2

Add Two Numbers

Medium

3

Longest Substring Without Repeating Characters

Medium

5

Longest Palindromic Substring

Medium

6

Zigzag Conversion

Medium

7

Reverse Integer

Medium

8

String to Integer (atoi)

Medium

11

Container With Most Water

Medium

12

Integer to Roman

Medium

15

3Sum

Medium

16

3Sum Closest

Medium

17

Letter Combinations of a Phone Number

Medium

18

4Sum

Medium

19

Remove Nth Node From End of List

Medium

22

Generate Parentheses

Medium

24

Swap Nodes in Pairs

Medium

29

Divide Two Integers

Medium

31

Next Permutation

Medium

33

Search in Rotated Sorted Array

Medium

34

Find First and Last Position of Element in Sorted Array

Medium

36

Valid Sudoku

Medium

38

Count and Say

Medium

39

Combination Sum

Medium

40

Combination Sum II

Medium

43

Multiply Strings

Medium

45

Jump Game II

Medium

46

Permutations

Medium

47

Permutations II

Medium

48

Rotate Image

Medium

49

Group Anagrams

Medium

50

Pow(x, n)

Medium

54

Spiral Matrix

Medium

55

Jump Game

Medium

56

Merge Intervals

Medium

57

Insert Interval

Medium

59

Spiral Matrix II

Medium

61

Rotate List

Medium

62

Unique Paths

Medium

63

Unique Paths II

Medium

64

Minimum Path Sum

Medium

71

Simplify Path

Medium

73

Set Matrix Zeroes

Medium

74

Search a 2D Matrix

Medium

75

Sort Colors

Medium

77

Combinations

Medium

78

Subsets

Medium

79

Word Search

Medium

80

Remove Duplicates from Sorted Array II

Medium

81

Search in Rotated Sorted Array II

Medium

82

Remove Duplicates from Sorted List II

Medium

86

Partition List

Medium

89

Gray Code

Medium

90

Subsets II

Medium

91

Decode Ways

Medium

92

Reverse Linked List II

Medium

93

Restore IP Addresses

Medium

95

Unique Binary Search Trees II

Medium

96

Unique Binary Search Trees

Medium

97

Interleaving String

Medium

98

Validate Binary Search Tree

Medium

99

Recover Binary Search Tree

Medium

102

Binary Tree Level Order Traversal

Medium

103

Binary Tree Zigzag Level Order Traversal

Medium

105

Construct Binary Tree from Preorder and Inorder Traversal

Medium

106

Construct Binary Tree from Inorder and Postorder Traversal

Medium

107

Binary Tree Level Order Traversal II

Medium

109

Convert Sorted List to Binary Search Tree

Medium

113

Path Sum II

Medium

114

Flatten Binary Tree to Linked List

Medium

120

Triangle

Medium

122

Best Time to Buy and Sell Stock II

Medium

128

Longest Consecutive Sequence

Medium

129

Sum Root to Leaf Numbers

Medium

130

Surrounded Regions

Medium

131

Palindrome Partitioning

Medium

134

Gas Station

Medium

137

Single Number II

Medium

139

Word Break

Medium

143

Reorder List

Medium

146

LRU Cache

Medium

147

Insertion Sort List

Medium

148

Sort List

Medium

150

Evaluate Reverse Polish Notation

Medium

151

Reverse Words in a String

Medium

152

Maximum Product Subarray

Medium

153

Find Minimum in Rotated Sorted Array

Medium

156

Binary Tree Upside Down

Medium

159

Longest Substring with At Most Two Distinct Characters

Medium

161

One Edit Distance

Medium

162

Find Peak Element

Medium

165

Compare Version Numbers

Medium

166

Fraction to Recurring Decimal

Medium

172

Factorial Trailing Zeroes

Medium

173

Binary Search Tree Iterator

Medium

179

Largest Number

Medium

186

Reverse Words in a String II

Medium

187

Repeated DNA Sequences

Medium

189

Rotate Array

Medium

198

House Robber

Medium

199

Binary Tree Right Side View

Medium

200

Number of Islands

Medium

201

Bitwise AND of Numbers Range

Medium

204

Count Primes

Medium

207

Course Schedule

Medium

208

Implement Trie (Prefix Tree)

