General
Introductory Problems
- Weird Algorithm98775 / 103463
- Missing Number84053 / 88674
- Repetitions73384 / 76892
- Increasing Array68485 / 71378
- Permutations60220 / 62283
- Number Spiral42625 / 46493
- Two Knights31960 / 33112
- Two Sets34548 / 37562
- Bit Strings40251 / 42516
- Trailing Zeros37684 / 40312
- Coin Piles33171 / 36619
- Palindrome Reorder30288 / 32298
- Gray Code18834 / 21538
- Tower of Hanoi17560 / 18316
- Creating Strings26124 / 26923
- Apple Division25329 / 29083
- Chessboard and Queens15054 / 15368
- Digit Queries10152 / 12214
- Grid Paths6267 / 8008
Sorting and Searching
- Distinct Numbers46216 / 50690
- Apartments33697 / 38302
- Ferris Wheel32055 / 35077
- Concert Tickets25649 / 30557
- Restaurant Customers26359 / 28785
- Movie Festival24800 / 26530
- Sum of Two Values29247 / 33380
- Maximum Subarray Sum28851 / 30356
- Stick Lengths25547 / 26993
- Missing Coin Sum17813 / 18542
- Collecting Numbers18470 / 20007
- Collecting Numbers II7358 / 9640
- Playlist19204 / 22408
- Towers19697 / 21315
- Traffic Lights15434 / 17406
- Josephus Problem I10488 / 11897
- Josephus Problem II6077 / 7928
- Nested Ranges Check5966 / 7014
- Nested Ranges Count4260 / 4915
- Room Allocation11223 / 13076
- Factory Machines14424 / 16181
- Tasks and Deadlines13059 / 13373
- Reading Books10410 / 11188
- Sum of Three Values15175 / 17204
- Sum of Four Values9621 / 10890
- Nearest Smaller Values12850 / 13361
- Subarray Sums I16564 / 17847
- Subarray Sums II15334 / 17518
- Subarray Divisibility13458 / 14858
- Subarray Distinct Values7638 / 8277
- Array Division12296 / 13056
- Sliding Window Median8123 / 9289
- Sliding Window Cost5675 / 6539
- Movie Festival II7011 / 8506
- Maximum Subarray Sum II6419 / 7706
Dynamic Programming
- Dice Combinations45604 / 48606
- Minimizing Coins39252 / 42508
- Coin Combinations I36109 / 39413
- Coin Combinations II30299 / 34799
- Removing Digits33501 / 34369
- Grid Paths31866 / 32945
- Book Shop28000 / 31335
- Array Description20236 / 22846
- Counting Towers11514 / 12223
- Edit Distance20999 / 22341
- Rectangle Cutting17522 / 19229
- Money Sums20900 / 21836
- Removal Game14931 / 16620
- Two Sets II16483 / 18002
- Increasing Subsequence16941 / 19260
- Projects11405 / 12959
- Elevator Rides6864 / 8842
- Counting Tilings3921 / 4317
- Counting Numbers5291 / 6042
Graph Algorithms
- Counting Rooms31162 / 33174
- Labyrinth20417 / 25388
- Building Roads26972 / 28129
- Message Route22920 / 24043
- Building Teams21988 / 23108
- Round Trip17069 / 18859
- Monsters10741 / 13240
- Shortest Routes I18285 / 20920
- Shortest Routes II15481 / 16981
- High Score7752 / 12756
- Flight Discount10792 / 13240
- Cycle Finding8026 / 10124
- Flight Routes7462 / 8421
- Round Trip II8954 / 10304
- Course Schedule12430 / 12985
- Longest Flight Route7664 / 10313
- Game Routes8984 / 9908
- Investigation6572 / 7151
- Planets Queries I5563 / 6806
- Planets Queries II2228 / 2773
- Planets Cycles3715 / 4182
- Road Reparation8899 / 9358
- Road Construction9386 / 9759
- Flight Routes Check7983 / 8826
- Planets and Kingdoms6430 / 6710
