N-Ary Tree
  849. Number of 1 Bits
  850. Minimum Number of Days to Eat N Oranges
  851. Contains Duplicate III
  852. Unique Binary Search Trees II
  853. Student Attendance Record II
  854. Dot Product of Two Sparse Vectors
  855. Kth Smallest Element in a Sorted Matrix
  856. Reaching Points
  857. Wiggle Sort
  858. Find All People With Secret
  859. The Latest Time to Catch a Bus
  860. Integer to Roman
  861. Positions of Large Groups
  862. How Many Numbers Are Smaller Than the Current Number
  863. Convert a Number to Hexadecimal
  864. Minimum Window Subsequence
  865. Design Twitter
  866. Prefix and Suffix Search
  867. Max Value of Equation
  868. Element Appearing More Than 25% In Sorted Array
  869. Find Minimum in Rotated Sorted Array II
  870. Find the Safest Path in a Grid
  871. Add Two Numbers
  872. Kth Largest Element in a Stream
  873. Unique Morse Code Words
  874. Min Stack
  875. Populating Next Right Pointers in Each Node
  876. Count Good Triplets
  877. Extract Kth Character From The Rope Tree
  878. Search Insert Position
  879. Complement of Base 10 Integer
  880. Output Contest Matches
  881. Increasing Triplet Subsequence
  882. Meeting Rooms
  883. Generalized Abbreviation
  884. Remove Covered Intervals
  885. Find Elements in a Contaminated Binary Tree
  886. Accounts Merge
  887. Tree of Coprimes
  888. Strobogrammatic Number
  889. Magical String
  890. Diagonal Traverse
  891. Count Nodes Equal to Average of Subtree
  892. Reverse Linked List
  893. Split Array into Consecutive Subsequences
  894. Maximum Sum of 3 Non-Overlapping Subarrays
  895. The Most Similar Path in a Graph
  896. Detonate the Maximum Bombs
  897. Rank Transform of a Matrix
  898. Count Pairs of Points With Distance k
  899. Closest Dessert Cost
  900. Contains Duplicate II
  901. Increment Submatrices by One
  902. Word Break II
  903. First Missing Positive
  904. Longest Common Subsequence
  905. Cheapest Flights Within K Stops
  906. Bitwise AND of Numbers Range
  907. Rearrange String k Distance Apart
  908. Valid Sudoku
  909. Smallest String With Swaps
  910. Balanced Binary Tree
  911. Combination Sum III
  912. First Letter to Appear Twice
  913. Partition Array Into Two Arrays to Minimize Sum Difference
  914. Remove Zero Sum Consecutive Nodes from Linked List
  915. Count Good Nodes in Binary Tree
  916. Product Price at a Given Date
  917. Best Time to Buy and Sell Stock
  918. String Compression
  919. Palindrome Pairs
  920. Linked List Cycle II
  921. Operations on Tree
  922. Palindromic Substrings
  923. House Robber II
  924. Asteroid Collision
  925. Hamming Distance
  926. Relative Ranks
  927. Minimum Cost to Make at Least One Valid Path in a Grid
  928. Numbers With Same Consecutive Differences
  929. Best Time to Buy and Sell Stock IV
  930. Design a Text Editor
  931. Determine if Two Events Have Conflict
  932. Split a String Into the Max Number of Unique Substrings
  933. Partition Array According to Given Pivot
  934. Search in a Sorted Array of Unknown Size
  935. Pyramid Transition Matrix
  936. Shortest Common Supersequence
  937. Find Nearest Right Node in Binary Tree
  938. Minimum Time to Remove All Cars Containing Illegal Goods
  939. Maximum Performance of a Team
  940. Binary Tree Paths
  941. Minimum Number of Swaps to Make the Binary String Alternating
  942. Count Pairs With XOR in a Range
  943. Minimum Height Trees
  944. Longest Increasing Path in a Matrix
  945. Longest Palindromic Substring
  946. Maximum White Tiles Covered by a Carpet
  947. Maximum XOR of Two Numbers in an Array
  948. Decompress Run-Length Encoded List
  949. Permutations
  950. Basic Calculator
  951. House Robber III
  952. Sentence Similarity III
  953. Random Pick Index
  954. Valid Word Abbreviation
  955. Check if There Is a Valid Parentheses String Path
  956. Sentence Similarity II
  957. Snakes and Ladders
  958. Predict the Winner
  959. Meeting Rooms III
  960. Koko Eating Bananas
  961. Smallest Integer Divisible by K
  962. Path Sum II
  963. My Calendar II
  964. Nested List Weight Sum
  965. Unique Paths III
  966. Magic Squares In Grid
  967. Minimize Maximum Pair Sum in Array
  968. Design Search Autocomplete System
