General
Introductory Problems
- Weird Algorithm162476 / 169944
- Missing Number140254 / 146858
- Repetitions121987 / 126763
- Increasing Array114836 / 118809
- Permutations100849 / 103837
- Number Spiral71352 / 77609
- Two Knights54727 / 56420
- Two Sets59562 / 63944
- Bit Strings68113 / 71815
- Trailing Zeros63201 / 67142
- Coin Piles56036 / 61165
- Palindrome Reorder52130 / 54970
- Gray Code35193 / 39422
- Tower of Hanoi32704 / 33995
- Creating Strings43970 / 45081
- Apple Division44272 / 49898
- Chessboard and Queens26762 / 27237
- Raab Game I5594 / 6356
- Mex Grid Construction5434 / 5741
- Knight Moves Grid5469 / 5589
- Grid Coloring I4574 / 4736
- Digit Queries18873 / 21832
- String Reorder4153 / 4816
- Grid Path Description10477 / 13562
Sorting and Searching
- Distinct Numbers80317 / 86686
- Apartments59961 / 66317
- Ferris Wheel57554 / 61897
- Concert Tickets46173 / 53582
- Restaurant Customers46972 / 50601
- Movie Festival45396 / 48008
- Sum of Two Values52843 / 59003
- Maximum Subarray Sum50801 / 53004
- Stick Lengths45400 / 47446
- Missing Coin Sum34384 / 35622
- Collecting Numbers35260 / 37659
- Collecting Numbers II14967 / 18963
- Playlist35179 / 40066
- Towers35287 / 37761
- Traffic Lights27400 / 30595
- Distinct Values Subarrays7514 / 8707
- Distinct Values Subsequences5742 / 6345
- Josephus Problem I21044 / 23121
- Josephus Problem II11441 / 15731
- Nested Ranges Check12315 / 14080
- Nested Ranges Count8280 / 9744
- Room Allocation20630 / 23609
- Factory Machines29738 / 32298
- Tasks and Deadlines23774 / 24272
- Reading Books19234 / 20596
- Sum of Three Values28096 / 31045
- Sum of Four Values17460 / 19379
- Nearest Smaller Values23436 / 24229
- Subarray Sums I31108 / 33118
- Subarray Sums II28278 / 33429
- Subarray Divisibility25611 / 27851
- Distinct Values Subarrays II15512 / 16985
- Array Division24296 / 25548
- Movie Festival II13029 / 15686
- Maximum Subarray Sum II12112 / 14411
Dynamic Programming
- Dice Combinations83578 / 88331
- Minimizing Coins72264 / 77535
- Coin Combinations I66063 / 71360
- Coin Combinations II55911 / 63079
- Removing Digits62172 / 63406
- Grid Paths I58476 / 60097
- Book Shop52355 / 57448
- Array Description38602 / 42770
- Counting Towers23599 / 24994
- Edit Distance38672 / 40797
- Longest Common Subsequence10853 / 11253
- Rectangle Cutting31891 / 34785
- Minimal Grid Path4776 / 8449
- Money Sums37711 / 39119
- Removal Game22746 / 30123
- Two Sets II29658 / 31860
- Mountain Range3312 / 5991
- Increasing Subsequence30314 / 34005
- Projects21018 / 23448
- Elevator Rides13496 / 16903
- Counting Tilings7922 / 8615
- Counting Numbers11251 / 12616
- Increasing Subsequence II4915 / 5722
Graph Algorithms
- Counting Rooms57762 / 60620
- Labyrinth40247 / 47932
- Building Roads50322 / 52126
- Message Route43370 / 45066
- Building Teams40960 / 43125
- Round Trip32405 / 35229
- Monsters22454 / 26309
- Shortest Routes I35700 / 39245
- Shortest Routes II28867 / 32289
- High Score17804 / 24788
- Flight Discount22996 / 26789
- Cycle Finding16249 / 19798
- Flight Routes15770 / 17576
- Round Trip II17837 / 19984
- Course Schedule23661 / 24943
- Longest Flight Route16870 / 20730
- Game Routes18711 / 19983
- Investigation13907 / 14915
