CSES Problem Set

General

• Introduction
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• Statistics

Introductory Problems

• Weird Algorithm150088 / 157157
• Missing Number129326 / 135625
• Repetitions112624 / 117214
• Increasing Array105785 / 109603
• Permutations93014 / 95888
• Number Spiral65727 / 71658
• Two Knights50193 / 51792
• Two Sets54562 / 58759
• Bit Strings62465 / 65966
• Trailing Zeros58315 / 62048
• Coin Piles51620 / 56512
• Palindrome Reorder48010 / 50703
• Gray Code31960 / 35956
• Tower of Hanoi29562 / 30757
• Creating Strings40481 / 41548
• Apple Division40615 / 45929
• Chessboard and Queens24467 / 24911
• Raab Game I3781 / 4310
• Mex Grid Construction3650 / 3896
• Knight Moves Grid3640 / 3722
• Grid Coloring I3031 / 3134
• Digit Queries17195 / 20064
• String Reorder2893 / 3370
• Grid Path Description9570 / 12459

Sorting and Searching

• Distinct Numbers73208 / 79233
• Apartments54139 / 60264
• Ferris Wheel51986 / 56179
• Concert Tickets41916 / 48858
• Restaurant Customers42577 / 45990
• Movie Festival40911 / 43351
• Sum of Two Values47806 / 53609
• Maximum Subarray Sum46214 / 48295
• Stick Lengths41183 / 43113
• Missing Coin Sum30961 / 32113
• Collecting Numbers31707 / 33998
• Collecting Numbers II13170 / 16877
• Playlist31809 / 36426
• Towers32210 / 34523
• Traffic Lights24938 / 27944
• Distinct Values Subarrays5558 / 5844
• Distinct Values Subsequences3835 / 4279
• Josephus Problem I19009 / 20995
• Josephus Problem II10255 / 14171
• Nested Ranges Check10862 / 12515
• Nested Ranges Count7360 / 8700
• Room Allocation18738 / 21544
• Factory Machines26669 / 29111
• Tasks and Deadlines21494 / 21965
• Reading Books17411 / 18662
• Sum of Three Values25592 / 28373
• Sum of Four Values15863 / 17716
• Nearest Smaller Values21201 / 21933
• Subarray Sums I28134 / 30035
• Subarray Sums II25520 / 30360
• Subarray Divisibility23300 / 25431
• Distinct Values Subarrays II13939 / 15386
• Array Division22048 / 23218
• Movie Festival II11777 / 14225
• Maximum Subarray Sum II10876 / 13014

Dynamic Programming

• Dice Combinations76589 / 81063
• Minimizing Coins66123 / 71098
• Coin Combinations I60362 / 65413
• Coin Combinations II50986 / 57816
• Removing Digits56831 / 57997
• Grid Paths I53454 / 54997
• Book Shop47726 / 52560
• Array Description35122 / 39068
• Counting Towers21302 / 22587
• Edit Distance35291 / 37258
• Longest Common Subsequence7598 / 7881
• Rectangle Cutting29296 / 32023
• Minimal Grid Path3265 / 6159
• Money Sums34734 / 36074
• Removal Game20473 / 27752
• Two Sets II27369 / 29488
• Mountain Range2295 / 4348
• Increasing Subsequence27961 / 31406
• Projects19277 / 21593
• Elevator Rides12277 / 15494
• Counting Tilings7174 / 7835
• Counting Numbers9834 / 11125
• Increasing Subsequence II3872 / 4507