- Giant Pizza2590 / 2920
- Coin Collector4009 / 4552
- Mail Delivery3475 / 3872
- De Bruijn Sequence1869 / 1969
- Teleporters Path2752 / 3088
- Hamiltonian Flights3854 / 4389
- Knight's Tour1625 / 1927
- Download Speed2673 / 3803
- Police Chase2180 / 2506
- School Dance2401 / 2561
- Distinct Routes1535 / 2103
Range Queries
- Static Range Sum Queries21201 / 22196
- Static Range Minimum Queries15768 / 16889
- Dynamic Range Sum Queries16241 / 17012
- Dynamic Range Minimum Queries14771 / 15170
- Range Xor Queries14937 / 15165
- Range Update Queries11892 / 12824
- Forest Queries11676 / 12165
- Hotel Queries8516 / 9004
- List Removals7094 / 7499
- Salary Queries5241 / 6360
- Prefix Sum Queries4227 / 4630
- Pizzeria Queries3446 / 3577
- Subarray Sum Queries4399 / 4928
- Distinct Values Queries4121 / 5025
- Increasing Array Queries1489 / 1716
- Forest Queries II2837 / 3075
- Range Updates and Sums3397 / 4156
- Polynomial Queries2603 / 3061
- Range Queries and Copies1832 / 1987
Tree Algorithms
- Subordinates17527 / 18974
- Tree Matching9821 / 11594
- Tree Diameter14533 / 15583
- Tree Distances I10777 / 11703
- Tree Distances II8824 / 9222
- Company Queries I9744 / 10326
- Company Queries II9146 / 9668
- Distance Queries8541 / 9178
- Counting Paths5104 / 5474
- Subtree Queries6283 / 6738
- Path Queries5012 / 5309
- Path Queries II1770 / 2960
- Distinct Colors4779 / 5391
- Finding a Centroid3904 / 4087
- Fixed-Length Paths I1606 / 2321
- Fixed-Length Paths II664 / 1582
Mathematics
- Josephus Queries2546 / 3219
- Exponentiation14800 / 16003
- Exponentiation II10572 / 13033
- Counting Divisors12741 / 14606
- Common Divisors8552 / 10267
- Sum of Divisors4873 / 7477
- Divisor Analysis3163 / 4227
- Prime Multiples3435 / 4076
- Counting Coprime Pairs2166 / 2565
- Binomial Coefficients5975 / 6778
- Creating Strings II5017 / 5372
- Distributing Apples4899 / 5312
- Christmas Party3795 / 4129
- Bracket Sequences I2577 / 2860
- Bracket Sequences II1325 / 1530
- Counting Necklaces1284 / 1396
- Counting Grids1032 / 1104
- Fibonacci Numbers4377 / 5634
- Throwing Dice2369 / 2578
- Graph Paths I2163 / 2334
- Graph Paths II1814 / 1901
- Dice Probability2066 / 2195
- Moving Robots1036 / 1106
- Candy Lottery1592 / 1637
- Inversion Probability464 / 1429
- Stick Game2123 / 2183
- Nim Game I2678 / 2789
- Nim Game II2181 / 2280
- Stair Game1507 / 1653
- Grundy's Game963 / 1246
- Another Game1104 / 1204
String Algorithms
- Word Combinations3120 / 4796
- String Matching6235 / 8988
- Finding Borders4621 / 5178
- Finding Periods3155 / 3589
- Minimal Rotation1575 / 2580
- Longest Palindrome2376 / 3334
- Required Substring925 / 1509
- Palindrome Queries1146 / 1373
- Finding Patterns984 / 1458
- Counting Patterns888 / 1179
- Pattern Positions786 / 1008
- Distinct Substrings938 / 1131
- Repeating Substring957 / 1079
- String Functions909 / 960
- Substring Order I675 / 725
- Substring Order II443 / 562
- Substring Distribution614 / 672
Geometry
- Point Location Test4157 / 4792
- Line Segment Intersection2526 / 3296
- Polygon Area3026 / 3256
- Point in Polygon1661 / 2120
