General
Introductory Problems
- Weird Algorithm34602 / 36034
- Missing Number29201 / 30961
- Repetitions25717 / 27143
- Increasing Array23758 / 24789
- Permutations21146 / 21928
- Number Spiral14758 / 16103
- Two Knights10998 / 11378
- Two Sets11791 / 12847
- Bit Strings14203 / 15010
- Trailing Zeros13397 / 14287
- Coin Piles11625 / 12856
- Palindrome Reorder10274 / 11025
- Gray Code4192 / 4756
- Tower of Hanoi3808 / 3981
- Creating Strings9335 / 9595
- Apple Division8367 / 9752
- Chessboard and Queens4998 / 5090
- Digit Queries2077 / 2587
- Grid Paths2018 / 2658
Sorting and Searching
- Distinct Numbers14924 / 15453
- Apartments10211 / 11786
- Ferris Wheel9654 / 10709
- Concert Tickets7567 / 9307
- Restaurant Customers7716 / 8487
- Movie Festival7434 / 7901
- Sum of Two Values8739 / 9654
- Maximum Subarray Sum8651 / 9010
- Stick Lengths7597 / 8104
- Missing Coin Sum3414 / 3573
- Collecting Numbers3487 / 3823
- Collecting Numbers II1372 / 1811
- Playlist6216 / 7187
- Towers6227 / 6792
- Traffic Lights4743 / 5399
- Josephus Problem I1912 / 2229
- Josephus Problem II1149 / 1506
- Nested Ranges Check889 / 1127
- Nested Ranges Count734 / 820
- Room Allocation3711 / 4468
- Factory Machines4231 / 4623
- Tasks and Deadlines4169 / 4260
- Reading Books3533 / 3813
- Sum of Three Values4622 / 5186
- Sum of Four Values3240 / 3654
- Nearest Smaller Values4035 / 4235
- Subarray Sums I4659 / 5235
- Subarray Sums II4369 / 4899
- Subarray Divisibility4081 / 4381
- Subarray Distinct Values1411 / 1506
- Array Division3318 / 3526
- Sliding Median2601 / 3072
- Sliding Cost1829 / 2085
- Movie Festival II2078 / 2555
- Maximum Subarray Sum II1988 / 2385
Dynamic Programming
- Dice Combinations13633 / 14485
- Minimizing Coins11855 / 12665
- Coin Combinations I11032 / 11893
- Coin Combinations II9222 / 10518
- Removing Digits10375 / 10557
- Grid Paths9550 / 9846
- Book Shop8619 / 9497
- Array Description5958 / 6725
- Counting Towers2068 / 2211
- Edit Distance6452 / 6855
- Rectangle Cutting5534 / 6031
- Money Sums6441 / 6675
- Removal Game4659 / 5107
- Two Sets II5198 / 5652
- Increasing Subsequence5204 / 5974
- Projects3387 / 3853
- Elevator Rides1294 / 1763
- Counting Tilings700 / 787
- Counting Numbers900 / 1011
Graph Algorithms
- Counting Rooms9178 / 9810
- Labyrinth5735 / 7093
- Building Roads7374 / 7716
- Message Route6347 / 6633
- Building Teams6111 / 6398
- Round Trip4921 / 5393
- Monsters2729 / 3490
- Shortest Routes I5040 / 5632
- Shortest Routes II4306 / 4652
- High Score2513 / 3494
- Flight Discount2928 / 3449
- Cycle Finding2412 / 2852
- Flight Routes2045 / 2256
- Round Trip II2376 / 2824
- Course Schedule3275 / 3403
- Longest Flight Route2114 / 2795
- Game Routes2555 / 2695
- Investigation1691 / 1840
- Planets Queries I1692 / 1808
- Planets Queries II723 / 872
- Planets Cycles1006 / 1125
- Road Reparation2087 / 2167
- Road Construction2087 / 2156
- Flight Routes Check1950 / 2145
- Planets and Kingdoms1674 / 1726
- Giant Pizza773 / 878
- Coin Collector1118 / 1231
- Mail Delivery986 / 1105
- De Bruijn Sequence609 / 633
- Teleporters Path739 / 887
- Hamiltonian Flights859 / 999
- Knight's Tour555 / 644
- Download Speed923 / 1015
- Police Chase703 / 761
- School Dance724 / 753
- Distinct Routes445 / 637
Range Queries
- Static Range Sum Queries5937 / 6200
- Static Range Minimum Queries4577 / 4902
- Dynamic Range Sum Queries4570 / 4786
- Dynamic Range Minimum Queries4090 / 4196
- Range Xor Queries4237 / 4308
- Range Update Queries3295 / 3543
- Forest Queries3025 / 3138
- Hotel Queries2380 / 2543
- List Removals2025 / 2148
- Salary Queries1532 / 1828
- Prefix Sum Queries733 / 794
- Pizzeria Queries584 / 607
- Subarray Sum Queries1322 / 1476
- Distinct Values Queries1288 / 1511
- Increasing Array Queries306 / 361
- Forest Queries II967 / 1031
- Range Updates and Sums976 / 1188
- Polynomial Queries785 / 915
- Range Queries and Copies524 / 551
Tree Algorithms
- Subordinates4858 / 5213
- Tree Matching2608 / 3158
- Tree Diameter3959 / 4212
- Tree Distances I2743 / 3015
- Tree Distances II2289 / 2383
- Company Queries I2456 / 2610
- Company Queries II2380 / 2488
- Distance Queries2344 / 2501
- Counting Paths1405 / 1497
- Subtree Queries1677 / 1791
- Path Queries1358 / 1423
- Path Queries II405 / 494
- Distinct Colors1235 / 1471
- Finding a Centroid701 / 726
- Fixed-Length Paths I353 / 395
- Fixed-Length Paths II274 / 301
Mathematics
- Josephus Queries393 / 511
