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Welcome to Subscribe On Youtube: ID Title Difficulty Lock 1 Two Sum Easy Normal 2 Add Two Numbers Medium Normal 3 Longest Substring Without Repeating Characters Medium Normal 4 Median of Two Sorted Arrays Hard Normal 5 Longest Palindromic Substring Medium Normal 6 ZigZag Conversion Medium Normal 7 Reverse Integer Easy Normal 8 String to Integer (atoi) Medium Normal 9 Palindrome Number Easy Normal 10 Regular Expression Matching Hard Normal 11 Container With Most Water Medium Normal 12 Integer to Roman Medium Normal 13 Roman to Integer Easy Normal 14 Longest Common Prefix Easy Normal 15 3Sum Medium Normal 16 3Sum Closest Medium Normal 17 Letter Combinations of a Phone Number Medium Normal 18 4Sum Medium Normal 19 Remove Nth Node From End of List Medium Normal 20 Valid Parentheses Easy Normal 21 Merge Two Sorted Lists Easy Normal 22 Generate Parentheses Medium Normal 23 Merge k Sorted Lists Hard Normal 24 Swap Nodes in Pairs Medium Normal 25 Reverse Nodes in k-Group Hard Normal 26 Remove Duplicates from Sorted Array Easy Normal 27 Remove Element Easy Normal 28 Implement strStr() Easy Normal 29 Divide Two Integers Medium Normal 30 Substring with Concatenation of All Words Hard Normal 31 Next Permutation Medium Normal 32 Longest Valid Parentheses Hard Normal 33 Search in Rotated Sorted Array Medium Normal 34 Find First and Last Position of Element in Sorted Array Medium Normal 35 Search Insert Position Easy Normal 36 Valid Sudoku Medium Normal 37 Sudoku Solver Hard Normal 38 Count and Say Easy Normal 39 Combination Sum Medium Normal 40 Combination Sum II Medium Normal 41 First Missing Positive Hard Normal 42 Trapping Rain Water Hard Normal 43 Multiply Strings Medium Normal 44 Wildcard Matching Hard Normal 45 Jump Game II Hard Normal 46 Permutations Medium Normal 47 Permutations II Medium Normal 48 Rotate Image Medium Normal 49 Group Anagrams Medium Normal 50 Pow(x, n) Medium Normal 51 N-Queens Hard Normal 52 N-Queens II Hard Normal 53 Maximum Subarray Easy Normal 54 Spiral Matrix Medium Normal 55 Jump Game Medium Normal 56 Merge Intervals Medium Normal 57 Insert Interval Hard Normal 58 Length of Last Word Easy Normal 59 Spiral Matrix II Medium Normal 60 Permutation Sequence Medium Normal 61 Rotate List Medium Normal 62 Unique Paths Medium Normal 63 Unique Paths II Medium Normal 64 Minimum Path Sum Medium Normal 65 Valid Number Hard Normal 66 Plus One Easy Normal 67 Add Binary Easy Normal 68 Text Justification Hard Normal 69 Sqrt(x) Easy Normal 70 Climbing Stairs Easy Normal 71 Simplify Path Medium Normal 72 Edit Distance Hard Normal 73 Set Matrix Zeroes Medium Normal 74 Search a 2D Matrix Medium Normal 75 Sort Colors Medium Normal 76 Minimum Window Substring Hard Normal 77 Combinations Medium Normal 78 Subsets Medium Normal 79 Word Search Medium Normal 80 Remove Duplicates from Sorted Array II Medium Normal 81 Search in Rotated Sorted Array II Medium Normal 82 Remove Duplicates from Sorted List II Medium Normal 83 Remove Duplicates from Sorted List Easy Normal 84 Largest Rectangle in Histogram Hard Normal 85 Maximal Rectangle Hard Normal 86 Partition List Medium Normal 87 Scramble String Hard Normal 88 Merge Sorted Array Easy Normal 89 Gray Code Medium Normal 90 Subsets II Medium Normal 91 Decode Ways Medium Normal 92 Reverse Linked List II Medium Normal 93 Restore IP Addresses Medium Normal 94 Binary Tree Inorder Traversal Medium Normal 95 Unique Binary Search Trees II Medium Normal 96 Unique Binary Search Trees Medium Normal 97 Interleaving String Hard Normal 98 Validate Binary Search Tree Medium Normal 99 Recover Binary Search Tree Hard Normal 100 Same Tree Easy Normal 101 Symmetric Tree Easy Normal 102 Binary Tree Level Order Traversal Medium Normal 103 Binary Tree Zigzag Level Order Traversal Medium Normal 104 Maximum Depth of Binary Tree Easy Normal 105 Construct Binary Tree from Preorder and Inorder Traversal Medium Normal 106 Construct Binary Tree from Inorder and Postorder Traversal Medium Normal 107 Binary Tree Level Order Traversal II Easy Normal 108 Convert Sorted Array to Binary Search Tree Easy Normal 109 Convert Sorted List to Binary Search Tree Medium Normal 110 Balanced Binary Tree Easy Normal 111 Minimum Depth of Binary Tree Easy Normal 112 Path Sum Easy Normal 113 Path Sum II Medium Normal 114 Flatten Binary Tree to Linked List Medium Normal 115 Distinct Subsequences Hard Normal 116 Populating Next Right Pointers in Each Node Medium Normal 117 Populating Next Right Pointers in Each Node II Medium Normal 118 Pascal's Triangle Easy Normal 119 Pascal's Triangle II Easy Normal 120 Triangle Medium Normal 121 Best Time to Buy and Sell Stock Easy Normal 122 Best Time to Buy and Sell Stock II Easy Normal 123 Best Time to Buy and Sell Stock III Hard Normal 124 Binary Tree Maximum Path Sum Hard Normal 125 Valid Palindrome Easy Normal 126 Word Ladder II Hard Normal 127 Word Ladder Medium Normal 128 Longest Consecutive Sequence Hard Normal 129 Sum Root to Leaf Numbers Medium Normal 130 Surrounded Regions Medium Normal 131 Palindrome Partitioning Medium Normal 132 Palindrome Partitioning II Hard Normal 133 Clone Graph Medium Normal 134 Gas Station Medium Normal 135 Candy Hard Normal 136 Single Number Easy Normal 137 Single Number II Medium Normal 138 Copy List with Random Pointer Medium Normal 139 Word Break Medium Normal 140 Word Break II Hard Normal 141 Linked List Cycle Easy Normal 142 Linked List Cycle II Medium Normal 143 Reorder List Medium Normal 144 Binary Tree Preorder Traversal Medium Normal 145 Binary Tree Postorder Traversal Hard Normal 146 LRU Cache Medium Normal 147 Insertion Sort List Medium Normal 148 Sort List Medium Normal 149 Max Points on a Line Hard Normal 150 Evaluate Reverse Polish Notation Medium Normal 151 Reverse Words in a String Medium Normal 152 Maximum Product Subarray Medium Normal 153 Find Minimum in Rotated Sorted Array Medium Normal 154 Find Minimum in Rotated Sorted Array II Hard Normal 155 Min Stack Easy Normal 156 Binary Tree Upside Down Medium Prime 157 Read N Characters Given Read4 Easy Prime 158 Read N Characters Given Read4 II - Call multiple times Hard Prime 159 Longest Substring with At Most Two Distinct Characters Medium Prime 160 Intersection of Two Linked Lists Easy Normal 161 One Edit Distance Medium Prime 162 Find Peak Element Medium Normal 163 Missing Ranges Medium Prime 164 Maximum Gap Hard Normal 165 Compare Version Numbers Medium Normal 166 Fraction to Recurring Decimal Medium Normal 167 Two Sum II - Input array is sorted Easy Normal 168 Excel Sheet Column Title Easy Normal 169 Majority Element Easy Normal 170 Two Sum III - Data structure design Easy Prime 171 Excel Sheet Column Number Easy Normal 172 Factorial Trailing Zeroes Easy Normal 173 Binary Search Tree Iterator Medium Normal 174 Dungeon Game Hard Normal 175 Combine Two Tables Easy Normal 176 Second Highest Salary Easy Normal 177 Nth Highest Salary Medium Normal 178 Rank Scores Medium Normal 179 Largest Number Medium Normal 180 Consecutive Numbers Medium Normal 181 Employees Earning More Than Their Managers Easy Normal 182 Duplicate Emails Easy Normal 183 Customers Who Never Order Easy Normal 184 Department Highest Salary Medium Normal 185 Department Top Three Salaries Hard Normal 186 Reverse Words in a String II Medium Prime 187 Repeated DNA Sequences Medium Normal 188 Best Time to Buy and Sell Stock IV Hard Normal 189 Rotate Array Easy Normal 190 Reverse Bits Easy Normal 191 Number of 1 Bits Easy Normal 192 Word Frequency Medium Normal 193 Valid Phone Numbers Easy Normal 194 Transpose File Medium Normal 195 Tenth Line Easy Normal 196 Delete Duplicate Emails Easy Normal 197 Rising Temperature Easy Normal 198 House Robber Easy Normal 199 Binary Tree Right Side View Medium Normal 200 Number of Islands Medium Normal 201 Bitwise AND of Numbers Range Medium Normal 202 Happy Number Easy Normal 203 Remove Linked List Elements Easy Normal 204 Count Primes Easy Normal 205 Isomorphic Strings Easy Normal 206 Reverse Linked List Easy Normal 207 Course Schedule Medium Normal 208 Implement Trie (Prefix Tree) Medium Normal 209 Minimum Size Subarray Sum Medium Normal 210 Course Schedule II Medium Normal 211 Add and Search Word - Data structure design Medium Normal 212 Word Search II Hard Normal 213 House Robber II Medium Normal 214 Shortest Palindrome Hard Normal 215 Kth Largest Element in an Array Medium Normal 216 Combination Sum III Medium Normal 217 Contains Duplicate Easy Normal 218 The Skyline Problem Hard Normal 219 Contains Duplicate II Easy Normal 220 Contains Duplicate III Medium Normal 221 Maximal Square Medium Normal 222 Count Complete Tree Nodes Medium Normal 223 Rectangle Area Medium Normal 224 Basic Calculator Hard Normal 225 Implement Stack using Queues Easy Normal 226 Invert Binary Tree Easy Normal 227 Basic Calculator II Medium Normal 228 Summary Ranges Medium Normal 229 Majority Element II Medium Normal 230 Kth Smallest Element in a BST Medium Normal 231 Power of Two Easy Normal 232 Implement Queue using Stacks Easy Normal 233 Number of Digit One Hard Normal 234 Palindrome Linked List Easy Normal 235 Lowest Common Ancestor of a Binary Search Tree Easy Normal 236 Lowest Common Ancestor of a Binary Tree Medium Normal 237 Delete Node in a Linked List Easy Normal 238 Product of Array Except Self Medium Normal 239 Sliding Window Maximum Hard Normal 240 Search a 2D Matrix II Medium Normal 241 Different Ways to Add Parentheses Medium Normal 242 Valid Anagram Easy Normal 243 Shortest Word Distance Easy Prime 244 Shortest Word Distance II Medium Prime 245 Shortest Word Distance III Medium Prime 246 Strobogrammatic Number Easy Prime 247 Strobogrammatic Number II Medium Prime 248 Strobogrammatic Number III Hard Prime 249 Group Shifted Strings Medium Prime 250 Count Univalue Subtrees Medium Prime 251 Flatten 2D Vector Medium Prime 252 Meeting Rooms Easy Prime 253 Meeting Rooms II Medium Prime 254 Factor Combinations Medium Prime 255 Verify Preorder Sequence in Binary Search Tree Medium Prime 256 Paint House Easy Prime 257 Binary Tree Paths Easy Normal 258 Add Digits Easy Normal 259 3Sum Smaller Medium Prime 260 Single Number III Medium Normal 261 Graph Valid Tree Medium Prime 262 Trips and Users Hard Normal 263 Ugly Number Easy Normal 264 Ugly Number II Medium Normal 265 Paint House II Hard Prime 266 Palindrome Permutation Easy Prime 267 Palindrome Permutation II Medium Prime 268 Missing Number Easy Normal 269 Alien Dictionary Hard Prime 270 Closest Binary Search Tree Value