General
Introductory Problems
- Weird Algorithm179118 / 187063
- Missing Number154611 / 161567
- Repetitions134245 / 139259
- Increasing Array126566 / 130735
- Permutations110817 / 114004
- Number Spiral78774 / 85379
- Two Knights60819 / 62597
- Two Sets66124 / 70722
- Bit Strings75126 / 79058
- Trailing Zeros69542 / 73734
- Coin Piles61918 / 67319
- Palindrome Reorder57517 / 60484
- Gray Code39388 / 43889
- Tower of Hanoi36712 / 38110
- Creating Strings48498 / 49662
- Apple Division49279 / 55176
- Chessboard and Queens30013 / 30516
- Raab Game I8052 / 9002
- Mex Grid Construction7799 / 8181
- Knight Moves Grid7874 / 8050
- Grid Coloring I6625 / 6858
- Digit Queries21069 / 24109
- String Reorder5905 / 6733
- Grid Path Description11829 / 15121
Sorting and Searching
- Distinct Numbers89193 / 95927
- Apartments67013 / 73643
- Ferris Wheel64642 / 69204
- Concert Tickets51895 / 59771
- Restaurant Customers52688 / 56521
- Movie Festival51239 / 53983
- Sum of Two Values59223 / 65748
- Maximum Subarray Sum56454 / 58742
- Stick Lengths50572 / 52718
- Missing Coin Sum38790 / 40098
- Collecting Numbers39695 / 42239
- Collecting Numbers II17538 / 21768
- Playlist39641 / 44824
- Towers39570 / 42196
- Traffic Lights30813 / 34215
- Distinct Values Subarrays10919 / 12181
- Distinct Values Subsequences8419 / 9137
- Josephus Problem I24078 / 26284
- Josephus Problem II13101 / 17930
- Nested Ranges Check14388 / 16234
- Nested Ranges Count9630 / 11238
- Room Allocation23439 / 26629
- Factory Machines33980 / 36648
- Tasks and Deadlines27080 / 27596
- Reading Books22021 / 23468
- Sum of Three Values31619 / 34705
- Sum of Four Values19738 / 21756
- Nearest Smaller Values26535 / 27378
- Subarray Sums I35161 / 37254
- Subarray Sums II32094 / 37550
- Subarray Divisibility28987 / 31340
- Distinct Values Subarrays II17760 / 19283
- Array Division27482 / 28793
- Movie Festival II14995 / 17822
- Maximum Subarray Sum II13980 / 16435
Dynamic Programming
- Dice Combinations93641 / 98774
- Minimizing Coins81046 / 86699
- Coin Combinations I74043 / 79745
- Coin Combinations II62873 / 70595
- Removing Digits69816 / 71187
- Grid Paths I65598 / 67336
- Book Shop59223 / 64693
- Array Description43905 / 48332
- Counting Towers27447 / 28944
- Edit Distance43643 / 45890
- Longest Common Subsequence15675 / 16188
- Rectangle Cutting36023 / 39106
- Minimal Grid Path7374 / 12099
- Money Sums42483 / 43964
- Removal Game26505 / 34029
- Two Sets II33594 / 35888
- Mountain Range5125 / 8657
- Increasing Subsequence34083 / 38121
- Projects24082 / 26715
- Elevator Rides15849 / 19554
- Counting Tilings9293 / 10030
- Counting Numbers13903 / 15363
- Increasing Subsequence II6353 / 7442
Graph Algorithms
- Counting Rooms65230 / 68264
- Labyrinth46425 / 54434
- Building Roads57139 / 59037
- Message Route49572 / 51345
- Building Teams46771 / 49027
- Round Trip37105 / 40085
- Monsters26463 / 30495
- Shortest Routes I40999 / 44656
- Shortest Routes II33114 / 36726
- High Score21340 / 28632
- Flight Discount27334 / 31328
- Cycle Finding19313 / 23013
- Flight Routes18823 / 20736
- Round Trip II20824 / 23077
- Course Schedule27511 / 28862
- Longest Flight Route20194 / 24213
- Game Routes21975 / 23293
- Investigation16762 / 17858
