Leetcode Solutions in Java

• 1 Two Sum
• 2 Add Two Numbers
• 3 Longest Substring Without Repeating Characters
• 4 Median of Two Sorted Arrays
• 5 Longest Palindromic Substring
• 6 ZigZag Conversion
• 7 Reverse Integer
• 8 String to Integer (atoi)
• 9 Palindrome Number
• 10 Regular Expression Matching
• 11 Container With Most Water
• 12 Integer to Roman
• 13 Roman to Integer
• 14 Longest Common Prefix
• 15 3Sum
• 16 3Sum Closest
• 17 Letter Combinations of a Phone Number
• 18 4Sum
• 19 Remove Nth Node From End of List
• 20 Valid Parentheses
• 21 Merge Two Sorted Lists
• 22 Generate Parentheses
• 23 Merge k Sorted Lists
• 24 Swap Nodes in Pairs
• 25 Reverse Nodes in k-Group
• 26 Remove Duplicates from Sorted Array
• 27 Remove Element
• 28 Implement strStr()
• 29 Divide Two Integers
• 30 Substring with Concatenation of All Words
• 31 Next Permutation
• 32 Longest Valid Parentheses
• 33 Search in Rotated Sorted Array
• 34 Find First and Last Position of Element in Sorted Array
• 35 Search Insert Position
• 36 Valid Sudoku
• 37 Sudoku Solver
• 38 Count and Say
• 39 Combination Sum
• 40 Combination Sum II
• 41 First Missing Positive
• 42 Trapping Rain Water
• 43 Multiply Strings
• 44 Wildcard Matching
• 45 Jump Game II
• 46 Permutations
• 47 Permutations II
• 48 Rotate Image
• 49 Group Anagrams
• 50 Pow(x n)
• 51 N-Queens
• 52 N-Queens II
• 53 Maximum Subarray
• 54 Spiral Matrix
• 55 Jump Game
• 56 Merge Intervals
• 57 Insert Interval
• 58 Length of Last Word
• 59 Spiral Matrix II
• 60 Permutation Sequence
• 61 Rotate List
• 62 Unique Paths
• 63 Unique Paths II
• 64 Minimum Path Sum
• 65 Valid Number
• 66 Plus One
• 67 Add Binary
• 68 Text Justification
• 69 Sqrt(x)
• 70 Climbing Stairs
• 71 Simplify Path
• 72 Edit Distance
• 73 Set Matrix Zeroes
• 74 Search a 2D Matrix
• 75 Sort Colors
• 76 Minimum Window Substring
• 77 Combinations
• 78 Subsets
• 79 Word Search
• 80 Remove Duplicates from Sorted Array II
• 81 Search in Rotated Sorted Array II
• 82 Remove Duplicates from Sorted List II
• 83 Remove Duplicates from Sorted List
• 84 Largest Rectangle in Histogram
• 85 Maximal Rectangle
• 86 Partition List
• 87 Scramble String
• 88 Merge Sorted Array
• 89 Gray Code
• 90 Subsets II
• 91 Decode Ways
• 92 Reverse Linked List II
• 93 Restore IP Addresses
• 94 Binary Tree Inorder Traversal
• 95 Unique Binary Search Trees II
• 96 Unique Binary Search Trees
• 97 Interleaving String
• 98 Validate Binary Search Tree
• 99 Recover Binary Search Tree
• 100 Same Tree
• 101 Symmetric Tree
• 102 Binary Tree Level Order Traversal
• 103 Binary Tree Zigzag Level Order Traversal
• 104 Maximum Depth of Binary Tree
• 105 Construct Binary Tree from Preorder and Inorder Traversal
• 106 Construct Binary Tree from Inorder and Postorder Traversal
• 107 Binary Tree Level Order Traversal II
• 108 Convert Sorted Array to Binary Search Tree
• 109 Convert Sorted List to Binary Search Tree
• 110 Balanced Binary Tree
• 111 Minimum Depth of Binary Tree
• 112 Path Sum
• 113 Path Sum II
• 114 Flatten Binary Tree to Linked List
• 115 Distinct Subsequences
• 116 Populating Next Right Pointers in Each Node
• 117 Populating Next Right Pointers in Each Node II
• 118 Pascal's Triangle
• 119 Pascal's Triangle II
• 120 Triangle
• 121 Best Time to Buy and Sell Stock
• 122 Best Time to Buy and Sell Stock II
• 123 Best Time to Buy and Sell Stock III
• 124 Binary Tree Maximum Path Sum
• 125 Valid Palindrome
• 126 Word Ladder II
• 127 Word Ladder
• 128 Longest Consecutive Sequence
• 129 Sum Root to Leaf Numbers
• 130 Surrounded Regions
• 131 Palindrome Partitioning
• 132 Palindrome Partitioning II
• 133 Clone Graph
• 134 Gas Station
• 135 Candy
• 136 Single Number
• 137 Single Number II
• 138 Copy List with Random Pointer
• 139 Word Break
• 140 Word Break II
• 141 Linked List Cycle
• 142 Linked List Cycle II
• 143 Reorder List
• 144 Binary Tree Preorder Traversal
• 145 Binary Tree Postorder Traversal
• 146 LRU Cache
• 147 Insertion Sort List
• 148 Sort List
• 149 Max Points on a Line
• 150 Evaluate Reverse Polish Notation
• 151 Reverse Words in a String
• 152 Maximum Product Subarray
• 153 Find Minimum in Rotated Sorted Array
• 154 Find Minimum in Rotated Sorted Array II
• 155 Min Stack
• 156 Binary Tree Upside Down
• 157 Read N Characters Given Read4
• 158 Read N Characters Given Read4 II - Call multiple times
• 159 Longest Substring with At Most Two Distinct Characters
• 160 Intersection of Two Linked Lists
• 161 One Edit Distance
• 162 Find Peak Element
• 163 Missing Ranges
• 164 Maximum Gap
• 165 Compare Version Numbers