Medium

209

Minimum Size Subarray Sum

Medium

210

Course Schedule II

Medium

211

Design Add and Search Words Data Structure

Medium

213

House Robber II

Medium

215

Kth Largest Element in an Array

Medium

216

Combination Sum III

Medium

220

Contains Duplicate III

Medium

221

Maximal Square

Medium

222

Count Complete Tree Nodes

Medium

223

Rectangle Area

Medium

227

Basic Calculator II

Medium

229

Majority Element II

Medium

230

Kth Smallest Element in a BST

Medium

236

Lowest Common Ancestor of a Binary Tree

Medium

238

Product of Array Except Self

Medium

240

Search a 2D Matrix II

Medium

241

Different Ways to Add Parentheses

Medium

244

Shortest Word Distance II

Medium

245

Shortest Word Distance III

Medium

247

Strobogrammatic Number II

Medium

249

Group Shifted Strings

Medium

250

Count Univalue Subtrees

Medium

251

Flatten 2D Vector

Medium

253

Meeting Rooms II

Medium

254

Factor Combinations

Medium

255

Verify Preorder Sequence in Binary Search Tree

Medium

256

Paint House

Medium

259

3Sum Smaller

Medium

260

Single Number III

Medium

261

Graph Valid Tree

Medium

264

Ugly Number II

Medium

267

Palindrome Permutation II

Medium

271

Encode and Decode Strings

Medium

274

HIndex

Medium

275

HIndex II

Medium

276

Paint Fence

Medium

277

Find the Celebrity

Medium

279

Perfect Squares

Medium

280

Wiggle Sort

Medium

281

Zigzag Iterator

Medium

285

Inorder Successor in BST

Medium

286

Walls and Gates

Medium

287

Find the Duplicate Number

Medium

288

Unique Word Abbreviation

Medium

289

Game of Life

Medium

291

Word Pattern II

Medium

294

Flip Game II

Medium

298

Binary Tree Longest Consecutive Sequence

Medium

299

Bulls and Cows

Medium

300

Longest Increasing Subsequence

Medium

304

Range Sum Query 2D  Immutable

Medium

306

Additive Number

Medium

307

Range Sum Query  Mutable

Medium

309

Best Time to Buy and Sell Stock with Cooldown

Medium

310

Minimum Height Trees

Medium

311

Sparse Matrix Multiplication

Medium

313

Super Ugly Number

Medium

314

Binary Tree Vertical Order Traversal

Medium

316

Remove Duplicate Letters

Medium

318

Maximum Product of Word Lengths

Medium

319

Bulb Switcher

Medium

320

Generalized Abbreviation

Medium

322

Coin Change

Medium

323

Number of Connected Components in an Undirected Graph

Medium

324

Wiggle Sort II

Medium

325

Maximum Size Subarray Sum Equals k

Medium

328

Odd Even Linked List

Medium

331

Verify Preorder Serialization of a Binary Tree

Medium

333

Largest BST Subtree

Medium

334

Increasing Triplet Subsequence

Medium

337

House Robber III

Medium

339

Nested List Weight Sum

Medium

340

Longest Substring with At Most K Distinct Characters

Medium

341

Flatten Nested List Iterator

Medium

343

Integer Break

Medium

347

Top K Frequent Elements

Medium

348

Design TicTacToe

Medium

351

Android Unlock Patterns

Medium

353

Design Snake Game

Medium

355

Design Twitter

Medium

356

Line Reflection

Medium

357

Count Numbers with Unique Digits

Medium

360

Sort Transformed Array

Medium

361

Bomb Enemy

Medium

362

Design Hit Counter

Medium

364

Nested List Weight Sum II

Medium

365

Water and Jug Problem

Medium

366

Find Leaves of Binary Tree

Medium

368

Largest Divisible Subset

Medium

369

Plus One Linked List

Medium

370

Range Addition

Medium

371

Sum of Two Integers

Medium

372

Super Pow

Medium

373

Find K Pairs with Smallest Sums

Medium

375

Guess Number Higher or Lower II

Medium

376

Wiggle Subsequence

Medium

377

Combination Sum IV

Medium

378

Kth Smallest Element in a Sorted Matrix

Medium

379

Design Phone Directory

Medium

380

Insert Delete GetRandom O(1)