- Planets Queries I12082 / 14123
- Planets Queries II4390 / 5533
- Planets Cycles7376 / 8216
- Road Reparation18331 / 19101
- Road Construction20129 / 20772
- Flight Routes Check16027 / 17340
- Planets and Kingdoms12872 / 13386
- Giant Pizza5393 / 5918
- Coin Collector8453 / 9325
- Mail Delivery6940 / 7583
- De Bruijn Sequence3675 / 3844
- Teleporters Path5322 / 6056
- Hamiltonian Flights8051 / 9158
- Knight's Tour3049 / 3682
- Download Speed5330 / 7087
- Police Chase4264 / 4771
- School Dance4677 / 4939
- Distinct Routes3302 / 4297
Range Queries
- Static Range Sum Queries40335 / 42116
- Static Range Minimum Queries28031 / 30007
- Dynamic Range Sum Queries29079 / 30354
- Dynamic Range Minimum Queries26324 / 26953
- Range Xor Queries27103 / 27462
- Range Update Queries21620 / 23155
- Forest Queries22175 / 22970
- Hotel Queries15709 / 16636
- List Removals13019 / 13668
- Salary Queries9858 / 12366
- Prefix Sum Queries8388 / 9054
- Pizzeria Queries6752 / 6994
- Visible Buildings Queries1757 / 1918
- Range Interval Queries1360 / 1828
- Subarray Sum Queries7895 / 8546
- Subarray Sum Queries II1947 / 2013
- Distinct Values Queries7418 / 9088
- Distinct Values Queries II1138 / 1293
- Increasing Array Queries2853 / 3262
- Movie Festival Queries1506 / 1670
- Forest Queries II4706 / 5055
- Range Updates and Sums6439 / 7610
- Polynomial Queries4762 / 5595
- Range Queries and Copies3378 / 3607
- Missing Coin Sum Queries778 / 1015
Tree Algorithms
- Subordinates33019 / 35330
- Tree Matching18810 / 21806
- Tree Diameter26912 / 28508
- Tree Distances I20664 / 22189
- Tree Distances II16860 / 17641
- Company Queries I18800 / 19782
- Company Queries II17601 / 18528
- Distance Queries15917 / 17078
- Counting Paths10015 / 10601
- Subtree Queries12013 / 12789
- Path Queries9658 / 10223
- Path Queries II4025 / 5990
- Distinct Colors9281 / 10210
- Finding a Centroid7497 / 7799
- Fixed-Length Paths I3686 / 4700
- Fixed-Length Paths II1748 / 3141
Mathematics
- Josephus Queries5198 / 6549
- Exponentiation26189 / 27927
- Exponentiation II18338 / 21873
- Counting Divisors23881 / 26939
- Common Divisors15444 / 17866
- Sum of Divisors8687 / 12891
- Divisor Analysis5962 / 7949
- Prime Multiples6904 / 8036
- Counting Coprime Pairs4568 / 5287
- Next Prime2112 / 2421
- Binomial Coefficients11112 / 12299
- Creating Strings II9280 / 9785
- Distributing Apples8847 / 9505
- Christmas Party7275 / 7782
- Permutation Order1016 / 1038
- Permutation Rounds1399 / 1558
- Bracket Sequences I4934 / 5368
- Bracket Sequences II2608 / 2978
- Counting Necklaces2388 / 2582
- Counting Grids1984 / 2108
- Fibonacci Numbers7433 / 9297
- Throwing Dice3885 / 4220
- Graph Paths I3746 / 4007
- Graph Paths II3128 / 3275
- System of Linear Equations511 / 558
- Sum of Four Squares744 / 873
- Triangle Number Sums637 / 774
- Dice Probability3331 / 3587
- Moving Robots1732 / 1829
- Candy Lottery1655 / 3268
- Inversion Probability464 / 2430
- Stick Game3786 / 3877
- Nim Game I5036 / 5219
- Nim Game II3984 / 4141
- Stair Game2717 / 2947
- Grundy's Game1893 / 2477
- Another Game2131 / 2293
String Algorithms
- Word Combinations6391 / 9182
- String Matching12343 / 16444
- Finding Borders9051 / 9883
