CSES Problem Set

General

• Introduction
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• Statistics

Introductory Problems

• Weird Algorithm143292 / 150071
• Missing Number123358 / 129449
• Repetitions107614 / 112078
• Increasing Array101023 / 104751
• Permutations88888 / 91673
• Number Spiral62842 / 68534
• Two Knights47918 / 49466
• Two Sets52113 / 56168
• Bit Strings59800 / 63153
• Trailing Zeros55842 / 59443
• Coin Piles49425 / 54139
• Palindrome Reorder45795 / 48395
• Gray Code30387 / 34241
• Tower of Hanoi28089 / 29215
• Creating Strings38712 / 39736
• Apple Division38643 / 43767
• Chessboard and Queens23322 / 23755
• Raab Game I2848 / 3259
• Mex Grid Construction2716 / 2910
• Knight Moves Grid2761 / 2819
• Grid Coloring I2240 / 2320
• Digit Queries16450 / 19274
• String Reorder2270 / 2631
• Grid Path Description9223 / 12010

Sorting and Searching

• Distinct Numbers69747 / 75568
• Apartments51699 / 57635
• Ferris Wheel49575 / 53644
• Concert Tickets39944 / 46658
• Restaurant Customers40729 / 44035
• Movie Festival39051 / 41412
• Sum of Two Values45531 / 51124
• Maximum Subarray Sum44233 / 46253
• Stick Lengths39462 / 41343
• Missing Coin Sum29531 / 30643
• Collecting Numbers30265 / 32472
• Collecting Numbers II12456 / 16053
• Playlist30317 / 34814
• Towers30722 / 32970
• Traffic Lights23724 / 26647
• Distinct Values Subarrays4173 / 4383
• Distinct Values Subsequences2890 / 3247
• Josephus Problem I17984 / 19927
• Josephus Problem II9702 / 13393
• Nested Ranges Check10263 / 11869
• Nested Ranges Count6981 / 8255
• Room Allocation17877 / 20590
• Factory Machines25235 / 27612
• Tasks and Deadlines20464 / 20915
• Reading Books16590 / 17775
• Sum of Three Values24279 / 26975
• Sum of Four Values15126 / 16947
• Nearest Smaller Values20269 / 20969
• Subarray Sums I26726 / 28586
• Subarray Sums II24096 / 28807
• Subarray Divisibility22211 / 24289
• Distinct Values Subarrays II13062 / 14502
• Array Division20996 / 22127
• Movie Festival II11144 / 13500
• Maximum Subarray Sum II10302 / 12381

Dynamic Programming

• Dice Combinations72934 / 77257
• Minimizing Coins63015 / 67796
• Coin Combinations I57579 / 62436
• Coin Combinations II48691 / 55252
• Removing Digits54323 / 55462
• Grid Paths I50997 / 52476
• Book Shop45530 / 50222
• Array Description33455 / 37281
• Counting Towers20212 / 21447
• Edit Distance33734 / 35630
• Longest Common Subsequence5797 / 6038
• Rectangle Cutting28057 / 30670
• Minimal Grid Path2453 / 4777
• Money Sums33280 / 34591
• Removal Game19352 / 26604
• Two Sets II26236 / 28320
• Mountain Range1705 / 3339
• Increasing Subsequence26800 / 30126
• Projects18414 / 20674
• Elevator Rides11613 / 14714
• Counting Tilings6763 / 7404
• Counting Numbers9156 / 10393
• Increasing Subsequence II3354 / 3881