Medium

382

Linked List Random Node

Medium

384

Shuffle an Array

Medium

385

Mini Parser

Medium

386

Lexicographical Numbers

Medium

388

Longest Absolute File Path

Medium

390

Elimination Game

Medium

393

UTF8 Validation

Medium

394

Decode String

Medium

395

Longest Substring with At Least K Repeating Characters

Medium

396

Rotate Function

Medium

397

Integer Replacement

Medium

398

Random Pick Index

Medium

399

Evaluate Division

Medium

400

Nth Digit

Medium

402

Remove K Digits

Medium

406

Queue Reconstruction by Height

Medium

413

Arithmetic Slices

Medium

416

Partition Equal Subset Sum

Medium

417

Pacific Atlantic Water Flow

Medium

418

Sentence Screen Fitting

Medium

419

Battleships in a Board

Medium

421

Maximum XOR of Two Numbers in an Array

Medium

423

Reconstruct Original Digits from English

Medium

424

Longest Repeating Character Replacement

Medium

433

Minimum Genetic Mutation

Medium

435

Nonoverlapping Intervals

Medium

436

Find Right Interval

Medium

437

Path Sum III

Medium

438

Find All Anagrams in a String

Medium

439

Ternary Expression Parser

Medium

442

Find All Duplicates in an Array

Medium

443

String Compression

Medium

444

Sequence Reconstruction

Medium

445

Add Two Numbers II

Medium

447

Number of Boomerangs

Medium

449

Serialize and Deserialize BST

Medium

450

Delete Node in a BST

Medium

451

Sort Characters By Frequency

Medium

452

Minimum Number of Arrows to Burst Balloons

Medium

453

Minimum Moves to Equal Array Elements

Medium

454

4Sum II

Medium

456

132 Pattern

Medium

457

Circular Array Loop

Medium

462

Minimum Moves to Equal Array Elements II

Medium

464

Can I Win

Medium

467

Unique Substrings in Wraparound String

Medium

468

Validate IP Address

Medium

469

Convex Polygon

Medium

470

Implement Rand10() Using Rand7()

