CSES Problem Set

General

• Introduction
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• Statistics

Introductory Problems

• Weird Algorithm149354 / 156403
• Missing Number128696 / 134966
• Repetitions112046 / 116630
• Increasing Array105271 / 109075
• Permutations92506 / 95375
• Number Spiral65397 / 71298
• Two Knights49909 / 51502
• Two Sets54272 / 58458
• Bit Strings62181 / 65669
• Trailing Zeros58028 / 61747
• Coin Piles51374 / 56252
• Palindrome Reorder47782 / 50465
• Gray Code31781 / 35754
• Tower of Hanoi29401 / 30589
• Creating Strings40260 / 41319
• Apple Division40403 / 45692
• Chessboard and Queens24337 / 24778
• Raab Game I3672 / 4186
• Mex Grid Construction3540 / 3780
• Knight Moves Grid3533 / 3615
• Grid Coloring I2920 / 3023
• Digit Queries17122 / 19985
• String Reorder2821 / 3287
• Grid Path Description9524 / 12400

Sorting and Searching

• Distinct Numbers72804 / 78812
• Apartments53888 / 60009
• Ferris Wheel51738 / 55924
• Concert Tickets41717 / 48631
• Restaurant Customers42382 / 45785
• Movie Festival40729 / 43158
• Sum of Two Values47593 / 53376
• Maximum Subarray Sum46024 / 48098
• Stick Lengths41024 / 42953
• Missing Coin Sum30824 / 31971
• Collecting Numbers31562 / 33845
• Collecting Numbers II13099 / 16799
• Playlist31686 / 36289
• Towers32088 / 34389
• Traffic Lights24841 / 27841
• Distinct Values Subarrays5425 / 5711
• Distinct Values Subsequences3748 / 4183
• Josephus Problem I18895 / 20880
• Josephus Problem II10195 / 14091
• Nested Ranges Check10806 / 12451
• Nested Ranges Count7315 / 8649
• Room Allocation18652 / 21449
• Factory Machines26491 / 28924
• Tasks and Deadlines21404 / 21876
• Reading Books17327 / 18566
• Sum of Three Values25424 / 28199
• Sum of Four Values15805 / 17655
• Nearest Smaller Values21117 / 21842
• Subarray Sums I28014 / 29914
• Subarray Sums II25396 / 30229
• Subarray Divisibility23200 / 25326
• Distinct Values Subarrays II13870 / 15319
• Array Division21947 / 23109
• Movie Festival II11703 / 14134
• Maximum Subarray Sum II10822 / 12958

Dynamic Programming

• Dice Combinations76229 / 80692
• Minimizing Coins65820 / 70782
• Coin Combinations I60101 / 65124
• Coin Combinations II50755 / 57564
• Removing Digits56588 / 57755
• Grid Paths I53243 / 54780
• Book Shop47513 / 52342
• Array Description34986 / 38915
• Counting Towers21214 / 22491
• Edit Distance35169 / 37132
• Longest Common Subsequence7435 / 7710
• Rectangle Cutting29196 / 31914
• Minimal Grid Path3163 / 6026
• Money Sums34619 / 35954
• Removal Game20380 / 27658
• Two Sets II27279 / 29396
• Mountain Range2233 / 4259
• Increasing Subsequence27854 / 31293
• Projects19212 / 21524
• Elevator Rides12225 / 15435
• Counting Tilings7123 / 7781
• Counting Numbers9746 / 11027
• Increasing Subsequence II3823 / 4444