- Planets Queries I14554 / 16740
- Planets Queries II5279 / 6543
- Planets Cycles8762 / 9664
- Road Reparation21471 / 22287
- Road Construction23405 / 24097
- Flight Routes Check18573 / 19943
- Planets and Kingdoms15176 / 15789
- Giant Pizza6398 / 6975
- Coin Collector10096 / 11026
- Mail Delivery8016 / 8694
- De Bruijn Sequence4222 / 4413
- Teleporters Path6216 / 6971
- Hamiltonian Flights9513 / 10742
- Knight's Tour3554 / 4242
- Download Speed6163 / 7997
- Police Chase4924 / 5454
- School Dance5412 / 5699
- Distinct Routes3822 / 4884
Range Queries
- Static Range Sum Queries45697 / 47701
- Static Range Minimum Queries31375 / 33567
- Dynamic Range Sum Queries32665 / 34044
- Dynamic Range Minimum Queries29480 / 30157
- Range Xor Queries30077 / 30468
- Range Update Queries24390 / 26015
- Forest Queries25008 / 25851
- Hotel Queries17794 / 18765
- List Removals14823 / 15513
- Salary Queries11493 / 14152
- Prefix Sum Queries9621 / 10326
- Pizzeria Queries7684 / 7941
- Visible Buildings Queries2405 / 2606
- Range Interval Queries1827 / 2431
- Subarray Sum Queries8830 / 9515
- Subarray Sum Queries II2715 / 2791
- Distinct Values Queries8375 / 10118
- Distinct Values Queries II1517 / 1713
- Increasing Array Queries3194 / 3625
- Movie Festival Queries1795 / 1967
- Forest Queries II5181 / 5538
- Range Updates and Sums7352 / 8578
- Polynomial Queries5391 / 6262
- Range Queries and Copies3788 / 4032
- Missing Coin Sum Queries910 / 1244
Tree Algorithms
- Subordinates37533 / 40023
- Tree Matching21814 / 25056
- Tree Diameter30773 / 32456
- Tree Distances I23923 / 25535
- Tree Distances II19529 / 20381
- Company Queries I21943 / 23006
- Company Queries II20522 / 21521
- Distance Queries18485 / 19724
- Counting Paths11727 / 12354
- Subtree Queries13723 / 14562
- Path Queries11082 / 11672
- Path Queries II4660 / 6790
- Distinct Colors10615 / 11599
- Finding a Centroid8625 / 8957
- Fixed-Length Paths I4330 / 5417
- Fixed-Length Paths II2131 / 3667
Mathematics
- Josephus Queries5987 / 7444
- Exponentiation28993 / 30834
- Exponentiation II20233 / 23954
- Counting Divisors26664 / 29971
- Common Divisors17135 / 19722
- Sum of Divisors9801 / 14263
- Divisor Analysis6709 / 8840
- Prime Multiples7817 / 9016
- Counting Coprime Pairs5177 / 5944
- Next Prime2834 / 3213
- Binomial Coefficients12519 / 13789
- Creating Strings II10361 / 10902
- Distributing Apples9891 / 10600
- Christmas Party8265 / 8796
- Permutation Order1364 / 1398
- Permutation Rounds1998 / 2191
- Bracket Sequences I5512 / 5968
- Bracket Sequences II2955 / 3351
- Counting Necklaces2687 / 2896
- Counting Grids2264 / 2398
- Fibonacci Numbers8246 / 10231
- Throwing Dice4320 / 4671
- Graph Paths I4195 / 4465
- Graph Paths II3516 / 3679
- System of Linear Equations691 / 744
- Sum of Four Squares988 / 1175
- Triangle Number Sums866 / 1031
- Dice Probability3699 / 3967
- Moving Robots1926 / 2026
- Candy Lottery2040 / 3705
- Inversion Probability618 / 2723
- Stick Game4221 / 4318
- Nim Game I5637 / 5842
- Nim Game II4466 / 4636
- Stair Game3030 / 3279
- Grundy's Game2120 / 2772
- Another Game2398 / 2572
String Algorithms
- Word Combinations7300 / 10288
- String Matching13822 / 18196
- Finding Borders10199 / 11076