Medium

473

Matchsticks to Square

Medium

474

Ones and Zeroes

Medium

475

Heaters

Medium

477

Total Hamming Distance

Medium

478

Generate Random Point in a Circle

Medium

481

Magical String

Medium

484

Find Permutation

Medium

486

Predict the Winner

Medium

487

Max Consecutive Ones II

Medium

490

The Maze

Medium

491

Increasing Subsequences

Medium

494

Target Sum

Medium

497

Random Point in Nonoverlapping Rectangles

Medium

498

Diagonal Traverse

Medium

503

Next Greater Element II

Medium

505

The Maze II

Medium

508

Most Frequent Subtree Sum

Medium

513

Find Bottom Left Tree Value

Medium

515

Find Largest Value in Each Tree Row

Medium

516

Longest Palindromic Subsequence

Medium

518

Coin Change 2

Medium

519

Random Flip Matrix

Medium

522

Longest Uncommon Subsequence II

Medium

523

Continuous Subarray Sum

Medium

524

Longest Word in Dictionary through Deleting

Medium

525

Contiguous Array

Medium

526

Beautiful Arrangement

Medium

528

Random Pick with Weight

Medium

529

Minesweeper

Medium

531

Lonely Pixel I

Medium

532

Kdiff Pairs in an Array

Medium

533

Lonely Pixel II

Medium

535

Encode and Decode TinyURL

Medium

536

Construct Binary Tree from String

Medium

537

Complex Number Multiplication

Medium

538

Convert BST to Greater Tree

Medium

539

Minimum Time Difference

Medium

540

Single Element in a Sorted Array

Medium

542

01 Matrix

Medium

544

Output Contest Matches

Medium

545

Boundary of Binary Tree

Medium

547

Number of Provinces

Medium

549

Binary Tree Longest Consecutive Sequence II

Medium

553

Optimal Division

Medium

554

Brick Wall

Medium

555

Split Concatenated Strings

Medium

556

Next Greater Element III

Medium

560

Subarray Sum Equals K

Medium

562

Longest Line of Consecutive One in Matrix

Medium

565

Array Nesting

Medium

567

Permutation in String

Medium

573

Squirrel Simulation

Medium

576

Out of Boundary Paths

Medium

581

Shortest Unsorted Continuous Subarray

Medium

582

Kill Process

Medium

583

Delete Operation for Two Strings

Medium

592

Fraction Addition and Subtraction

Medium

593

Valid Square

Medium

609

Find Duplicate File in System

Medium

611

Valid Triangle Number

Medium

616

Add Bold Tag in String

Medium

621

Task Scheduler

Medium

622

Design Circular Queue

Medium

623

Add One Row to Tree

Medium

624

Maximum Distance in Arrays

Medium

625

Minimum Factorization

Medium

633

Sum of Square Numbers

Medium

634

Find the Derangement of An Array

Medium

635

Design Log Storage System

Medium

636

Exclusive Time of Functions

Medium

638

Shopping Offers

Medium

640

Solve the Equation

Medium

641

Design Circular Deque

Medium

646

Maximum Length of Pair Chain

Medium

647

Palindromic Substrings

Medium

648

Replace Words

Medium

649

Dota2 Senate

Medium

650

2 Keys Keyboard

Medium

651

4 Keys Keyboard

Medium

652

Find Duplicate Subtrees

Medium

654

Maximum Binary Tree

Medium

655

Print Binary Tree

Medium

658

Find K Closest Elements

Medium

659

Split Array into Consecutive Subsequences

Medium

662

Maximum Width of Binary Tree

Medium

663

Equal Tree Partition

Medium

665

Nondecreasing Array

Medium

666

Path Sum IV

Medium

667

Beautiful Arrangement II

Medium

669

Trim a Binary Search Tree

Medium

670

Maximum Swap

Medium

672

Bulb Switcher II

Medium

673

Number of Longest Increasing Subsequence

Medium

676

Implement Magic Dictionary

Medium

677

Map Sum Pairs

Medium

678

Valid Parenthesis String

Medium

681

Next Closest Time

Medium

684

Redundant Connection

Medium

686

Repeated String Match

Medium

687

Longest Univalue Path

Medium

688

Knight Probability in Chessboard

Medium

692

Top K Frequent Words

Medium

694

Number of Distinct Islands

Medium

695

Max Area of Island

Medium

698

Partition to K Equal Sum Subsets

Medium

701

Insert into a Binary Search Tree

Medium

707

Design Linked List

Medium

712

Minimum ASCII Delete Sum for Two Strings

Medium

713

Subarray Product Less Than K

Medium

714

Best Time to Buy and Sell Stock with Transaction Fee

Medium

718

Maximum Length of Repeated Subarray

Medium

720

Longest Word in Dictionary

Medium

721

Accounts Merge

Medium

722

Remove Comments

Medium

723

Candy Crush

Medium

725

Split Linked List in Parts

Medium

729

My Calendar I

Medium

731

My Calendar II

Medium

735

Asteroid Collision

Medium

737

Sentence Similarity II

Medium

738

Monotone Increasing Digits

Medium

739

Daily Temperatures

Medium

740

Delete and Earn

Medium

742

Closest Leaf in a Binary Tree

Medium

743

Network Delay Time

Medium

750

Number Of Corner Rectangles

Medium

751

IP to CIDR

Medium

752

Open the Lock

Medium

754

Reach a Number

Medium

755

Pour Water

Medium

756

Pyramid Transition Matrix

Medium

758

Bold Words in String

Medium

763

Partition Labels

Medium

764

Largest Plus Sign

Medium

767

Reorganize String

Medium

769

Max Chunks To Make Sorted

Medium

775

Global and Local Inversions

Medium

776

Split BST

Medium

777

Swap Adjacent in LR String

Medium

779

Kth Symbol in Grammar

Medium

781

Rabbits in Forest

Medium

784

Letter Case Permutation

Medium

785

Is Graph Bipartite?