Easy Prime 271 Encode and Decode Strings Medium Prime 272 Closest Binary Search Tree Value II Hard Prime 273 Integer to English Words Hard Normal 274 H-Index Medium Normal 275 H-Index II Medium Normal 276 Paint Fence Easy Prime 277 Find the Celebrity Medium Prime 278 First Bad Version Easy Normal 279 Perfect Squares Medium Normal 280 Wiggle Sort Medium Prime 281 Zigzag Iterator Medium Prime 282 Expression Add Operators Hard Normal 283 Move Zeroes Easy Normal 284 Peeking Iterator Medium Normal 285 Inorder Successor in BST Medium Prime 286 Walls and Gates Medium Prime 287 Find the Duplicate Number Medium Normal 288 Unique Word Abbreviation Medium Prime 289 Game of Life Medium Normal 290 Word Pattern Easy Normal 291 Word Pattern II Hard Prime 292 Nim Game Easy Normal 293 Flip Game Easy Prime 294 Flip Game II Medium Prime 295 Find Median from Data Stream Hard Normal 296 Best Meeting Point Hard Prime 297 Serialize and Deserialize Binary Tree Hard Normal 298 Binary Tree Longest Consecutive Sequence Medium Prime 299 Bulls and Cows Easy Normal 300 Longest Increasing Subsequence Medium Normal 301 Remove Invalid Parentheses Hard Normal 302 Smallest Rectangle Enclosing Black Pixels Hard Prime 303 Range Sum Query - Immutable Easy Normal 304 Range Sum Query 2D - Immutable Medium Normal 305 Number of Islands II Hard Prime 306 Additive Number Medium Normal 307 Range Sum Query - Mutable Medium Normal 308 Range Sum Query 2D - Mutable Hard Prime 309 Best Time to Buy and Sell Stock with Cooldown Medium Normal 310 Minimum Height Trees Medium Normal 311 Sparse Matrix Multiplication Medium Prime 312 Burst Balloons Hard Normal 313 Super Ugly Number Medium Normal 314 Binary Tree Vertical Order Traversal Medium Prime 315 Count of Smaller Numbers After Self Hard Normal 316 Remove Duplicate Letters Hard Normal 317 Shortest Distance from All Buildings Hard Prime 318 Maximum Product of Word Lengths Medium Normal 319 Bulb Switcher Medium Normal 320 Generalized Abbreviation Medium Prime 321 Create Maximum Number Hard Normal 322 Coin Change Medium Normal 323 Number of Connected Components in an Undirected Graph Medium Prime 324 Wiggle Sort II Medium Normal 325 Maximum Size Subarray Sum Equals k Medium Prime 326 Power of Three Easy Normal 327 Count of Range Sum Hard Normal 328 Odd Even Linked List Medium Normal 329 Longest Increasing Path in a Matrix Hard Normal 330 Patching Array Hard Normal 331 Verify Preorder Serialization of a Binary Tree Medium Normal 332 Reconstruct Itinerary Medium Normal 333 Largest BST Subtree Medium Prime 334 Increasing Triplet Subsequence Medium Normal 335 Self Crossing Hard Normal 336 Palindrome Pairs Hard Normal 337 House Robber III Medium Normal 338 Counting Bits Medium Normal 339 Nested List Weight Sum Easy Prime 340 Longest Substring with At Most K Distinct Characters Hard Prime 341 Flatten Nested List Iterator Medium Normal 342 Power of Four Easy Normal 343 Integer Break Medium Normal 344 Reverse String Easy Normal 345 Reverse Vowels of a String Easy Normal 346 Moving Average from Data Stream Easy Prime 347 Top K Frequent Elements Medium Normal 348 Design Tic-Tac-Toe Medium Prime 349 Intersection of Two Arrays Easy Normal 350 Intersection of Two Arrays II Easy Normal 351 Android Unlock Patterns Medium Prime 352 Data Stream as Disjoint Intervals Hard Normal 353 Design Snake Game Medium Prime 354 Russian Doll Envelopes Hard Normal 355 Design Twitter Medium Normal 356 Line Reflection Medium Prime 357 Count Numbers with Unique Digits Medium Normal 358 Rearrange String k Distance Apart Hard Prime 359 Logger Rate Limiter Easy Prime 360 Sort Transformed Array Medium Prime 361 Bomb Enemy Medium Prime 362 Design Hit Counter Medium Prime 363 Max Sum of Rectangle No Larger Than K Hard Normal 364 Nested List Weight Sum II Medium Prime 365 Water and Jug Problem Medium Normal 366 Find Leaves of Binary Tree Medium Prime 367 Valid Perfect Square Easy Normal 368 Largest Divisible Subset Medium Normal 369 Plus One Linked List Medium Prime 370 Range Addition Medium Prime 371 Sum of Two Integers Easy Normal 372 Super Pow Medium Normal 373 Find K Pairs with Smallest Sums Medium Normal 374 Guess Number Higher or Lower Easy Normal 375 Guess Number Higher or Lower II Medium Normal 376 Wiggle Subsequence Medium Normal 377 Combination Sum IV Medium Normal 378 Kth Smallest Element in a Sorted Matrix Medium Normal 379 Design Phone Directory Medium Prime 380 Insert Delete GetRandom O(1) Medium Normal 381 Insert Delete GetRandom O(1) - Duplicates allowed Hard Normal 382 Linked List Random Node Medium Normal 383 Ransom Note Easy Normal 384 Shuffle an Array Medium Normal 385 Mini Parser Medium Normal 386 Lexicographical Numbers Medium Normal 387 First Unique Character in a String Easy Normal 388 Longest Absolute File Path Medium Normal 389 Find the Difference Easy Normal 390 Elimination Game Medium Normal 391 Perfect Rectangle Hard Normal 392 Is Subsequence Easy Normal 393 UTF-8 Validation Medium Normal 394 Decode String Medium Normal 395 Longest Substring with At Least K Repeating Characters Medium Normal 396 Rotate Function Medium Normal 397 Integer Replacement Medium Normal 398 Random Pick Index Medium Normal 399 Evaluate Division Medium Normal 400 Nth Digit Medium Normal 401 Binary Watch Easy Normal 402 Remove K Digits Medium Normal 403 Frog Jump Hard Normal 404 Sum of Left Leaves Easy Normal 405 Convert a Number to Hexadecimal Easy Normal 406 Queue Reconstruction by Height Medium Normal 407 Trapping Rain Water II Hard Normal 408 Valid Word Abbreviation Easy Prime 409 Longest Palindrome Easy Normal 410 Split Array Largest Sum Hard Normal 411 Minimum Unique Word Abbreviation Hard Prime 412 Fizz Buzz Easy Normal 413 Arithmetic Slices Medium Normal 414 Third Maximum Number Easy Normal 415 Add Strings Easy Normal 416 Partition Equal Subset Sum Medium Normal 417 Pacific Atlantic Water Flow Medium Normal 418 Sentence Screen Fitting Medium Prime 419 Battleships in a Board Medium Normal 420 Strong Password Checker Hard Normal 421 Maximum XOR of Two Numbers in an Array Medium Normal 422 Valid Word Square Easy Prime 423 Reconstruct Original Digits from English Medium Normal 424 Longest Repeating Character Replacement Medium Normal 425 Word Squares Hard Prime 426 Convert Binary Search Tree to Sorted Doubly Linked List Medium Prime 427 Construct Quad Tree Medium Normal 428 Serialize and Deserialize N-ary Tree Hard Prime 429 N-ary Tree Level Order Traversal Medium Normal 430 Flatten a Multilevel Doubly Linked List Medium Normal 431 Encode N-ary Tree to Binary Tree Hard Prime 432 All O`one Data Structure Hard Normal 433 Minimum Genetic Mutation Medium Normal 434 Number of Segments in a String Easy Normal 435 Non-overlapping Intervals Medium Normal 436 Find Right Interval Medium Normal 437 Path Sum III Easy Normal 438 Find All Anagrams in a String Medium Normal 439 Ternary Expression Parser Medium Prime 440 K-th Smallest in Lexicographical Order Hard Normal 441 Arranging Coins Easy Normal 442 Find All Duplicates in an Array Medium Normal 443 String Compression Easy Normal 444 Sequence Reconstruction Medium Prime 445 Add Two Numbers II Medium Normal 446 Arithmetic Slices II - Subsequence Hard Normal 447 Number of Boomerangs Easy Normal 448 Find All Numbers Disappeared in an Array Easy Normal 449 Serialize and Deserialize BST Medium Normal 450 Delete Node in a BST Medium Normal 451 Sort Characters By Frequency Medium Normal 452 Minimum Number of Arrows to Burst Balloons Medium Normal 453 Minimum Moves to Equal Array Elements Easy Normal 454 4Sum II Medium Normal 455 Assign Cookies Easy Normal 456 132 Pattern Medium Normal 457 Circular Array Loop Medium Normal 458 Poor Pigs Hard Normal 459 Repeated Substring Pattern Easy Normal 460 LFU Cache Hard Normal 461 Hamming Distance Easy Normal 462 Minimum Moves to Equal Array Elements II Medium Normal 463 Island Perimeter Easy Normal 464 Can I Win Medium Normal 465 Optimal Account Balancing Hard Prime 466 Count The Repetitions Hard Normal 467 Unique Substrings in Wraparound String Medium Normal 468 Validate IP Address Medium Normal 469 Convex Polygon Medium Prime 470 Implement Rand10() Using Rand7() Medium Normal 471 Encode String with Shortest Length Hard Prime 472 Concatenated Words Hard Normal 473 Matchsticks to Square Medium Normal 474 Ones and Zeroes Medium Normal 475 Heaters Easy Normal 476 Number Complement Easy Normal 477 Total Hamming Distance Medium Normal 478 Generate Random Point in a Circle Medium Normal 479 Largest Palindrome Product Hard Normal 480 Sliding Window Median Hard Normal 481 Magical String Medium Normal 482 License Key Formatting Easy Normal 483 Smallest Good Base Hard Normal 484 Find Permutation Medium Prime 485 Max Consecutive Ones Easy Normal 486 Predict the Winner Medium Normal 487 Max Consecutive Ones II Medium Prime 488 Zuma Game Hard Normal 489 Robot Room Cleaner Hard Prime 490 The Maze Medium Prime 491 Increasing Subsequences Medium Normal 492 Construct the Rectangle Easy Normal 493 Reverse Pairs Hard Normal 494 Target Sum Medium Normal 495 Teemo Attacking Medium Normal 496 Next Greater Element I Easy Normal 497 Random Point in Non-overlapping Rectangles Medium Normal 498 Diagonal Traverse Medium Normal 499 The Maze III Hard Prime 500 Keyboard Row Easy Normal 501 Find Mode in Binary Search Tree Easy Normal 502 IPO Hard Normal 503 Next Greater Element II Medium Normal 504 Base 7 Easy Normal 505 The Maze II Medium Prime 506 Relative Ranks Easy Normal 507 Perfect Number Easy Normal 508 Most Frequent Subtree Sum Medium Normal 509 Fibonacci Number Easy Normal 510 Inorder Successor in BST II Medium Prime 511 Game Play Analysis I Easy Prime 512 Game Play Analysis II Easy Prime 513 Find Bottom Left Tree Value Medium Normal 514 Freedom Trail Hard Normal 515 Find Largest Value in Each Tree Row Medium Normal 516 Longest Palindromic Subsequence Medium Normal 517 Super Washing Machines Hard Normal 518 Coin Change 2 Medium Normal 519 Random Flip Matrix Medium Normal 520 Detect Capital Easy Normal 521 Longest Uncommon Subsequence I Easy Normal 522 Longest Uncommon Subsequence II Medium Normal 523 Continuous Subarray Sum Medium Normal 524 Longest Word in Dictionary through Deleting Medium Normal 525 Contiguous Array Medium Normal 526 Beautiful Arrangement Medium Normal 527 Word Abbreviation Hard Prime 528 Random Pick with Weight Medium Normal 529 Minesweeper Medium Normal 530 Minimum Absolute Difference in BST Easy Normal 531 Lonely Pixel I Medium Prime 532 K-diff Pairs in an Array Easy Normal 533 Lonely Pixel