- Finding Periods7304 / 8202
- Minimal Rotation3654 / 5301
- Longest Palindrome5362 / 6929
- All Palindromes1026 / 1142
- Required Substring2049 / 3025
- Palindrome Queries2514 / 2892
- Finding Patterns2400 / 3298
- Counting Patterns2275 / 2755
- Pattern Positions1924 / 2300
- Distinct Substrings2147 / 2534
- Distinct Subsequences1387 / 1464
- Repeating Substring2306 / 2637
- String Functions2016 / 2108
- Inverse Suffix Array395 / 449
- String Transform696 / 822
- Substring Order I1464 / 1612
- Substring Order II996 / 1266
- Substring Distribution1362 / 1470
Geometry
- Point Location Test8725 / 9662
- Line Segment Intersection5177 / 6414
- Polygon Area5926 / 6242
- Point in Polygon3330 / 4172
- Polygon Lattice Points2701 / 2884
- Minimum Euclidean Distance2392 / 3326
- Convex Hull3973 / 4693
- Maximum Manhattan Distances895 / 930
- All Manhattan Distances941 / 1035
- Intersection Points2383 / 2565
- Line Segments Trace I485 / 501
- Line Segments Trace II406 / 425
- Lines and Queries I529 / 554
- Lines and Queries II475 / 496
- Area of Rectangles1399 / 1552
- Robot Path386 / 698
Advanced Techniques
- Meet in the Middle8471 / 11334
- Hamming Distance3719 / 4058
- Corner Subgrid Check346 / 726
- Corner Subgrid Count2521 / 2867
- Reachable Nodes2641 / 2826
- Reachability Queries1778 / 2079
- Cut and Paste1823 / 2010
- Substring Reversals1611 / 1736
- Reversals and Sums1638 / 1748
- Necessary Roads2361 / 2422
- Necessary Cities2197 / 2291
- Eulerian Subgraphs934 / 983
- Monster Game I1412 / 1560
- Monster Game II1238 / 1320
- Subarray Squares1767 / 2042
- Houses and Schools959 / 1131
- Knuth Division1141 / 1279
- Apples and Bananas1343 / 1451
- One Bit Positions1011 / 1099
- Signal Processing1005 / 1074
- New Roads Queries2670 / 3193
- Dynamic Connectivity1221 / 1364
- Parcel Delivery968 / 1054
- Task Assignment1115 / 1201
- Distinct Routes II741 / 832
Sliding Window Problems
- Sliding Window Sum8292 / 8558
- Sliding Window Minimum6244 / 7091
- Sliding Window Xor6102 / 6180
- Sliding Window Or2755 / 4539
- Sliding Window Distinct Values4371 / 5066
- Sliding Window Mode3392 / 3588
- Sliding Window Mex3204 / 3369
- Sliding Window Median15410 / 17493
- Sliding Window Cost10059 / 11549
- Sliding Window Inversions1719 / 1816
- Sliding Window Advertisement331 / 518
Interactive Problems
- Hidden Integer2980 / 3106
- Hidden Permutation1344 / 1552
- K-th Highest Score612 / 736
- Permuted Binary Strings714 / 733
- Colored Chairs672 / 712
- Inversion Sorting395 / 443
Bitwise Operations
- Counting Bits6378 / 8180
- Maximum Xor Subarray3761 / 4296
- Maximum Xor Subset1442 / 1584
- Number of Subset Xors1254 / 1283
- K Subset Xors651 / 763
- All Subarray Xors396 / 610
- Xor Pyramid Peak2502 / 2991
- Xor Pyramid Diagonal449 / 502
- Xor Pyramid Row388 / 453
- SOS Bit Problem2641 / 2795
- And Subset Count645 / 669
Construction Problems
- Inverse Inversions2111 / 2253
- Monotone Subsequences1275 / 1507
- Third Permutation571 / 701
- Permutation Prime Sums573 / 615
- Chess Tournament1403 / 1616
- Distinct Sums Grid205 / 306
- Filling Trominos311 / 536
- Grid Path Construction173 / 504
Advanced Graph Problems
- Nearest Shops1004 / 1283
- Prüfer Code1755 / 1879
- Tree Traversals1439 / 1572
