General
Introductory Problems
- Weird Algorithm34076 / 35486
- Missing Number28720 / 30459
- Repetitions25302 / 26705
- Increasing Array23381 / 24386
- Permutations20816 / 21584
- Number Spiral14538 / 15869
- Two Knights10838 / 11216
- Two Sets11599 / 12645
- Bit Strings13978 / 14771
- Trailing Zeros13196 / 14065
- Coin Piles11444 / 12662
- Palindrome Reorder10116 / 10855
- Gray Code4067 / 4618
- Tower of Hanoi3686 / 3855
- Creating Strings9200 / 9462
- Apple Division8251 / 9621
- Chessboard and Queens4910 / 5002
- Digit Queries2007 / 2501
- Grid Paths1991 / 2617
Sorting and Searching
- Distinct Numbers14657 / 15180
- Apartments10011 / 11574
- Ferris Wheel9473 / 10515
- Concert Tickets7435 / 9151
- Restaurant Customers7576 / 8344
- Movie Festival7295 / 7758
- Sum of Two Values8577 / 9478
- Maximum Subarray Sum8491 / 8853
- Stick Lengths7448 / 7947
- Missing Coin Sum3265 / 3421
- Collecting Numbers3342 / 3671
- Collecting Numbers II1325 / 1743
- Playlist6102 / 7060
- Towers6106 / 6659
- Traffic Lights4652 / 5290
- Josephus Problem I1853 / 2164
- Josephus Problem II1107 / 1453
- Nested Ranges Check894 / 1085
- Nested Ranges Count714 / 793
- Room Allocation3668 / 4389
- Factory Machines4146 / 4530
- Tasks and Deadlines4093 / 4184
- Reading Books3467 / 3742
- Sum of Three Values4523 / 5076
- Sum of Four Values3176 / 3585
- Nearest Smaller Values3963 / 4163
- Subarray Sums I4611 / 5118
- Subarray Sums II4276 / 4799
- Subarray Divisibility3994 / 4280
- Subarray Distinct Values1356 / 1449
- Array Division3259 / 3459
- Sliding Median2560 / 3020
- Sliding Cost1798 / 2049
- Movie Festival II2041 / 2512
- Maximum Subarray Sum II1960 / 2350
Dynamic Programming
- Dice Combinations13354 / 14191
- Minimizing Coins11623 / 12419
- Coin Combinations I10836 / 11684
- Coin Combinations II9033 / 10316
- Removing Digits10167 / 10346
- Grid Paths9350 / 9649
- Book Shop8444 / 9314
- Array Description5844 / 6589
- Counting Towers1983 / 2119
- Edit Distance6330 / 6724
- Rectangle Cutting5429 / 5922
- Money Sums6315 / 6545
- Removal Game4558 / 5000
- Two Sets II5107 / 5553
- Increasing Subsequence5119 / 5882
- Projects3322 / 3778
- Elevator Rides1260 / 1706
- Counting Tilings675 / 759
- Counting Numbers865 / 972
Graph Algorithms
- Counting Rooms8961 / 9574
- Labyrinth5593 / 6915
- Building Roads7196 / 7527
- Message Route6193 / 6471
- Building Teams5972 / 6254
- Round Trip4813 / 5270
- Monsters2672 / 3409
- Shortest Routes I4908 / 5488
- Shortest Routes II4205 / 4539
- High Score2441 / 3396
- Flight Discount2848 / 3357
- Cycle Finding2351 / 2778
- Flight Routes2000 / 2204
- Round Trip II2317 / 2753
- Course Schedule3190 / 3316
- Longest Flight Route2068 / 2739
- Game Routes2504 / 2641
- Investigation1658 / 1808
- Planets Queries I1658 / 1773
- Planets Queries II714 / 860
- Planets Cycles994 / 1113
- Road Reparation2032 / 2108
- Road Construction2029 / 2095
- Flight Routes Check1906 / 2096
- Planets and Kingdoms1639 / 1691
- Giant Pizza760 / 864
- Coin Collector1097 / 1208
- Mail Delivery978 / 1095
- De Bruijn Sequence599 / 623
- Teleporters Path731 / 880
- Hamiltonian Flights842 / 976
- Knight's Tour546 / 631
- Download Speed912 / 1004
- Police Chase688 / 746
- School Dance711 / 740
- Distinct Routes433 / 626
Range Queries
- Static Range Sum Queries5786 / 6036
- Static Range Minimum Queries4462 / 4779
- Dynamic Range Sum Queries4465 / 4675
- Dynamic Range Minimum Queries3995 / 4099
- Range Xor Queries4138 / 4207
- Range Update Queries3203 / 3445
- Forest Queries2938 / 3050
- Hotel Queries2329 / 2492
- List Removals1981 / 2104
- Salary Queries1494 / 1782
- Prefix Sum Queries703 / 763
- Pizzeria Queries564 / 588
- Subarray Sum Queries1294 / 1449
- Distinct Values Queries1267 / 1482
- Increasing Array Queries300 / 353
- Forest Queries II955 / 1017
- Range Updates and Sums957 / 1169
- Polynomial Queries772 / 902
- Range Queries and Copies521 / 546
Tree Algorithms
- Subordinates4753 / 5096
- Tree Matching2556 / 3090
- Tree Diameter3879 / 4128
- Tree Distances I2684 / 2953
- Tree Distances II2245 / 2336
- Company Queries I2406 / 2555
- Company Queries II2332 / 2439
- Distance Queries2295 / 2445
- Counting Paths1383 / 1473
- Subtree Queries1632 / 1741
- Path Queries1331 / 1393
- Path Queries II392 / 478
- Distinct Colors1195 / 1428
- Finding a Centroid681 / 706
- Fixed-Length Paths I342 / 383
- Fixed-Length Paths II265 / 292
Mathematics
- Josephus Queries378 / 493
