General
Introductory Problems
- Weird Algorithm27009 / 28115
- Missing Number22659 / 24063
- Repetitions19952 / 21087
- Increasing Array18427 / 19270
- Permutations16405 / 17023
- Number Spiral11376 / 12424
- Two Knights8475 / 8790
- Two Sets9059 / 9875
- Bit Strings10930 / 11567
- Trailing Zeros10333 / 11016
- Coin Piles8940 / 9923
- Palindrome Reorder7893 / 8493
- Gray Code2139 / 2461
- Tower of Hanoi1843 / 1930
- Creating Strings7365 / 7586
- Apple Division6535 / 7642
- Chessboard and Queens3862 / 3941
- Digit Queries1044 / 1311
- Grid Paths1581 / 2094
Sorting and Searching
- Distinct Numbers11221 / 11634
- Apartments7598 / 8846
- Ferris Wheel7246 / 8082
- Concert Tickets5596 / 6976
- Restaurant Customers5814 / 6409
- Movie Festival5541 / 5921
- Sum of Two Values6567 / 7245
- Maximum Subarray Sum6520 / 6819
- Stick Lengths5922 / 6166
- Missing Coin Sum1709 / 1797
- Collecting Numbers1703 / 1902
- Collecting Numbers II644 / 847
- Playlist4805 / 5629
- Towers4838 / 5244
- Traffic Lights3560 / 4084
- Josephus Problem I890 / 1076
- Josephus Problem II515 / 705
- Nested Ranges Check412 / 517
- Nested Ranges Count352 / 393
- Room Allocation2865 / 3484
- Factory Machines3298 / 3599
- Tasks and Deadlines3237 / 3312
- Reading Books2824 / 3024
- Sum of Three Values3517 / 3990
- Sum of Four Values2538 / 2864
- Nearest Smaller Values3117 / 3286
- Subarray Sums I3817 / 3991
- Subarray Sums II3259 / 3664
- Subarray Divisibility3080 / 3306
- Subarray Distinct Values657 / 706
- Array Division2580 / 2714
- Sliding Median2025 / 2427
- Sliding Cost1428 / 1643
- Movie Festival II1548 / 1933
- Maximum Subarray Sum II1568 / 1885
Dynamic Programming
- Dice Combinations9754 / 10389
- Minimizing Coins8477 / 9058
- Coin Combinations I7852 / 8432
- Coin Combinations II6449 / 7392
- Removing Digits7338 / 7471
- Grid Paths6727 / 6975
- Book Shop6028 / 6685
- Array Description4169 / 4638
- Counting Towers836 / 919
- Edit Distance4534 / 4809
- Rectangle Cutting3965 / 4322
- Money Sums4562 / 4737
- Removal Game3243 / 3607
- Two Sets II3591 / 3910
- Increasing Subsequence3739 / 4301
- Projects2404 / 2749
- Elevator Rides656 / 924
- Counting Tilings314 / 353
- Counting Numbers423 / 470
Graph Algorithms
- Counting Rooms6561 / 6969
- Labyrinth4037 / 5011
- Building Roads5189 / 5436
- Message Route4450 / 4660
- Building Teams4335 / 4546
- Round Trip3435 / 3782
- Monsters1895 / 2441
- Shortest Routes I3437 / 3858
- Shortest Routes II3031 / 3277
- High Score1707 / 2421
- Flight Discount2040 / 2428
- Cycle Finding1701 / 2005
- Flight Routes1430 / 1586
- Round Trip II1699 / 1950
- Course Schedule2263 / 2368
- Longest Flight Route1538 / 1993
- Game Routes1754 / 1856
- Investigation1195 / 1315
- Planets Queries I1228 / 1322
- Planets Queries II549 / 666
- Planets Cycles725 / 819
- Road Reparation1442 / 1486
- Road Construction1390 / 1437
- Flight Routes Check1301 / 1441
- Planets and Kingdoms1145 / 1191
- Giant Pizza600 / 658
- Coin Collector797 / 881
- Mail Delivery700 / 794
- De Bruijn Sequence476 / 497
- Teleporters Path513 / 642
- Hamiltonian Flights577 / 674
- Knight's Tour435 / 500
- Download Speed623 / 704
- Police Chase502 / 538
- School Dance519 / 538
- Distinct Routes345 / 494
Range Queries
- Static Range Sum Queries4204 / 4387
- Static Range Minimum Queries3240 / 3466
- Dynamic Range Sum Queries3223 / 3383
- Dynamic Range Minimum Queries2894 / 2968
- Range Xor Queries3058 / 3114
- Range Update Queries2312 / 2491
- Forest Queries2179 / 2266
- Hotel Queries1740 / 1879
- List Removals1514 / 1613
- Salary Queries1153 / 1382
- Prefix Sum Queries358 / 393
- Pizzeria Queries284 / 296
- Subarray Sum Queries1020 / 1123
- Distinct Values Queries972 / 1155
- Increasing Array Queries159 / 189
- Forest Queries II765 / 810
- Range Updates and Sums730 / 890
- Polynomial Queries599 / 701
- Range Queries and Copies414 / 434
Tree Algorithms
- Subordinates3208 / 3464
- Tree Matching1765 / 2148
- Tree Diameter2672 / 2818
- Tree Distances I1858 / 2055
- Tree Distances II1538 / 1602
- Company Queries I1636 / 1733
- Company Queries II1581 / 1661
- Distance Queries1539 / 1631
- Counting Paths981 / 1041
- Subtree Queries1164 / 1239
- Path Queries966 / 1017
- Path Queries II188 / 231
- Distinct Colors806 / 1016
- Finding a Centroid330 / 342
- Fixed-Length Paths I162 / 185
- Fixed-Length Paths II131 / 142
Mathematics
- Josephus Queries158 / 222