II Medium Prime 534 Game Play Analysis III Medium Prime 535 Encode and Decode TinyURL Medium Normal 536 Construct Binary Tree from String Medium Prime 537 Complex Number Multiplication Medium Normal 538 Convert BST to Greater Tree Easy Normal 539 Minimum Time Difference Medium Normal 540 Single Element in a Sorted Array Medium Normal 541 Reverse String II Easy Normal 542 01 Matrix Medium Normal 543 Diameter of Binary Tree Easy Normal 544 Output Contest Matches Medium Prime 545 Boundary of Binary Tree Medium Prime 546 Remove Boxes Hard Normal 547 Friend Circles Medium Normal 548 Split Array with Equal Sum Medium Prime 549 Binary Tree Longest Consecutive Sequence II Medium Prime 550 Game Play Analysis IV Medium Prime 551 Student Attendance Record I Easy Normal 552 Student Attendance Record II Hard Normal 553 Optimal Division Medium Normal 554 Brick Wall Medium Normal 555 Split Concatenated Strings Medium Prime 556 Next Greater Element III Medium Normal 557 Reverse Words in a String III Easy Normal 558 Quad Tree Intersection Medium Normal 559 Maximum Depth of N-ary Tree Easy Normal 560 Subarray Sum Equals K Medium Normal 561 Array Partition I Easy Normal 562 Longest Line of Consecutive One in Matrix Medium Prime 563 Binary Tree Tilt Easy Normal 564 Find the Closest Palindrome Hard Normal 565 Array Nesting Medium Normal 566 Reshape the Matrix Easy Normal 567 Permutation in String Medium Normal 568 Maximum Vacation Days Hard Prime 569 Median Employee Salary Hard Prime 570 Managers with at Least 5 Direct Reports Medium Prime 571 Find Median Given Frequency of Numbers Hard Prime 572 Subtree of Another Tree Easy Normal 573 Squirrel Simulation Medium Prime 574 Winning Candidate Medium Prime 575 Distribute Candies Easy Normal 576 Out of Boundary Paths Medium Normal 577 Employee Bonus Easy Prime 578 Get Highest Answer Rate Question Medium Prime 579 Find Cumulative Salary of an Employee Hard Prime 580 Count Student Number in Departments Medium Prime 581 Shortest Unsorted Continuous Subarray Easy Normal 582 Kill Process Medium Prime 583 Delete Operation for Two Strings Medium Normal 584 Find Customer Referee Easy Prime 585 Investments in 2016 Medium Prime 586 Customer Placing the Largest Number of Orders Easy Prime 587 Erect the Fence Hard Normal 588 Design In-Memory File System Hard Prime 589 N-ary Tree Preorder Traversal Easy Normal 590 N-ary Tree Postorder Traversal Easy Normal 591 Tag Validator Hard Normal 592 Fraction Addition and Subtraction Medium Normal 593 Valid Square Medium Normal 594 Longest Harmonious Subsequence Easy Normal 595 Big Countries Easy Normal 596 Classes More Than 5 Students Easy Normal 597 Friend Requests I: Overall Acceptance Rate Easy Prime 598 Range Addition II Easy Normal 599 Minimum Index Sum of Two Lists Easy Normal 600 Non-negative Integers without Consecutive Ones Hard Normal 601 Human Traffic of Stadium Hard Normal 602 Friend Requests II: Who Has the Most Friends Medium Prime 603 Consecutive Available Seats Easy Prime 604 Design Compressed String Iterator Easy Prime 605 Can Place Flowers Easy Normal 606 Construct String from Binary Tree Easy Normal 607 Sales Person Easy Prime 608 Tree Node Medium Prime 609 Find Duplicate File in System Medium Normal 610 Triangle Judgement Easy Prime 611 Valid Triangle Number Medium Normal 612 Shortest Distance in a Plane Medium Prime 613 Shortest Distance in a Line Easy Prime 614 Second Degree Follower Medium Prime 615 Average Salary: Departments VS Company Hard Prime 616 Add Bold Tag in String Medium Prime 617 Merge Two Binary Trees Easy Normal 618 Students Report By Geography Hard Prime 619 Biggest Single Number Easy Prime 620 Not Boring Movies Easy Normal 621 Task Scheduler Medium Normal 622 Design Circular Queue Medium Normal 623 Add One Row to Tree Medium Normal 624 Maximum Distance in Arrays Easy Prime 625 Minimum Factorization Medium Prime 626 Exchange Seats Medium Normal 627 Swap Salary 628 Maximum Product of Three Numbers Easy Normal 629 K Inverse Pairs Array Hard Normal 630 Course Schedule III Hard Normal 631 Design Excel Sum Formula Hard Prime 632 Smallest Range Covering Elements from K Lists Hard Normal 633 Sum of Square Numbers Easy Normal 634 Find the Derangement of An Array Medium Prime 635 Design Log Storage System Medium Prime 636 Exclusive Time of Functions Medium Normal 637 Average of Levels in Binary Tree Easy Normal 638 Shopping Offers Medium Normal 639 Decode Ways II Hard Normal 640 Solve the Equation Medium Normal 641 Design Circular Deque Medium Normal 642 Design Search Autocomplete System Hard Prime 643 Maximum Average Subarray I Easy Normal 644 Maximum Average Subarray II Hard Prime 645 Set Mismatch Easy Normal 646 Maximum Length of Pair Chain Medium Normal 647 Palindromic Substrings Medium Normal 648 Replace Words Medium Normal 649 Dota2 Senate Medium Normal 650 2 Keys Keyboard Medium Normal 651 4 Keys Keyboard Medium Prime 652 Find Duplicate Subtrees Medium Normal 653 Two Sum IV - Input is a BST Easy Normal 654 Maximum Binary Tree Medium Normal 655 Print Binary Tree Medium Normal 656 Coin Path Hard Prime 657 Robot Return to Origin Easy Normal 658 Find K Closest Elements Medium Normal 659 Split Array into Consecutive Subsequences Medium Normal 660 Remove 9 Hard Prime 661 Image Smoother Easy Normal 662 Maximum Width of Binary Tree Medium Normal 663 Equal Tree Partition Medium Prime 664 Strange Printer Hard Normal 665 Non-decreasing Array Easy Normal 666 Path Sum IV Medium Prime 667 Beautiful Arrangement II Medium Normal 668 Kth Smallest Number in Multiplication Table Hard Normal 669 Trim a Binary Search Tree Easy Normal 670 Maximum Swap Medium Normal 671 Second Minimum Node In a Binary Tree Easy Normal 672 Bulb Switcher II Medium Normal 673 Number of Longest Increasing Subsequence Medium Normal 674 Longest Continuous Increasing Subsequence Easy Normal 675 Cut Off Trees for Golf Event Hard Normal 676 Implement Magic Dictionary Medium Normal 677 Map Sum Pairs Medium Normal 678 Valid Parenthesis String Medium Normal 679 24 Game Hard Normal 680 Valid Palindrome II Easy Normal 681 Next Closest Time Medium Prime 682 Baseball Game Easy Normal 683 K Empty Slots Hard Prime 684 Redundant Connection Medium Normal 685 Redundant Connection II Hard Normal 686 Repeated String Match Easy Normal 687 Longest Univalue Path Easy Normal 688 Knight Probability in Chessboard Medium Normal 689 Maximum Sum of 3 Non-Overlapping Subarrays Hard Normal 690 Employee Importance Easy Normal 691 Stickers to Spell Word Hard Normal 692 Top K Frequent Words Medium Normal 693 Binary Number with Alternating Bits Easy Normal 694 Number of Distinct Islands Medium Prime 695 Max Area of Island Medium Normal 696 Count Binary Substrings Easy Normal 697 Degree of an Array Easy Normal 698 Partition to K Equal Sum Subsets Medium Normal 699 Falling Squares Hard Normal 700 Search in a Binary Search Tree Easy Normal 701 Insert into a Binary Search Tree Medium Normal 702 Search in a Sorted Array of Unknown Size Medium Prime 703 Kth Largest Element in a Stream Easy Normal 704 Binary Search Easy Normal 705 Design HashSet Easy Normal 706 Design HashMap Easy Normal 707 Design Linked List Medium Normal 708 Insert into a Cyclic Sorted List Medium Prime 709 To Lower Case Easy Normal 710 Random Pick with Blacklist Hard Normal 711 Number of Distinct Islands II Hard Prime 712 Minimum ASCII Delete Sum for Two Strings Medium Normal 713 Subarray Product Less Than K Medium Normal 714 Best Time to Buy and Sell Stock with Transaction Fee Medium Normal 715 Range Module Hard Normal 716 Max Stack Easy Prime 717 1-bit and 2-bit Characters Easy Normal 718 Maximum Length of Repeated Subarray Medium Normal 719 Find K-th Smallest Pair Distance Hard Normal 720 Longest Word in Dictionary Easy Normal 721 Accounts Merge Medium Normal 722 Remove Comments Medium Normal 723 Candy Crush Medium Prime 724 Find Pivot Index Easy Normal 725 Split Linked List in Parts Medium Normal 726 Number of Atoms Hard Normal 727 Minimum Window Subsequence Hard Prime 728 Self Dividing Numbers Easy Normal 729 My Calendar I Medium Normal 730 Count Different Palindromic Subsequences Hard Normal 731 My Calendar II Medium Normal 732 My Calendar III Hard Normal 733 Flood Fill Easy Normal 734 Sentence Similarity Easy Prime 735 Asteroid Collision Medium Normal 736 Parse Lisp Expression Hard Normal 737 Sentence Similarity II Medium Prime 738 Monotone Increasing Digits Medium Normal 739 Daily Temperatures Medium Normal 740 Delete and Earn Medium Normal 741 Cherry Pickup Hard Normal 742 Closest Leaf in a Binary Tree Medium Prime 743 Network Delay Time Medium Normal 744 Find Smallest Letter Greater Than Target Easy Normal 745 Prefix and Suffix Search Hard Normal 746 Min Cost Climbing Stairs Easy Normal 747 Largest Number At Least Twice of Others Easy Normal 748 Shortest Completing Word Easy Normal 749 Contain Virus Hard Normal 750 Number Of Corner Rectangles Medium Prime 751 IP to CIDR Easy Prime 752 Open the Lock Medium Normal 753 Cracking the Safe Hard Normal 754 Reach a Number Medium Normal 755 Pour Water Medium Prime 756 Pyramid Transition Matrix Medium Normal 757 Set Intersection Size At Least Two Hard Normal 758 Bold Words in String Easy Prime 759 Employee Free Time Hard Prime 760 Find Anagram Mappings Easy Prime 761 Special Binary String Hard Normal 762 Prime Number of Set Bits in Binary Representation Easy Normal 763 Partition Labels Medium Normal 764 Largest Plus Sign Medium Normal 765 Couples Holding Hands Hard Normal 766 Toeplitz Matrix Easy Normal 767 Reorganize String Medium Normal 768 Max Chunks To Make Sorted II Hard Normal 769 Max Chunks To Make Sorted Medium Normal 770 Basic Calculator IV Hard Normal 771 Jewels and Stones Easy Normal 772 Basic Calculator III Hard Prime 773 Sliding Puzzle Hard Normal 774 Minimize Max Distance to Gas Station Hard Prime 775 Global and Local Inversions Medium Normal 776 Split BST Medium Prime 777 Swap Adjacent in LR String Medium Normal 778 Swim in Rising Water Hard Normal 779 K-th Symbol in Grammar Medium Normal 780 Reaching Points Hard Normal 781 Rabbits in Forest Medium Normal 782 Transform to Chessboard Hard Normal 783 Minimum Distance Between BST Nodes Easy Normal 784 Letter Case Permutation Easy Normal 785 Is Graph Bipartite? Medium Normal 786 K-th Smallest Prime Fraction Hard Normal 787 Cheapest Flights Within K Stops Medium Normal 788 Rotated Digits Easy Normal 789 Escape The Ghosts Medium Normal 790 Domino and Tromino Tiling Medium Normal 791 Custom Sort String Medium Normal 792 Number of Matching