• 166 Fraction to Recurring Decimal
• 167 Two Sum II - Input array is sorted
• 168 Excel Sheet Column Title
• 169 Majority Element
• 170 Two Sum III - Data structure design
• 171 Excel Sheet Column Number
• 172 Factorial Trailing Zeroes
• 173 Binary Search Tree Iterator
• 174 Dungeon Game
• 175 Combine Two Tables
• 176 Second Highest Salary
• 177 Nth Highest Salary
• 178 Rank Scores
• 179 Largest Number
• 180 Consecutive Numbers
• 181 Employees Earning More Than Their Managers
• 182 Duplicate Emails
• 183 Customers Who Never Order
• 184 Department Highest Salary
• 185 Department Top Three Salaries
• 186 Reverse Words in a String II
• 187 Repeated DNA Sequences
• 188 Best Time to Buy and Sell Stock IV
• 189 Rotate Array
• 190 Reverse Bits
• 191 Number of 1 Bits
• 192 Word Frequency
• 193 Valid Phone Numbers
• 194 Transpose File
• 195 Tenth Line
• 196 Delete Duplicate Emails
• 197 Rising Temperature
• 198 House Robber
• 199 Binary Tree Right Side View
• 200 Number of Islands
• 201 Bitwise AND of Numbers Range
• 202 Happy Number
• 203 Remove Linked List Elements
• 204 Count Primes
• 205 Isomorphic Strings
• 206 Reverse Linked List
• 207 Course Schedule
• 208 Implement Trie (Prefix Tree)
• 209 Minimum Size Subarray Sum
• 210 Course Schedule II
• 211 Add and Search Word - Data structure design
• 212 Word Search II
• 213 House Robber II
• 214 Shortest Palindrome
• 215 Kth Largest Element in an Array
• 216 Combination Sum III
• 217 Contains Duplicate
• 218 The Skyline Problem
• 219 Contains Duplicate II
• 220 Contains Duplicate III
• 221 Maximal Square
• 222 Count Complete Tree Nodes
• 223 Rectangle Area
• 224 Basic Calculator
• 225 Implement Stack using Queues
• 226 Invert Binary Tree
• 227 Basic Calculator II
• 228 Summary Ranges
• 229 Majority Element II
• 230 Kth Smallest Element in a BST
• 231 Power of Two
• 232 Implement Queue using Stacks
• 233 Number of Digit One
• 234 Palindrome Linked List
• 235 Lowest Common Ancestor of a Binary Search Tree
• 236 Lowest Common Ancestor of a Binary Tree
• 237 Delete Node in a Linked List
• 238 Product of Array Except Self
• 239 Sliding Window Maximum
• 240 Search a 2D Matrix II
• 241 Different Ways to Add Parentheses
• 242 Valid Anagram
• 243 Shortest Word Distance
• 244 Shortest Word Distance II
• 245 Shortest Word Distance III
• 246 Strobogrammatic Number
• 247 Strobogrammatic Number II
• 248 Strobogrammatic Number III
• 249 Group Shifted Strings
• 250 Count Univalue Subtrees
• 251 Flatten 2D Vector
• 252 Meeting Rooms
• 253 Meeting Rooms II
• 254 Factor Combinations
• 255 Verify Preorder Sequence in Binary Search Tree
• 256 Paint House
• 257 Binary Tree Paths
• 258 Add Digits
• 259 3Sum Smaller
• 260 Single Number III
• 261 Graph Valid Tree
• 262 Trips and Users
• 263 Ugly Number
• 264 Ugly Number II
• 265 Paint House II
• 266 Palindrome Permutation
• 267 Palindrome Permutation II
• 268 Missing Number
• 269 Alien Dictionary
• 270 Closest Binary Search Tree Value
• 271 Encode and Decode Strings
• 272 Closest Binary Search Tree Value II
• 273 Integer to English Words
• 274 H-Index
• 275 H-Index II
• 276 Paint Fence
• 277 Find the Celebrity
• 278 First Bad Version
• 279 Perfect Squares
• 280 Wiggle Sort
• 281 Zigzag Iterator
• 282 Expression Add Operators
• 283 Move Zeroes
• 284 Peeking Iterator
• 285 Inorder Successor in BST
• 286 Walls and Gates
• 287 Find the Duplicate Number
• 288 Unique Word Abbreviation
• 289 Game of Life
• 290 Word Pattern
• 291 Word Pattern II
• 292 Nim Game
• 293 Flip Game
• 294 Flip Game II
• 295 Find Median from Data Stream
• 296 Best Meeting Point
• 297 Serialize and Deserialize Binary Tree
• 298 Binary Tree Longest Consecutive Sequence
• 299 Bulls and Cows
• 300 Longest Increasing Subsequence
• 301 Remove Invalid Parentheses
• 302 Smallest Rectangle Enclosing Black Pixels
• 303 Range Sum Query - Immutable
• 304 Range Sum Query 2D - Immutable
• 305 Number of Islands II
• 306 Additive Number
• 307 Range Sum Query - Mutable
• 308 Range Sum Query 2D - Mutable
• 309 Best Time to Buy and Sell Stock with Cooldown
• 310 Minimum Height Trees
• 311 Sparse Matrix Multiplication
• 312 Burst Balloons
• 313 Super Ugly Number
• 314 Binary Tree Vertical Order Traversal
• 315 Count of Smaller Numbers After Self
• 316 Remove Duplicate Letters
• 317 Shortest Distance from All Buildings
• 318 Maximum Product of Word Lengths
• 319 Bulb Switcher
• 320 Generalized Abbreviation
• 321 Create Maximum Number
• 322 Coin Change
• 323 Number of Connected Components in an Undirected Graph
• 324 Wiggle Sort II
• 325 Maximum Size Subarray Sum Equals k
