CSES Problem Set

General

• Introduction
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• Statistics

Introductory Problems

• Weird Algorithm151048 / 158151
• Missing Number130187 / 136501
• Repetitions113358 / 117971
• Increasing Array106512 / 110355
• Permutations93678 / 96566
• Number Spiral66214 / 72179
• Two Knights50551 / 52153
• Two Sets55001 / 59221
• Bit Strings62884 / 66405
• Trailing Zeros58721 / 62493
• Coin Piles51975 / 56898
• Palindrome Reorder48355 / 51054
• Gray Code32217 / 36241
• Tower of Hanoi29795 / 30997
• Creating Strings40757 / 41830
• Apple Division40888 / 46236
• Chessboard and Queens24619 / 25068
• Raab Game I3935 / 4470
• Mex Grid Construction3790 / 4043
• Knight Moves Grid3783 / 3871
• Grid Coloring I3160 / 3271
• Digit Queries17314 / 20187
• String Reorder2983 / 3472
• Grid Path Description9620 / 12527

Sorting and Searching

• Distinct Numbers73822 / 79890
• Apartments54569 / 60729
• Ferris Wheel52377 / 56585
• Concert Tickets42234 / 49210
• Restaurant Customers42899 / 46340
• Movie Festival41223 / 43671
• Sum of Two Values48157 / 53994
• Maximum Subarray Sum46568 / 48659
• Stick Lengths41490 / 43425
• Missing Coin Sum31202 / 32357
• Collecting Numbers31954 / 34261
• Collecting Numbers II13287 / 17019
• Playlist32025 / 36661
• Towers32437 / 34759
• Traffic Lights25118 / 28140
• Distinct Values Subarrays5793 / 6096
• Distinct Values Subsequences3966 / 4418
• Josephus Problem I19154 / 21135
• Josephus Problem II10340 / 14285
• Nested Ranges Check10955 / 12622
• Nested Ranges Count7415 / 8768
• Room Allocation18871 / 21688
• Factory Machines26868 / 29317
• Tasks and Deadlines21644 / 22116
• Reading Books17546 / 18804
• Sum of Three Values25800 / 28602
• Sum of Four Values15983 / 17838
• Nearest Smaller Values21373 / 22114
• Subarray Sums I28344 / 30248
• Subarray Sums II25711 / 30574
• Subarray Divisibility23463 / 25601
• Distinct Values Subarrays II14081 / 15536
• Array Division22270 / 23457
• Movie Festival II11884 / 14357
• Maximum Subarray Sum II10961 / 13108

Dynamic Programming

• Dice Combinations77209 / 81719
• Minimizing Coins66651 / 71656
• Coin Combinations I60853 / 65940
• Coin Combinations II51404 / 58267
• Removing Digits57240 / 58417
• Grid Paths I53891 / 55449
• Book Shop48076 / 52927
• Array Description35399 / 39365
• Counting Towers21473 / 22778
• Edit Distance35549 / 37531
• Longest Common Subsequence7879 / 8175
• Rectangle Cutting29481 / 32232
• Minimal Grid Path3373 / 6335
• Money Sums34953 / 36298
• Removal Game20660 / 27976
• Two Sets II27546 / 29679
• Mountain Range2380 / 4474
• Increasing Subsequence28151 / 31612
• Projects19384 / 21708
• Elevator Rides12356 / 15593
• Counting Tilings7225 / 7889
• Counting Numbers9909 / 11205
• Increasing Subsequence II3944 / 4586