Graph Algorithms

• Counting Rooms52391 / 55062
• Labyrinth36210 / 43484
• Building Roads45656 / 47317
• Message Route39242 / 40820
• Building Teams37094 / 39145
• Round Trip29473 / 32142
• Monsters20064 / 23763
• Shortest Routes I32147 / 35553
• Shortest Routes II26200 / 29409
• High Score15844 / 22602
• Flight Discount20526 / 24098
• Cycle Finding14606 / 18005
• Flight Routes14288 / 15967
• Round Trip II16292 / 18342
• Course Schedule21376 / 22618
• Longest Flight Route14979 / 18703
• Game Routes16847 / 18077
• Investigation12461 / 13416
• Planets Queries I10861 / 12750
• Planets Queries II3882 / 4933
• Planets Cycles6636 / 7421
• Road Reparation16364 / 17073
• Road Construction17940 / 18519
• Flight Routes Check14567 / 15804
• Planets and Kingdoms11718 / 12138
• Giant Pizza4812 / 5305
• Coin Collector7576 / 8424
• Mail Delivery6324 / 6930
• De Bruijn Sequence3310 / 3466
• Teleporters Path4783 / 5496
• Hamiltonian Flights7171 / 8198
• Knight's Tour2678 / 3260
• Download Speed4738 / 6416
• Police Chase3787 / 4266
• School Dance4178 / 4422
• Distinct Routes2938 / 3868

Range Queries

• Static Range Sum Queries36350 / 37981
• Static Range Minimum Queries25504 / 27311
• Dynamic Range Sum Queries26495 / 27668
• Dynamic Range Minimum Queries24003 / 24577
• Range Xor Queries24834 / 25171
• Range Update Queries19640 / 21071
• Forest Queries20129 / 20893
• Hotel Queries14194 / 15088
• List Removals11827 / 12449
• Salary Queries8753 / 11103
• Prefix Sum Queries7511 / 8151
• Pizzeria Queries6049 / 6279
• Visible Buildings Queries1233 / 1354
• Range Interval Queries968 / 1282
• Subarray Sum Queries7227 / 7852
• Subarray Sum Queries II1302 / 1369
• Distinct Values Queries6631 / 8230
• Distinct Values Queries II771 / 892
• Increasing Array Queries2560 / 2941
• Movie Festival Queries1259 / 1398
• Forest Queries II4334 / 4666
• Range Updates and Sums5770 / 6875
• Polynomial Queries4238 / 4974
• Range Queries and Copies3029 / 3246
• Missing Coin Sum Queries623 / 820

Tree Algorithms

• Subordinates30178 / 32291
• Tree Matching17128 / 19983
• Tree Diameter24585 / 26081
• Tree Distances I18787 / 20206
• Tree Distances II15381 / 16038
• Company Queries I17074 / 17974
• Company Queries II16009 / 16795
• Distance Queries14564 / 15637
• Counting Paths9134 / 9688
• Subtree Queries10954 / 11694
• Path Queries8774 / 9298
• Path Queries II3551 / 5318
• Distinct Colors8443 / 9338
• Finding a Centroid6806 / 7091
• Fixed-Length Paths I3218 / 4188
• Fixed-Length Paths II1503 / 2785

Mathematics

• Josephus Queries4626 / 5830
• Exponentiation23733 / 25361
• Exponentiation II16830 / 20199
• Counting Divisors21570 / 24373
• Common Divisors14144 / 16464
• Sum of Divisors7899 / 11892
• Divisor Analysis5375 / 7240
• Prime Multiples6183 / 7235
• Counting Coprime Pairs4028 / 4721
• Next Prime1482 / 1695
• Binomial Coefficients9953 / 11066
• Creating Strings II8407 / 8876
• Distributing Apples8072 / 8688
• Christmas Party6521 / 7010
• Permutation Order694 / 707
• Permutation Rounds821 / 925
• Bracket Sequences I4478 / 4876
• Bracket Sequences II2314 / 2662
• Counting Necklaces2150 / 2330
• Counting Grids1760 / 1881
• Fibonacci Numbers6891 / 8655
• Throwing Dice3566 / 3880
• Graph Paths I3390 / 3643
• Graph Paths II2835 / 2972
• System of Linear Equations326 / 365
• Sum of Four Squares520 / 604
• Triangle Number Sums438 / 552
• Dice Probability3060 / 3304
• Moving Robots1580 / 1672
• Candy Lottery1360 / 2939
• Inversion Probability325 / 2240
• Stick Game3441 / 3523
• Nim Game I4552 / 4723
• Nim Game II3600 / 3751
• Stair Game2437 / 2653
• Grundy's Game1686 / 2221
• Another Game1896 / 2048