• 326 Power of Three
• 327 Count of Range Sum
• 328 Odd Even Linked List
• 329 Longest Increasing Path in a Matrix
• 330 Patching Array
• 331 Verify Preorder Serialization of a Binary Tree
• 332 Reconstruct Itinerary
• 333 Largest BST Subtree
• 334 Increasing Triplet Subsequence
• 335 Self Crossing
• 336 Palindrome Pairs
• 337 House Robber III
• 338 Counting Bits
• 339 Nested List Weight Sum
• 340 Longest Substring with At Most K Distinct Characters
• 341 Flatten Nested List Iterator
• 342 Power of Four
• 343 Integer Break
• 344 Reverse String
• 345 Reverse Vowels of a String
• 346 Moving Average from Data Stream
• 347 Top K Frequent Elements
• 348 Design Tic-Tac-Toe
• 349 Intersection of Two Arrays
• 350 Intersection of Two Arrays II
• 351 Android Unlock Patterns
• 352 Data Stream as Disjoint Intervals
• 353 Design Snake Game
• 354 Russian Doll Envelopes
• 355 Design Twitter
• 356 Line Reflection
• 357 Count Numbers with Unique Digits
• 358 Rearrange String k Distance Apart
• 359 Logger Rate Limiter
• 360 Sort Transformed Array
• 361 Bomb Enemy
• 362 Design Hit Counter
• 363 Max Sum of Rectangle No Larger Than K
• 364 Nested List Weight Sum II
• 365 Water and Jug Problem
• 366 Find Leaves of Binary Tree
• 367 Valid Perfect Square
• 368 Largest Divisible Subset
• 369 Plus One Linked List
• 370 Range Addition
• 371 Sum of Two Integers
• 372 Super Pow
• 373 Find K Pairs with Smallest Sums
• 374 Guess Number Higher or Lower
• 375 Guess Number Higher or Lower II
• 376 Wiggle Subsequence
• 377 Combination Sum IV
• 378 Kth Smallest Element in a Sorted Matrix
• 379 Design Phone Directory
• 380 Insert Delete GetRandom O(1)
• 381 Insert Delete GetRandom O(1) - Duplicates allowed
• 382 Linked List Random Node
• 383 Ransom Note
• 384 Shuffle an Array
• 385 Mini Parser
• 386 Lexicographical Numbers
• 387 First Unique Character in a String
• 388 Longest Absolute File Path
• 389 Find the Difference
• 390 Elimination Game
• 391 Perfect Rectangle
• 392 Is Subsequence
• 393 UTF-8 Validation
• 394 Decode String
• 395 Longest Substring with At Least K Repeating Characters
• 396 Rotate Function
• 397 Integer Replacement
• 398 Random Pick Index
• 399 Evaluate Division
• 400 Nth Digit
• 401 Binary Watch
• 402 Remove K Digits
• 403 Frog Jump
• 404 Sum of Left Leaves
• 405 Convert a Number to Hexadecimal
• 406 Queue Reconstruction by Height
• 407 Trapping Rain Water II
• 408 Valid Word Abbreviation
• 409 Longest Palindrome
• 410 Split Array Largest Sum
• 411 Minimum Unique Word Abbreviation
• 412 Fizz Buzz
• 413 Arithmetic Slices
• 414 Third Maximum Number
• 415 Add Strings
• 416 Partition Equal Subset Sum
• 417 Pacific Atlantic Water Flow
• 418 Sentence Screen Fitting
• 419 Battleships in a Board
• 420 Strong Password Checker
• 421 Maximum XOR of Two Numbers in an Array
• 422 Valid Word Square
• 423 Reconstruct Original Digits from English
• 424 Longest Repeating Character Replacement
• 425 Word Squares
• 426 Convert Binary Search Tree to Sorted Doubly Linked List
• 427 Construct Quad Tree
• 428 Serialize and Deserialize N-ary Tree
• 429 N-ary Tree Level Order Traversal
• 430 Flatten a Multilevel Doubly Linked List
• 431 Encode N-ary Tree to Binary Tree
• 432 All O`one Data Structure
• 433 Minimum Genetic Mutation
• 434 Number of Segments in a String
• 435 Non-overlapping Intervals
• 436 Find Right Interval
• 437 Path Sum III
• 438 Find All Anagrams in a String
• 439 Ternary Expression Parser
• 440 K-th Smallest in Lexicographical Order
• 441 Arranging Coins
• 442 Find All Duplicates in an Array
• 443 String Compression
• 444 Sequence Reconstruction
• 445 Add Two Numbers II
• 446 Arithmetic Slices II - Subsequence
• 447 Number of Boomerangs
• 448 Find All Numbers Disappeared in an Array
• 449 Serialize and Deserialize BST
• 450 Delete Node in a BST
• 451 Sort Characters By Frequency
• 452 Minimum Number of Arrows to Burst Balloons
• 453 Minimum Moves to Equal Array Elements
• 454 4Sum II
• 455 Assign Cookies
• 456 132 Pattern
• 457 Circular Array Loop
• 458 Poor Pigs
• 459 Repeated Substring Pattern
• 460 LFU Cache
• 461 Hamming Distance
• 462 Minimum Moves to Equal Array Elements II
• 463 Island Perimeter
• 464 Can I Win
• 465 Optimal Account Balancing
• 466 Count The Repetitions
• 467 Unique Substrings in Wraparound String
• 468 Validate IP Address
• 469 Convex Polygon
• 470 Implement Rand10() Using Rand7()
• 471 Encode String with Shortest Length
• 472 Concatenated Words
• 473 Matchsticks to Square
• 474 Ones and Zeroes
• 475 Heaters
• 476 Number Complement