  969. Flatten 2D Vector
  970. Find All Numbers Disappeared in an Array
  971. Frog Position After T Seconds
  972. Ransom Note
  973. Valid Boomerang
  974. Sort Array by Moving Items to Empty Space
  975. Shortest Way to Form String
  976. Count Number of Bad Pairs
  977. Throne Inheritance
  978. Sum of Imbalance Numbers of All Subarrays
  979. Largest Subarray Length K
  980. Find the Index of the First Occurrence in a String
  981. Binary Search
  982. Cutting Ribbons
  983. Word Squares
  984. Find Eventual Safe States
  985. Reverse Only Letters
  986. Max Chunks To Make Sorted II
  987. Word Abbreviation
  988. Find Closest Number to Zero
  989. Check if There is a Valid Partition For The Array
  990. Valid Palindrome
  991. Distribute Repeating Integers
  992. Find Customer Referee
  993. Delete Nodes And Return Forest
  994. Maximum Number of Events That Can Be Attended
  995. Design Excel Sum Formula
  996. Minimum Domino Rotations For Equal Row
  997. Binary Trees With Factors
  998. Furthest Building You Can Reach
  999. Delete and Earn
  1000. Possible Bipartition
  1001. Brace Expansion II
  1002. Sequence Reconstruction
  1003. Design Hit Counter
  1004. Encode and Decode Strings
  1005. Maximum Split of Positive Even Integers
  1006. Maximum Number of Groups Getting Fresh Donuts
  1007. Make Number of Distinct Characters Equal
  1008. Maximum Score From Removing Stones
  1009. Maximum Subarray
  1010. Binary Tree Coloring Game
  1011. Latest Time by Replacing Hidden Digits
  1012. Range Frequency Queries
  1013. Maximum Score From Removing Substrings
  1014. Merge In Between Linked Lists
  1015. Valid Parenthesis String
  1016. Minimum Number of Refueling Stops
  1017. Minimum Sum of Four Digit Number After Splitting Digits
  1018. Shuffle String
  1019. Maximum Average Subarray I
  1020. Number of Ways to Rearrange Sticks With K Sticks Visible
  1021. 3Sum
  1022. Construct Quad Tree
  1023. Maximum Product of Word Lengths
  1024. Count Odd Numbers in an Interval Range
  1025. Soup Servings
  1026. RLE Iterator
  1027. Surrounded Regions
  1028. Next Greater Element I
  1029. Find Mode in Binary Search Tree
  1030. Bus Routes
  1031. Minimum Path Cost in a Hidden Grid
  1032. Last Stone Weight
  1033. Find Permutation
  1034. Number of Good Paths
  1035. Restore the Array From Adjacent Pairs
  1036. Paint Fence
  1037. Longest Increasing Subsequence II
  1038. Linked List Components
  1039. Longest Repeating Character Replacement
  1040. Flip Game
  1041. Count Complete Tree Nodes
  1042. Detect Capital
  1043. Insert into a Sorted Circular Linked List
  1044. Shortest Path to Get All Keys
  1045. Longest Duplicate Substring
  1046. Number of Islands
  1047. Palindrome Permutation II
  1048. Maximum Score of a Good Subarray
  1049. Remove Interval
  1050. Number of Enclaves
  1051. Find in Mountain Array
  1052. Add Binary
  1053. Keys and Rooms
  1054. Number of Ways of Cutting a Pizza
  1055. Design Tic-Tac-Toe
  1056. Minimize Maximum Value in a Grid
  1057. Design a Number Container System
  1058. Largest Multiple of Three
  1059. Reverse Pairs
  1060. The Number of Weak Characters in the Game
  1061. Add Two Integers
  1062. Check If Two Expression Trees are Equivalent
  1063. Number of Pairs Satisfying Inequality
  1064. Minimum Cost to Merge Stones
  1065. Count Vowels Permutation
  1066. Kth Smallest Number in Multiplication Table
  1067. H-Index
  1068. Valid Anagram
  1069. Perfect Squares
  1070. Rearrange Spaces Between Words
  1071. DI String Match
  1072. Squares of a Sorted Array
  1073. Peeking Iterator
  1074. Paths in Matrix Whose Sum Is Divisible by K
  1075. Middle of the Linked List
  1076. Flip Equivalent Binary Trees
  1077. Profitable Schemes
  1078. Minimum Cost Tree From Leaf Values
  1079. Subarray Sum Equals K
  1080. Build Array from Permutation
  1081. Rank Teams by Votes
  1082. Minimum Deletions to Make Character Frequencies Unique
  1083. Count Subarrays With Score Less Than K
  1084. Add Digits
  1085. Reorder List
  1086. Exclusive Time of Functions
  1087. Climbing Stairs
  1088. Number of Closed Islands
  1089. Design Phone Directory
  1090. Escape The Ghosts