String Algorithms

• Word Combinations5808 / 8450
• String Matching11311 / 15158
• Finding Borders8275 / 9056
• Finding Periods5892 / 6697
• Minimal Rotation2858 / 4369
• Longest Palindrome4336 / 5731
• All Palindromes505 / 575
• Required Substring1638 / 2518
• Palindrome Queries2031 / 2367
• Finding Patterns1879 / 2691
• Counting Patterns1772 / 2208
• Pattern Positions1480 / 1817
• Distinct Substrings1698 / 2030
• Distinct Subsequences1065 / 1135
• Repeating Substring1836 / 2144
• String Functions1602 / 1678
• Inverse Suffix Array166 / 198
• String Transform512 / 626
• Substring Order I1149 / 1289
• Substring Order II759 / 987
• Substring Distribution1068 / 1160

Geometry

• Point Location Test7203 / 8051
• Line Segment Intersection4282 / 5391
• Polygon Area4954 / 5252
• Point in Polygon2691 / 3463
• Polygon Lattice Points2305 / 2386
• Minimum Euclidean Distance1998 / 2772
• Convex Hull3283 / 3956
• Maximum Manhattan Distances459 / 473
• All Manhattan Distances470 / 514
• Intersection Points1929 / 2077
• Line Segments Trace I256 / 265
• Line Segments Trace II208 / 220
• Lines and Queries I285 / 293
• Lines and Queries II242 / 250
• Area of Rectangles1101 / 1231
• Robot Path285 / 529

Advanced Techniques

• Meet in the Middle6577 / 9200
• Hamming Distance3199 / 3485
• Corner Subgrid Check249 / 397
• Corner Subgrid Count2210 / 2483
• Reachable Nodes2221 / 2389
• Reachability Queries1477 / 1752
• Cut and Paste1479 / 1647
• Substring Reversals1297 / 1414
• Reversals and Sums1306 / 1408
• Necessary Roads1899 / 1945
• Necessary Cities1759 / 1845
• Eulerian Subgraphs774 / 815
• Monster Game I1125 / 1253
• Monster Game II1002 / 1076
• Subarray Squares1352 / 1604
• Houses and Schools749 / 899
• Knuth Division909 / 1028
• Apples and Bananas1024 / 1114
• One Bit Positions821 / 901
• Signal Processing774 / 832
• New Roads Queries2134 / 2599
• Dynamic Connectivity969 / 1094
• Parcel Delivery746 / 828
• Task Assignment874 / 931
• Distinct Routes II565 / 648

Sliding Window Problems

• Sliding Window Sum3757 / 3921
• Sliding Window Minimum2872 / 3285
• Sliding Window Xor2797 / 2831
• Sliding Window Or1190 / 2156
• Sliding Window Distinct Values1724 / 2371
• Sliding Window Mode1618 / 1705
• Sliding Window Mex1443 / 1522
• Sliding Window Median13363 / 15291
• Sliding Window Cost8828 / 10204
• Sliding Window Inversions817 / 876
• Sliding Window Advertisement159 / 258

Interactive Problems

• Hidden Integer1608 / 1668
• Hidden Permutation688 / 826
• K-th Highest Score294 / 356
• Permuted Binary Strings385 / 396
• Colored Chairs336 / 355
• Inversion Sorting202 / 217

Bitwise Operations

• Counting Bits4555 / 5859
• Maximum Xor Subarray2753 / 3106
• Maximum Xor Subset741 / 799
• Number of Subset Xors641 / 653
• K Subset Xors300 / 360
• All Subarray Xors203 / 322
• Xor Pyramid Peak1870 / 2291
• Xor Pyramid Diagonal231 / 262
• Xor Pyramid Row189 / 223
• SOS Bit Problem1946 / 2077
• And Subset Count293 / 297

Construction Problems

• Inverse Inversions1416 / 1508
• Monotone Subsequences855 / 1007
• Third Permutation295 / 345
• Permutation Prime Sums287 / 311
• Chess Tournament1125 / 1299
• Distinct Sums Grid81 / 136
• Filling Trominos232 / 400
• Grid Path Construction117 / 421