- Polygon Lattice Points1416 / 1472
- Minimum Euclidean Distance1292 / 1776
- Convex Hull2083 / 2534
Advanced Techniques
- Meet in the Middle3589 / 5546
- Hamming Distance1977 / 2143
- Beautiful Subgrids1393 / 1569
- Reachable Nodes1407 / 1528
- Reachability Queries967 / 1149
- Cut and Paste917 / 1032
- Substring Reversals802 / 882
- Reversals and Sums799 / 872
- Necessary Roads1207 / 1243
- Necessary Cities1128 / 1186
- Eulerian Subgraphs508 / 537
- Monster Game I732 / 805
- Monster Game II655 / 710
- Subarray Squares727 / 857
- Houses and Schools474 / 547
- Knuth Division555 / 628
- Apples and Bananas516 / 573
- One Bit Positions491 / 546
- Signal Processing459 / 502
- New Roads Queries1202 / 1466
- Dynamic Connectivity548 / 623
- Parcel Delivery439 / 500
- Task Assignment418 / 454
- Distinct Routes II349 / 407
Additional Problems
- Shortest Subsequence1988 / 2555
- Counting Bits2275 / 2946
- Swap Game1234 / 1592
- Prüfer Code874 / 969
- Acyclic Graph Edges1363 / 1455
- Strongly Connected Edges852 / 938
- Even Outdegree Edges776 / 906
- Multiplication Table2941 / 3357
- Advertisement2539 / 2709
- Special Substrings578 / 626
- Permutation Inversions623 / 689
- Maximum Xor Subarray1460 / 1598
- Movie Festival Queries644 / 721
- Chess Tournament726 / 831
- Tree Traversals699 / 785
- Network Renovation616 / 817
- Graph Girth1881 / 2197
- Intersection Points1150 / 1236
- Inverse Inversions632 / 663
- Monotone Subsequences429 / 476
- String Reorder510 / 563
- Stack Weights370 / 431
- Pyramid Array497 / 591
- Increasing Subsequence II1458 / 1582
- String Removals634 / 689
- Bit Inversions1479 / 1726
- Xor Pyramid778 / 989
- Writing Numbers509 / 550
- String Transform327 / 406
- Letter Pair Move Game116 / 171
- Maximum Building I1329 / 1393
- Sorting Methods531 / 568
- Cyclic Array662 / 762
- List of Sums299 / 401
- Increasing Array II498 / 567
- Food Division366 / 433
- Bit Problem963 / 1038
- Swap Round Sorting282 / 351
- Binary Subsequences148 / 235
- Tree Isomorphism I660 / 767
- Counting Sequences379 / 409
- Critical Cities251 / 397
- School Excursion863 / 921
- Coin Grid467 / 556
- Robot Path197 / 340
- Programmers and Artists314 / 403
- Course Schedule II1024 / 1456
- Removing Digits II127 / 269
- Coin Arrangement214 / 282
- Counting Bishops225 / 253
- Grid Puzzle I329 / 359
- Grid Puzzle II241 / 270
- Empty String923 / 1111
- Grid Paths502 / 624
- Bit Substrings224 / 280
- Reversal Sorting215 / 261
- Counting Reorders131 / 198
- Book Shop II651 / 741
- Network Breakdown618 / 657
- Visiting Cities457 / 594
- Missing Coin Sum Queries250 / 332
- Number Grid589 / 705
- Maximum Building II293 / 360
- Filling Trominos125 / 212
- Stick Divisions2355 / 2794
- Coding Company891 / 1137
- Flight Route Requests285 / 347
- Two Stacks Sorting94 / 324
- Tree Isomorphism II544 / 633
- Forbidden Cities454 / 594
- Area of Rectangles685 / 772
- Grid Completion132 / 174
- Creating Offices257 / 335
- Permutations II575 / 658
- Functional Graph Distribution146 / 183
- New Flight Routes202 / 485
- Grid Path Construction66 / 238