Graph Algorithms

• Counting Rooms52680 / 55366
• Labyrinth36412 / 43709
• Building Roads45872 / 47533
• Message Route39472 / 41057
• Building Teams37281 / 39335
• Round Trip29616 / 32295
• Monsters20181 / 23897
• Shortest Routes I32337 / 35748
• Shortest Routes II26364 / 29588
• High Score15942 / 22720
• Flight Discount20631 / 24215
• Cycle Finding14691 / 18095
• Flight Routes14360 / 16041
• Round Trip II16361 / 18409
• Course Schedule21457 / 22698
• Longest Flight Route15052 / 18782
• Game Routes16915 / 18146
• Investigation12527 / 13486
• Planets Queries I10907 / 12803
• Planets Queries II3907 / 4962
• Planets Cycles6670 / 7455
• Road Reparation16447 / 17158
• Road Construction18014 / 18594
• Flight Routes Check14632 / 15872
• Planets and Kingdoms11772 / 12193
• Giant Pizza4835 / 5330
• Coin Collector7609 / 8458
• Mail Delivery6354 / 6962
• De Bruijn Sequence3323 / 3479
• Teleporters Path4805 / 5517
• Hamiltonian Flights7206 / 8232
• Knight's Tour2696 / 3280
• Download Speed4763 / 6444
• Police Chase3801 / 4278
• School Dance4194 / 4438
• Distinct Routes2946 / 3881

Range Queries

• Static Range Sum Queries36513 / 38151
• Static Range Minimum Queries25609 / 27428
• Dynamic Range Sum Queries26603 / 27786
• Dynamic Range Minimum Queries24095 / 24671
• Range Xor Queries24938 / 25276
• Range Update Queries19736 / 21172
• Forest Queries20226 / 20992
• Hotel Queries14268 / 15162
• List Removals11877 / 12502
• Salary Queries8802 / 11164
• Prefix Sum Queries7559 / 8202
• Pizzeria Queries6085 / 6315
• Visible Buildings Queries1275 / 1398
• Range Interval Queries999 / 1328
• Subarray Sum Queries7264 / 7890
• Subarray Sum Queries II1343 / 1410
• Distinct Values Queries6685 / 8288
• Distinct Values Queries II793 / 918
• Increasing Array Queries2568 / 2950
• Movie Festival Queries1275 / 1417
• Forest Queries II4351 / 4687
• Range Updates and Sums5793 / 6903
• Polynomial Queries4256 / 4996
• Range Queries and Copies3049 / 3267
• Missing Coin Sum Queries630 / 831

Tree Algorithms

• Subordinates30328 / 32446
• Tree Matching17202 / 20059
• Tree Diameter24711 / 26207
• Tree Distances I18881 / 20303
• Tree Distances II15461 / 16122
• Company Queries I17173 / 18076
• Company Queries II16101 / 16890
• Distance Queries14639 / 15714
• Counting Paths9172 / 9728
• Subtree Queries10998 / 11740
• Path Queries8815 / 9342
• Path Queries II3534 / 5357
• Distinct Colors8481 / 9377
• Finding a Centroid6849 / 7137
• Fixed-Length Paths I3250 / 4223
• Fixed-Length Paths II1517 / 2805

Mathematics

• Josephus Queries4655 / 5865
• Exponentiation23818 / 25457
• Exponentiation II16895 / 20275
• Counting Divisors21676 / 24491
• Common Divisors14227 / 16550
• Sum of Divisors7933 / 11935
• Divisor Analysis5394 / 7267
• Prime Multiples6229 / 7281
• Counting Coprime Pairs4049 / 4744
• Next Prime1520 / 1737
• Binomial Coefficients9999 / 11114
• Creating Strings II8447 / 8921
• Distributing Apples8110 / 8729
• Christmas Party6543 / 7033
• Permutation Order712 / 724
• Permutation Rounds855 / 960
• Bracket Sequences I4494 / 4895
• Bracket Sequences II2327 / 2675
• Counting Necklaces2158 / 2338
• Counting Grids1770 / 1893
• Fibonacci Numbers6928 / 8694
• Throwing Dice3581 / 3895
• Graph Paths I3412 / 3665
• Graph Paths II2854 / 2992
• System of Linear Equations339 / 377
• Sum of Four Squares532 / 615
• Triangle Number Sums445 / 561
• Dice Probability3078 / 3323
• Moving Robots1583 / 1675
• Candy Lottery1381 / 2958
• Inversion Probability328 / 2245
• Stick Game3461 / 3544
• Nim Game I4571 / 4742
• Nim Game II3615 / 3766
• Stair Game2442 / 2659
• Grundy's Game1691 / 2226
• Another Game1922 / 2075