Medium

787

Cheapest Flights Within K Stops

Medium

788

Rotated Digits

Medium

789

Escape The Ghosts

Medium

790

Domino and Tromino Tiling

Medium

791

Custom Sort String

Medium

792

Number of Matching Subsequences

Medium

794

Valid TicTacToe State

Medium

795

Number of Subarrays with Bounded Maximum

Medium

797

All Paths From Source to Target

Medium

799

Champagne Tower

Medium

802

Find Eventual Safe States

Medium

807

Max Increase to Keep City Skyline

Medium

808

Soup Servings

Medium

809

Expressive Words

Medium

811

Subdomain Visit Count

Medium

813

Largest Sum of Averages

Medium

814

Binary Tree Pruning

Medium

816

Ambiguous Coordinates

Medium

817

Linked List Components

Medium

820

Short Encoding of Words

Medium

822

Card Flipping Game

Medium

823

Binary Trees With Factors

Medium

825

Friends Of Appropriate Ages

Medium

826

Most Profit Assigning Work

Medium

831

Masking Personal Information

Medium

833

Find And Replace in String

Medium

835

Image Overlap

Medium

837

New 21 Game

Medium

838

Push Dominoes

Medium

840

Magic Squares In Grid

Medium

841

Keys and Rooms

Medium

842

Split Array into Fibonacci Sequence

Medium

845

Longest Mountain in Array

Medium

846

Hand of Straights

Medium

848

Shifting Letters

Medium

849

Maximize Distance to Closest Person

Medium

851

Loud and Rich

Medium

853

Car Fleet

Medium

855

Exam Room

Medium

856

Score of Parentheses

Medium

858

Mirror Reflection

Medium

861

Score After Flipping Matrix

Medium

863

All Nodes Distance K in Binary Tree

Medium

865

Smallest Subtree with all the Deepest Nodes

Medium

866

Prime Palindrome

Medium

869

Reordered Power of 2

Medium

870

Advantage Shuffle

Medium

873

Length of Longest Fibonacci Subsequence

Medium

874

Walking Robot Simulation

Medium

875

Koko Eating Bananas

Medium

877

Stone Game

Medium

880

Decoded String at Index

Medium

881

Boats to Save People

Medium

885

Spiral Matrix III

Medium

886

Possible Bipartition

Medium

889

Construct Binary Tree from Preorder and Postorder Traversal

Medium

890

Find and Replace Pattern

Medium

893

Groups of SpecialEquivalent Strings

Medium

894

All Possible Full Binary Trees

Medium

898

Bitwise ORs of Subarrays

Medium

900

RLE Iterator

Medium

901

Online Stock Span

Medium

904

Fruit Into Baskets

Medium

907

Sum of Subarray Minimums

Medium

909

Snakes and Ladders

Medium

910

Smallest Range II

Medium

911

Online Election

Medium

912

Sort an Array

Medium

915

Partition Array into Disjoint Intervals

Medium

916

Word Subsets

Medium

918

Maximum Sum Circular Subarray

Medium

919

Complete Binary Tree Inserter

Medium

921

Minimum Add to Make Parentheses Valid

Medium

923

3Sum With Multiplicity

Medium

926

Flip String to Monotone Increasing

Medium

930

Binary Subarrays With Sum

Medium

931

Minimum Falling Path Sum

Medium

932

Beautiful Array

Medium

934

Shortest Bridge

Medium

935

Knight Dialer

Medium

939

Minimum Area Rectangle

Medium

945

Minimum Increment to Make Array Unique

Medium

946

Validate Stack Sequences

Medium

947

Most Stones Removed with Same Row or Column

Medium

948

Bag of Tokens

Medium

949

Largest Time for Given Digits

Medium

950

Reveal Cards In Increasing Order

Medium

951

Flip Equivalent Binary Trees

Medium

954

Array of Doubled Pairs

Medium

955

Delete Columns to Make Sorted II

Medium

957

Prison Cells After N Days

Medium

958

Check Completeness of a Binary Tree

Medium

959

Regions Cut By Slashes

Medium

962

Maximum Width Ramp

Medium

963

Minimum Area Rectangle II

Medium

966

Vowel Spellchecker

Medium

967

Numbers With Same Consecutive Differences

Medium

969

Pancake Sorting

Medium

970

Powerful Integers

Medium

971

Flip Binary Tree To Match Preorder Traversal

Medium

973

K Closest Points to Origin

Medium

974

Subarray Sums Divisible by K

Medium

978

Longest Turbulent Subarray

Medium

979

Distribute Coins in Binary Tree

Medium

981

Time Based KeyValue Store

Medium

983

Minimum Cost For Tickets

Medium

984

String Without AAA or BBB

Medium

985

Sum of Even Numbers After Queries

Medium

986

Interval List Intersections

Medium

988

Smallest String Starting From Leaf

Medium