• 477 Total Hamming Distance
• 478 Generate Random Point in a Circle
• 479 Largest Palindrome Product
• 480 Sliding Window Median
• 481 Magical String
• 482 License Key Formatting
• 483 Smallest Good Base
• 484 Find Permutation
• 485 Max Consecutive Ones
• 486 Predict the Winner
• 487 Max Consecutive Ones II
• 488 Zuma Game
• 489 Robot Room Cleaner
• 490 The Maze
• 491 Increasing Subsequences
• 492 Construct the Rectangle
• 493 Reverse Pairs
• 494 Target Sum
• 495 Teemo Attacking
• 496 Next Greater Element I
• 497 Random Point in Non-overlapping Rectangles
• 498 Diagonal Traverse
• 499 The Maze III
• 500 Keyboard Row
• 501 Find Mode in Binary Search Tree
• 502 IPO
• 503 Next Greater Element II
• 504 Base 7
• 505 The Maze II
• 506 Relative Ranks
• 507 Perfect Number
• 508 Most Frequent Subtree Sum
• 509 Fibonacci Number
• 510 Inorder Successor in BST II
• 511 Game Play Analysis I
• 512 Game Play Analysis II
• 513 Find Bottom Left Tree Value
• 514 Freedom Trail
• 515 Find Largest Value in Each Tree Row
• 516 Longest Palindromic Subsequence
• 517 Super Washing Machines
• 518 Coin Change 2
• 519 Random Flip Matrix
• 520 Detect Capital
• 521 Longest Uncommon Subsequence I
• 522 Longest Uncommon Subsequence II
• 523 Continuous Subarray Sum
• 524 Longest Word in Dictionary through Deleting
• 525 Contiguous Array
• 526 Beautiful Arrangement
• 527 Word Abbreviation
• 528 Random Pick with Weight
• 529 Minesweeper
• 530 Minimum Absolute Difference in BST
• 531 Lonely Pixel I
• 532 K-diff Pairs in an Array
• 533 Lonely Pixel II
• 534 Game Play Analysis III
• 535 Encode and Decode TinyURL
• 536 Construct Binary Tree from String
• 537 Complex Number Multiplication
• 538 Convert BST to Greater Tree
• 539 Minimum Time Difference
• 540 Single Element in a Sorted Array
• 541 Reverse String II
• 542 01 Matrix
• 543 Diameter of Binary Tree
• 544 Output Contest Matches
• 545 Boundary of Binary Tree
• 546 Remove Boxes
• 547 Friend Circles
• 548 Split Array with Equal Sum
• 549 Binary Tree Longest Consecutive Sequence II
• 550 Game Play Analysis IV
• 551 Student Attendance Record I
• 552 Student Attendance Record II
• 553 Optimal Division
• 554 Brick Wall
• 555 Split Concatenated Strings
• 556 Next Greater Element III
• 557 Reverse Words in a String III
• 558 Quad Tree Intersection
• 559 Maximum Depth of N-ary Tree
• 560 Subarray Sum Equals K
• 561 Array Partition I
• 562 Longest Line of Consecutive One in Matrix
• 563 Binary Tree Tilt
• 564 Find the Closest Palindrome
• 565 Array Nesting
• 566 Reshape the Matrix
• 567 Permutation in String
• 568 Maximum Vacation Days
• 569 Median Employee Salary
• 570 Managers with at Least 5 Direct Reports
• 571 Find Median Given Frequency of Numbers
• 572 Subtree of Another Tree
• 573 Squirrel Simulation
• 574 Winning Candidate
• 575 Distribute Candies
• 576 Out of Boundary Paths
• 577 Employee Bonus
• 578 Get Highest Answer Rate Question
• 579 Find Cumulative Salary of an Employee
• 580 Count Student Number in Departments
• 581 Shortest Unsorted Continuous Subarray
• 582 Kill Process
• 583 Delete Operation for Two Strings
• 584 Find Customer Referee
• 585 Investments in 2016
• 586 Customer Placing the Largest Number of Orders
• 587 Erect the Fence
• 588 Design In-Memory File System
• 589 N-ary Tree Preorder Traversal
• 590 N-ary Tree Postorder Traversal
• 591 Tag Validator
• 592 Fraction Addition and Subtraction
• 593 Valid Square
• 594 Longest Harmonious Subsequence
• 595 Big Countries
• 596 Classes More Than 5 Students
• 597 Friend Requests I: Overall Acceptance Rate
• 598 Range Addition II
• 599 Minimum Index Sum of Two Lists
• 600 Non-negative Integers without Consecutive Ones
• 601 Human Traffic of Stadium
• 602 Friend Requests II: Who Has the Most Friends
• 603 Consecutive Available Seats
• 604 Design Compressed String Iterator
• 605 Can Place Flowers
• 606 Construct String from Binary Tree
• 607 Sales Person
• 608 Tree Node
• 609 Find Duplicate File in System
• 610 Triangle Judgement
• 611 Valid Triangle Number
• 612 Shortest Distance in a Plane
• 613 Shortest Distance in a Line
• 614 Second Degree Follower
• 615 Average Salary: Departments VS Company
• 616 Add Bold Tag in String
• 617 Merge Two Binary Trees
• 618 Students Report By Geography
• 619 Biggest Single Number
• 620 Not Boring Movies
• 621 Task Scheduler
• 622 Design Circular Queue
• 623 Add One Row to Tree
• 624 Maximum Distance in Arrays
• 625 Minimum Factorization
• 626 Exchange Seats
• 627 Swap Salary
• 628 Maximum Product of Three Numbers
• 629 K Inverse Pairs Array
• 630 Course Schedule III