  1091. Binary Tree Longest Consecutive Sequence
  1092. Reverse Vowels of a String
  1093. Binary Tree Maximum Path Sum
  1094. Sum of All Odd Length Subarrays
  1095. Product Sales Analysis I
  1096. Swap Nodes in Pairs
  1097. Step-By-Step Directions From a Binary Tree Node to Another
  1098. Find the City With the Smallest Number of Neighbors at a Threshold Distance
  1099. Longest Increasing Subsequence
  1100. One Edit Distance
  1101. Transform to Chessboard
  1102. Smallest String Starting From Leaf
  1103. Optimize Water Distribution in a Village
  1104. Minimum Consecutive Cards to Pick Up
  1105. Zigzag Iterator
  1106. Find K Pairs with Smallest Sums
  1107. Generate Parentheses
  1108. Maximum Number of Non-Overlapping Subarrays With Sum Equals Target
  1109. Open the Lock
  1110. Burst Balloons
  1111. Sort Integers by The Power Value
  1112. Maximum Units on a Truck
  1113. Shortest Distance from All Buildings
  1114. Leftmost Column with at Least a One
  1115. Insert Delete GetRandom O(1) - Duplicates allowed
  1116. Basic Calculator II
  1117. Find Leaves of Binary Tree
  1118. Max Consecutive Ones II
  1119. Prime Subtraction Operation
  1120. Maximum Gap
  1121. Delete Node in a BST
  1122. String Transforms Into Another String
  1123. Majority Element
  1124. Count Univalue Subtrees
  1125. Find Root of N-Ary Tree
  1126. Binary Watch
  1127. Candy
  1128. Frequency of the Most Frequent Element
  1129. Rotate List
  1130. Divide Array Into Increasing Sequences
  1131. Maximum Score of a Node Sequence
  1132. Employees Earning More Than Their Managers
  1133. Similar String Groups
  1134. Simplify Path
  1135. Find Valid Matrix Given Row and Column Sums
  1136. Jump Game VII
  1137. Minimum Skips to Arrive at Meeting On Time
  1138. Beautiful Arrangement II
  1139. Maximum Score from Performing Multiplication Operations
  1140. Minimum Weighted Subgraph With the Required Paths
  1141. Disconnect Path in a Binary Matrix by at Most One Flip
  1142. Beautiful Arrangement
  1143. Convert 1D Array Into 2D Array
  1144. Number of Connected Components in an Undirected Graph
  1145. Find K Closest Elements
  1146. Range Addition
  1147. Contiguous Array
  1148. Guess the Majority in a Hidden Array
  1149. Count Integers in Intervals
  1150. Counter
  1151. Wildcard Matching
  1152. Video Stitching
  1153. Brace Expansion
  1154. Maximum Difference Between Node and Ancestor
  1155. Count of Range Sum
  1156. Longest Palindrome
  1157. Stone Game III
  1158. Put Boxes Into the Warehouse I
  1159. Number of Good Ways to Split a String
  1160. The Skyline Problem
  1161. Painting a Grid With Three Different Colors
  1162. Course Schedule II
  1163. Kth Missing Positive Number
  1164. Sum of Prefix Scores of Strings
  1165. Strictly Palindromic Number
  1166. Verify Preorder Serialization of a Binary Tree
  1167. Android Unlock Patterns
  1168. Check Completeness of a Binary Tree
  1169. Tuple with Same Product
  1170. Subtract the Product and Sum of Digits of an Integer
  1171. Number of Wonderful Substrings
  1172. Iterator for Combination
  1173. Toeplitz Matrix
  1174. Count All Valid Pickup and Delivery Options
  1175. Campus Bikes II
  1176. Article Views I
  1177. Spiral Matrix
  1178. Customer Placing the Largest Number of Orders
  1179. Binary Searchable Numbers in an Unsorted Array
  1180. Number of Ways to Stay in the Same Place After Some Steps
  1181. Second Highest Salary
  1182. Find Duplicate Subtrees
  1183. Employee Free Time
  1184. Smallest Range Covering Elements from K Lists
  1185. Sort Array by Increasing Frequency
  1186. Minimum Cost to Connect Two Groups of Points
  1187. Unique Length-3 Palindromic Subsequences
  1188. Determine if a Cell Is Reachable at a Given Time
  1189. Remove Linked List Elements
  1190. Kth Ancestor of a Tree Node
  1191. Flip Game II
  1192. Check if Array Is Sorted and Rotated
  1193. Stock Price Fluctuation
  1194. Power of Two
  1195. Range Sum Query 2D - Immutable
  1196. Evaluate Reverse Polish Notation
  1197. Minimum Adjacent Swaps for K Consecutive Ones
  1198. Maximum Number of Achievable Transfer Requests
  1199. Find the Town Judge
  1200. Making A Large Island
  1201. Boundary of Binary Tree