990

Satisfiability of Equality Equations

Medium

991

Broken Calculator

Medium

994

Rotting Oranges

Medium

998

Maximum Binary Tree II

Medium

1003

Check If Word Is Valid After Substitutions

Medium

1004

Max Consecutive Ones III

Medium

1006

Clumsy Factorial

Medium

1007

Minimum Domino Rotations For Equal Row

Medium

1008

Construct Binary Search Tree from Preorder Traversal

Medium

1010

Pairs of Songs With Total Durations Divisible by 60

Medium

1011

Capacity To Ship Packages Within D Days

Medium

1014

Best Sightseeing Pair

Medium

1015

Smallest Integer Divisible by K

Medium

1016

Binary String With Substrings Representing 1 To N

Medium

1017

Convert to Base 2

Medium

1019

Next Greater Node In Linked List

Medium

1020

Number of Enclaves

Medium

1023

Camelcase Matching

Medium

1024

Video Stitching

Medium

1026

Maximum Difference Between Node and Ancestor

Medium

1027

Longest Arithmetic Subsequence

Medium

1029

Two City Scheduling

Medium

1031

Maximum Sum of Two NonOverlapping Subarrays

Medium

1033

Moving Stones Until Consecutive

Medium

1034

Coloring A Border

Medium

1035

Uncrossed Lines

Medium

1038

Binary Search Tree to Greater Sum Tree

Medium

1039

Minimum Score Triangulation of Polygon

Medium

1040

Moving Stones Until Consecutive II

Medium

1041

Robot Bounded In Circle

Medium

1042

Flower Planting With No Adjacent

Medium

1043

Partition Array for Maximum Sum

Medium

1048

Longest String Chain

Medium

1049

Last Stone Weight II

Medium

1052

Grumpy Bookstore Owner

Medium

1053

Previous Permutation With One Swap

Medium

1054

Distant Barcodes

Medium

1055

Shortest Way to Form String

Medium

1057

Campus Bikes

Medium

1058

Minimize Rounding Error to Meet Target

Medium

1059

All Paths from Source Lead to Destination

Medium

1060

Missing Element in Sorted Array

Medium

1061

Lexicographically Smallest Equivalent String

Medium

1062

Longest Repeating Substring

Medium

1066

Campus Bikes II

Medium

1072

Flip Columns For Maximum Number of Equal Rows

Medium

1073

Adding Two Negabinary Numbers

Medium

1079

Letter Tile Possibilities

Medium

1080

Insufficient Nodes in Root to Leaf Paths

Medium

1081

Smallest Subsequence of Distinct Characters

Medium

1087

Brace Expansion

Medium

1090

Largest Values From Labels

Medium

1091

Shortest Path in Binary Matrix

Medium

1093

Statistics from a Large Sample

Medium

1094

Car Pooling

Medium

1100

Find KLength Substrings With No Repeated Characters

Medium

1101

The Earliest Moment When Everyone Become Friends

Medium

1102

Path With Maximum Minimum Value

Medium

1104

Path In Zigzag Labelled Binary Tree

Medium

1105

Filling Bookcase Shelves

Medium

1109

Corporate Flight Bookings

Medium

1110

Delete Nodes And Return Forest

Medium

1111

Maximum Nesting Depth of Two Valid Parentheses Strings

Medium

1116

Print Zero Even Odd

Medium

1117

Building H2O

Medium

1120

Maximum Average Subtree

Medium

1123

Lowest Common Ancestor of Deepest Leaves

Medium

1124

Longest WellPerforming Interval

Medium

1129

Shortest Path with Alternating Colors

Medium

1130

Minimum Cost Tree From Leaf Values

Medium

1131

Maximum of Absolute Value Expression

Medium

1135

Connecting Cities With Minimum Cost

Medium

1136

Parallel Courses

Medium

1138

Alphabet Board Path

Medium

1139

Largest 1Bordered Square

Medium

1140

Stone Game II

Medium

1143

Longest Common Subsequence

Medium

1144

Decrease Elements To Make Array Zigzag

Medium

1145

Binary Tree Coloring Game

Medium

1146

Snapshot Array

Medium

1151

Minimum Swaps to Group All 1's Together

Medium

1152

Analyze User Website Visit Pattern

Medium

1155

Number of Dice Rolls With Target Sum

Medium

1156

Swap For Longest Repeated Character Substring

Medium

1161

Maximum Level Sum of a Binary Tree

Medium

1162

As Far from Land as Possible

Medium

1166

Design File System

Medium

1167

Minimum Cost to Connect Sticks

Medium

1169

Invalid Transactions

Medium

1170

Compare Strings by Frequency of the Smallest Character

Medium

1171

Remove Zero Sum Consecutive Nodes from Linked List

Medium

1177

Can Make Palindrome from Substring

Medium

1181

Before and After Puzzle

Medium

1182

Shortest Distance to Target Color