Subsequences Medium Normal 793 Preimage Size of Factorial Zeroes Function Hard Normal 794 Valid Tic-Tac-Toe State Medium Normal 795 Number of Subarrays with Bounded Maximum Medium Normal 796 Rotate String Easy Normal 797 All Paths From Source to Target Medium Normal 798 Smallest Rotation with Highest Score Hard Normal 799 Champagne Tower Medium Normal 800 Similar RGB Color Easy Prime 801 Minimum Swaps To Make Sequences Increasing Medium Normal 802 Find Eventual Safe States Medium Normal 803 Bricks Falling When Hit Hard Normal 804 Unique Morse Code Words Easy Normal 805 Split Array With Same Average Hard Normal 806 Number of Lines To Write String Easy Normal 807 Max Increase to Keep City Skyline Medium Normal 808 Soup Servings Medium Normal 809 Expressive Words Medium Normal 810 Chalkboard XOR Game Hard Normal 811 Subdomain Visit Count Easy Normal 812 Largest Triangle Area Easy Normal 813 Largest Sum of Averages Medium Normal 814 Binary Tree Pruning Medium Normal 815 Bus Routes Hard Normal 816 Ambiguous Coordinates Medium Normal 817 Linked List Components Medium Normal 818 Race Car Hard Normal 819 Most Common Word Easy Normal 820 Short Encoding of Words Medium Normal 821 Shortest Distance to a Character Easy Normal 822 Card Flipping Game Medium Normal 823 Binary Trees With Factors Medium Normal 824 Goat Latin Easy Normal 825 Friends Of Appropriate Ages Medium Normal 826 Most Profit Assigning Work Medium Normal 827 Making A Large Island Hard Normal 828 Unique Letter String Hard Normal 829 Consecutive Numbers Sum Hard Normal 830 Positions of Large Groups Easy Normal 831 Masking Personal Information Medium Normal 832 Flipping an Image Easy Normal 833 Find And Replace in String Medium Normal 834 Sum of Distances in Tree Hard Normal 835 Image Overlap Medium Normal 836 Rectangle Overlap Easy Normal 837 New 21 Game Medium Normal 838 Push Dominoes Medium Normal 839 Similar String Groups Hard Normal 840 Magic Squares In Grid Easy Normal 841 Keys and Rooms Medium Normal 842 Split Array into Fibonacci Sequence Medium Normal 843 Guess the Word Hard Normal 844 Backspace String Compare Easy Normal 845 Longest Mountain in Array Medium Normal 846 Hand of Straights Medium Normal 847 Shortest Path Visiting All Nodes Hard Normal 848 Shifting Letters Medium Normal 849 Maximize Distance to Closest Person Easy Normal 850 Rectangle Area II Hard Normal 851 Loud and Rich Medium Normal 852 Peak Index in a Mountain Array Easy Normal 853 Car Fleet Medium Normal 854 K-Similar Strings Hard Normal 855 Exam Room Medium Normal 856 Score of Parentheses Medium Normal 857 Minimum Cost to Hire K Workers Hard Normal 858 Mirror Reflection Medium Normal 859 Buddy Strings Easy Normal 860 Lemonade Change Easy Normal 861 Score After Flipping Matrix Medium Normal 862 Shortest Subarray with Sum at Least K Hard Normal 863 All Nodes Distance K in Binary Tree Medium Normal 864 Shortest Path to Get All Keys Hard Normal 865 Smallest Subtree with all the Deepest Nodes Medium Normal 866 Prime Palindrome Medium Normal 867 Transpose Matrix Easy Normal 868 Binary Gap Easy Normal 869 Reordered Power of 2 Medium Normal 870 Advantage Shuffle Medium Normal 871 Minimum Number of Refueling Stops Hard Normal 872 Leaf-Similar Trees Easy Normal 873 Length of Longest Fibonacci Subsequence Medium Normal 874 Walking Robot Simulation Easy Normal 875 Koko Eating Bananas Medium Normal 876 Middle of the Linked List Easy Normal 877 Stone Game Medium Normal 878 Nth Magical Number Hard Normal 879 Profitable Schemes Hard Normal 880 Decoded String at Index Medium Normal 881 Boats to Save People Medium Normal 882 Reachable Nodes In Subdivided Graph Hard Normal 883 Projection Area of 3D Shapes Easy Normal 884 Uncommon Words from Two Sentences Easy Normal 885 Spiral Matrix III Medium Normal 886 Possible Bipartition Medium Normal 887 Super Egg Drop Hard Normal 888 Fair Candy Swap Easy Normal 889 Construct Binary Tree from Preorder and Postorder Traversal Medium Normal 890 Find and Replace Pattern Medium Normal 891 Sum of Subsequence Widths Hard Normal 892 Surface Area of 3D Shapes Easy Normal 893 Groups of Special-Equivalent Strings Easy Normal 894 All Possible Full Binary Trees Medium Normal 895 Maximum Frequency Stack Hard Normal 896 Monotonic Array Easy Normal 897 Increasing Order Search Tree Easy Normal 898 Bitwise ORs of Subarrays Medium Normal 899 Orderly Queue Hard Normal 900 RLE Iterator Medium Normal 901 Online Stock Span Medium Normal 902 Numbers At Most N Given Digit Set Hard Normal 903 Valid Permutations for DI Sequence Hard Normal 904 Fruit Into Baskets Medium Normal 905 Sort Array By Parity Easy Normal 906 Super Palindromes Hard Normal 907 Sum of Subarray Minimums Medium Normal 908 Smallest Range I Easy Normal 909 Snakes and Ladders Medium Normal 910 Smallest Range II Medium Normal 911 Online Election Medium Normal 912 Sort an Array Medium Normal 913 Cat and Mouse Hard Normal 914 X of a Kind in a Deck of Cards Easy Normal 915 Partition Array into Disjoint Intervals Medium Normal 916 Word Subsets Medium Normal 917 Reverse Only Letters Easy Normal 918 Maximum Sum Circular Subarray Medium Normal 919 Complete Binary Tree Inserter Medium Normal 920 Number of Music Playlists Hard Normal 921 Minimum Add to Make Parentheses Valid Medium Normal 922 Sort Array By Parity II Easy Normal 923 3Sum With Multiplicity Medium Normal 924 Minimize Malware Spread Hard Normal 925 Long Pressed Name Easy Normal 926 Flip String to Monotone Increasing Medium Normal 927 Three Equal Parts Hard Normal 928 Minimize Malware Spread II Hard Normal 929 Unique Email Addresses Easy Normal 930 Binary Subarrays With Sum Medium Normal 931 Minimum Falling Path Sum Medium Normal 932 Beautiful Array Medium Normal 933 Number of Recent Calls Easy Normal 934 Shortest Bridge Medium Normal 935 Knight Dialer Medium Normal 936 Stamping The Sequence Hard Normal 937 Reorder Data in Log Files Easy Normal 938 Range Sum of BST Easy Normal 939 Minimum Area Rectangle Medium Normal 940 Distinct Subsequences II Hard Normal 941 Valid Mountain Array Easy Normal 942 DI String Match Easy Normal 943 Find the Shortest Superstring Hard Normal 944 Delete Columns to Make Sorted Easy Normal 945 Minimum Increment to Make Array Unique Medium Normal 946 Validate Stack Sequences Medium Normal 947 Most Stones Removed with Same Row or Column Medium Normal 948 Bag of Tokens Medium Normal 949 Largest Time for Given Digits Easy Normal 950 Reveal Cards In Increasing Order Medium Normal 951 Flip Equivalent Binary Trees Medium Normal 952 Largest Component Size by Common Factor Hard Normal 953 Verifying an Alien Dictionary Easy Normal 954 Array of Doubled Pairs Medium Normal 955 Delete Columns to Make Sorted II Medium Normal 956 Tallest Billboard Hard Normal 957 Prison Cells After N Days Medium Normal 958 Check Completeness of a Binary Tree Medium Normal 959 Regions Cut By Slashes Medium Normal 960 Delete Columns to Make Sorted III Hard Normal 961 N-Repeated Element in Size 2N Array Easy Normal 962 Maximum Width Ramp Medium Normal 963 Minimum Area Rectangle II Medium Normal 964 Least Operators to Express Number Hard Normal 965 Univalued Binary Tree Easy Normal 966 Vowel Spellchecker Medium Normal 967 Numbers With Same Consecutive Differences Medium Normal 968 Binary Tree Cameras Hard Normal 969 Pancake Sorting Medium Normal 970 Powerful Integers Easy Normal 971 Flip Binary Tree To Match Preorder Traversal Medium Normal 972 Equal Rational Numbers Hard Normal 973 K Closest Points to Origin Medium Normal 974 Subarray Sums Divisible by K Medium Normal 975 Odd Even Jump Hard Normal 976 Largest Perimeter Triangle Easy Normal 977 Squares of a Sorted Array Easy Normal 978 Longest Turbulent Subarray Medium Normal 979 Distribute Coins in Binary Tree Medium Normal 980 Unique Paths III Hard Normal 981 Time Based Key-Value Store Medium Normal 982 Triples with Bitwise AND Equal To Zero Hard Normal 983 Minimum Cost For Tickets Medium Normal 984 String Without AAA or BBB Medium Normal 985 Sum of Even Numbers After Queries Easy Normal 986 Interval List Intersections Medium Normal 987 Vertical Order Traversal of a Binary Tree Medium Normal 988 Smallest String Starting From Leaf Medium Normal 989 Add to Array-Form of Integer Easy Normal 990 Satisfiability of Equality Equations Medium Normal 991 Broken Calculator Medium Normal 992 Subarrays with K Different Integers Hard Normal 993 Cousins in Binary Tree Easy Normal 994 Rotting Oranges Easy Normal 995 Minimum Number of K Consecutive Bit Flips Hard Normal 996 Number of Squareful Arrays Hard Normal 997 Find the Town Judge Easy Normal 998 Maximum Binary Tree II Medium Normal 999 Available Captures for Rook Easy Normal 1000 Minimum Cost to Merge Stones Hard Normal 1001 Grid Illumination Hard Normal 1002 Find Common Characters Easy Normal 1003 Check If Word Is Valid After Substitutions Medium Normal 1004 Max Consecutive Ones III Medium Normal 1005 Maximize Sum Of Array After K Negations Easy Normal 1006 Clumsy Factorial Medium Normal 1007 Minimum Domino Rotations For Equal Row Medium Normal 1008 Construct Binary Search Tree from Preorder Traversal Medium Normal 1009 Complement of Base 10 Integer Easy Normal 1010 Pairs of Songs With Total Durations Divisible by 60 Easy Normal 1011 Capacity To Ship Packages Within D Days Medium Normal 1012 Numbers With Repeated Digits Hard Normal 1013 Partition Array Into Three Parts With Equal Sum Easy Normal 1014 Best Sightseeing Pair Medium Normal 1015 Smallest Integer Divisible by K Medium Normal 1016 Binary String With Substrings Representing 1 To N Medium Normal 1017 Convert to Base -2 Medium Normal 1018 Binary Prefix Divisible By 5 Easy Normal 1019 Next Greater Node In Linked List Medium Normal 1020 Number of Enclaves Medium Normal 1021 Remove Outermost Parentheses Easy Normal 1022 Sum of Root To Leaf Binary Numbers Easy Normal 1023 Camelcase Matching Medium Normal 1024 Video Stitching Medium Normal 1025 Divisor Game Easy Normal 1026 Maximum Difference Between Node and Ancestor Medium Normal 1027 Longest Arithmetic Sequence Medium Normal 1028 Recover a Tree From Preorder Traversal Hard Normal 1029 Two City Scheduling Easy Normal 1030 Matrix Cells in Distance Order Easy Normal 1031 Maximum Sum of Two Non-Overlapping Subarrays Medium Normal 1032 Stream of Characters Hard Normal 1033 Moving Stones Until Consecutive Easy Normal 1034 Coloring A Border Medium Normal 1035 Uncrossed Lines Medium Normal 1036 Escape a Large Maze Hard Normal 1037 Valid Boomerang Easy Normal 1038 Binary Search Tree to Greater Sum Tree Medium