• 631 Design Excel Sum Formula
• 632 Smallest Range Covering Elements from K Lists
• 633 Sum of Square Numbers
• 634 Find the Derangement of An Array
• 635 Design Log Storage System
• 636 Exclusive Time of Functions
• 637 Average of Levels in Binary Tree
• 638 Shopping Offers
• 639 Decode Ways II
• 640 Solve the Equation
• 641 Design Circular Deque
• 642 Design Search Autocomplete System
• 643 Maximum Average Subarray I
• 644 Maximum Average Subarray II
• 645 Set Mismatch
• 646 Maximum Length of Pair Chain
• 647 Palindromic Substrings
• 648 Replace Words
• 649 Dota2 Senate
• 650 2 Keys Keyboard
• 651 4 Keys Keyboard
• 652 Find Duplicate Subtrees
• 653 Two Sum IV - Input is a BST
• 654 Maximum Binary Tree
• 655 Print Binary Tree
• 656 Coin Path
• 657 Robot Return to Origin
• 658 Find K Closest Elements
• 659 Split Array into Consecutive Subsequences
• 660 Remove 9
• 661 Image Smoother
• 662 Maximum Width of Binary Tree
• 663 Equal Tree Partition
• 664 Strange Printer
• 665 Non-decreasing Array
• 666 Path Sum IV
• 667 Beautiful Arrangement II
• 668 Kth Smallest Number in Multiplication Table
• 669 Trim a Binary Search Tree
• 670 Maximum Swap
• 671 Second Minimum Node In a Binary Tree
• 672 Bulb Switcher II
• 673 Number of Longest Increasing Subsequence
• 674 Longest Continuous Increasing Subsequence
• 675 Cut Off Trees for Golf Event
• 676 Implement Magic Dictionary
• 677 Map Sum Pairs
• 678 Valid Parenthesis String
• 679 24 Game
• 680 Valid Palindrome II
• 681 Next Closest Time
• 682 Baseball Game
• 683 K Empty Slots
• 684 Redundant Connection
• 685 Redundant Connection II
• 686 Repeated String Match
• 687 Longest Univalue Path
• 688 Knight Probability in Chessboard
• 689 Maximum Sum of 3 Non-Overlapping Subarrays
• 690 Employee Importance
• 691 Stickers to Spell Word
• 692 Top K Frequent Words
• 693 Binary Number with Alternating Bits
• 694 Number of Distinct Islands
• 695 Max Area of Island
• 696 Count Binary Substrings
• 697 Degree of an Array
• 698 Partition to K Equal Sum Subsets
• 699 Falling Squares
• 700 Search in a Binary Search Tree
• 701 Insert into a Binary Search Tree
• 702 Search in a Sorted Array of Unknown Size
• 703 Kth Largest Element in a Stream
• 704 Binary Search
• 705 Design HashSet
• 706 Design HashMap
• 707 Design Linked List
• 708 Insert into a Cyclic Sorted List
• 709 To Lower Case
• 710 Random Pick with Blacklist
• 711 Number of Distinct Islands II
• 712 Minimum ASCII Delete Sum for Two Strings
• 713 Subarray Product Less Than K
• 714 Best Time to Buy and Sell Stock with Transaction Fee
• 715 Range Module
• 716 Max Stack
• 717 1-bit and 2-bit Characters
• 718 Maximum Length of Repeated Subarray
• 719 Find K-th Smallest Pair Distance
• 720 Longest Word in Dictionary
• 721 Accounts Merge
• 722 Remove Comments
• 723 Candy Crush
• 724 Find Pivot Index
• 725 Split Linked List in Parts
• 726 Number of Atoms
• 727 Minimum Window Subsequence
• 728 Self Dividing Numbers
• 729 My Calendar I
• 730 Count Different Palindromic Subsequences
• 731 My Calendar II
• 732 My Calendar III
• 733 Flood Fill
• 734 Sentence Similarity
• 735 Asteroid Collision
• 736 Parse Lisp Expression
• 737 Sentence Similarity II
• 738 Monotone Increasing Digits
• 739 Daily Temperatures
• 740 Delete and Earn
• 741 Cherry Pickup
• 742 Closest Leaf in a Binary Tree
• 743 Network Delay Time
• 744 Find Smallest Letter Greater Than Target
• 745 Prefix and Suffix Search
• 746 Min Cost Climbing Stairs
• 747 Largest Number At Least Twice of Others
• 748 Shortest Completing Word
• 749 Contain Virus
• 750 Number Of Corner Rectangles
• 751 IP to CIDR
• 752 Open the Lock
• 753 Cracking the Safe
• 754 Reach a Number
• 755 Pour Water
• 756 Pyramid Transition Matrix
• 757 Set Intersection Size At Least Two
• 758 Bold Words in String
• 759 Employee Free Time
• 760 Find Anagram Mappings
• 761 Special Binary String
• 762 Prime Number of Set Bits in Binary Representation
• 763 Partition Labels
• 764 Largest Plus Sign
• 765 Couples Holding Hands
• 766 Toeplitz Matrix
• 767 Reorganize String
• 768 Max Chunks To Make Sorted II
• 769 Max Chunks To Make Sorted
• 770 Basic Calculator IV
• 771 Jewels and Stones
• 772 Basic Calculator III
• 773 Sliding Puzzle
• 774 Minimize Max Distance to Gas Station
• 775 Global and Local Inversions
• 776 Split BST
• 777 Swap Adjacent in LR String
• 778 Swim in Rising Water
• 779 K-th Symbol in Grammar
• 780 Reaching Points
• 781 Rabbits in Forest
• 782 Transform to Chessboard
• 783 Minimum Distance Between BST Nodes
• 784 Letter Case Permutation
• 785 Is Graph Bipartite?