Medium

1186

Maximum Subarray Sum with One Deletion

Medium

1188

Design Bounded Blocking Queue

Medium

1190

Reverse Substrings Between Each Pair of Parentheses

Medium

1191

KConcatenation Maximum Sum

Medium

1195

Fizz Buzz Multithreaded

Medium

1197

Minimum Knight Moves

Medium

1198

Find Smallest Common Element in All Rows

Medium

1201

Ugly Number III

Medium

1202

Smallest String With Swaps

Medium

1208

Get Equal Substrings Within Budget

Medium

1209

Remove All Adjacent Duplicates in String II

Medium

1214

Two Sum BSTs

Medium

1215

Stepping Numbers

Medium

1218

Longest Arithmetic Subsequence of Given Difference

Medium

1219

Path with Maximum Gold

Medium

1222

Queens That Can Attack the King

Medium

1226

The Dining Philosophers

Medium

1227

Airplane Seat Assignment Probability

Medium

1229

Meeting Scheduler

Medium

1230

Toss Strange Coins

Medium

1233

Remove SubFolders from the Filesystem

Medium

1234

Replace the Substring for Balanced String

Medium

1237

Find Positive Integer Solution for a Given Equation

Medium

1238

Circular Permutation in Binary Representation

Medium

1239

Maximum Length of a Concatenated String with Unique Characters

Medium

1242

Web Crawler Multithreaded

Medium

1244

Design A Leaderboard

Medium

1245

Tree Diameter

Medium

1247

Minimum Swaps to Make Strings Equal

Medium

1248

Count Number of Nice Subarrays

Medium

1249

Minimum Remove to Make Valid Parentheses

Medium

1253

Reconstruct a 2Row Binary Matrix

Medium

1254

Number of Closed Islands

Medium

1256

Encode Number

Medium

1257

Smallest Common Region

Medium

1258

Synonymous Sentences

Medium

1261

Find Elements in a Contaminated Binary Tree

Medium

1262

Greatest Sum Divisible by Three

Medium

1265

Print Immutable Linked List in Reverse

Medium

1267

Count Servers that Communicate

Medium

1268

Search Suggestions System

Medium

1272

Remove Interval

Medium

1273

Delete Tree Nodes

Medium

1276

Number of Burgers with No Waste of Ingredients

Medium

1277

Count Square Submatrices with All Ones

Medium

1282

Group the People Given the Group Size They Belong To

Medium

1283

Find the Smallest Divisor Given a Threshold

Medium

1286

Iterator for Combination

Medium

1288

Remove Covered Intervals

Medium

1291

Sequential Digits

Medium

1292

Maximum Side Length of a Square with Sum Less than or Equal to Threshold

Medium

1296

Divide Array in Sets of K Consecutive Numbers

Medium

1297

Maximum Number of Occurrences of a Substring

Medium

1300

Sum of Mutated Array Closest to Target

Medium

1302

Deepest Leaves Sum

Medium

1305

All Elements in Two Binary Search Trees

Medium

1306

Jump Game III

Medium

1310

XOR Queries of a Subarray

Medium

1311

Get Watched Videos by Your Friends

Medium

1314

Matrix Block Sum

Medium

1315

Sum of Nodes with EvenValued Grandparent

Medium

1318

Minimum Flips to Make a OR b Equal to c

Medium

1319

Number of Operations to Make Network Connected

Medium

1324

Print Words Vertically

Medium

1325

Delete Leaves With a Given Value

Medium

1328

Break a Palindrome

Medium

1329

Sort the Matrix Diagonally

Medium

1333

Filter Restaurants by VeganFriendly, Price and Distance

Medium

1334

Find the City With the Smallest Number of Neighbors at a Threshold Distance

Medium

1338

Reduce Array Size to The Half

Medium

1339

Maximum Product of Splitted Binary Tree

Medium

1343

Number of Subarrays of Size K and Average Greater than or Equal to Threshold

Medium

1344

Angle Between Hands of a Clock

Medium

1347

Minimum Number of Steps to Make Two Strings Anagram

Medium

1348

Tweet Counts Per Frequency

Medium

1352

Product of the Last K Numbers

Medium

1353

Maximum Number of Events That Can Be Attended

Medium

1357

Apply Discount Every n Orders

Medium

1358

Number of Substrings Containing All Three Characters

Medium

1361

Validate Binary Tree Nodes

Medium

1362

Closest Divisors

Medium

1366

Rank Teams by Votes

Medium

1367

Linked List in Binary Tree

Medium

1371

Find the Longest Substring Containing Vowels in Even Counts

Medium

1372

Longest ZigZag Path in a Binary Tree

Medium

1375

Number of Times Binary String Is PrefixAligned

Medium

1376

Time Needed to Inform All Employees