Advanced Graph Problems

• Nearest Shops534 / 697
• Prüfer Code1439 / 1555
• Tree Traversals1139 / 1252
• Course Schedule II1795 / 2581
• Acyclic Graph Edges2118 / 2252
• Strongly Connected Edges1473 / 1634
• Even Outdegree Edges1257 / 1480
• Graph Girth3220 / 3686
• Fixed Length Walk Queries266 / 292
• Transfer Speeds Sum311 / 320
• MST Edge Check452 / 485
• MST Edge Set Check169 / 191
• MST Edge Cost286 / 299
• Network Breakdown971 / 1030
• Tree Coin Collecting I241 / 267
• Tree Coin Collecting II124 / 146
• Tree Isomorphism I1032 / 1241
• Tree Isomorphism II838 / 980
• Flight Route Requests459 / 562
• Critical Cities389 / 604
• Visiting Cities646 / 858
• Graph Coloring170 / 198
• Bus Companies194 / 200
• Split into Two Paths65 / 120
• Network Renovation901 / 1205
• Forbidden Cities782 / 1024
• Creating Offices388 / 509
• New Flight Routes296 / 802

Counting Problems

• Filled Subgrid Count I412 / 454
• Filled Subgrid Count II208 / 257
• All Letter Subgrid Count I110 / 175
• All Letter Subgrid Count II94 / 114
• Border Subgrid Count I71 / 122
• Border Subgrid Count II71 / 82
• Raab Game II74 / 88
• Empty String1536 / 1876
• Permutation Inversions977 / 1078
• Counting Bishops366 / 409
• Counting Sequences628 / 673
• Grid Paths II717 / 895
• Counting Permutations843 / 954
• Grid Completion213 / 269
• Counting Reorders223 / 328
• Tournament Graph Distribution82 / 86
• Collecting Numbers Distribution86 / 93
• Functional Graph Distribution229 / 283

Additional Problems I

• Shortest Subsequence2874 / 3811
• Distinct Values Sum491 / 505
• Distinct Values Splits342 / 362
• Swap Game1957 / 2489
• Beautiful Permutation II302 / 455
• Multiplication Table6313 / 7052
• Bubble Sort Rounds I272 / 311
• Bubble Sort Rounds II153 / 180
• Nearest Campsites I122 / 140
• Nearest Campsites II121 / 130
• Advertisement4103 / 4349
• Special Substrings930 / 1021
• Counting LCM Arrays192 / 208
• Square Subsets154 / 173
• Subarray Sum Constraints207 / 223
• Water Containers Moves116 / 123
• Water Containers Queries144 / 151
• Stack Weights558 / 662
• Maximum Average Subarrays115 / 127
• Subsets with Fixed Average150 / 165
• Two Array Average142 / 159
• Pyramid Array676 / 824
• Permutation Subsequence160 / 163
• Bit Inversions2208 / 2515
• Writing Numbers706 / 763
• Letter Pair Move Game189 / 268
• Maximum Building I1972 / 2057
• Sorting Methods733 / 785
• Cyclic Array1115 / 1271
• List of Sums450 / 593

Additional Problems II

• Bouncing Ball Steps163 / 179
• Bouncing Ball Cycle65 / 92
• Knight Moves Queries87 / 106
• K Subset Sums I125 / 171
• K Subset Sums II62 / 85
• Increasing Array II746 / 862
• Food Division499 / 591
• Swap Round Sorting396 / 488
• Binary Subsequences275 / 405
• School Excursion1305 / 1385
• Coin Grid819 / 959
• Grid Coloring II98 / 126
• Programmers and Artists466 / 652
• Removing Digits II208 / 455
• Coin Arrangement307 / 416
• Replace with Difference90 / 111
• Grid Puzzle I503 / 551
• Grid Puzzle II471 / 519
• Bit Substrings367 / 446
• Reversal Sorting335 / 407
• Book Shop II1127 / 1294
• GCD Subsets315 / 323
• Minimum Cost Pairs73 / 103
• Same Sum Subsets82 / 153
• Mex Grid Queries807 / 946
• Maximum Building II427 / 525
• Stick Divisions3623 / 4256
• Stick Difference30 / 166
• Coding Company1391 / 1838
• Two Stacks Sorting163 / 514