General
Introductory Problems
- Weird Algorithm28943 / 30111
- Missing Number24348 / 25831
- Repetitions21420 / 22635
- Increasing Array19785 / 20683
- Permutations17627 / 18283
- Number Spiral12269 / 13388
- Two Knights9136 / 9472
- Two Sets9755 / 10633
- Bit Strings11791 / 12471
- Trailing Zeros11106 / 11859
- Coin Piles9625 / 10670
- Palindrome Reorder8496 / 9133
- Gray Code2680 / 3064
- Tower of Hanoi2316 / 2426
- Creating Strings7849 / 8085
- Apple Division6991 / 8178
- Chessboard and Queens4136 / 4216
- Digit Queries1320 / 1662
- Grid Paths1674 / 2225
Sorting and Searching
- Distinct Numbers12115 / 12554
- Apartments8233 / 9571
- Ferris Wheel7808 / 8696
- Concert Tickets6067 / 7530
- Restaurant Customers6247 / 6891
- Movie Festival5989 / 6393
- Sum of Two Values7071 / 7831
- Maximum Subarray Sum7005 / 7314
- Stick Lengths6349 / 6608
- Missing Coin Sum2123 / 2232
- Collecting Numbers2130 / 2362
- Collecting Numbers II801 / 1064
- Playlist5127 / 5980
- Towers5104 / 5587
- Traffic Lights3817 / 4374
- Josephus Problem I1149 / 1366
- Josephus Problem II669 / 896
- Nested Ranges Check521 / 651
- Nested Ranges Count429 / 479
- Room Allocation3057 / 3686
- Factory Machines3503 / 3818
- Tasks and Deadlines3460 / 3537
- Reading Books2961 / 3227
- Sum of Three Values3764 / 4247
- Sum of Four Values2719 / 3051
- Nearest Smaller Values3337 / 3512
- Subarray Sums I3760 / 4259
- Subarray Sums II3466 / 3922
- Subarray Divisibility3286 / 3527
- Subarray Distinct Values826 / 889
- Array Division2691 / 2880
- Sliding Median2151 / 2572
- Sliding Cost1523 / 1746
- Movie Festival II1656 / 2054
- Maximum Subarray Sum II1620 / 1983
Dynamic Programming
- Dice Combinations10691 / 11386
- Minimizing Coins9281 / 9933
- Coin Combinations I8607 / 9243
- Coin Combinations II7057 / 8102
- Removing Digits8039 / 8187
- Grid Paths7391 / 7650
- Book Shop6642 / 7353
- Array Description4590 / 5106
- Counting Towers1082 / 1180
- Edit Distance4947 / 5248
- Rectangle Cutting4328 / 4717
- Money Sums4989 / 5173
- Removal Game3549 / 3936
- Two Sets II3946 / 4291
- Increasing Subsequence4056 / 4665
- Projects2620 / 2989
- Elevator Rides787 / 1110
- Counting Tilings391 / 447
- Counting Numbers524 / 594
Graph Algorithms
- Counting Rooms7111 / 7547
- Labyrinth4392 / 5441
- Building Roads5648 / 5908
- Message Route4860 / 5087
- Building Teams4714 / 4945
- Round Trip3796 / 4150
- Monsters2063 / 2678
- Shortest Routes I3778 / 4226
- Shortest Routes II3313 / 3579
- High Score1885 / 2653
- Flight Discount2227 / 2654
- Cycle Finding1853 / 2183
- Flight Routes1563 / 1736
- Round Trip II1876 / 2145
- Course Schedule2491 / 2600
- Longest Flight Route1701 / 2183
- Game Routes1921 / 2024
- Investigation1324 / 1454
- Planets Queries I1347 / 1446
- Planets Queries II589 / 714
- Planets Cycles787 / 886
- Road Reparation1589 / 1638
- Road Construction1538 / 1587
- Flight Routes Check1443 / 1599
- Planets and Kingdoms1274 / 1323
- Giant Pizza618 / 715
- Coin Collector868 / 959
- Mail Delivery778 / 875
- De Bruijn Sequence505 / 528
- Teleporters Path575 / 711
- Hamiltonian Flights646 / 753
- Knight's Tour466 / 537
- Download Speed703 / 790
- Police Chase554 / 597
- School Dance575 / 594
- Distinct Routes358 / 526
Range Queries
- Static Range Sum Queries4630 / 4830
- Static Range Minimum Queries3595 / 3847
- Dynamic Range Sum Queries3568 / 3749
- Dynamic Range Minimum Queries3185 / 3268
- Range Xor Queries3351 / 3412
- Range Update Queries2542 / 2733
- Forest Queries2365 / 2452
- Hotel Queries1895 / 2037
- List Removals1635 / 1748
- Salary Queries1249 / 1490
- Prefix Sum Queries459 / 498
- Pizzeria Queries376 / 390
- Subarray Sum Queries1062 / 1216
- Distinct Values Queries1057 / 1250
- Increasing Array Queries208 / 242
- Forest Queries II821 / 872
- Range Updates and Sums797 / 963
- Polynomial Queries657 / 771
- Range Queries and Copies443 / 465
Tree Algorithms
- Subordinates3524 / 3786
- Tree Matching1925 / 2347
- Tree Diameter2920 / 3092
- Tree Distances I2047 / 2262
- Tree Distances II1705 / 1769
- Company Queries I1825 / 1935
- Company Queries II1751 / 1836
- Distance Queries1731 / 1837
- Counting Paths1085 / 1148
- Subtree Queries1289 / 1369
- Path Queries1064 / 1116
- Path Queries II239 / 294
- Distinct Colors910 / 1124
- Finding a Centroid442 / 459
- Fixed-Length Paths I213 / 245
- Fixed-Length Paths II168 / 181
Mathematics
- Josephus Queries219 / 299