Medium

1381

Design a Stack With Increment Operation

Medium

1382

Balance a Binary Search Tree

Medium

1386

Cinema Seat Allocation

Medium

1387

Sort Integers by The Power Value

Medium

1390

Four Divisors

Medium

1391

Check if There is a Valid Path in a Grid

Medium

1395

Count Number of Teams

Medium

1396

Design Underground System

Medium

1428

Leftmost Column with at Least a One

Medium

1533

Find the Index of the Large Integer

Medium

1538

Guess the Majority in a Hidden Array

Medium

1631

Path With Minimum Effort

Medium

1637

Widest Vertical Area Between Two Points Containing No Points

Medium

1638

Count Substrings That Differ by One Character

Medium

1641

Count Sorted Vowel Strings

Medium

1642

Furthest Building You Can Reach

Medium

1647

Minimum Deletions to Make Character Frequencies Unique

Medium

1648

Sell DiminishingValued Colored Balls

Medium

1653

Minimum Deletions to Make String Balanced

Medium

1654

Minimum Jumps to Reach Home

Medium

1657

Determine if Two Strings Are Close

Medium

1658

Minimum Operations to Reduce X to Zero

Medium

1669

Merge In Between Linked Lists

Medium

1670

Design Front Middle Back Queue

Medium

1673

Find the Most Competitive Subsequence

Medium

1674

Minimum Moves to Make Array Complementary

Medium

1679

Max Number of KSum Pairs

Medium

1680

Concatenation of Consecutive Binary Numbers

Medium

1682

Longest Palindromic Subsequence II

Medium

1685

Sum of Absolute Differences in a Sorted Array

Medium

1686

Stone Game VI

Medium

1689

Partitioning Into Minimum Number Of DeciBinary Numbers

Medium

1690

Stone Game VII

Medium

1695

Maximum Erasure Value

Medium

1696

Jump Game VI

Medium

1698

Number of Distinct Substrings in a String

Medium

1701

Average Waiting Time

Medium

1702

Maximum Binary String After Change

Medium

1705

Maximum Number of Eaten Apples

Medium

1706

Where Will the Ball Fall

Medium

1711

Count Good Meals

Medium

1712

Ways to Split Array Into Three Subarrays

Medium

1717

Maximum Score From Removing Substrings

Medium

1718

Construct the Lexicographically Largest Valid Sequence

Medium

1721

Swapping Nodes in a Linked List

Medium

1722

Minimize Hamming Distance After Swap Operations

Medium

1726

Tuple with Same Product

Medium

1727

Largest Submatrix With Rearrangements

Medium

1730

Shortest Path to Get Food

Medium

1733

Minimum Number of People to Teach

Medium

1734

Decode XORed Permutation

Medium

1737

Change Minimum Characters to Satisfy One of Three Conditions

Medium

1738

Find Kth Largest XOR Coordinate Value

Medium

1740

Find Distance in a Binary Tree

Medium

1746

Maximum Subarray Sum After One Operation

Medium

1749

Maximum Absolute Sum of Any Subarray

Medium

1750

Minimum Length of String After Deleting Similar Ends

Medium

1753

Maximum Score From Removing Stones

Medium

1754

Largest Merge Of Two Strings

Medium

1760

Minimum Limit of Balls in a Bag

Medium

1762

Buildings With an Ocean View

Medium

1769

Minimum Number of Operations to Move All Balls to Each Box

Medium

1792

Maximum Average Pass Ratio

Medium

1794

Count Pairs of Equal Substrings With Minimum Difference

Medium

1797

Design Authentication Manager

Medium

1798

Maximum Number of Consecutive Values You Can Make

Medium

1801

Number of Orders in the Backlog

Medium

1802

Maximum Value at a Given Index in a Bounded Array

Medium

1804

Implement Trie II (Prefix Tree)

Medium

1806

Minimum Number of Operations to Reinitialize a Permutation

Medium

1807

Evaluate the Bracket Pairs of a String

Medium

1810

Minimum Path Cost in a Hidden Grid

Medium

1813

Sentence Similarity III

Medium

1814

Count Nice Pairs in an Array

Medium

1817

Finding the Users Active Minutes

Medium

1818

Minimum Absolute Sum Difference

Medium

1820

Maximum Number of Accepted Invitations

Medium

1823

Find the Winner of the Circular Game

Medium

1824

Minimum Sideway Jumps

Medium

1828

Queries on Number of Points Inside a Circle

Medium

1829

Maximum XOR for Each Query

Medium

1833

Maximum Ice Cream Bars

Medium

1836

Remove Duplicates From an Unsorted Linked List

Medium

1838

Frequency of the Most Frequent Element

Medium

1839

Longest Substring Of All Vowels in Order

Medium