• 786 K-th Smallest Prime Fraction
• 787 Cheapest Flights Within K Stops
• 788 Rotated Digits
• 789 Escape The Ghosts
• 790 Domino and Tromino Tiling
• 791 Custom Sort String
• 792 Number of Matching Subsequences
• 793 Preimage Size of Factorial Zeroes Function
• 794 Valid Tic-Tac-Toe State
• 795 Number of Subarrays with Bounded Maximum
• 796 Rotate String
• 797 All Paths From Source to Target
• 798 Smallest Rotation with Highest Score
• 799 Champagne Tower
• 800 Similar RGB Color
• 801 Minimum Swaps To Make Sequences Increasing
• 802 Find Eventual Safe States
• 803 Bricks Falling When Hit
• 804 Unique Morse Code Words
• 805 Split Array With Same Average
• 806 Number of Lines To Write String
• 807 Max Increase to Keep City Skyline
• 808 Soup Servings
• 809 Expressive Words
• 810 Chalkboard XOR Game
• 811 Subdomain Visit Count
• 812 Largest Triangle Area
• 813 Largest Sum of Averages
• 814 Binary Tree Pruning
• 815 Bus Routes
• 816 Ambiguous Coordinates
• 817 Linked List Components
• 818 Race Car
• 819 Most Common Word
• 820 Short Encoding of Words
• 821 Shortest Distance to a Character
• 822 Card Flipping Game
• 823 Binary Trees With Factors
• 824 Goat Latin
• 825 Friends Of Appropriate Ages
• 826 Most Profit Assigning Work
• 827 Making A Large Island
• 828 Unique Letter String
• 829 Consecutive Numbers Sum
• 830 Positions of Large Groups
• 831 Masking Personal Information
• 832 Flipping an Image
• 833 Find And Replace in String
• 834 Sum of Distances in Tree
• 835 Image Overlap
• 836 Rectangle Overlap
• 837 New 21 Game
• 838 Push Dominoes
• 839 Similar String Groups
• 840 Magic Squares In Grid
• 841 Keys and Rooms
• 842 Split Array into Fibonacci Sequence
• 843 Guess the Word
• 844 Backspace String Compare
• 845 Longest Mountain in Array
• 846 Hand of Straights
• 847 Shortest Path Visiting All Nodes
• 848 Shifting Letters
• 849 Maximize Distance to Closest Person
• 850 Rectangle Area II
• 851 Loud and Rich
• 852 Peak Index in a Mountain Array
• 853 Car Fleet
• 854 K-Similar Strings
• 855 Exam Room
• 856 Score of Parentheses
• 857 Minimum Cost to Hire K Workers
• 858 Mirror Reflection
• 859 Buddy Strings
• 860 Lemonade Change
• 861 Score After Flipping Matrix
• 862 Shortest Subarray with Sum at Least K
• 863 All Nodes Distance K in Binary Tree
• 864 Shortest Path to Get All Keys
• 865 Smallest Subtree with all the Deepest Nodes
• 866 Prime Palindrome
• 867 Transpose Matrix
• 868 Binary Gap
• 869 Reordered Power of 2
• 870 Advantage Shuffle
• 871 Minimum Number of Refueling Stops
• 872 Leaf-Similar Trees
• 873 Length of Longest Fibonacci Subsequence
• 874 Walking Robot Simulation
• 875 Koko Eating Bananas
• 876 Middle of the Linked List
• 877 Stone Game
• 878 Nth Magical Number
• 879 Profitable Schemes
• 880 Decoded String at Index
• 881 Boats to Save People
• 882 Reachable Nodes In Subdivided Graph
• 883 Projection Area of 3D Shapes
• 884 Uncommon Words from Two Sentences
• 885 Spiral Matrix III
• 886 Possible Bipartition
• 887 Super Egg Drop
• 888 Fair Candy Swap
• 889 Construct Binary Tree from Preorder and Postorder Traversal
• 890 Find and Replace Pattern
• 891 Sum of Subsequence Widths
• 892 Surface Area of 3D Shapes
• 893 Groups of Special-Equivalent Strings
• 894 All Possible Full Binary Trees
• 895 Maximum Frequency Stack
• 896 Monotonic Array
• 897 Increasing Order Search Tree
• 898 Bitwise ORs of Subarrays
• 899 Orderly Queue
• 900 RLE Iterator
• 901 Online Stock Span
• 902 Numbers At Most N Given Digit Set
• 903 Valid Permutations for DI Sequence
• 904 Fruit Into Baskets
• 905 Sort Array By Parity
• 906 Super Palindromes
• 907 Sum of Subarray Minimums
• 908 Smallest Range I
• 909 Snakes and Ladders
• 910 Smallest Range II
• 911 Online Election
• 912 Sort an Array
• 913 Cat and Mouse
• 914 X of a Kind in a Deck of Cards
• 915 Partition Array into Disjoint Intervals
• 916 Word Subsets
• 917 Reverse Only Letters
• 918 Maximum Sum Circular Subarray
• 919 Complete Binary Tree Inserter
• 920 Number of Music Playlists
• 921 Minimum Add to Make Parentheses Valid
• 922 Sort Array By Parity II
• 923 3Sum With Multiplicity
• 924 Minimize Malware Spread
• 925 Long Pressed Name
• 926 Flip String to Monotone Increasing
• 927 Three Equal Parts
• 928 Minimize Malware Spread II
• 929 Unique Email Addresses
• 930 Binary Subarrays With Sum
• 931 Minimum Falling Path Sum
• 932 Beautiful Array
• 933 Number of Recent Calls
• 934 Shortest Bridge
• 935 Knight Dialer
• 936 Stamping The Sequence
• 937 Reorder Data in Log Files
• 938 Range Sum of BST
• 939 Minimum Area Rectangle
• 940 Distinct Subsequences II
• 941 Valid Mountain Array
• 942 DI String Match
• 943 Find the Shortest Superstring
• 944 Delete Columns to Make Sorted
• 945 Minimum Increment to Make Array Unique
• 946 Validate Stack Sequences
• 947 Most Stones Removed with Same Row or Column
• 948 Bag of Tokens
• 949 Largest Time for Given Digits
• 950 Reveal Cards In Increasing Order
• 951 Flip Equivalent Binary Trees
• 952 Largest Component Size by Common Factor
• 953 Verifying an Alien Dictionary
• 954 Array of Doubled Pairs
• 955 Delete Columns to Make Sorted II
• 956 Tallest Billboard
• 957 Prison Cells After N Days
• 958 Check Completeness of a Binary Tree