- Course Schedule II2402 / 3358
- Acyclic Graph Edges2492 / 2638
- Strongly Connected Edges1830 / 2122
- Even Outdegree Edges1597 / 1857
- Graph Girth4037 / 4546
- Fixed Length Walk Queries492 / 544
- Transfer Speeds Sum553 / 571
- MST Edge Check913 / 985
- MST Edge Set Check343 / 388
- MST Edge Cost540 / 562
- Network Breakdown1363 / 1477
- Tree Coin Collecting I472 / 511
- Tree Coin Collecting II270 / 308
- Tree Isomorphism I1246 / 1468
- Tree Isomorphism II1031 / 1177
- Flight Route Requests588 / 728
- Critical Cities512 / 762
- Visiting Cities777 / 1013
- Graph Coloring308 / 357
- Bus Companies355 / 365
- Split into Two Paths142 / 242
- Network Renovation1051 / 1379
- Forbidden Cities1001 / 1284
- Creating Offices486 / 629
- New Flight Routes416 / 1053
Counting Problems
- Filled Subgrid Count I826 / 917
- Filled Subgrid Count II445 / 547
- All Letter Subgrid Count I255 / 362
- All Letter Subgrid Count II161 / 239
- Border Subgrid Count I131 / 224
- Border Subgrid Count II146 / 169
- Raab Game II150 / 171
- Empty String1948 / 2359
- Permutation Inversions1151 / 1268
- Counting Bishops458 / 510
- Counting Sequences781 / 836
- Grid Paths II863 / 1088
- Counting Permutations998 / 1123
- Grid Completion268 / 336
- Counting Reorders306 / 421
- Tournament Graph Distribution150 / 161
- Collecting Numbers Distribution158 / 166
- Functional Graph Distribution284 / 347
Additional Problems I
- Shortest Subsequence3312 / 4312
- Distinct Values Sum894 / 918
- Distinct Values Splits630 / 674
- Swap Game2284 / 2913
- Beautiful Permutation II791 / 1211
- Multiplication Table7899 / 8763
- Bubble Sort Rounds I575 / 650
- Bubble Sort Rounds II397 / 443
- Nearest Campsites I249 / 292
- Nearest Campsites II243 / 262
- Advertisement4975 / 5256
- Special Substrings1103 / 1207
- Counting LCM Arrays386 / 419
- Square Subsets298 / 328
- Subarray Sum Constraints612 / 651
- Water Containers Moves241 / 255
- Water Containers Queries274 / 289
- Stack Weights660 / 787
- Maximum Average Subarrays234 / 257
- Subsets with Fixed Average280 / 304
- Two Array Average282 / 314
- Pyramid Array883 / 1063
- Permutation Subsequence325 / 336
- Bit Inversions2610 / 2929
- Writing Numbers819 / 886
- Letter Pair Move Game239 / 330
- Maximum Building I2299 / 2400
- Sorting Methods854 / 911
- Cyclic Array1399 / 1575
- List of Sums550 / 711
Additional Problems II
- Bouncing Ball Steps327 / 361
- Bouncing Ball Cycle136 / 185
- Knight Moves Queries169 / 202
- K Subset Sums I267 / 331
- K Subset Sums II159 / 198
- Increasing Array II927 / 1058
- Food Division585 / 696
- Swap Round Sorting454 / 563
- Binary Subsequences325 / 467
- School Excursion1549 / 1638
- Coin Grid1046 / 1210
- Grid Coloring II178 / 228
- Programmers and Artists571 / 791
- Removing Digits II248 / 523
- Coin Arrangement378 / 500
- Replace with Difference181 / 214
- Grid Puzzle I617 / 675
- Grid Puzzle II601 / 657
- Bit Substrings454 / 547
- Reversal Sorting398 / 479
- Book Shop II1452 / 1653
- GCD Subsets533 / 549
- Minimum Cost Pairs187 / 233
- Same Sum Subsets162 / 310
- Mex Grid Queries938 / 1093
- Maximum Building II495 / 607
- Stick Divisions4196 / 4887
- Stick Difference109 / 349
- Coding Company1683 / 2192
- Two Stacks Sorting212 / 649