General
Introductory Problems
- Weird Algorithm99103 / 103811
- Missing Number84343 / 88977
- Repetitions73637 / 77161
- Increasing Array68727 / 71626
- Permutations60455 / 62528
- Number Spiral42800 / 46678
- Two Knights32093 / 33247
- Two Sets34682 / 37704
- Bit Strings40408 / 42687
- Trailing Zeros37829 / 40462
- Coin Piles33316 / 36773
- Palindrome Reorder30418 / 32440
- Gray Code18919 / 21643
- Tower of Hanoi17658 / 18414
- Creating Strings26230 / 27033
- Apple Division25433 / 29191
- Chessboard and Queens15117 / 15432
- Digit Queries10203 / 12274
- Grid Paths6298 / 8050
Sorting and Searching
- Distinct Numbers46444 / 50935
- Apartments33833 / 38465
- Ferris Wheel32185 / 35228
- Concert Tickets25767 / 30689
- Restaurant Customers26473 / 28901
- Movie Festival24905 / 26646
- Sum of Two Values29380 / 33535
- Maximum Subarray Sum28950 / 30458
- Stick Lengths25646 / 27098
- Missing Coin Sum17908 / 18645
- Collecting Numbers18546 / 20084
- Collecting Numbers II7389 / 9686
- Playlist19270 / 22492
- Towers19759 / 21379
- Traffic Lights15489 / 17466
- Josephus Problem I10538 / 11951
- Josephus Problem II6102 / 7958
- Nested Ranges Check5993 / 7049
- Nested Ranges Count4271 / 4930
- Room Allocation11259 / 13120
- Factory Machines14575 / 16339
- Tasks and Deadlines13118 / 13432
- Reading Books10449 / 11233
- Sum of Three Values15233 / 17282
- Sum of Four Values9659 / 10930
- Nearest Smaller Values12892 / 13404
- Subarray Sums I16631 / 17918
- Subarray Sums II15386 / 17571
- Subarray Divisibility13495 / 14899
- Subarray Distinct Values7685 / 8328
- Array Division12353 / 13117
- Sliding Window Median8169 / 9347
- Sliding Window Cost5697 / 6562
- Movie Festival II7049 / 8546
- Maximum Subarray Sum II6452 / 7750
Dynamic Programming
- Dice Combinations45829 / 48836
- Minimizing Coins39447 / 42722
- Coin Combinations I36266 / 39584
- Coin Combinations II30450 / 34966
- Removing Digits33659 / 34534
- Grid Paths32014 / 33101
- Book Shop28147 / 31496
- Array Description20323 / 22947
- Counting Towers11570 / 12286
- Edit Distance21096 / 22441
- Rectangle Cutting17596 / 19314
- Money Sums21000 / 21941
- Removal Game14992 / 16688
- Two Sets II16548 / 18079
- Increasing Subsequence17012 / 19339
- Projects11450 / 13005
- Elevator Rides6912 / 8898
- Counting Tilings3942 / 4345
- Counting Numbers5315 / 6071
Graph Algorithms
- Counting Rooms31292 / 33311
- Labyrinth20513 / 25509
- Building Roads27086 / 28253
- Message Route23007 / 24136
- Building Teams22077 / 23203
- Round Trip17140 / 18942
- Monsters10805 / 13316
- Shortest Routes I18379 / 21019
- Shortest Routes II15539 / 17048
- High Score7788 / 12805
- Flight Discount10839 / 13294
- Cycle Finding8053 / 10155
- Flight Routes7486 / 8450
- Round Trip II8991 / 10345
- Course Schedule12473 / 13033
- Longest Flight Route7700 / 10356
- Game Routes9022 / 9947
- Investigation6605 / 7184
- Planets Queries I5593 / 6837
- Planets Queries II2240 / 2786
- Planets Cycles3736 / 4209
- Road Reparation8944 / 9406
- Road Construction9438 / 9814
- Flight Routes Check8014 / 8861
- Planets and Kingdoms6456 / 6736