• 959 Regions Cut By Slashes
• 960 Delete Columns to Make Sorted III
• 961 N-Repeated Element in Size 2N Array
• 962 Maximum Width Ramp
• 963 Minimum Area Rectangle II
• 964 Least Operators to Express Number
• 965 Univalued Binary Tree
• 966 Vowel Spellchecker
• 967 Numbers With Same Consecutive Differences
• 968 Binary Tree Cameras
• 969 Pancake Sorting
• 970 Powerful Integers
• 971 Flip Binary Tree To Match Preorder Traversal
• 972 Equal Rational Numbers
• 973 K Closest Points to Origin
• 974 Subarray Sums Divisible by K
• 975 Odd Even Jump
• 976 Largest Perimeter Triangle
• 977 Squares of a Sorted Array
• 978 Longest Turbulent Subarray
• 979 Distribute Coins in Binary Tree
• 980 Unique Paths III
• 981 Time Based Key-Value Store
• 982 Triples with Bitwise AND Equal To Zero
• 983 Minimum Cost For Tickets
• 984 String Without AAA or BBB
• 985 Sum of Even Numbers After Queries
• 986 Interval List Intersections
• 987 Vertical Order Traversal of a Binary Tree
• 988 Smallest String Starting From Leaf
• 989 Add to Array-Form of Integer
• 990 Satisfiability of Equality Equations
• 991 Broken Calculator
• 992 Subarrays with K Different Integers
• 993 Cousins in Binary Tree
• 994 Rotting Oranges
• 995 Minimum Number of K Consecutive Bit Flips
• 996 Number of Squareful Arrays
• 997 Find the Town Judge
• 998 Maximum Binary Tree II
• 999 Available Captures for Rook
• 1000 Minimum Cost to Merge Stones
• 1001 Grid Illumination
• 1002 Find Common Characters
• 1003 Check If Word Is Valid After Substitutions
• 1004 Max Consecutive Ones III
• 1005 Maximize Sum Of Array After K Negations
• 1006 Clumsy Factorial
• 1007 Minimum Domino Rotations For Equal Row
• 1008 Construct Binary Search Tree from Preorder Traversal
• 1009 Complement of Base 10 Integer
• 1010 Pairs of Songs With Total Durations Divisible by 60
• 1011 Capacity To Ship Packages Within D Days
• 1012 Numbers With Repeated Digits
• 1013 Partition Array Into Three Parts With Equal Sum
• 1014 Best Sightseeing Pair
• 1015 Smallest Integer Divisible by K
• 1016 Binary String With Substrings Representing 1 To N
• 1017 Convert to Base -2
• 1018 Binary Prefix Divisible By 5
• 1019 Next Greater Node In Linked List
• 1020 Number of Enclaves
• 1021 Remove Outermost Parentheses
• 1022 Sum of Root To Leaf Binary Numbers
• 1023 Camelcase Matching
• 1024 Video Stitching
• 1025 Divisor Game
• 1026 Maximum Difference Between Node and Ancestor
• 1027 Longest Arithmetic Sequence
• 1028 Recover a Tree From Preorder Traversal
• 1029 Two City Scheduling
• 1030 Matrix Cells in Distance Order
• 1031 Maximum Sum of Two Non-Overlapping Subarrays
• 1032 Stream of Characters
• 1033 Moving Stones Until Consecutive
• 1034 Coloring A Border
• 1035 Uncrossed Lines
• 1036 Escape a Large Maze
• 1037 Valid Boomerang
• 1038 Binary Search Tree to Greater Sum Tree
• 1039 Minimum Score Triangulation of Polygon
• 1040 Moving Stones Until Consecutive II
• 1041 Robot Bounded In Circle
• 1042 Flower Planting With No Adjacent
• 1043 Partition Array for Maximum Sum
• 1044 Longest Duplicate Substring
• 1045 Customers Who Bought All Products
• 1046 Last Stone Weight
• 1047 Remove All Adjacent Duplicates In String
• 1048 Longest String Chain
• 1049 Last Stone Weight II
• 1050 Actors and Directors Who Cooperated At Least Three Times
• 1051 Height Checker
• 1052 Grumpy Bookstore Owner
• 1053 Previous Permutation With One Swap
• 1054 Distant Barcodes
• 1055 Shortest Way to Form String
• 1056 Confusing Number
• 1057 Campus Bikes
• 1058 Minimize Rounding Error to Meet Target
• 1059 All Paths from Source Lead to Destination
• 1060 Missing Element in Sorted Array
• 1061 Lexicographically Smallest Equivalent String
• 1062 Longest Repeating Substring
• 1063 Number of Valid Subarrays
• 1064 Fixed Point
• 1065 Index Pairs of a String
• 1066 Campus Bikes II
• 1067 Digit Count in Range
• 1068 Product Sales Analysis I
• 1069 Product Sales Analysis II
• 1070 Product Sales Analysis III
• 1071 Greatest Common Divisor of Strings
• 1072 Flip Columns For Maximum Number of Equal Rows
• 1073 Adding Two Negabinary Numbers
• 1074 Number of Submatrices That Sum to Target
• 1075 Project Employees I
• 1076 Project Employees II
• 1077 Project Employees III
• 1078 Occurrences After Bigram
• 1079 Letter Tile Possibilities
• 1080 Insufficient Nodes in Root to Leaf Paths
• 1081 Smallest Subsequence of Distinct Characters
• 1082 Sales Analysis I
• 1083 Sales Analysis II
• 1084 Sales Analysis III
• 1085 Sum of Digits in the Minimum Number
• 1086 High Five
• 1087 Brace Expansion
• 1088 Confusing Number II
• 1089 Duplicate Zeros
• 1090 Largest Values From Labels
• 1091 Shortest Path in Binary Matrix
• 1092 Shortest Common Supersequence
• 1093 Statistics from a Large Sample
• 1094 Car Pooling
• 1095 Find in Mountain Array
• 1096 Brace Expansion II
• 1097 Game Play Analysis V
• 1098 Unpopular Books
• 1099 Two Sum Less Than K
• 1100 Find K-Length Substrings With No Repeated Characters
• 1101 The Earliest Moment When Everyone Become Friends
• 1102 Path With Maximum Minimum Value
• 1103 Distribute Candies to People
• 1104 Path In Zigzag Labelled Binary Tree
• 1105 Filling Bookcase Shelves
• 1106 Parsing A Boolean Expression
• 1107 New Users Daily Count