Normal 1039 Minimum Score Triangulation of Polygon Medium Normal 1040 Moving Stones Until Consecutive II Medium Normal 1041 Robot Bounded In Circle Medium Normal 1042 Flower Planting With No Adjacent Easy Normal 1043 Partition Array for Maximum Sum Medium Normal 1044 Longest Duplicate Substring Hard Normal 1045 Customers Who Bought All Products Medium Prime 1046 Last Stone Weight Easy Normal 1047 Remove All Adjacent Duplicates In String Easy Normal 1048 Longest String Chain Medium Normal 1049 Last Stone Weight II Medium Normal 1050 Actors and Directors Who Cooperated At Least Three Times Easy Prime 1051 Height Checker Easy Normal 1052 Grumpy Bookstore Owner Medium Normal 1053 Previous Permutation With One Swap Medium Normal 1054 Distant Barcodes Medium Normal 1055 Shortest Way to Form String Medium Prime 1056 Confusing Number Easy Prime 1057 Campus Bikes Medium Prime 1058 Minimize Rounding Error to Meet Target Medium Prime 1059 All Paths from Source Lead to Destination Medium Prime 1060 Missing Element in Sorted Array Medium Prime 1061 Lexicographically Smallest Equivalent String Medium Prime 1062 Longest Repeating Substring Medium Prime 1063 Number of Valid Subarrays Hard Prime 1064 Fixed Point Easy Prime 1065 Index Pairs of a String Easy Prime 1066 Campus Bikes II Medium Prime 1067 Digit Count in Range Hard Prime 1068 Product Sales Analysis I Easy Prime 1069 Product Sales Analysis II Easy Prime 1070 Product Sales Analysis III Medium Prime 1071 Greatest Common Divisor of Strings Easy Normal 1072 Flip Columns For Maximum Number of Equal Rows Medium Normal 1073 Adding Two Negabinary Numbers Medium Normal 1074 Number of Submatrices That Sum to Target Hard Normal 1075 Project Employees I Easy Prime 1076 Project Employees II Easy Prime 1077 Project Employees III Medium Prime 1078 Occurrences After Bigram Easy Normal 1079 Letter Tile Possibilities Medium Normal 1080 Insufficient Nodes in Root to Leaf Paths Medium Normal 1081 Smallest Subsequence of Distinct Characters Medium Normal 1082 Sales Analysis I Easy Prime 1083 Sales Analysis II Easy Prime 1084 Sales Analysis III Easy Prime 1085 Sum of Digits in the Minimum Number Easy Prime 1086 High Five Easy Prime 1087 Brace Expansion Medium Prime 1088 Confusing Number II Hard Prime 1089 Duplicate Zeros Easy Normal 1090 Largest Values From Labels Medium Normal 1091 Shortest Path in Binary Matrix Medium Normal 1092 Shortest Common Supersequence Hard Normal 1093 Statistics from a Large Sample Medium Normal 1094 Car Pooling Medium Normal 1095 Find in Mountain Array Hard Normal 1096 Brace Expansion II Hard Normal 1097 Game Play Analysis V Hard Prime 1098 Unpopular Books Medium Prime 1099 Two Sum Less Than K Easy Prime 1100 Find K-Length Substrings With No Repeated Characters Medium Prime 1101 The Earliest Moment When Everyone Become Friends Medium Prime 1102 Path With Maximum Minimum Value Medium Prime 1103 Distribute Candies to People Easy Normal 1104 Path In Zigzag Labelled Binary Tree Medium Normal 1105 Filling Bookcase Shelves Medium Normal 1106 Parsing A Boolean Expression Hard Normal 1107 New Users Daily Count Medium Prime 1108 Defanging an IP Address Easy Normal 1109 Corporate Flight Bookings Medium Normal 1110 Delete Nodes And Return Forest Medium Normal 1111 Maximum Nesting Depth of Two Valid Parentheses Strings Medium Normal 1112 Highest Grade For Each Student Medium Prime 1113 Reported Posts Easy Prime 1114 Print in Order Easy Normal 1115 Print FooBar Alternately Medium Normal 1116 Print Zero Even Odd Medium Normal 1117 Building H2O Medium Normal 1118 Number of Days in a Month Easy Prime 1119 Remove Vowels from a String Easy Prime 1120 Maximum Average Subtree Medium Prime 1121 Divide Array Into Increasing Sequences Hard Prime 1122 Relative Sort Array Easy Normal 1123 Lowest Common Ancestor of Deepest Leaves Medium Normal 1124 Longest Well-Performing Interval Medium Normal 1125 Smallest Sufficient Team Hard Normal 1126 Active Businesses Medium Prime 1127 User Purchase Platform Hard Prime 1128 Number of Equivalent Domino Pairs Easy Normal 1129 Shortest Path with Alternating Colors Medium Normal 1130 Minimum Cost Tree From Leaf Values Medium Normal 1131 Maximum of Absolute Value Expression Medium Normal 1132 Reported Posts II Medium Prime 1133 Largest Unique Number Easy Prime 1134 Armstrong Number Easy Prime 1135 Connecting Cities With Minimum Cost Medium Prime 1136 Parallel Courses Hard Prime 1137 N-th Tribonacci Number Easy Normal 1138 Alphabet Board Path Medium Normal 1139 Largest 1-Bordered Square Medium Normal 1140 Stone Game II Medium Normal 1141 User Activity for the Past 30 Days I Easy Prime 1142 User Activity for the Past 30 Days II Easy Prime 1143 Longest Common Subsequence Medium Normal 1144 Decrease Elements To Make Array Zigzag Medium Normal 1145 Binary Tree Coloring Game Medium Normal 1146 Snapshot Array Medium Normal 1147 Longest Chunked Palindrome Decomposition Hard Normal 1148 Article Views I Easy Prime 1149 Article Views II Medium Prime 1150 Check If a Number Is Majority Element in a Sorted Array Easy Prime 1151 Minimum Swaps to Group All 1's Together Medium Prime 1152 Analyze User Website Visit Pattern Medium Prime 1153 String Transforms Into Another String Hard Prime 1154 Day of the Year Easy Normal 1155 Number of Dice Rolls With Target Sum Medium Normal 1156 Swap For Longest Repeated Character Substring Medium Normal 1157 Online Majority Element In Subarray Hard Normal 1158 Market Analysis I Medium Prime 1159 Market Analysis II Hard Prime 1160 Find Words That Can Be Formed by Characters Easy Normal 1161 Maximum Level Sum of a Binary Tree Medium Normal 1162 As Far from Land as Possible Medium Normal 1163 Last Substring in Lexicographical Order Hard Normal 1164 Product Price at a Given Date Medium Prime 1165 Single-Row Keyboard Easy Prime 1166 Design File System Medium Prime 1167 Minimum Cost to Connect Sticks Medium Prime 1168 Optimize Water Distribution in a Village Hard Prime 1169 Invalid Transactions Medium Normal 1170 Compare Strings by Frequency of the Smallest Character Easy Normal 1171 Remove Zero Sum Consecutive Nodes from Linked List Medium Normal 1172 Dinner Plate Stacks Hard Normal 1173 Immediate Food Delivery I Easy Prime 1174 Immediate Food Delivery II Medium Prime 1175 Prime Arrangements Easy Normal 1176 Diet Plan Performance Easy Prime 1177 Can Make Palindrome from Substring Medium Normal 1178 Number of Valid Words for Each Puzzle Hard Normal 1179 Reformat Department Table Easy Normal 1180 Count Substrings with Only One Distinct Letter Easy Prime 1181 Before and After Puzzle Medium Prime 1182 Shortest Distance to Target Color Medium Prime 1183 Maximum Number of Ones Hard Prime 1184 Distance Between Bus Stops Easy Normal 1185 Day of the Week Easy Normal 1186 Maximum Subarray Sum with One Deletion Medium Normal 1187 Make Array Strictly Increasing Hard Normal 1188 Design Bounded Blocking Queue Medium Prime 1189 Maximum Number of Balloons Easy Normal 1190 Reverse Substrings Between Each Pair of Parentheses Medium Normal 1191 K-Concatenation Maximum Sum Medium Normal 1192 Critical Connections in a Network Hard Normal 1193 Monthly Transactions I Medium Prime 1194 Tournament Winners Hard Prime 1195 Fizz Buzz Multithreaded Medium Normal 1196 How Many Apples Can You Put into the Basket Easy Prime 1197 Minimum Knight Moves Medium Prime 1198 Find Smallest Common Element in All Rows Medium Prime 1199 Minimum Time to Build Blocks Hard Prime 1200 Minimum Absolute Difference Easy Normal 1201 Ugly Number III Medium Normal 1202 Smallest String With Swaps Medium Normal 1203 Sort Items by Groups Respecting Dependencies Hard Normal 1204 Last Person to Fit in the Elevator Medium Prime 1205 Monthly Transactions II Medium Prime 1206 Design Skiplist Hard Normal 1207 Unique Number of Occurrences Easy Normal 1208 Get Equal Substrings Within Budget Medium Normal 1209 Remove All Adjacent Duplicates in String II Medium Normal 1210 Minimum Moves to Reach Target with Rotations Hard Normal 1211 Queries Quality and Percentage Easy Prime 1212 Team Scores in Football Tournament Medium Prime 1213 Intersection of Three Sorted Arrays Easy Prime 1214 Two Sum BSTs Medium Prime 1215 Stepping Numbers Medium Prime 1216 Valid Palindrome III Hard Prime 1217 Play with Chips Easy Normal 1218 Longest Arithmetic Subsequence of Given Difference Medium Normal 1219 Path with Maximum Gold Medium Normal 1220 Count Vowels Permutation Hard Normal 1221 Split a String in Balanced Strings Easy Normal 1222 Queens That Can Attack the King Medium Normal 1223 Dice Roll Simulation Medium Normal 1224 Maximum Equal Frequency Hard Normal 1225 Report Contiguous Dates Hard Prime 1226 The Dining Philosophers Medium Normal 1227 Airplane Seat Assignment Probability Medium Normal 1228 Missing Number In Arithmetic Progression Easy Prime 1229 Meeting Scheduler Medium Prime 1230 Toss Strange Coins Medium Prime 1231 Divide Chocolate Hard Prime 1232 Check If It Is a Straight Line Easy Normal 1233 Remove Sub-Folders from the Filesystem Medium Normal 1234 Replace the Substring for Balanced String Medium Normal 1235 Maximum Profit in Job Scheduling Hard Normal 1236 Web Crawler Medium Prime 1237 Find Positive Integer Solution for a Given Equation Easy Normal 1238 Circular Permutation in Binary Representation Medium Normal 1239 Maximum Length of a Concatenated String with Unique Characters Medium Normal 1240 Tiling a Rectangle with the Fewest Squares Hard Normal 1241 Number of Comments per Post Easy Prime 1242 Web Crawler Multithreaded Medium Prime 1243 Array Transformation Easy Prime 1244 Design A Leaderboard Medium Prime 1245 Tree Diameter Medium Prime 1246 Palindrome Removal Hard Prime 1247 Minimum Swaps to Make Strings Equal Medium Normal 1248 Count Number of Nice Subarrays Medium Normal 1249 Minimum Remove to Make Valid Parentheses Medium Normal 1250 Check If It Is a Good Array Hard Normal 1251 Average Selling Price Easy Prime 1252 Cells with Odd Values in a Matrix Easy Normal 1253 Reconstruct a 2-Row Binary Matrix Medium Normal 1254 Number of Closed Islands Medium Normal 1255 Maximum Score Words Formed by Letters Hard Normal 1256 Encode Number Medium Prime 1257 Smallest Common Region Medium Prime 1258 Synonymous Sentences Medium Prime 1259 Handshakes That Don't Cross Hard Prime 1260 Shift 2D Grid Easy Normal 1261 Find Elements in a Contaminated Binary Tree Medium Normal 1262 Greatest Sum Divisible by Three Medium Normal 1263 Minimum Moves to Move a Box to Their Target Location Hard Normal 1264 Page Recommendations Medium Prime 