- Exponentiation4894 / 5397
- Exponentiation II3405 / 4309
- Counting Divisors3776 / 4381
- Common Divisors2675 / 3110
- Sum of Divisors1501 / 2460
- Divisor Analysis537 / 759
- Prime Multiples569 / 706
- Counting Coprime Pairs369 / 469
- Binomial Coefficients1862 / 2133
- Creating Strings II1553 / 1693
- Distributing Apples1456 / 1572
- Christmas Party1312 / 1409
- Bracket Sequences I493 / 550
- Bracket Sequences II212 / 259
- Counting Necklaces251 / 270
- Counting Grids190 / 204
- Fibonacci Numbers1586 / 2041
- Throwing Dice951 / 1036
- Graph Paths I813 / 872
- Graph Paths II679 / 703
- Dice Probability804 / 854
- Moving Robots432 / 459
- Candy Lottery593 / 609
- Inversion Probability520 / 531
- Stick Game782 / 801
- Nim Game I960 / 993
- Nim Game II786 / 818
- Stair Game528 / 604
- Grundy's Game197 / 254
- Another Game183 / 199
String Algorithms
- Word Combinations802 / 1288
- String Matching1758 / 2401
- Finding Borders1181 / 1349
- Finding Periods753 / 872
- Minimal Rotation548 / 826
- Longest Palindrome685 / 949
- Required Substring318 / 554
- Palindrome Queries164 / 205
- Finding Patterns184 / 271
- Counting Patterns183 / 227
- Pattern Positions160 / 198
- Distinct Substrings169 / 206
- Repeating Substring158 / 170
- String Functions152 / 158
- Substring Order I113 / 119
- Substring Order II80 / 97
- Substring Distribution113 / 124
Geometry
- Point Location Test873 / 961
- Line Segment Intersection519 / 653
- Polygon Area593 / 615
- Point in Polygon326 / 420
- Polygon Lattice Points279 / 290
- Minimum Euclidean Distance237 / 333
- Convex Hull378 / 461
Advanced Techniques
- Meet in the Middle911 / 1230
- Hamming Distance395 / 432
- Beautiful Subgrids213 / 272
- Reachable Nodes215 / 242
- Reachability Queries166 / 192
- Cut and Paste134 / 150
- Substring Reversals118 / 125
- Reversals and Sums115 / 120
- Necessary Roads180 / 182
- Necessary Cities162 / 170
- Eulerian Subgraphs92 / 96
- Monster Game I107 / 118
- Monster Game II106 / 111
- Subarray Squares123 / 146
- Houses and Schools85 / 94
- Knuth Division104 / 118
- Apples and Bananas103 / 114
- One Bit Positions99 / 112
- Signal Processing95 / 99
- New Roads Queries134 / 155
- Dynamic Connectivity83 / 90
- Parcel Delivery69 / 82
- Task Assignment70 / 73
- Distinct Routes II66 / 76
Additional Problems
- Shortest Subsequence803 / 1067
- Counting Bits866 / 1125
- Swap Game332 / 454
- Prüfer Code356 / 376
- Acyclic Graph Edges486 / 519
- Strongly Connected Edges145 / 155
- Even Outdegree Edges132 / 158
- Multiplication Table335 / 366
- Advertisement617 / 653
- Special Substrings110 / 119
- Permutation Inversions116 / 133
- Maximum Xor Subarray473 / 511
- Movie Festival Queries223 / 255
- Chess Tournament260 / 301
- Tree Traversals265 / 273
- Network Renovation197 / 285
- Graph Girth458 / 520
- Intersection Points312 / 339
- Inverse Inversions121 / 125
- Monotone Subsequences73 / 84
- String Reorder190 / 210
- Stack Weights59 / 66
- Pyramid Array174 / 209
- Increasing Subsequence II414 / 443
- String Removals233 / 266
- Bit Inversions446 / 492
- Xor Pyramid162 / 205
- Writing Numbers220 / 240
- String Transform144 / 169
- Letter Pair Move Game20 / 29
- Maximum Building I409 / 420
- Sorting Methods229 / 243
- Cyclic Array150 / 198
- List of Sums65 / 91
- Increasing Array II79 / 92
- Food Division143 / 170
- Bit Problem236 / 257
- Swap Round Sorting95 / 126
- Binary Subsequences21 / 42
- Tree Isomorphism I187 / 242
- Counting Sequences72 / 77
- Critical Cities90 / 135
- School Excursion255 / 271
- Coin Grid145 / 176
- Robot Path70 / 133
- Programmers and Artists41 / 55
- Course Schedule II285 / 413
- Removing Digits II25 / 44
- Coin Arrangement27 / 40
- Counting Bishops39 / 43
- Grid Puzzle I62 / 72
- Grid Puzzle II44 / 48
- Empty String226 / 288
- Grid Paths193 / 245
- Bit Substrings48 / 53
- Reversal Sorting40 / 54
- Counting Reorders25 / 34
- Book Shop II212 / 237
- Network Breakdown201 / 210
- Visiting Cities163 / 217
- Missing Coin Sum Queries34 / 52
- Number Grid256 / 313
- Maximum Building II110 / 134
- Filling Trominos27 / 45
- Stick Divisions496 / 589
- Coding Company216 / 275
- Flight Route Requests123 / 136
- Two Stacks Sorting18 / 64
- Tree Isomorphism II167 / 189
- Forbidden Cities132 / 163
- Area of Rectangles197 / 228
- Grid Completion19 / 26
- Creating Offices79 / 114
- Permutations II226 / 253
- Functional Graph Distribution19 / 22
- New Flight Routes94 / 197
- Grid Path Construction14 / 24