- Finding Periods6421 / 7265
- Minimal Rotation3123 / 4705
- Longest Palindrome4704 / 6189
- All Palindromes685 / 778
- Required Substring1807 / 2722
- Palindrome Queries2207 / 2573
- Finding Patterns2074 / 2919
- Counting Patterns1962 / 2424
- Pattern Positions1654 / 2008
- Distinct Substrings1863 / 2219
- Distinct Subsequences1168 / 1242
- Repeating Substring2015 / 2335
- String Functions1758 / 1844
- Inverse Suffix Array255 / 302
- String Transform572 / 692
- Substring Order I1268 / 1412
- Substring Order II839 / 1091
- Substring Distribution1175 / 1275
Geometry
- Point Location Test7909 / 8806
- Line Segment Intersection4692 / 5869
- Polygon Area5411 / 5718
- Point in Polygon2982 / 3790
- Polygon Lattice Points2512 / 2595
- Minimum Euclidean Distance2161 / 3062
- Convex Hull3634 / 4334
- Maximum Manhattan Distances647 / 670
- All Manhattan Distances637 / 696
- Intersection Points2127 / 2292
- Line Segments Trace I344 / 358
- Line Segments Trace II284 / 301
- Lines and Queries I398 / 416
- Lines and Queries II343 / 355
- Area of Rectangles1227 / 1372
- Robot Path330 / 611
Advanced Techniques
- Meet in the Middle7180 / 9879
- Hamming Distance3408 / 3727
- Corner Subgrid Check359 / 553
- Corner Subgrid Count2350 / 2638
- Reachable Nodes2424 / 2604
- Reachability Queries1620 / 1905
- Cut and Paste1648 / 1826
- Substring Reversals1434 / 1555
- Reversals and Sums1456 / 1561
- Necessary Roads2113 / 2170
- Necessary Cities1954 / 2044
- Eulerian Subgraphs852 / 896
- Monster Game I1238 / 1376
- Monster Game II1096 / 1173
- Subarray Squares1547 / 1811
- Houses and Schools829 / 991
- Knuth Division1014 / 1144
- Apples and Bananas1160 / 1257
- One Bit Positions905 / 986
- Signal Processing867 / 928
- New Roads Queries2357 / 2847
- Dynamic Connectivity1082 / 1219
- Parcel Delivery830 / 915
- Task Assignment962 / 1036
- Distinct Routes II625 / 712
Sliding Window Problems
- Sliding Window Sum5963 / 6183
- Sliding Window Minimum4457 / 5096
- Sliding Window Xor4370 / 4429
- Sliding Window Or1926 / 3296
- Sliding Window Distinct Values2972 / 3637
- Sliding Window Mode2413 / 2564
- Sliding Window Mex2228 / 2351
- Sliding Window Median14299 / 16318
- Sliding Window Cost9364 / 10797
- Sliding Window Inversions1250 / 1326
- Sliding Window Advertisement236 / 378
Interactive Problems
- Hidden Integer2351 / 2446
- Hidden Permutation1003 / 1172
- K-th Highest Score439 / 533
- Permuted Binary Strings548 / 563
- Colored Chairs496 / 523
- Inversion Sorting285 / 318
Bitwise Operations
- Counting Bits5340 / 6903
- Maximum Xor Subarray3179 / 3626
- Maximum Xor Subset1053 / 1148
- Number of Subset Xors932 / 951
- K Subset Xors466 / 553
- All Subarray Xors284 / 469
- Xor Pyramid Peak2155 / 2607
- Xor Pyramid Diagonal331 / 370
- Xor Pyramid Row282 / 333
- SOS Bit Problem2260 / 2401
- And Subset Count444 / 462
Construction Problems
- Inverse Inversions1762 / 1876
- Monotone Subsequences1062 / 1253
- Third Permutation428 / 517
- Permutation Prime Sums430 / 465
- Chess Tournament1256 / 1452
- Distinct Sums Grid135 / 211
- Filling Trominos244 / 442
- Grid Path Construction123 / 440
Advanced Graph Problems
- Nearest Shops735 / 948
- Prüfer Code1594 / 1712
- Tree Traversals1293 / 1424
