General
Introductory Problems
- Weird Algorithm22087 / 22999
- Missing Number18451 / 19652
- Repetitions16247 / 17199
- Increasing Array15038 / 15720
- Permutations13366 / 13875
- Number Spiral9247 / 10112
- Two Knights6893 / 7156
- Two Sets7318 / 7968
- Bit Strings8829 / 9337
- Trailing Zeros8360 / 8913
- Coin Piles7261 / 8035
- Palindrome Reorder6362 / 6880
- Gray Code666 / 790
- Tower of Hanoi568 / 594
- Creating Strings6102 / 6274
- Apple Division5331 / 6243
- Chessboard and Queens3150 / 3215
- Digit Queries339 / 419
- Grid Paths1319 / 1738
Sorting and Searching
- Distinct Numbers8925 / 9244
- Apartments5991 / 7019
- Ferris Wheel5761 / 6429
- Concert Tickets4439 / 5606
- Restaurant Customers4633 / 5090
- Movie Festival4403 / 4683
- Sum of Two Values5181 / 5702
- Maximum Subarray Sum5164 / 5367
- Stick Lengths4724 / 4926
- Missing Coin Sum425 / 461
- Collecting Numbers452 / 530
- Collecting Numbers II183 / 239
- Playlist3942 / 4652
- Towers3942 / 4274
- Traffic Lights2888 / 3320
- Josephus Problem I221 / 263
- Josephus Problem II106 / 157
- Nested Ranges Check116 / 128
- Nested Ranges Count98 / 108
- Room Allocation2403 / 2929
- Factory Machines2716 / 2966
- Tasks and Deadlines2691 / 2747
- Reading Books2389 / 2555
- Sum of Three Values2831 / 3215
- Sum of Four Values2121 / 2412
- Nearest Smaller Values2599 / 2755
- Subarray Sums I3117 / 3258
- Subarray Sums II2655 / 2958
- Subarray Divisibility2515 / 2676
- Subarray Distinct Values175 / 193
- Array Division2172 / 2292
- Sliding Median1678 / 2033
- Sliding Cost1207 / 1398
- Movie Festival II1241 / 1550
- Maximum Subarray Sum II1283 / 1551
Dynamic Programming
- Dice Combinations7706 / 8189
- Minimizing Coins6689 / 7135
- Coin Combinations I6169 / 6614
- Coin Combinations II5020 / 5779
- Removing Digits5777 / 5888
- Grid Paths5258 / 5468
- Book Shop4753 / 5281
- Array Description3246 / 3624
- Counting Towers215 / 238
- Edit Distance3629 / 3849
- Rectangle Cutting3184 / 3463
- Money Sums3642 / 3780
- Removal Game2600 / 2921
- Two Sets II2886 / 3150
- Increasing Subsequence3036 / 3494
- Projects1971 / 2258
- Elevator Rides334 / 479
- Counting Tilings66 / 75
- Counting Numbers104 / 115
Graph Algorithms
- Counting Rooms5152 / 5470
- Labyrinth3124 / 3920
- Building Roads4009 / 4176
- Message Route3514 / 3679
- Building Teams3413 / 3580
- Round Trip2675 / 2972
- Monsters1425 / 1908
- Shortest Routes I2642 / 2991
- Shortest Routes II2341 / 2531
- High Score1282 / 1871
- Flight Discount1583 / 1900
- Cycle Finding1291 / 1550
- Flight Routes1083 / 1205
- Round Trip II1291 / 1513
- Course Schedule1709 / 1783
- Longest Flight Route1167 / 1524
- Game Routes1333 / 1415
- Investigation912 / 1002
- Planets Queries I924 / 996
- Planets Queries II442 / 539
- Planets Cycles564 / 627
- Road Reparation1082 / 1115
- Road Construction1031 / 1059
- Flight Routes Check917 / 1008
- Planets and Kingdoms866 / 901
- Giant Pizza476 / 522
- Coin Collector601 / 666
- Mail Delivery532 / 612
- De Bruijn Sequence389 / 408
- Teleporters Path375 / 497
- Hamiltonian Flights430 / 509
- Knight's Tour348 / 401
- Download Speed464 / 538
- Police Chase391 / 417
- School Dance405 / 423
- Distinct Routes312 / 392
Range Queries
- Static Range Sum Queries3344 / 3493
- Static Range Minimum Queries2618 / 2789
- Dynamic Range Sum Queries2581 / 2694
- Dynamic Range Minimum Queries2325 / 2387
- Range Xor Queries2394 / 2438
- Range Update Queries1825 / 1962
- Forest Queries1588 / 1638
- Hotel Queries1387 / 1504
- List Removals1200 / 1283
- Salary Queries956 / 1132
- Prefix Sum Queries106 / 114
- Pizzeria Queries83 / 87
- Subarray Sum Queries839 / 941
- Distinct Values Queries807 / 957
- Increasing Array Queries43 / 52
- Forest Queries II647 / 682
- Range Updates and Sums588 / 706
- Polynomial Queries503 / 583
- Range Queries and Copies334 / 350
Tree Algorithms
- Subordinates2494 / 2704
- Tree Matching1378 / 1692
- Tree Diameter2104 / 2226
- Tree Distances I1443 / 1608
- Tree Distances II1199 / 1248
- Company Queries I1267 / 1348
- Company Queries II1226 / 1283
- Distance Queries1202 / 1275
- Counting Paths788 / 840
- Subtree Queries913 / 971
- Path Queries750 / 788
- Path Queries II48 / 62
- Distinct Colors640 / 839
- Finding a Centroid107 / 111
- Fixed-Length Paths I40 / 44
- Fixed-Length Paths II31 / 34
Mathematics
- Josephus Queries43 / 63