1265 Print Immutable Linked List in Reverse Medium Prime 1266 Minimum Time Visiting All Points Easy Normal 1267 Count Servers that Communicate Medium Normal 1268 Search Suggestions System Medium Normal 1269 Number of Ways to Stay in the Same Place After Some Steps Hard Normal 1270 All People Report to the Given Manager Medium Prime 1271 Hexspeak Easy Prime 1272 Remove Interval Medium Prime 1273 Delete Tree Nodes Medium Prime 1274 Number of Ships in a Rectangle Hard Prime 1275 Find Winner on a Tic Tac Toe Game Easy Normal 1276 Number of Burgers with No Waste of Ingredients Medium Normal 1277 Count Square Submatrices with All Ones Medium Normal 1278 Palindrome Partitioning III Hard Normal 1279 Traffic Light Controlled Intersection Easy Prime 1280 Students and Examinations Easy Prime 1281 Subtract the Product and Sum of Digits of an Integer Easy Normal 1282 Group the People Given the Group Size They Belong To Medium Normal 1283 Find the Smallest Divisor Given a Threshold Medium Normal 1284 Minimum Number of Flips to Convert Binary Matrix to Zero Matrix Hard Normal 1285 Find the Start and End Number of Continuous Ranges Medium Prime 1286 Iterator for Combination Medium Normal 1287 Element Appearing More Than 25% In Sorted Array Easy Normal 1288 Remove Covered Intervals Medium Normal 1289 Minimum Falling Path Sum II Hard Normal 1290 Convert Binary Number in a Linked List to Integer Easy Normal 1291 Sequential Digits Medium Normal 1292 Maximum Side Length of a Square with Sum Less than or Equal to Threshold Medium Normal 1293 Shortest Path in a Grid with Obstacles Elimination Hard Normal 1294 Weather Type in Each Country Easy Prime 1295 Find Numbers with Even Number of Digits Easy Normal 1296 Divide Array in Sets of K Consecutive Numbers Medium Normal 1297 Maximum Number of Occurrences of a Substring Medium Normal 1298 Maximum Candies You Can Get from Boxes Hard Normal 1299 Replace Elements with Greatest Element on Right Side Easy Normal 1300 Sum of Mutated Array Closest to Target Medium Normal 1301 Number of Paths with Max Score Hard Normal 1302 Deepest Leaves Sum Medium Normal 1303 Find the Team Size Easy Prime 1304 Find N Unique Integers Sum up to Zero Easy Normal 1305 All Elements in Two Binary Search Trees Medium Normal 1306 Jump Game III Medium Normal 1307 Verbal Arithmetic Puzzle Hard Normal 1308 Running Total for Different Genders Medium Prime 1309 Decrypt String from Alphabet to Integer Mapping Easy Normal 1310 XOR Queries of a Subarray Medium Normal 1311 Get Watched Videos by Your Friends Medium Normal 1312 Minimum Insertion Steps to Make a String Palindrome Hard Normal 1313 Decompress Run-Length Encoded List Easy Normal 1314 Matrix Block Sum Medium Normal 1315 Sum of Nodes with Even-Valued Grandparent Medium Normal 1316 Distinct Echo Substrings Hard Normal 1317 Convert Integer to the Sum of Two No-Zero Integers Easy Normal 1318 Minimum Flips to Make a OR b Equal to c Medium Normal 1319 Number of Operations to Make Network Connected Medium Normal 1320 Minimum Distance to Type a Word Using Two Fingers Hard Normal 1321 Restaurant Growth Medium Prime 1322 1322. Ads Performance Easy Prime 1323 1323. Maximum 69 Number Easy Normal 1324 1324. Print Words Vertically Medium Normal 1325 1325. Delete Leaves With a Given Value Medium Normal 1326 1326. Minimum Number of Taps to Open to Water a Garden Hard Normal 1327 List the Products Ordered in a Period Easy Prime 1328 Break a Palindrome Medium Normal 1329 Sort the Matrix Diagonally Medium Normal 1330 Reverse Subarray To Maximize Array Value Hard Normal 1331 Rank Transform of an Array Easy Normal 1332 Remove Palindromic Subsequences Easy Normal 1333 Filter Restaurants by Vegan-Friendly, Price and Distance Medium Normal 1334 Find the City With the Smallest Number of Neighbors at a Threshold Distance Medium Normal 1335 Minimum Difficulty of a Job Schedule Hard Normal 1336 Number of Transactions per Visit Hard Prime 1337 The K Weakest Rows in a Matrix Easy Normal 1338 Reduce Array Size to The Half Medium Normal 1339 Maximum Product of Splitted Binary Tree Medium Normal 1340 Jump Game V Hard Normal 1341 Movie Rating Medium Prime 1342 Number of Steps to Reduce a Number to Zero Easy Normal 1343 Number of Sub-arrays of Size K and Average Greater than or Equal to Threshold Medium Normal 1344 Angle Between Hands of a Clock Medium Normal 1345 Jump Game IV Hard Normal 1346 Check If N and Its Double Exist Easy Normal 1347 Minimum Number of Steps to Make Two Strings Anagram Medium Normal 1348 Tweet Counts Per Frequency Medium Normal 1349 Maximum Students Taking Exam Hard Normal 1350 Students With Invalid Departments Easy Prime 1351 Count Negative Numbers in a Sorted Matrix Easy Normal 1352 Product of the Last K Numbers Medium Normal 1353 Maximum Number of Events That Can Be Attended Medium Normal 1354 Construct Target Array With Multiple Sums Hard Normal 1355 Activity Participants Medium Prime 1356 Sort Integers by The Number of 1 Bits Easy Normal 1357 Apply Discount Every n Orders Medium Normal 1358 Number of Substrings Containing All Three Characters Medium Normal 1359 Count All Valid Pickup and Delivery Options Hard Normal 1360 Number of Days Between Two Dates Easy Normal 1361 Validate Binary Tree Nodes Medium Normal 1362 Closest Divisors Medium Normal 1363 Largest Multiple of Three Hard Normal 1364 Number of Trusted Contacts of a Customer Medium Prime 1365 How Many Numbers Are Smaller Than the Current Number Easy Normal 1366 Rank Teams by Votes Medium Normal 1367 Linked List in Binary Tree Medium Normal 1368 Minimum Cost to Make at Least One Valid Path in a Grid Hard Normal 1369 Get the Second Most Recent Activity Hard Prime 1370 Increasing Decreasing String Easy Normal 1371 Find the Longest Substring Containing Vowels in Even Counts Medium Normal 1372 Longest ZigZag Path in a Binary Tree Medium Normal 1373 Maximum Sum BST in Binary Tree Hard Normal 1374 Generate a String With Characters That Have Odd Counts Easy Normal 1375 Bulb Switcher III Medium Normal 1376 Time Needed to Inform All Employees Medium Normal 1377 Frog Position After T Seconds Hard Normal 1378 Replace Employee ID With The Unique Identifier Easy Prime 1379 Find a Corresponding Node of a Binary Tree in a Clone of That Tree Medium Normal 1380 Lucky Numbers in a Matrix Easy Normal 1381 Design a Stack With Increment Operation Medium Normal 1382 Balance a Binary Search Tree Medium Normal 1383 Maximum Performance of a Team Hard Normal 1384 Total Sales Amount by Year Hard Prime 1385 Find the Distance Value Between Two Arrays Easy Normal 1386 Cinema Seat Allocation Medium Normal 1387 Sort Integers by The Power Value Medium Normal 1388 Pizza With 3n Slices Hard Normal 1389 Create Target Array in the Given Order Easy Normal 1390 Four Divisors Medium Normal 1391 Check if There is a Valid Path in a Grid Medium Normal 1392 Longest Happy Prefix Hard Normal 1393 Capital Gain/Loss Medium Prime 1394 Find Lucky Integer in an Array Easy Normal 1395 Count Number of Teams Medium Normal 1396 Design Underground System Medium Normal 1397 Find All Good Strings Hard Normal 1398 Customers Who Bought Products A and B but Not C Medium Prime 1399 Count Largest Group Easy Normal 1400 Construct K Palindrome Strings Medium Normal 1401 Circle and Rectangle Overlapping Medium Normal 1402 Reducing Dishes Hard Normal 1403 Minimum Subsequence in Non-Increasing Order Easy Normal 1404 Number of Steps to Reduce a Number in Binary Representation to One Medium Normal 1405 Longest Happy String Medium Normal 1406 Stone Game III Hard Normal 1407 Top Travellers Easy Prime 1408 String Matching in an Array Easy Normal 1409 Queries on a Permutation With Key Medium Normal 1410 HTML Entity Parser Medium Normal 1411 Number of Ways to Paint N × 3 Grid Hard Normal 1412 Find the Quiet Students in All Exams Hard Prime 1413 Minimum Value to Get Positive Step by Step Sum Easy Normal 1414 Find the Minimum Number of Fibonacci Numbers Whose Sum Is K Medium Normal 1415 The k-th Lexicographical String of All Happy Strings of Length n Medium Normal 1416 Restore The Array Hard Normal 1417 Reformat The String Easy Normal 1418 Display Table of Food Orders in a Restaurant Medium Normal 1419 Minimum Number of Frogs Croaking Medium Normal 1420 Build Array Where You Can Find The Maximum Exactly K Comparisons Hard Normal 1421 NPV Queries Medium Prime 1422 Maximum Score After Splitting a String Easy Normal 1423 Maximum Points You Can Obtain from Cards Medium Normal 1424 Diagonal Traverse II Medium Normal 1425 Constrained Subset Sum Hard Normal 1426 Counting Elements Easy Prime 1427 Perform String Shifts Easy Prime 1428 Leftmost Column with at Least a One Medium Prime 1429 First Unique Number Medium Prime 1430 Check If a String Is a Valid Sequence from Root to Leaves Path in a Binary Tree Medium Prime 1431 Kids With the Greatest Number of Candies Easy Normal 1432 Max Difference You Can Get From Changing an Integer Medium Normal 1433 Check If a String Can Break Another String Medium Normal 1434 Number of Ways to Wear Different Hats to Each Other Hard Normal 1435 Create a Session Bar Chart Easy Prime 1436 Destination City Easy Normal 1437 Check If All 1's Are at Least Length K Places Away Medium Normal 1438 Longest Continuous Subarray With Absolute Diff Less Than or Equal to Limit Medium Normal 1439 Find the Kth Smallest Sum of a Matrix With Sorted Rows Hard Normal 1440 Evaluate Boolean Expression Medium Prime 1441 Build an Array With Stack Operations Easy Normal 1442 Count Triplets That Can Form Two Arrays of Equal XOR Medium Normal 1443 Minimum Time to Collect All Apples in a Tree Medium Normal 1444 Number of Ways of Cutting a Pizza Hard Normal 1445 Apples & Oranges Medium Prime 1446 Consecutive Characters Easy Normal 1447 Simplified Fractions Medium Normal 1448 Count Good Nodes in Binary Tree Medium Normal 1449 Form Largest Integer With Digits That Add up to Target Hard Normal 1450 Number of Students Doing Homework at a Given Time Easy Normal 1451 Rearrange Words in a Sentence Medium Normal 1452 People Whose List of Favorite Companies Is Not a Subset of Another List Medium Normal 1453 Maximum Number of Darts Inside of a Circular Dartboard Hard Normal 1454 Active Users Medium Prime 1455 Check If a Word Occurs As a Prefix of Any Word in a Sentence Easy Normal 1456 Maximum Number of Vowels in a Substring of Given Length Medium Normal 1457 Pseudo-Palindromic Paths in a Binary Tree Medium Normal 1458 Max Dot Product of Two Subsequences Hard Normal 1459 Rectangles Area Medium Prime 1460 Make Two Arrays