Graph Algorithms

• Counting Rooms50054 / 52665
• Labyrinth34517 / 41615
• Building Roads43785 / 45395
• Message Route37550 / 39099
• Building Teams35433 / 37459
• Round Trip28128 / 30735
• Monsters19027 / 22641
• Shortest Routes I30584 / 33941
• Shortest Routes II24946 / 28091
• High Score14931 / 21548
• Flight Discount19523 / 23003
• Cycle Finding13858 / 17172
• Flight Routes13506 / 15111
• Round Trip II15499 / 17478
• Course Schedule20368 / 21595
• Longest Flight Route14158 / 17815
• Game Routes15996 / 17204
• Investigation11836 / 12764
• Planets Queries I10227 / 12058
• Planets Queries II3664 / 4664
• Planets Cycles6323 / 7084
• Road Reparation15540 / 16215
• Road Construction17086 / 17642
• Flight Routes Check13863 / 15083
• Planets and Kingdoms11118 / 11523
• Giant Pizza4533 / 5012
• Coin Collector7170 / 8001
• Mail Delivery6010 / 6600
• De Bruijn Sequence3123 / 3275
• Teleporters Path4522 / 5232
• Hamiltonian Flights6793 / 7777
• Knight's Tour2522 / 3081
• Download Speed4458 / 6074
• Police Chase3571 / 4032
• School Dance3959 / 4199
• Distinct Routes2716 / 3596

Range Queries

• Static Range Sum Queries34386 / 35947
• Static Range Minimum Queries24252 / 26013
• Dynamic Range Sum Queries25241 / 26389
• Dynamic Range Minimum Queries22868 / 23426
• Range Xor Queries23652 / 23976
• Range Update Queries18643 / 20037
• Forest Queries19066 / 19806
• Hotel Queries13436 / 14319
• List Removals11194 / 11805
• Salary Queries8226 / 10513
• Prefix Sum Queries7064 / 7680
• Pizzeria Queries5706 / 5935
• Visible Buildings Queries929 / 1021
• Range Interval Queries737 / 969
• Subarray Sum Queries6902 / 7522
• Subarray Sum Queries II999 / 1034
• Distinct Values Queries6289 / 7847
• Distinct Values Queries II584 / 677
• Increasing Array Queries2430 / 2792
• Movie Festival Queries1141 / 1271
• Forest Queries II4170 / 4498
• Range Updates and Sums5497 / 6580
• Polynomial Queries4059 / 4776
• Range Queries and Copies2885 / 3103
• Missing Coin Sum Queries559 / 744

Tree Algorithms

• Subordinates28867 / 30915
• Tree Matching16336 / 19103
• Tree Diameter23506 / 24963
• Tree Distances I17838 / 19223
• Tree Distances II14690 / 15323
• Company Queries I16271 / 17151
• Company Queries II15243 / 16010
• Distance Queries13891 / 14933
• Counting Paths8630 / 9176
• Subtree Queries10400 / 11117
• Path Queries8265 / 8765
• Path Queries II3301 / 5011
• Distinct Colors8009 / 8873
• Finding a Centroid6463 / 6742
• Fixed-Length Paths I3037 / 3981
• Fixed-Length Paths II1406 / 2640

Mathematics

• Josephus Queries4376 / 5519
• Exponentiation22793 / 24360
• Exponentiation II16169 / 19451
• Counting Divisors20646 / 23359
• Common Divisors13564 / 15828
• Sum of Divisors7543 / 11421
• Divisor Analysis5133 / 6918
• Prime Multiples5825 / 6850
• Counting Coprime Pairs3806 / 4474
• Next Prime1138 / 1302
• Binomial Coefficients9539 / 10618
• Creating Strings II8047 / 8515
• Distributing Apples7750 / 8349
• Christmas Party6206 / 6681
• Permutation Order534 / 544
• Permutation Rounds589 / 656
• Bracket Sequences I4273 / 4664
• Bracket Sequences II2223 / 2562
• Counting Necklaces2048 / 2224
• Counting Grids1661 / 1778
• Fibonacci Numbers6612 / 8336
• Throwing Dice3423 / 3730
• Graph Paths I3251 / 3493
• Graph Paths II2713 / 2845
• System of Linear Equations266 / 288
• Sum of Four Squares406 / 479
• Triangle Number Sums349 / 436
• Dice Probability2956 / 3195
• Moving Robots1516 / 1607
• Candy Lottery1221 / 2788
• Inversion Probability418 / 2149
• Stick Game3278 / 3357
• Nim Game I4336 / 4502
• Nim Game II3438 / 3590
• Stair Game2328 / 2535
• Grundy's Game1589 / 2100
• Another Game1802 / 1948