- Exponentiation3201 / 3575
- Exponentiation II2216 / 2809
- Counting Divisors2360 / 2758
- Common Divisors1630 / 1946
- Sum of Divisors929 / 1552
- Divisor Analysis64 / 96
- Prime Multiples97 / 114
- Counting Coprime Pairs55 / 68
- Binomial Coefficients1288 / 1503
- Creating Strings II1084 / 1196
- Distributing Apples995 / 1075
- Christmas Party863 / 940
- Bracket Sequences I77 / 85
- Bracket Sequences II29 / 37
- Counting Necklaces36 / 38
- Counting Grids30 / 32
- Fibonacci Numbers1094 / 1392
- Throwing Dice692 / 761
- Graph Paths I570 / 617
- Graph Paths II468 / 486
- Dice Probability559 / 604
- Moving Robots300 / 320
- Candy Lottery408 / 422
- Inversion Probability368 / 376
- Stick Game541 / 556
- Nim Game I670 / 695
- Nim Game II556 / 582
- Stair Game360 / 419
- Grundy's Game33 / 50
- Another Game38 / 44
String Algorithms
- Word Combinations452 / 747
- String Matching921 / 1283
- Finding Borders647 / 762
- Finding Periods407 / 490
- Minimal Rotation356 / 524
- Longest Palindrome423 / 570
- Required Substring230 / 393
- Palindrome Queries32 / 36
- Finding Patterns38 / 49
- Counting Patterns36 / 40
- Pattern Positions33 / 35
- Distinct Substrings34 / 38
- Repeating Substring32 / 35
- String Functions28 / 29
- Substring Order I24 / 25
- Substring Order II17 / 21
- Substring Distribution26 / 28
Geometry
- Point Location Test207 / 231
- Line Segment Intersection96 / 130
- Polygon Area113 / 119
- Point in Polygon55 / 71
- Polygon Lattice Points57 / 59
- Minimum Euclidean Distance35 / 48
- Convex Hull75 / 95
Advanced Techniques
- Meet in the Middle462 / 601
- Hamming Distance55 / 61
- Beautiful Subgrids28 / 42
- Reachable Nodes32 / 37
- Reachability Queries23 / 31
- Cut and Paste27 / 30
- Substring Reversals24 / 27
- Reversals and Sums24 / 25
- Necessary Roads24 / 25
- Necessary Cities23 / 24
- Eulerian Subgraphs17 / 18
- Monster Game I20 / 21
- Monster Game II20 / 21
- Subarray Squares17 / 18
- Houses and Schools8 / 9
- Knuth Division13 / 19
- Apples and Bananas18 / 21
- One Bit Positions19 / 21
- Signal Processing19 / 20
- New Roads Queries26 / 29
- Dynamic Connectivity14 / 16
- Parcel Delivery17 / 20
- Task Assignment16 / 17
- Distinct Routes II14 / 15
Additional Problems
- Shortest Subsequence596 / 805
- Counting Bits635 / 802
- Swap Game228 / 310
- Prüfer Code257 / 272
- Acyclic Graph Edges341 / 361
- Strongly Connected Edges20 / 21
- Even Outdegree Edges14 / 16
- Multiplication Table28 / 32
- Advertisement406 / 431
- Special Substrings14 / 16
- Permutation Inversions16 / 19
- Maximum Xor Subarray318 / 346
- Movie Festival Queries162 / 185
- Chess Tournament182 / 213
- Tree Traversals182 / 187
- Network Renovation143 / 214
- Graph Girth258 / 291
- Intersection Points194 / 208
- Inverse Inversions32 / 33
- Monotone Subsequences16 / 18
- String Reorder129 / 144
- Stack Weights11 / 13
- Pyramid Array121 / 150
- Increasing Subsequence II258 / 280
- String Removals182 / 189
- Bit Inversions270 / 298
- Xor Pyramid32 / 36
- Writing Numbers176 / 192
- String Transform109 / 136
- Letter Pair Move Game3 / 4
- Maximum Building I263 / 272
- Sorting Methods167 / 178
- Cyclic Array110 / 152
- List of Sums13 / 16
- Increasing Array II12 / 19
- Food Division97 / 118
- Bit Problem126 / 140
- Swap Round Sorting73 / 97
- Binary Subsequences8 / 11
- Tree Isomorphism I141 / 172
- Counting Sequences20 / 21
- Critical Cities68 / 101
- School Excursion154 / 168
- Coin Grid86 / 109
- Robot Path49 / 99
- Programmers and Artists9 / 11
- Course Schedule II136 / 210
- Removing Digits II6 / 9
- Coin Arrangement5 / 8
- Counting Bishops10 / 11
- Grid Puzzle I12 / 14
- Grid Puzzle II9 / 10
- Empty String132 / 173
- Grid Paths144 / 183
- Bit Substrings8 / 9
- Reversal Sorting9 / 10
- Counting Reorders5 / 6
- Book Shop II149 / 169
- Network Breakdown141 / 146
- Visiting Cities126 / 167
- Missing Coin Sum Queries10 / 16
- Number Grid185 / 234
- Maximum Building II78 / 95
- Filling Trominos6 / 12
- Stick Divisions261 / 315
- Coding Company109 / 139
- Flight Route Requests92 / 99
- Two Stacks Sorting4 / 12
- Tree Isomorphism II112 / 135
- Forbidden Cities88 / 107
- Area of Rectangles124 / 142
- Grid Completion4 / 6
- Creating Offices63 / 88
- Permutations II167 / 185
- Functional Graph Distribution6 / 7
- New Flight Routes60 / 130
- Grid Path Construction5 / 6