- Exponentiation4824 / 5320
- Exponentiation II3346 / 4243
- Counting Divisors3713 / 4307
- Common Divisors2639 / 3064
- Sum of Divisors1483 / 2434
- Divisor Analysis518 / 734
- Prime Multiples545 / 677
- Counting Coprime Pairs355 / 451
- Binomial Coefficients1838 / 2108
- Creating Strings II1529 / 1666
- Distributing Apples1437 / 1549
- Christmas Party1286 / 1382
- Bracket Sequences I478 / 533
- Bracket Sequences II205 / 251
- Counting Necklaces239 / 259
- Counting Grids182 / 195
- Fibonacci Numbers1562 / 2006
- Throwing Dice938 / 1023
- Graph Paths I796 / 853
- Graph Paths II667 / 690
- Dice Probability792 / 842
- Moving Robots427 / 454
- Candy Lottery583 / 599
- Inversion Probability511 / 522
- Stick Game771 / 790
- Nim Game I948 / 981
- Nim Game II779 / 811
- Stair Game519 / 596
- Grundy's Game189 / 243
- Another Game176 / 192
String Algorithms
- Word Combinations797 / 1257
- String Matching1718 / 2350
- Finding Borders1156 / 1323
- Finding Periods731 / 849
- Minimal Rotation534 / 804
- Longest Palindrome665 / 926
- Required Substring314 / 548
- Palindrome Queries160 / 200
- Finding Patterns175 / 258
- Counting Patterns177 / 220
- Pattern Positions154 / 188
- Distinct Substrings166 / 199
- Repeating Substring151 / 163
- String Functions143 / 149
- Substring Order I111 / 117
- Substring Order II78 / 95
- Substring Distribution111 / 122
Geometry
- Point Location Test849 / 936
- Line Segment Intersection503 / 631
- Polygon Area572 / 593
- Point in Polygon318 / 408
- Polygon Lattice Points269 / 281
- Minimum Euclidean Distance235 / 324
- Convex Hull368 / 449
Advanced Techniques
- Meet in the Middle894 / 1206
- Hamming Distance382 / 420
- Beautiful Subgrids202 / 259
- Reachable Nodes207 / 234
- Reachability Queries159 / 184
- Cut and Paste128 / 144
- Substring Reversals114 / 120
- Reversals and Sums113 / 117
- Necessary Roads174 / 176
- Necessary Cities156 / 164
- Eulerian Subgraphs87 / 91
- Monster Game I104 / 115
- Monster Game II103 / 108
- Subarray Squares121 / 141
- Houses and Schools82 / 90
- Knuth Division101 / 115
- Apples and Bananas99 / 110
- One Bit Positions93 / 106
- Signal Processing92 / 96
- New Roads Queries128 / 147
- Dynamic Connectivity81 / 87
- Parcel Delivery64 / 76
- Task Assignment68 / 71
- Distinct Routes II60 / 71
Additional Problems
- Shortest Subsequence794 / 1056
- Counting Bits854 / 1108
- Swap Game330 / 448
- Prüfer Code349 / 369
- Acyclic Graph Edges480 / 513
- Strongly Connected Edges140 / 150
- Even Outdegree Edges126 / 152
- Multiplication Table323 / 349
- Advertisement603 / 637
- Special Substrings107 / 116
- Permutation Inversions108 / 124
- Maximum Xor Subarray465 / 502
- Movie Festival Queries218 / 250
- Chess Tournament254 / 294
- Tree Traversals258 / 266
- Network Renovation195 / 282
- Graph Girth452 / 511
- Intersection Points305 / 331
- Inverse Inversions116 / 120
- Monotone Subsequences72 / 83
- String Reorder190 / 210
- Stack Weights56 / 64
- Pyramid Array171 / 208
- Increasing Subsequence II404 / 433
- String Removals219 / 251
- Bit Inversions439 / 485
- Xor Pyramid157 / 199
- Writing Numbers215 / 235
- String Transform144 / 169
- Letter Pair Move Game20 / 26
- Maximum Building I402 / 413
- Sorting Methods226 / 241
- Cyclic Array147 / 196
- List of Sums58 / 79
- Increasing Array II76 / 88
- Food Division139 / 167
- Bit Problem234 / 255
- Swap Round Sorting93 / 124
- Binary Subsequences23 / 39
- Tree Isomorphism I185 / 240
- Counting Sequences68 / 73
- Critical Cities90 / 135
- School Excursion248 / 264
- Coin Grid135 / 166
- Robot Path70 / 133
- Programmers and Artists39 / 52
- Course Schedule II266 / 384
- Removing Digits II24 / 41
- Coin Arrangement24 / 37
- Counting Bishops34 / 37
- Grid Puzzle I55 / 65
- Grid Puzzle II40 / 44
- Empty String221 / 284
- Grid Paths189 / 240
- Bit Substrings46 / 50
- Reversal Sorting38 / 51
- Counting Reorders23 / 31
- Book Shop II211 / 235
- Network Breakdown201 / 210
- Visiting Cities161 / 215
- Missing Coin Sum Queries30 / 46
- Number Grid254 / 311
- Maximum Building II104 / 128
- Filling Trominos25 / 43
- Stick Divisions480 / 569
- Coding Company208 / 267
- Flight Route Requests119 / 132
- Two Stacks Sorting16 / 53
- Tree Isomorphism II165 / 187
- Forbidden Cities129 / 160
- Area of Rectangles192 / 221
- Grid Completion18 / 25
- Creating Offices78 / 113
- Permutations II224 / 251
- Functional Graph Distribution19 / 22
- New Flight Routes91 / 193
- Grid Path Construction14 / 23