- Giant Pizza2597 / 2928
- Coin Collector4024 / 4567
- Mail Delivery3493 / 3891
- De Bruijn Sequence1875 / 1976
- Teleporters Path2765 / 3102
- Hamiltonian Flights3872 / 4410
- Knight's Tour1630 / 1933
- Download Speed2698 / 3828
- Police Chase2195 / 2522
- School Dance2413 / 2575
- Distinct Routes1546 / 2116
Range Queries
- Static Range Sum Queries21309 / 22308
- Static Range Minimum Queries15847 / 16974
- Dynamic Range Sum Queries16324 / 17098
- Dynamic Range Minimum Queries14839 / 15243
- Range Xor Queries15009 / 15240
- Range Update Queries11951 / 12890
- Forest Queries11723 / 12210
- Hotel Queries8562 / 9051
- List Removals7129 / 7536
- Salary Queries5277 / 6405
- Prefix Sum Queries4252 / 4654
- Pizzeria Queries3470 / 3604
- Subarray Sum Queries4418 / 4948
- Distinct Values Queries4141 / 5053
- Increasing Array Queries1494 / 1723
- Forest Queries II2851 / 3091
- Range Updates and Sums3409 / 4175
- Polynomial Queries2613 / 3076
- Range Queries and Copies1840 / 1996
Tree Algorithms
- Subordinates17623 / 19075
- Tree Matching9862 / 11650
- Tree Diameter14595 / 15648
- Tree Distances I10833 / 11762
- Tree Distances II8873 / 9276
- Company Queries I9795 / 10379
- Company Queries II9185 / 9710
- Distance Queries8573 / 9212
- Counting Paths5122 / 5493
- Subtree Queries6321 / 6776
- Path Queries5033 / 5331
- Path Queries II1785 / 2979
- Distinct Colors4795 / 5408
- Finding a Centroid3935 / 4119
- Fixed-Length Paths I1641 / 2357
- Fixed-Length Paths II668 / 1592
Mathematics
- Josephus Queries2557 / 3232
- Exponentiation14849 / 16060
- Exponentiation II10611 / 13078
- Counting Divisors12809 / 14680
- Common Divisors8588 / 10316
- Sum of Divisors4897 / 7511
- Divisor Analysis3178 / 4246
- Prime Multiples3456 / 4098
- Counting Coprime Pairs2179 / 2580
- Binomial Coefficients6002 / 6812
- Creating Strings II5041 / 5401
- Distributing Apples4927 / 5344
- Christmas Party3819 / 4154
- Bracket Sequences I2592 / 2877
- Bracket Sequences II1334 / 1540
- Counting Necklaces1292 / 1407
- Counting Grids1038 / 1111
- Fibonacci Numbers4395 / 5661
- Throwing Dice2388 / 2597
- Graph Paths I2179 / 2350
- Graph Paths II1825 / 1914
- Dice Probability2074 / 2204
- Moving Robots1042 / 1113
- Candy Lottery1601 / 1647
- Inversion Probability471 / 1438
- Stick Game2131 / 2192
- Nim Game I2689 / 2804
- Nim Game II2191 / 2291
- Stair Game1511 / 1658
- Grundy's Game970 / 1254
- Another Game1106 / 1207
String Algorithms
- Word Combinations3143 / 4824
- String Matching6277 / 9030
- Finding Borders4636 / 5194
- Finding Periods3166 / 3602
- Minimal Rotation1588 / 2595
- Longest Palindrome2395 / 3357
- Required Substring933 / 1516
- Palindrome Queries1156 / 1389
- Finding Patterns994 / 1469
- Counting Patterns895 / 1186
- Pattern Positions794 / 1015
- Distinct Substrings943 / 1138
- Repeating Substring962 / 1085
- String Functions915 / 967
- Substring Order I681 / 732
- Substring Order II446 / 567
- Substring Distribution619 / 678
Geometry
- Point Location Test4196 / 4837
- Line Segment Intersection2539 / 3320
- Polygon Area3046 / 3277
- Point in Polygon1671 / 2132