String Algorithms

• Word Combinations5842 / 8488
• String Matching11375 / 15230
• Finding Borders8317 / 9101
• Finding Periods5923 / 6736
• Minimal Rotation2867 / 4382
• Longest Palindrome4349 / 5751
• All Palindromes520 / 590
• Required Substring1646 / 2526
• Palindrome Queries2038 / 2374
• Finding Patterns1894 / 2706
• Counting Patterns1790 / 2230
• Pattern Positions1497 / 1835
• Distinct Substrings1713 / 2047
• Distinct Subsequences1074 / 1144
• Repeating Substring1852 / 2159
• String Functions1614 / 1690
• Inverse Suffix Array172 / 204
• String Transform521 / 634
• Substring Order I1159 / 1299
• Substring Order II768 / 997
• Substring Distribution1079 / 1171

Geometry

• Point Location Test7250 / 8097
• Line Segment Intersection4316 / 5426
• Polygon Area4980 / 5278
• Point in Polygon2722 / 3501
• Polygon Lattice Points2319 / 2400
• Minimum Euclidean Distance2012 / 2790
• Convex Hull3302 / 3980
• Maximum Manhattan Distances474 / 489
• All Manhattan Distances484 / 529
• Intersection Points1943 / 2092
• Line Segments Trace I264 / 273
• Line Segments Trace II216 / 228
• Lines and Queries I295 / 304
• Lines and Queries II255 / 263
• Area of Rectangles1112 / 1243
• Robot Path288 / 534

Advanced Techniques

• Meet in the Middle6623 / 9249
• Hamming Distance3213 / 3500
• Corner Subgrid Check257 / 412
• Corner Subgrid Count2226 / 2501
• Reachable Nodes2234 / 2403
• Reachability Queries1483 / 1758
• Cut and Paste1492 / 1662
• Substring Reversals1304 / 1421
• Reversals and Sums1314 / 1416
• Necessary Roads1914 / 1959
• Necessary Cities1777 / 1863
• Eulerian Subgraphs780 / 821
• Monster Game I1134 / 1261
• Monster Game II1012 / 1086
• Subarray Squares1365 / 1618
• Houses and Schools755 / 905
• Knuth Division917 / 1036
• Apples and Bananas1037 / 1126
• One Bit Positions830 / 910
• Signal Processing785 / 843
• New Roads Queries2147 / 2613
• Dynamic Connectivity978 / 1105
• Parcel Delivery751 / 833
• Task Assignment884 / 941
• Distinct Routes II569 / 652

Sliding Window Problems

• Sliding Window Sum3849 / 4018
• Sliding Window Minimum2933 / 3359
• Sliding Window Xor2877 / 2913
• Sliding Window Or1218 / 2202
• Sliding Window Distinct Values1781 / 2425
• Sliding Window Mode1651 / 1740
• Sliding Window Mex1471 / 1553
• Sliding Window Median13417 / 15349
• Sliding Window Cost8846 / 10224
• Sliding Window Inversions845 / 905
• Sliding Window Advertisement165 / 267

Interactive Problems

• Hidden Integer1645 / 1704
• Hidden Permutation709 / 846
• K-th Highest Score310 / 376
• Permuted Binary Strings394 / 405
• Colored Chairs346 / 365
• Inversion Sorting209 / 226

Bitwise Operations

• Counting Bits4601 / 5913
• Maximum Xor Subarray2777 / 3134
• Maximum Xor Subset767 / 827
• Number of Subset Xors662 / 676
• K Subset Xors314 / 378
• All Subarray Xors210 / 333
• Xor Pyramid Peak1887 / 2310
• Xor Pyramid Diagonal239 / 270
• Xor Pyramid Row192 / 227
• SOS Bit Problem1987 / 2119
• And Subset Count306 / 310

Construction Problems

• Inverse Inversions1436 / 1529
• Monotone Subsequences885 / 1039
• Third Permutation304 / 353
• Permutation Prime Sums296 / 320
• Chess Tournament1132 / 1307
• Distinct Sums Grid84 / 142
• Filling Trominos232 / 402
• Grid Path Construction118 / 421