- Exponentiation4120 / 4573
- Exponentiation II2870 / 3631
- Counting Divisors3139 / 3646
- Common Divisors2230 / 2618
- Sum of Divisors1282 / 2097
- Divisor Analysis335 / 483
- Prime Multiples375 / 473
- Counting Coprime Pairs225 / 299
- Binomial Coefficients1621 / 1870
- Creating Strings II1351 / 1477
- Distributing Apples1250 / 1348
- Christmas Party1116 / 1204
- Bracket Sequences I325 / 368
- Bracket Sequences II127 / 165
- Counting Necklaces145 / 161
- Counting Grids120 / 129
- Fibonacci Numbers1378 / 1757
- Throwing Dice838 / 918
- Graph Paths I694 / 747
- Graph Paths II582 / 602
- Dice Probability694 / 744
- Moving Robots374 / 395
- Candy Lottery507 / 522
- Inversion Probability442 / 452
- Stick Game673 / 692
- Nim Game I826 / 858
- Nim Game II680 / 710
- Stair Game441 / 513
- Grundy's Game125 / 169
- Another Game119 / 131
String Algorithms
- Word Combinations609 / 986
- String Matching1312 / 1825
- Finding Borders895 / 1033
- Finding Periods556 / 660
- Minimal Rotation425 / 661
- Longest Palindrome535 / 716
- Required Substring267 / 470
- Palindrome Queries101 / 129
- Finding Patterns128 / 172
- Counting Patterns117 / 143
- Pattern Positions104 / 127
- Distinct Substrings105 / 122
- Repeating Substring95 / 103
- String Functions93 / 96
- Substring Order I73 / 76
- Substring Order II49 / 58
- Substring Distribution78 / 84
Geometry
- Point Location Test639 / 703
- Line Segment Intersection374 / 474
- Polygon Area417 / 433
- Point in Polygon232 / 299
- Polygon Lattice Points204 / 214
- Minimum Euclidean Distance156 / 226
- Convex Hull266 / 337
Advanced Techniques
- Meet in the Middle675 / 883
- Hamming Distance231 / 258
- Beautiful Subgrids114 / 157
- Reachable Nodes119 / 138
- Reachability Queries87 / 105
- Cut and Paste89 / 99
- Substring Reversals77 / 82
- Reversals and Sums76 / 79
- Necessary Roads111 / 112
- Necessary Cities97 / 103
- Eulerian Subgraphs53 / 55
- Monster Game I68 / 75
- Monster Game II68 / 71
- Subarray Squares71 / 82
- Houses and Schools48 / 54
- Knuth Division59 / 77
- Apples and Bananas66 / 75
- One Bit Positions62 / 72
- Signal Processing62 / 65
- New Roads Queries75 / 86
- Dynamic Connectivity52 / 55
- Parcel Delivery40 / 46
- Task Assignment43 / 45
- Distinct Routes II38 / 45
Additional Problems
- Shortest Subsequence705 / 951
- Counting Bits744 / 956
- Swap Game280 / 382
- Prüfer Code311 / 330
- Acyclic Graph Edges423 / 451
- Strongly Connected Edges88 / 95
- Even Outdegree Edges72 / 86
- Multiplication Table167 / 184
- Advertisement474 / 503
- Special Substrings67 / 73
- Permutation Inversions58 / 68
- Maximum Xor Subarray396 / 428
- Movie Festival Queries190 / 217
- Chess Tournament217 / 252
- Tree Traversals216 / 222
- Network Renovation170 / 251
- Graph Girth361 / 410
- Intersection Points254 / 279
- Inverse Inversions75 / 79
- Monotone Subsequences45 / 54
- String Reorder159 / 176
- Stack Weights34 / 40
- Pyramid Array145 / 179
- Increasing Subsequence II337 / 362
- String Removals188 / 220
- Bit Inversions366 / 403
- Xor Pyramid104 / 136
- Writing Numbers198 / 216
- String Transform127 / 152
- Letter Pair Move Game12 / 15
- Maximum Building I327 / 335
- Sorting Methods201 / 214
- Cyclic Array130 / 177
- List of Sums38 / 47
- Increasing Array II41 / 54
- Food Division111 / 136
- Bit Problem163 / 177
- Swap Round Sorting82 / 110
- Binary Subsequences15 / 23
- Tree Isomorphism I175 / 209
- Counting Sequences46 / 48
- Critical Cities78 / 118
- School Excursion205 / 220
- Coin Grid114 / 141
- Robot Path57 / 114
- Programmers and Artists23 / 32
- Course Schedule II197 / 292
- Removing Digits II15 / 27
- Coin Arrangement13 / 20
- Counting Bishops21 / 23
- Grid Puzzle I38 / 46
- Grid Puzzle II30 / 33
- Empty String173 / 221
- Grid Paths166 / 213
- Bit Substrings29 / 34
- Reversal Sorting26 / 35
- Counting Reorders13 / 17
- Book Shop II181 / 203
- Network Breakdown175 / 182
- Visiting Cities145 / 192
- Missing Coin Sum Queries17 / 30
- Number Grid224 / 278
- Maximum Building II88 / 109
- Filling Trominos17 / 29
- Stick Divisions396 / 466
- Coding Company160 / 215
- Flight Route Requests105 / 116
- Two Stacks Sorting12 / 33
- Tree Isomorphism II139 / 160
- Forbidden Cities114 / 138
- Area of Rectangles156 / 180
- Grid Completion9 / 12
- Creating Offices70 / 101
- Permutations II190 / 213
- Functional Graph Distribution12 / 13
- New Flight Routes76 / 166
- Grid Path Construction9 / 15