String Algorithms

• Word Combinations5494 / 8035
• String Matching10723 / 14467
• Finding Borders7844 / 8595
• Finding Periods5599 / 6370
• Minimal Rotation2720 / 4196
• Longest Palindrome4110 / 5459
• All Palindromes390 / 445
• Required Substring1547 / 2409
• Palindrome Queries1938 / 2265
• Finding Patterns1780 / 2561
• Counting Patterns1680 / 2101
• Pattern Positions1408 / 1726
• Distinct Substrings1609 / 1926
• Distinct Subsequences997 / 1066
• Repeating Substring1735 / 2036
• String Functions1522 / 1597
• Inverse Suffix Array138 / 158
• String Transform483 / 594
• Substring Order I1089 / 1228
• Substring Order II720 / 932
• Substring Distribution1013 / 1105

Geometry

• Point Location Test6821 / 7638
• Line Segment Intersection4069 / 5149
• Polygon Area4747 / 5042
• Point in Polygon2586 / 3292
• Polygon Lattice Points2187 / 2268
• Minimum Euclidean Distance1900 / 2653
• Convex Hull3108 / 3767
• Maximum Manhattan Distances362 / 372
• All Manhattan Distances372 / 408
• Intersection Points1842 / 1986
• Line Segments Trace I205 / 211
• Line Segments Trace II163 / 173
• Lines and Queries I220 / 229
• Lines and Queries II190 / 198
• Area of Rectangles1036 / 1159
• Robot Path291 / 502

Advanced Techniques

• Meet in the Middle6284 / 8860
• Hamming Distance3082 / 3358
• Corner Subgrid Check186 / 322
• Corner Subgrid Count2149 / 2407
• Reachable Nodes2121 / 2288
• Reachability Queries1417 / 1683
• Cut and Paste1420 / 1582
• Substring Reversals1244 / 1360
• Reversals and Sums1253 / 1355
• Necessary Roads1827 / 1871
• Necessary Cities1702 / 1788
• Eulerian Subgraphs748 / 789
• Monster Game I1081 / 1206
• Monster Game II960 / 1033
• Subarray Squares1266 / 1513
• Houses and Schools712 / 852
• Knuth Division856 / 974
• Apples and Bananas944 / 1028
• One Bit Positions769 / 846
• Signal Processing711 / 767
• New Roads Queries2025 / 2477
• Dynamic Connectivity907 / 1031
• Parcel Delivery695 / 777
• Task Assignment819 / 871
• Distinct Routes II533 / 617

Sliding Window Problems

• Sliding Window Sum2879 / 3020
• Sliding Window Minimum2232 / 2562
• Sliding Window Xor2172 / 2199
• Sliding Window Or912 / 1680
• Sliding Window Distinct Values1817 / 1854
• Sliding Window Mode1276 / 1339
• Sliding Window Mex1136 / 1200
• Sliding Window Median12930 / 14808
• Sliding Window Cost8605 / 9941
• Sliding Window Inversions662 / 704
• Sliding Window Advertisement126 / 199

Interactive Problems

• Hidden Integer1232 / 1271
• Hidden Permutation544 / 642
• K-th Highest Score224 / 272
• Permuted Binary Strings318 / 326
• Colored Chairs264 / 278
• Inversion Sorting160 / 170

Bitwise Operations

• Counting Bits4128 / 5312
• Maximum Xor Subarray2548 / 2844
• Maximum Xor Subset549 / 594
• Number of Subset Xors469 / 481
• K Subset Xors227 / 267
• All Subarray Xors166 / 249
• Xor Pyramid Peak1751 / 2158
• Xor Pyramid Diagonal185 / 210
• Xor Pyramid Row154 / 175
• SOS Bit Problem1810 / 1935
• And Subset Count231 / 236

Construction Problems

• Inverse Inversions1260 / 1343
• Monotone Subsequences769 / 902
• Third Permutation229 / 264
• Permutation Prime Sums223 / 241
• Chess Tournament1063 / 1226
• Distinct Sums Grid62 / 107
• Filling Trominos221 / 378
• Grid Path Construction111 / 409