Advanced Graph Problems

• Nearest Shops544 / 708
• Prüfer Code1451 / 1567
• Tree Traversals1144 / 1258
• Course Schedule II1808 / 2598
• Acyclic Graph Edges2152 / 2286
• Strongly Connected Edges1484 / 1647
• Even Outdegree Edges1267 / 1491
• Graph Girth3251 / 3717
• Fixed Length Walk Queries271 / 299
• Transfer Speeds Sum323 / 333
• MST Edge Check464 / 499
• MST Edge Set Check174 / 198
• MST Edge Cost290 / 303
• Network Breakdown977 / 1036
• Tree Coin Collecting I245 / 273
• Tree Coin Collecting II127 / 150
• Tree Isomorphism I1036 / 1245
• Tree Isomorphism II842 / 984
• Flight Route Requests463 / 567
• Critical Cities393 / 610
• Visiting Cities652 / 867
• Graph Coloring174 / 203
• Bus Companies199 / 205
• Split into Two Paths66 / 127
• Network Renovation907 / 1210
• Forbidden Cities794 / 1040
• Creating Offices394 / 516
• New Flight Routes298 / 809

Counting Problems

• Filled Subgrid Count I423 / 466
• Filled Subgrid Count II218 / 269
• All Letter Subgrid Count I116 / 180
• All Letter Subgrid Count II96 / 118
• Border Subgrid Count I72 / 124
• Border Subgrid Count II74 / 86
• Raab Game II76 / 91
• Empty String1545 / 1890
• Permutation Inversions982 / 1084
• Counting Bishops367 / 410
• Counting Sequences632 / 677
• Grid Paths II719 / 897
• Counting Permutations847 / 958
• Grid Completion214 / 270
• Counting Reorders225 / 330
• Tournament Graph Distribution83 / 87
• Collecting Numbers Distribution87 / 95
• Functional Graph Distribution230 / 284

Additional Problems I

• Shortest Subsequence2909 / 3849
• Distinct Values Sum502 / 518
• Distinct Values Splits351 / 371
• Swap Game1978 / 2513
• Beautiful Permutation II318 / 477
• Multiplication Table6363 / 7108
• Bubble Sort Rounds I287 / 328
• Bubble Sort Rounds II161 / 188
• Nearest Campsites I127 / 147
• Nearest Campsites II126 / 135
• Advertisement4129 / 4375
• Special Substrings935 / 1027
• Counting LCM Arrays201 / 219
• Square Subsets163 / 181
• Subarray Sum Constraints219 / 236
• Water Containers Moves119 / 126
• Water Containers Queries148 / 155
• Stack Weights560 / 664
• Maximum Average Subarrays119 / 131
• Subsets with Fixed Average155 / 171
• Two Array Average149 / 167
• Pyramid Array682 / 832
• Permutation Subsequence167 / 170
• Bit Inversions2222 / 2530
• Writing Numbers711 / 768
• Letter Pair Move Game190 / 268
• Maximum Building I1983 / 2068
• Sorting Methods736 / 789
• Cyclic Array1120 / 1277
• List of Sums452 / 595

Additional Problems II

• Bouncing Ball Steps168 / 184
• Bouncing Ball Cycle66 / 94
• Knight Moves Queries90 / 111
• K Subset Sums I127 / 174
• K Subset Sums II64 / 87
• Increasing Array II753 / 869
• Food Division502 / 594
• Swap Round Sorting398 / 490
• Binary Subsequences275 / 406
• School Excursion1315 / 1396
• Coin Grid824 / 964
• Grid Coloring II101 / 130
• Programmers and Artists466 / 653
• Removing Digits II208 / 455
• Coin Arrangement309 / 417
• Replace with Difference92 / 113
• Grid Puzzle I505 / 554
• Grid Puzzle II477 / 525
• Bit Substrings368 / 447
• Reversal Sorting335 / 407
• Book Shop II1137 / 1304
• GCD Subsets323 / 331
• Minimum Cost Pairs78 / 108
• Same Sum Subsets84 / 158
• Mex Grid Queries811 / 951
• Maximum Building II429 / 527
• Stick Divisions3631 / 4263
• Stick Difference31 / 166
• Coding Company1400 / 1846
• Two Stacks Sorting163 / 518