• 1108 Defanging an IP Address
• 1109 Corporate Flight Bookings
• 1110 Delete Nodes And Return Forest
• 1111 Maximum Nesting Depth of Two Valid Parentheses Strings
• 1112 Highest Grade For Each Student
• 1113 Reported Posts
• 1114 Print in Order
• 1115 Print FooBar Alternately
• 1116 Print Zero Even Odd
• 1117 Building H2O
• 1118 Number of Days in a Month
• 1119 Remove Vowels from a String
• 1120 Maximum Average Subtree
• 1121 Divide Array Into Increasing Sequences
• 1122 Relative Sort Array
• 1123 Lowest Common Ancestor of Deepest Leaves
• 1124 Longest Well-Performing Interval
• 1125 Smallest Sufficient Team
• 1126 Active Businesses
• 1127 User Purchase Platform
• 1128 Number of Equivalent Domino Pairs
• 1129 Shortest Path with Alternating Colors
• 1130 Minimum Cost Tree From Leaf Values
• 1131 Maximum of Absolute Value Expression
• 1132 Reported Posts II
• 1133 Largest Unique Number
• 1134 Armstrong Number
• 1135 Connecting Cities With Minimum Cost
• 1136 Parallel Courses
• 1137 N-th Tribonacci Number
• 1138 Alphabet Board Path
• 1139 Largest 1-Bordered Square
• 1140 Stone Game II
• 1141 User Activity for the Past 30 Days I
• 1142 User Activity for the Past 30 Days II
• 1143 Longest Common Subsequence
• 1144 Decrease Elements To Make Array Zigzag
• 1145 Binary Tree Coloring Game
• 1146 Snapshot Array
• 1147 Longest Chunked Palindrome Decomposition
• 1148 Article Views I
• 1149 Article Views II
• 1150 Check If a Number Is Majority Element in a Sorted Array
• 1151 Minimum Swaps to Group All 1's Together
• 1152 Analyze User Website Visit Pattern
• 1153 String Transforms Into Another String
• 1154 Day of the Year
• 1155 Number of Dice Rolls With Target Sum
• 1156 Swap For Longest Repeated Character Substring
• 1157 Online Majority Element In Subarray
• 1158 Market Analysis I
• 1159 Market Analysis II
• 1160 Find Words That Can Be Formed by Characters
• 1161 Maximum Level Sum of a Binary Tree
• 1162 As Far from Land as Possible
• 1163 Last Substring in Lexicographical Order
• 1164 Product Price at a Given Date
• 1165 Single-Row Keyboard
• 1166 Design File System
• 1167 Minimum Cost to Connect Sticks
• 1168 Optimize Water Distribution in a Village
• 1169 Invalid Transactions
• 1170 Compare Strings by Frequency of the Smallest Character
• 1171 Remove Zero Sum Consecutive Nodes from Linked List
• 1172 Dinner Plate Stacks
• 1173 Immediate Food Delivery I
• 1174 Immediate Food Delivery II
• 1175 Prime Arrangements
• 1176 Diet Plan Performance
• 1177 Can Make Palindrome from Substring
• 1178 Number of Valid Words for Each Puzzle
• 1179 Reformat Department Table
• 1180 Count Substrings with Only One Distinct Letter
• 1181 Before and After Puzzle
• 1182 Shortest Distance to Target Color
• 1183 Maximum Number of Ones
• 1184 Distance Between Bus Stops
• 1185 Day of the Week
• 1186 Maximum Subarray Sum with One Deletion
• 1187 Make Array Strictly Increasing
• 1188 Design Bounded Blocking Queue
• 1189 Maximum Number of Balloons
• 1190 Reverse Substrings Between Each Pair of Parentheses
• 1191 K-Concatenation Maximum Sum
• 1192 Critical Connections in a Network
• 1193 Monthly Transactions I
• 1194 Tournament Winners
• 1195 Fizz Buzz Multithreaded
• 1196 How Many Apples Can You Put into the Basket
• 1197 Minimum Knight Moves
• 1198 Find Smallest Common Element in All Rows
• 1199 Minimum Time to Build Blocks
• 1200 Minimum Absolute Difference
• 1201 Ugly Number III
• 1202 Smallest String With Swaps
• 1203 Sort Items by Groups Respecting Dependencies
• 1204 Last Person to Fit in the Elevator
• 1205 Monthly Transactions II
• 1206 Design Skiplist
• 1207 Unique Number of Occurrences
• 1208 Get Equal Substrings Within Budget
• 1209 Remove All Adjacent Duplicates in String II
• 1210 Minimum Moves to Reach Target with Rotations
• 1211 Queries Quality and Percentage
• 1212 Team Scores in Football Tournament
• 1213 Intersection of Three Sorted Arrays
• 1214 Two Sum BSTs
• 1215 Stepping Numbers
• 1216 Valid Palindrome III
• 1217 Play with Chips
• 1218 Longest Arithmetic Subsequence of Given Difference
• 1219 Path with Maximum Gold
• 1220 Count Vowels Permutation
• 1221 Split a String in Balanced Strings
• 1222 Queens That Can Attack the King
• 1223 Dice Roll Simulation
• 1224 Maximum Equal Frequency
• 1225 Report Contiguous Dates
• 1226 The Dining Philosophers
• 1227 Airplane Seat Assignment Probability
• 1228 Missing Number In Arithmetic Progression
• 1229 Meeting Scheduler
• 1230 Toss Strange Coins
• 1231 Divide Chocolate
• 1232 Check If It Is a Straight Line
• 1233 Remove Sub-Folders from the Filesystem
• 1234 Replace the Substring for Balanced String
• 1235 Maximum Profit in Job Scheduling
• 1236 Web Crawler
• 1237 Find Positive Integer Solution for a Given Equation
• 1238 Circular Permutation in Binary Representation
• 1239 Maximum Length of a Concatenated String with Unique Characters
• 1240 Tiling a Rectangle with the Fewest Squares
• 1241 Number of Comments per Post New
• 1242
• 1243
• 1243 Array Transformation
• 1244 Design A Leaderboard
• 1245 Tree Diameter
• 1246 Palindrome Removal
• 1247 Minimum Swaps to Make Strings Equal
• 1248 Count Number of Nice Subarrays
• 1249 Minimum Remove to Make Valid Parentheses
• 1250 Check If It Is a Good Array