Equal by Reversing Sub-arrays Easy Normal 1461 Check If a String Contains All Binary Codes of Size K Medium Normal 1462 Course Schedule IV Medium Normal 1463 Cherry Pickup II Hard Normal 1464 Maximum Product of Two Elements in an Array Easy Normal 1465 Maximum Area of a Piece of Cake After Horizontal and Vertical Cuts Medium Normal 1466 Reorder Routes to Make All Paths Lead to the City Zero Medium Normal 1467 Probability of a Two Boxes Having The Same Number of Distinct Balls Hard Normal 1468 Calculate Salaries Medium Prime 1469 Find All the Lonely Nodes Easy Prime 1470 Shuffle the Array Easy Normal 1471 The k Strongest Values in an Array Medium Normal 1472 Design Browser History Medium Normal 1473 Paint House III Hard Normal 1474 Delete N Nodes After M Nodes of a Linked List Easy Prime 1475 Final Prices With a Special Discount in a Shop Easy Normal 1476 Subrectangle Queries Medium Normal 1477 Find Two Non-overlapping Sub-arrays Each With Target Sum Medium Normal 1478 Allocate Mailboxes Hard Normal 1479 Sales by Day of the Week Hard Prime 1480 Running Sum of 1d Array Easy Normal 1481 Least Number of Unique Integers after K Removals Medium Normal 1482 Minimum Number of Days to Make m Bouquets Medium Normal 1483 Kth Ancestor of a Tree Node Hard Normal 1484 Group Sold Products By The Date Easy Prime 1485 Clone Binary Tree With Random Pointer Medium Prime 1486 XOR Operation in an Array Easy Normal 1487 Making File Names Unique Medium Normal 1488 Avoid Flood in The City Medium Normal 1489 Find Critical and Pseudo-Critical Edges in Minimum Spanning Tree Hard Normal 1490 Clone N-ary Tree Medium Prime 1491 Average Salary Excluding the Minimum and Maximum Salary Easy Normal 1492 The kth Factor of n Medium Normal 1493 Longest Subarray of 1's After Deleting One Element Medium Normal 1494 Parallel Courses II Hard Normal 1495 Friendly Movies Streamed Last Month Easy Prime 1496 Path Crossing Easy Normal 1497 Check If Array Pairs Are Divisible by k Medium Normal 1498 Number of Subsequences That Satisfy the Given Sum Condition Medium Normal 1499 Max Value of Equation Hard Normal 1500 Design a File Sharing System Medium Prime 1501 Countries You Can Safely Invest In Medium Prime 1502 Can Make Arithmetic Progression From Sequence Easy Normal 1503 Last Moment Before All Ants Fall Out of a Plank Medium Normal 1504 Count Submatrices With All Ones Medium Normal 1505 Minimum Possible Integer After at Most K Adjacent Swaps On Digits Hard Normal 1506 Find Root of N-Ary Tree Medium Prime 1507 Reformat Date Easy Normal 1508 Range Sum of Sorted Subarray Sums Medium Normal 1509 Minimum Difference Between Largest and Smallest Value in Three Moves Medium Normal 1510 Stone Game IV Hard Normal 1511 Customer Order Frequency Easy Prime 1512 Number of Good Pairs Easy Normal 1513 Number of Substrings With Only 1s Medium Normal 1514 Path with Maximum Probability Medium Normal 1515 Best Position for a Service Centre Hard Normal 1516 Move Sub-Tree of N-Ary Tree Hard Prime 1517 Find Users With Valid E-Mails Easy Prime 1518 Water Bottles Easy Normal 1519 Number of Nodes in the Sub-Tree With the Same Label Medium Normal 1520 Maximum Number of Non-Overlapping Substrings Hard Normal 1521 Find a Value of a Mysterious Function Closest to Target Hard Normal 1522 Diameter of N-Ary Tree Medium Prime 1523 Count Odd Numbers in an Interval Range Easy Normal 1524 Number of Sub-arrays With Odd Sum Medium Normal 1525 Number of Good Ways to Split a String Medium Normal 1526 Minimum Number of Increments on Subarrays to Form a Target Array Hard Normal 1527 Patients With a Condition Easy Prime 1528 Shuffle String Easy Normal 1529 Bulb Switcher IV Medium Normal 1530 Number of Good Leaf Nodes Pairs Medium Normal 1531 String Compression II Hard Normal 1532 The Most Recent Three Orders Medium Prime 1533 Find the Index of the Large Integer Medium Prime 1534 Count Good Triplets Easy Normal 1535 Find the Winner of an Array Game Medium Normal 1536 Minimum Swaps to Arrange a Binary Grid Medium Normal 1537 Get the Maximum Score Hard Normal 1538 Guess the Majority in a Hidden Array Medium Prime 1539 Kth Missing Positive Number Easy Normal 1540 Can Convert String in K Moves Medium Normal 1541 Minimum Insertions to Balance a Parentheses String Medium Normal 1542 Find Longest Awesome Substring Hard Normal 1543 Fix Product Name Format Easy Prime 1544 Make The String Great Easy Normal 1545 Find Kth Bit in Nth Binary String Medium Normal 1546 Maximum Number of Non-Overlapping Subarrays With Sum Equals Target Medium Normal 1547 Minimum Cost to Cut a Stick Hard Normal 1548 The Most Similar Path in a Graph Hard Prime 1549 The Most Recent Orders for Each Product Medium Prime 1550 Three Consecutive Odds Easy Normal 1551 Minimum Operations to Make Array Equal Medium Normal 1552 Magnetic Force Between Two Balls Medium Normal 1553 Minimum Number of Days to Eat N Oranges Hard Normal 1554 Strings Differ by One Character Medium Prime 1555 Bank Account Summary Medium Prime 1556 Thousand Separator Easy Normal 1557 Minimum Number of Vertices to Reach All Nodes Medium Normal 1558 Minimum Numbers of Function Calls to Make Target Array Medium Normal 1559 Detect Cycles in 2D Grid Hard Normal 1560 Most Visited Sector in a Circular Track Easy Normal 1561 Maximum Number of Coins You Can Get Medium Normal 1562 Find Latest Group of Size M Medium Normal 1563 Stone Game V Hard Normal 1564 Put Boxes Into the Warehouse I Medium Prime 1565 Unique Orders and Customers Per Month Easy Prime 1566 Detect Pattern of Length M Repeated K or More Times Easy Normal 1567 Maximum Length of Subarray With Positive Product Medium Normal 1568 Minimum Number of Days to Disconnect Island Medium Normal 1569 Number of Ways to Reorder Array to Get Same BST Hard Normal 1570 Dot Product of Two Sparse Vectors Medium Prime 1571 Warehouse Manager Easy Prime 1572 Matrix Diagonal Sum Easy Normal 1573 Number of Ways to Split a String Medium Normal 1574 Shortest Subarray to be Removed to Make Array Sorted Medium Normal 1575 Count All Possible Routes Hard Normal 1576 Replace All ?'s to Avoid Consecutive Repeating Characters Easy Normal 1577 Number of Ways Where Square of Number Is Equal to Product of Two Numbers Medium Normal 1578 Minimum Deletion Cost to Avoid Repeating Letters Medium Normal 1579 Remove Max Number of Edges to Keep Graph Fully Traversable Hard Normal 1580 Put Boxes Into the Warehouse II Medium Prime 1581 Customer Who Visited but Did Not Make Any Transactions Easy Prime 1582 Special Positions in a Binary Matrix Easy Normal 1583 Count Unhappy Friends Medium Normal 1584 Min Cost to Connect All Points Medium Normal 1585 Check If String Is Transformable With Substring Sort Operations Hard Normal 1586 Binary Search Tree Iterator II Medium Prime 1587 Bank Account Summary II Easy Prime 1588 Sum of All Odd Length Subarrays Easy Normal 1589 Maximum Sum Obtained of Any Permutation Medium Normal 1590 Make Sum Divisible by P Medium Normal 1591 Strange Printer II Hard Normal 1592 Rearrange Spaces Between Words Easy Normal 1593 Split a String Into the Max Number of Unique Substrings Medium Normal 1594 Maximum Non Negative Product in a Matrix Medium Normal 1595 Minimum Cost to Connect Two Groups of Points Hard Normal 1596 The Most Frequently Ordered Products for Each Customer Medium Prime 1597 Build Binary Expression Tree From Infix Expression Medium Prime 1598 Crawler Log Folder Easy Normal 1599 Maximum Profit of Operating a Centennial Wheel Medium Normal 1600 Throne Inheritance Medium Normal 1601 Maximum Number of Achievable Transfer Requests Hard Normal 1602 Find Nearest Right Node in Binary Tree Medium Prime 1603 Design Parking System Easy Normal 1604 Alert Using Same Key-Card Three or More Times in a One Hour Period Medium Normal 1605 Find Valid Matrix Given Row and Column Sums Medium Normal 1606 Find Servers That Handled Most Number of Requests Hard Normal 1607 Sellers With No Sales Easy Prime 1608 Special Array With X Elements Greater Than or Equal X Easy Normal 1609 Even Odd Tree Medium Normal 1610 Maximum Number of Visible Points Medium Normal 1611 Minimum One Bit Operations to Make Integers Zero Hard Normal 1612 Check If Two Expression Trees are Equivalent Medium Prime 1613 Find the Missing IDs Medium Prime 1614 Maximum Nesting Depth of the Parentheses Easy Normal 1615 Maximal Network Rank Medium Normal 1616 Split Two Strings to Make Palindrome Medium Normal 1617 Count Subtrees With Max Distance Between Cities Hard Normal 1618 Maximum Font to Fit a Sentence in a Screen Medium Prime 1619 Mean of Array After Removing Some Elements Easy Normal 1620 Coordinate With Maximum Network Quality Medium Normal 1621 Number of Sets of K Non-Overlapping Line Segments Medium Normal 1622 Fancy Sequence Hard Normal 1623 All Valid Triplets That Can Represent a Country Easy Prime 1624 Largest Substring Between Two Equal Characters Easy Normal 1625 Lexicographically Smallest String After Applying Operations Medium Normal 1626 Best Team With No Conflicts Medium Normal 1627 Graph Connectivity With Threshold Hard Normal 1628 Design an Expression Tree With Evaluate Function Medium Prime 1629 Slowest Key Easy Normal 1630 Arithmetic Subarrays Medium Normal 1631 Path With Minimum Effort Medium Normal 1632 Rank Transform of a Matrix Hard Normal 1633 Percentage of Users Attended a Contest Easy Prime 1634 Add Two Polynomials Represented as Linked Lists Medium Prime 1635 Hopper Company Queries I Hard Prime 1636 Sort Array by Increasing Frequency Easy Normal 1637 Widest Vertical Area Between Two Points Containing No Points Medium Normal 1638 Count Substrings That Differ by One Character Medium Normal 1639 Number of Ways to Form a Target String Given a Dictionary Hard Normal 1640 Check Array Formation Through Concatenation Easy Normal 1641 Count Sorted Vowel Strings Medium Normal 1642 Furthest Building You Can Reach Medium Normal 1643 Kth Smallest Instructions Hard Normal 1644 Lowest Common Ancestor of a Binary Tree II Medium Prime 1645 Hopper Company Queries II Hard Prime 1646 Get Maximum in Generated Array Easy Normal 1647 Minimum Deletions to Make Character Frequencies Unique Medium Normal 1648 Sell Diminishing-Valued Colored Balls Medium Normal 1649 Create Sorted Array through Instructions Hard Normal 1650 Lowest Common Ancestor of a Binary Tree III Medium Prime 1651 Hopper Company Queries III Hard Prime 1652 Defuse the Bomb Easy Normal 1653 Minimum Deletions to Make String Balanced Medium Normal 1654 Minimum Jumps to Reach Home Medium Normal 1655 Distribute Repeating Integers Hard