- Polygon Lattice Points1428 / 1485
- Minimum Euclidean Distance1301 / 1787
- Convex Hull2098 / 2554
Advanced Techniques
- Meet in the Middle3612 / 5572
- Hamming Distance1989 / 2156
- Beautiful Subgrids1402 / 1578
- Reachable Nodes1415 / 1538
- Reachability Queries976 / 1157
- Cut and Paste921 / 1039
- Substring Reversals807 / 887
- Reversals and Sums806 / 881
- Necessary Roads1215 / 1252
- Necessary Cities1134 / 1193
- Eulerian Subgraphs512 / 542
- Monster Game I739 / 813
- Monster Game II661 / 717
- Subarray Squares732 / 864
- Houses and Schools477 / 552
- Knuth Division559 / 634
- Apples and Bananas519 / 577
- One Bit Positions494 / 550
- Signal Processing462 / 506
- New Roads Queries1209 / 1475
- Dynamic Connectivity557 / 633
- Parcel Delivery442 / 504
- Task Assignment422 / 459
- Distinct Routes II349 / 408
Additional Problems
- Shortest Subsequence1998 / 2568
- Counting Bits2281 / 2953
- Swap Game1243 / 1602
- Prüfer Code878 / 974
- Acyclic Graph Edges1367 / 1461
- Strongly Connected Edges857 / 944
- Even Outdegree Edges784 / 913
- Multiplication Table2965 / 3385
- Advertisement2551 / 2722
- Special Substrings582 / 631
- Permutation Inversions630 / 697
- Maximum Xor Subarray1470 / 1609
- Movie Festival Queries646 / 724
- Chess Tournament731 / 838
- Tree Traversals703 / 789
- Network Renovation620 / 823
- Graph Girth1891 / 2209
- Intersection Points1158 / 1246
- Inverse Inversions634 / 666
- Monotone Subsequences431 / 480
- String Reorder512 / 566
- Stack Weights373 / 436
- Pyramid Array498 / 593
- Increasing Subsequence II1465 / 1591
- String Removals637 / 693
- Bit Inversions1491 / 1741
- Xor Pyramid781 / 996
- Writing Numbers510 / 554
- String Transform329 / 409
- Letter Pair Move Game117 / 173
- Maximum Building I1335 / 1400
- Sorting Methods536 / 574
- Cyclic Array667 / 768
- List of Sums301 / 405
- Increasing Array II505 / 575
- Food Division368 / 436
- Bit Problem971 / 1047
- Swap Round Sorting285 / 355
- Binary Subsequences149 / 237
- Tree Isomorphism I661 / 769
- Counting Sequences382 / 413
- Critical Cities252 / 400
- School Excursion867 / 926
- Coin Grid470 / 560
- Robot Path198 / 342
- Programmers and Artists317 / 407
- Course Schedule II1033 / 1466
- Removing Digits II127 / 271
- Coin Arrangement215 / 284
- Counting Bishops226 / 255
- Grid Puzzle I330 / 361
- Grid Puzzle II242 / 272
- Empty String929 / 1118
- Grid Paths506 / 630
- Bit Substrings228 / 285
- Reversal Sorting218 / 265
- Counting Reorders132 / 200
- Book Shop II656 / 747
- Network Breakdown621 / 661
- Visiting Cities460 / 599
- Missing Coin Sum Queries254 / 338
- Number Grid592 / 709
- Maximum Building II295 / 363
- Filling Trominos126 / 215
- Stick Divisions2366 / 2806
- Coding Company901 / 1147
- Flight Route Requests289 / 351
- Two Stacks Sorting94 / 325
- Tree Isomorphism II544 / 634
- Forbidden Cities454 / 595
- Area of Rectangles687 / 775
- Grid Completion132 / 175
- Creating Offices257 / 336
- Permutations II579 / 663
- Functional Graph Distribution146 / 184
- New Flight Routes204 / 489
- Grid Path Construction66 / 239