- Course Schedule II2016 / 2879
- Acyclic Graph Edges2297 / 2433
- Strongly Connected Edges1569 / 1850
- Even Outdegree Edges1427 / 1664
- Graph Girth3565 / 4049
- Fixed Length Walk Queries368 / 409
- Transfer Speeds Sum428 / 442
- MST Edge Check651 / 708
- MST Edge Set Check246 / 279
- MST Edge Cost397 / 414
- Network Breakdown1210 / 1318
- Tree Coin Collecting I351 / 383
- Tree Coin Collecting II189 / 222
- Tree Isomorphism I1133 / 1348
- Tree Isomorphism II931 / 1074
- Flight Route Requests517 / 637
- Critical Cities438 / 675
- Visiting Cities702 / 926
- Graph Coloring232 / 272
- Bus Companies273 / 281
- Split into Two Paths98 / 176
- Network Renovation964 / 1281
- Forbidden Cities876 / 1143
- Creating Offices431 / 563
- New Flight Routes343 / 921
Counting Problems
- Filled Subgrid Count I594 / 668
- Filled Subgrid Count II320 / 393
- All Letter Subgrid Count I176 / 267
- All Letter Subgrid Count II142 / 180
- Border Subgrid Count I95 / 165
- Border Subgrid Count II103 / 120
- Raab Game II108 / 124
- Empty String1736 / 2113
- Permutation Inversions1065 / 1174
- Counting Bishops409 / 456
- Counting Sequences678 / 732
- Grid Paths II783 / 981
- Counting Permutations919 / 1037
- Grid Completion231 / 293
- Counting Reorders251 / 361
- Tournament Graph Distribution108 / 115
- Collecting Numbers Distribution114 / 122
- Functional Graph Distribution252 / 310
Additional Problems I
- Shortest Subsequence3074 / 4050
- Distinct Values Sum674 / 697
- Distinct Values Splits489 / 518
- Swap Game2091 / 2691
- Beautiful Permutation II546 / 829
- Multiplication Table7077 / 7881
- Bubble Sort Rounds I411 / 472
- Bubble Sort Rounds II268 / 304
- Nearest Campsites I182 / 212
- Nearest Campsites II178 / 190
- Advertisement4523 / 4792
- Special Substrings1006 / 1105
- Counting LCM Arrays275 / 301
- Square Subsets225 / 250
- Subarray Sum Constraints405 / 432
- Water Containers Moves174 / 184
- Water Containers Queries210 / 220
- Stack Weights602 / 719
- Maximum Average Subarrays172 / 190
- Subsets with Fixed Average213 / 231
- Two Array Average209 / 234
- Pyramid Array774 / 938
- Permutation Subsequence251 / 259
- Bit Inversions2388 / 2702
- Writing Numbers755 / 815
- Letter Pair Move Game208 / 288
- Maximum Building I2139 / 2231
- Sorting Methods790 / 844
- Cyclic Array1237 / 1407
- List of Sums501 / 650
Additional Problems II
- Bouncing Ball Steps235 / 260
- Bouncing Ball Cycle91 / 129
- Knight Moves Queries119 / 142
- K Subset Sums I190 / 245
- K Subset Sums II109 / 142
- Increasing Array II818 / 934
- Food Division532 / 639
- Swap Round Sorting423 / 520
- Binary Subsequences297 / 432
- School Excursion1420 / 1504
- Coin Grid911 / 1064
- Grid Coloring II138 / 179
- Programmers and Artists514 / 718
- Removing Digits II218 / 475
- Coin Arrangement343 / 456
- Replace with Difference129 / 154
- Grid Puzzle I553 / 608
- Grid Puzzle II529 / 582
- Bit Substrings407 / 494
- Reversal Sorting362 / 438
- Book Shop II1272 / 1448
- GCD Subsets415 / 427
- Minimum Cost Pairs142 / 186
- Same Sum Subsets115 / 220
- Mex Grid Queries868 / 1016
- Maximum Building II457 / 563
- Stick Divisions3903 / 4572
- Stick Difference60 / 257
- Coding Company1546 / 2020
- Two Stacks Sorting183 / 587