Normal 1656 Design an Ordered Stream Easy Normal 1657 Determine if Two Strings Are Close Medium Normal 1658 Minimum Operations to Reduce X to Zero Medium Normal 1659 Maximize Grid Happiness Hard Normal 1660 Correct a Binary Tree Medium Prime 1661 Average Time of Process per Machine Easy Prime 1662 Check If Two String Arrays are Equivalent Easy Normal 1663 Smallest String With A Given Numeric Value Medium Normal 1664 Ways to Make a Fair Array Medium Normal 1665 Minimum Initial Energy to Finish Tasks Hard Normal 1666 Change the Root of a Binary Tree Medium Prime 1667 Fix Names in a Table Easy Prime 1668 Maximum Repeating Substring Easy Normal 1669 Merge In Between Linked Lists Medium Normal 1670 Design Front Middle Back Queue Medium Normal 1671 Minimum Number of Removals to Make Mountain Array Hard Normal 1672 Richest Customer Wealth Easy Normal 1673 Find the Most Competitive Subsequence Medium Normal 1674 Minimum Moves to Make Array Complementary Medium Normal 1675 Minimize Deviation in Array Hard Normal 1676 Lowest Common Ancestor of a Binary Tree IV Medium Prime 1677 Product's Worth Over Invoices Easy Prime 1678 Goal Parser Interpretation Easy Normal 1679 Max Number of K-Sum Pairs Medium Normal 1680 Concatenation of Consecutive Binary Numbers Medium Normal 1681 Minimum Incompatibility Hard Normal 1682 Longest Palindromic Subsequence II Medium Prime 1683 Invalid Tweets Easy Prime 1684 Count the Number of Consistent Strings Easy Normal 1685 Sum of Absolute Differences in a Sorted Array Medium Normal 1686 Stone Game VI Medium Normal 1687 Delivering Boxes from Storage to Ports Hard Normal 1688 Count of Matches in Tournament Easy Normal 1689 Partitioning Into Minimum Number Of Deci-Binary Numbers Medium Normal 1690 Stone Game VII Medium Normal 1691 Maximum Height by Stacking Cuboids Hard Normal 1692 Count Ways to Distribute Candies Hard Prime 1693 Daily Leads and Partners Easy Prime 1694 Reformat Phone Number Easy Normal 1695 Maximum Erasure Value Medium Normal 1696 Jump Game VI Medium Normal 1697 Checking Existence of Edge Length Limited Paths Hard Normal 1698 Number of Distinct Substrings in a String Medium Prime 1699 Number of Calls Between Two Persons Medium Prime 1700 Number of Students Unable to Eat Lunch Easy Normal 1701 Average Waiting Time Medium Normal 1702 Maximum Binary String After Change Medium Normal 1703 Minimum Adjacent Swaps for K Consecutive Ones Hard Normal 1704 Determine if String Halves Are Alike Easy Normal 1705 Maximum Number of Eaten Apples Medium Normal 1706 Where Will the Ball Fall Medium Normal 1707 Maximum XOR With an Element From Array Hard Normal 1708 Largest Subarray Length K Easy Prime 1709 Biggest Window Between Visits Medium Prime 1710 Maximum Units on a Truck Easy Normal 1711 Count Good Meals Medium Normal 1712 Ways to Split Array Into Three Subarrays Medium Normal 1713 Minimum Operations to Make a Subsequence Hard Normal 1714 Sum Of Special Evenly-Spaced Elements In Array Hard Prime 1715 Count Apples and Oranges Medium Prime 1716 Calculate Money in Leetcode Bank Easy Normal 1717 Maximum Score From Removing Substrings Medium Normal 1718 Construct the Lexicographically Largest Valid Sequence Medium Normal 1719 Number Of Ways To Reconstruct A Tree Hard Normal 1720 Decode XORed Array Easy Normal 1721 Swapping Nodes in a Linked List Hard Normal 1722 Minimize Hamming Distance After Swap Operations Medium Normal 1723 Find Minimum Time to Finish All Jobs Hard Normal 1724 Checking Existence of Edge Length Limited Paths II Hard Prime 1725 Number Of Rectangles That Can Form The Largest Square Easy Normal 1726 Tuple with Same Product Medium Normal 1727 Largest Submatrix With Rearrangements Medium Normal 1728 Cat and Mouse II Hard Normal 1729 Find Followers Count Easy Prime 1730 Shortest Path to Get Food Medium Prime 1731 The Number of Employees Which Report to Each Employee Easy Prime 1732 Find the Highest Altitude Easy Normal 1733 Minimum Number of People to Teach Medium Normal 1734 Decode XORed Permutation Medium Normal 1735 Count Ways to Make Array With Product Hard Normal 1736 Latest Time by Replacing Hidden Digits Easy Normal 1737 Change Minimum Characters to Satisfy One of Three Conditions Medium Normal 1738 Find Kth Largest XOR Coordinate Value Medium Normal 1739 Building Boxes Hard Normal 1740 Find Distance in a Binary Tree Medium Prime 1741 Find Total Time Spent by Each Employee Easy Prime 1742 Maximum Number of Balls in a Box Easy Normal 1743 Restore the Array From Adjacent Pairs Medium Normal 1744 Can You Eat Your Favorite Candy on Your Favorite Day? Medium Normal 1745 Palindrome Partitioning IV Hard Normal 1746 Maximum Subarray Sum After One Operation Medium Prime 1747 Leetflex Banned Accounts Medium Prime 1748 Sum of Unique Elements Easy Normal 1749 Maximum Absolute Sum of Any Subarray Medium Normal 1750 Minimum Length of String After Deleting Similar Ends Medium Normal 1751 Maximum Number of Events That Can Be Attended II Hard Normal 1752 Check if Array Is Sorted and Rotated Easy Normal 1753 Maximum Score From Removing Stones Medium Normal 1754 Largest Merge Of Two Strings Medium Normal 1755 Closest Subsequence Sum Hard Normal 1756 Design Most Recently Used Queue Medium Prime 1757 Recyclable and Low Fat Products Easy Prime 1758 Minimum Changes To Make Alternating Binary String Easy Normal 1759 Count Number of Homogenous Substrings Medium Normal 1760 Minimum Limit of Balls in a Bag Medium Normal 1761 Minimum Degree of a Connected Trio in a Graph Hard Normal 1762 Buildings With an Ocean View Medium Prime 1763 Longest Nice Substring Easy Normal 1764 Form Array by Concatenating Subarrays of Another Array Medium Normal 1765 Map of Highest Peak Medium Normal 1766 Tree of Coprimes Hard Normal 1767 Find the Subtasks That Did Not Execute Hard Prime 1768 Merge Strings Alternately Easy Normal 1769 Minimum Number of Operations to Move All Balls to Each Box Medium Normal 1770 Maximum Score from Performing Multiplication Operations Medium Normal 1771 Maximize Palindrome Length From Subsequences Hard Normal 1772 Sort Features by Popularity Medium Prime 1773 Count Items Matching a Rule Easy Normal 1774 Closest Dessert Cost Medium Normal 1775 Equal Sum Arrays With Minimum Number of Operations Medium Normal 1776 Car Fleet II Hard Normal 1777 Product's Price for Each Store Easy Prime 1778 Shortest Path in a Hidden Grid Medium Prime 1779 Find Nearest Point That Has the Same X or Y Coordinate Easy Normal 1780 Check if Number is a Sum of Powers of Three Medium Normal 1781 Sum of Beauty of All Substrings Medium Normal 1782 Count Pairs Of Nodes Hard Normal 1783 Grand Slam Titles Medium Prime 1784 Check if Binary String Has at Most One Segment of Ones Easy Normal 1785 Minimum Elements to Add to Form a Given Sum Medium Normal 1786 Number of Restricted Paths From First to Last Node Medium Normal 1787 Make the XOR of All Segments Equal to Zero Hard Normal 1788 Maximize the Beauty of the Garden Hard Prime 1789 Primary Department for Each Employee Easy Prime 1790 Check if One String Swap Can Make Strings Equal Easy Normal 1791 Find Center of Star Graph Medium Normal 1792 Maximum Average Pass Ratio Medium Normal 1793 Maximum Score of a Good Subarray Hard Normal 1794 Count Pairs of Equal Substrings With Minimum Difference Medium Prime 1795 Rearrange Products Table Easy Prime 1796 Second Largest Digit in a String Easy Normal 1797 Design Authentication Manager Medium Normal 1798 Maximum Number of Consecutive Values You Can Make Medium Normal 1799 Maximize Score After N Operations Hard Normal 1800 Maximum Ascending Subarray Sum Easy Normal 1801 Number of Orders in the Backlog Medium Normal 1802 Maximum Value at a Given Index in a Bounded Array Medium Normal 1803 Count Pairs With XOR in a Range Hard Normal 1804 Implement Trie II (Prefix Tree) Medium Prime 1805 Number of Different Integers in a String Easy Normal 1806 Minimum Number of Operations to Reinitialize a Permutation Medium Normal 1807 Evaluate the Bracket Pairs of a String Medium Normal 1808 Maximize Number of Nice Divisors Hard Normal 1809 Ad-Free Sessions Easy Prime 1810 Minimum Path Cost in a Hidden Grid Medium Prime 1811 Find Interview Candidates Medium Prime 1812 Determine Color of a Chessboard Square Easy Normal 1813 Sentence Similarity III Medium Normal 1814 Count Nice Pairs in an Array Medium Normal 1815 Maximum Number of Groups Getting Fresh Donuts Hard Normal 1816 Truncate Sentence Easy Normal 1817 Finding the Users Active Minutes Medium Normal 1818 Minimum Absolute Sum Difference Medium Normal 1819 Number of Different Subsequences GCDs Hard Normal 1820 Maximum Number of Accepted Invitations Medium Prime 1821 Find Customers With Positive Revenue this Year Easy Prime 1822 Sign of the Product of an Array Easy Normal 1823 Find the Winner of the Circular Game Medium Normal 1824 Minimum Sideway Jumps Medium Normal 1825 Finding MK Average Hard Normal 1826 Faulty Sensor Easy Prime 1827 Minimum Operations to Make the Array Increasing Easy Normal 1828 Queries on Number of Points Inside a Circle Medium Normal 1829 Maximum XOR for Each Query Medium Normal 1830 Minimum Number of Operations to Make String Sorted Hard Normal 1831 Maximum Transaction Each Day Medium Prime 1832 Check if the Sentence Is Pangram Easy Normal 1833 Maximum Ice Cream Bars Medium Normal 1834 Single-Threaded CPU Medium Normal 1835 Find XOR Sum of All Pairs Bitwise AND Hard Normal 1836 Remove Duplicates From an Unsorted Linked List Medium Prime 1837 Sum of Digits in Base K Easy Normal 1838 Frequency of the Most Frequent Element Medium Normal 1839 Longest Substring Of All Vowels in Order Medium Normal 1840 Maximum Building Height Hard Normal 1841 League Statistics Medium Prime 1842 Next Palindrome Using Same Digits Hard Prime 1843 Suspicious Bank Accounts Medium Prime 1844 Replace All Digits with Characters Easy Normal 1845 Seat Reservation Manager Medium Normal 1846 Maximum Element After Decreasing and Rearranging Medium Normal 1847 Closest Room Hard Normal 1848 Minimum Distance to the Target Element Easy Normal 1849 Splitting a String Into Descending Consecutive Values Medium Normal 1850 Minimum Adjacent Swaps to Reach the Kth Smallest Number Medium Normal 1851 Minimum Interval to Include Each Query Hard Normal 1852 Distinct Numbers in Each Subarray Medium Prime 1853 Convert Date Format Easy Prime 1854 Maximum Population Year Easy Normal 1855 Maximum Distance Between a Pair of Values Medium Normal 1856 Maximum Subarray Min-Product Medium Normal 1857 Largest Color Value in a Directed Graph Hard Normal