- Exponentiation3844 / 4276
- Exponentiation II2654 / 3370
- Counting Divisors2917 / 3397
- Common Divisors2044 / 2411
- Sum of Divisors1170 / 1916
- Divisor Analysis258 / 369
- Prime Multiples286 / 371
- Counting Coprime Pairs179 / 228
- Binomial Coefficients1518 / 1768
- Creating Strings II1268 / 1387
- Distributing Apples1173 / 1268
- Christmas Party1017 / 1100
- Bracket Sequences I249 / 286
- Bracket Sequences II90 / 115
- Counting Necklaces111 / 123
- Counting Grids93 / 97
- Fibonacci Numbers1296 / 1656
- Throwing Dice793 / 871
- Graph Paths I657 / 706
- Graph Paths II549 / 568
- Dice Probability649 / 696
- Moving Robots350 / 371
- Candy Lottery473 / 488
- Inversion Probability421 / 431
- Stick Game641 / 661
- Nim Game I789 / 821
- Nim Game II647 / 677
- Stair Game432 / 492
- Grundy's Game100 / 140
- Another Game103 / 112
String Algorithms
- Word Combinations569 / 927
- String Matching1205 / 1674
- Finding Borders824 / 959
- Finding Periods513 / 612
- Minimal Rotation395 / 619
- Longest Palindrome502 / 672
- Required Substring251 / 443
- Palindrome Queries85 / 108
- Finding Patterns104 / 141
- Counting Patterns91 / 111
- Pattern Positions85 / 102
- Distinct Substrings85 / 100
- Repeating Substring79 / 86
- String Functions71 / 73
- Substring Order I55 / 57
- Substring Order II38 / 45
- Substring Distribution63 / 68
Geometry
- Point Location Test537 / 595
- Line Segment Intersection317 / 401
- Polygon Area347 / 360
- Point in Polygon188 / 245
- Polygon Lattice Points168 / 178
- Minimum Euclidean Distance130 / 187
- Convex Hull235 / 285
Advanced Techniques
- Meet in the Middle609 / 794
- Hamming Distance190 / 214
- Beautiful Subgrids82 / 124
- Reachable Nodes91 / 106
- Reachability Queries64 / 80
- Cut and Paste75 / 84
- Substring Reversals63 / 68
- Reversals and Sums62 / 65
- Necessary Roads81 / 83
- Necessary Cities72 / 75
- Eulerian Subgraphs39 / 40
- Monster Game I52 / 61
- Monster Game II52 / 55
- Subarray Squares57 / 61
- Houses and Schools35 / 39
- Knuth Division43 / 56
- Apples and Bananas52 / 60
- One Bit Positions48 / 56
- Signal Processing49 / 52
- New Roads Queries59 / 68
- Dynamic Connectivity40 / 43
- Parcel Delivery34 / 39
- Task Assignment34 / 36
- Distinct Routes II30 / 36
Additional Problems
- Shortest Subsequence674 / 910
- Counting Bits705 / 901
- Swap Game261 / 360
- Prüfer Code296 / 314
- Acyclic Graph Edges399 / 425
- Strongly Connected Edges65 / 70
- Even Outdegree Edges50 / 62
- Multiplication Table127 / 140
- Advertisement452 / 478
- Special Substrings54 / 57
- Permutation Inversions48 / 55
- Maximum Xor Subarray367 / 398
- Movie Festival Queries182 / 206
- Chess Tournament202 / 238
- Tree Traversals206 / 211
- Network Renovation162 / 238
- Graph Girth329 / 375
- Intersection Points230 / 255
- Inverse Inversions60 / 63
- Monotone Subsequences33 / 41
- String Reorder148 / 163
- Stack Weights27 / 31
- Pyramid Array134 / 168
- Increasing Subsequence II322 / 347
- String Removals179 / 211
- Bit Inversions336 / 369
- Xor Pyramid84 / 114
- Writing Numbers190 / 208
- String Transform117 / 144
- Letter Pair Move Game10 / 12
- Maximum Building I311 / 319
- Sorting Methods188 / 201
- Cyclic Array123 / 169
- List of Sums30 / 38
- Increasing Array II24 / 34
- Food Division104 / 128
- Bit Problem149 / 163
- Swap Round Sorting77 / 104
- Binary Subsequences12 / 16
- Tree Isomorphism I165 / 200
- Counting Sequences38 / 39
- Critical Cities72 / 111
- School Excursion189 / 204
- Coin Grid107 / 134
- Robot Path55 / 109
- Programmers and Artists19 / 26
- Course Schedule II181 / 269
- Removing Digits II9 / 18
- Coin Arrangement10 / 17
- Counting Bishops17 / 19
- Grid Puzzle I35 / 39
- Grid Puzzle II24 / 27
- Empty String157 / 204
- Grid Paths156 / 202
- Bit Substrings24 / 26
- Reversal Sorting21 / 27
- Counting Reorders10 / 14
- Book Shop II171 / 193
- Network Breakdown160 / 167
- Visiting Cities140 / 187
- Missing Coin Sum Queries11 / 24
- Number Grid211 / 262
- Maximum Building II86 / 107
- Filling Trominos14 / 23
- Stick Divisions352 / 417
- Coding Company150 / 196
- Flight Route Requests101 / 110
- Two Stacks Sorting10 / 27
- Tree Isomorphism II132 / 154
- Forbidden Cities106 / 130
- Area of Rectangles145 / 169
- Grid Completion7 / 10
- Creating Offices68 / 98
- Permutations II181 / 204
- Functional Graph Distribution10 / 11
- New Flight Routes75 / 161
- Grid Path Construction8 / 13