Advanced Graph Problems

• Nearest Shops426 / 556
• Prüfer Code1373 / 1487
• Tree Traversals1079 / 1191
• Course Schedule II1682 / 2421
• Acyclic Graph Edges2038 / 2165
• Strongly Connected Edges1405 / 1558
• Even Outdegree Edges1210 / 1427
• Graph Girth3079 / 3534
• Fixed Length Walk Queries225 / 241
• Transfer Speeds Sum250 / 256
• MST Edge Check320 / 345
• MST Edge Set Check132 / 149
• MST Edge Cost230 / 242
• Network Breakdown910 / 964
• Tree Coin Collecting I190 / 208
• Tree Coin Collecting II102 / 118
• Tree Isomorphism I991 / 1189
• Tree Isomorphism II803 / 946
• Flight Route Requests434 / 529
• Critical Cities379 / 580
• Visiting Cities622 / 827
• Graph Coloring123 / 149
• Bus Companies161 / 164
• Split into Two Paths56 / 100
• Network Renovation871 / 1164
• Forbidden Cities738 / 976
• Creating Offices380 / 493
• New Flight Routes283 / 758

Counting Problems

• Filled Subgrid Count I310 / 346
• Filled Subgrid Count II163 / 195
• All Letter Subgrid Count I76 / 130
• All Letter Subgrid Count II64 / 75
• Border Subgrid Count I55 / 99
• Border Subgrid Count II60 / 70
• Raab Game II58 / 69
• Empty String1465 / 1788
• Permutation Inversions926 / 1017
• Counting Bishops353 / 395
• Counting Sequences599 / 645
• Grid Paths II694 / 864
• Counting Permutations811 / 919
• Grid Completion201 / 255
• Counting Reorders210 / 306
• Tournament Graph Distribution64 / 66
• Collecting Numbers Distribution69 / 71
• Functional Graph Distribution217 / 273

Additional Problems I

• Shortest Subsequence2795 / 3717
• Distinct Values Sum364 / 374
• Distinct Values Splits256 / 273
• Swap Game1887 / 2399
• Beautiful Permutation II176 / 249
• Multiplication Table5988 / 6703
• Bubble Sort Rounds I195 / 226
• Bubble Sort Rounds II100 / 117
• Nearest Campsites I92 / 106
• Nearest Campsites II88 / 99
• Advertisement3951 / 4188
• Special Substrings900 / 985
• Counting LCM Arrays152 / 163
• Square Subsets121 / 137
• Subarray Sum Constraints130 / 141
• Water Containers Moves85 / 93
• Water Containers Queries118 / 123
• Stack Weights533 / 634
• Maximum Average Subarrays88 / 97
• Subsets with Fixed Average114 / 123
• Two Array Average106 / 120
• Pyramid Array653 / 792
• Permutation Subsequence133 / 135
• Bit Inversions2139 / 2447
• Writing Numbers688 / 745
• Letter Pair Move Game178 / 257
• Maximum Building I1923 / 2008
• Sorting Methods716 / 767
• Cyclic Array1063 / 1213
• List of Sums431 / 562

Additional Problems II

• Bouncing Ball Steps133 / 144
• Bouncing Ball Cycle52 / 71
• Knight Moves Queries77 / 92
• K Subset Sums I93 / 129
• K Subset Sums II51 / 69
• Increasing Array II733 / 846
• Food Division488 / 577
• Swap Round Sorting386 / 477
• Binary Subsequences265 / 392
• School Excursion1249 / 1329
• Coin Grid770 / 909
• Grid Coloring II79 / 101
• Programmers and Artists473 / 624
• Removing Digits II195 / 441
• Coin Arrangement294 / 400
• Replace with Difference65 / 82
• Grid Puzzle I477 / 524
• Grid Puzzle II432 / 476
• Bit Substrings344 / 422
• Reversal Sorting323 / 395
• Book Shop II1071 / 1234
• GCD Subsets243 / 249
• Minimum Cost Pairs55 / 73
• Same Sum Subsets64 / 117
• Mex Grid Queries782 / 921
• Maximum Building II410 / 505
• Stick Divisions3528 / 4147
• Stick Difference19 / 128
• Coding Company1330 / 1764
• Two Stacks Sorting154 / 483