Graph Algorithms

• Counting Rooms52994 / 55695
• Labyrinth36648 / 43988
• Building Roads46148 / 47815
• Message Route39716 / 41304
• Building Teams37511 / 39573
• Round Trip29802 / 32499
• Monsters20303 / 24026
• Shortest Routes I32568 / 35986
• Shortest Routes II26547 / 29783
• High Score16074 / 22863
• Flight Discount20779 / 24381
• Cycle Finding14797 / 18208
• Flight Routes14447 / 16140
• Round Trip II16463 / 18514
• Course Schedule21595 / 22839
• Longest Flight Route15165 / 18902
• Game Routes17018 / 18251
• Investigation12613 / 13580
• Planets Queries I11005 / 12904
• Planets Queries II3943 / 5003
• Planets Cycles6724 / 7515
• Road Reparation16540 / 17252
• Road Construction18136 / 18715
• Flight Routes Check14717 / 15964
• Planets and Kingdoms11822 / 12246
• Giant Pizza4876 / 5374
• Coin Collector7661 / 8511
• Mail Delivery6397 / 7009
• De Bruijn Sequence3342 / 3501
• Teleporters Path4840 / 5550
• Hamiltonian Flights7257 / 8290
• Knight's Tour2717 / 3302
• Download Speed4809 / 6491
• Police Chase3835 / 4314
• School Dance4235 / 4480
• Distinct Routes2975 / 3915

Range Queries

• Static Range Sum Queries36738 / 38383
• Static Range Minimum Queries25768 / 27601
• Dynamic Range Sum Queries26742 / 27928
• Dynamic Range Minimum Queries24236 / 24815
• Range Xor Queries25084 / 25423
• Range Update Queries19870 / 21309
• Forest Queries20354 / 21125
• Hotel Queries14374 / 15272
• List Removals11954 / 12583
• Salary Queries8872 / 11250
• Prefix Sum Queries7630 / 8276
• Pizzeria Queries6129 / 6361
• Visible Buildings Queries1299 / 1424
• Range Interval Queries1025 / 1362
• Subarray Sum Queries7323 / 7950
• Subarray Sum Queries II1386 / 1453
• Distinct Values Queries6750 / 8369
• Distinct Values Queries II817 / 945
• Increasing Array Queries2590 / 2978
• Movie Festival Queries1292 / 1438
• Forest Queries II4370 / 4710
• Range Updates and Sums5839 / 6956
• Polynomial Queries4280 / 5028
• Range Queries and Copies3074 / 3295
• Missing Coin Sum Queries644 / 846

Tree Algorithms

• Subordinates30537 / 32664
• Tree Matching17326 / 20192
• Tree Diameter24871 / 26375
• Tree Distances I18999 / 20425
• Tree Distances II15545 / 16209
• Company Queries I17266 / 18173
• Company Queries II16200 / 16990
• Distance Queries14735 / 15815
• Counting Paths9229 / 9788
• Subtree Queries11053 / 11800
• Path Queries8866 / 9395
• Path Queries II3566 / 5397
• Distinct Colors8524 / 9422
• Finding a Centroid6886 / 7176
• Fixed-Length Paths I3286 / 4262
• Fixed-Length Paths II1537 / 2836

Mathematics

• Josephus Queries4699 / 5920
• Exponentiation23964 / 25604
• Exponentiation II17001 / 20398
• Counting Divisors21807 / 24636
• Common Divisors14304 / 16640
• Sum of Divisors7980 / 12004
• Divisor Analysis5435 / 7313
• Prime Multiples6286 / 7348
• Counting Coprime Pairs4085 / 4784
• Next Prime1577 / 1806
• Binomial Coefficients10069 / 11193
• Creating Strings II8517 / 8991
• Distributing Apples8179 / 8801
• Christmas Party6588 / 7083
• Permutation Order743 / 758
• Permutation Rounds900 / 1006
• Bracket Sequences I4530 / 4934
• Bracket Sequences II2353 / 2703
• Counting Necklaces2177 / 2358
• Counting Grids1789 / 1913
• Fibonacci Numbers6974 / 8753
• Throwing Dice3609 / 3926
• Graph Paths I3429 / 3687
• Graph Paths II2870 / 3011
• System of Linear Equations349 / 388
• Sum of Four Squares552 / 636
• Triangle Number Sums461 / 578
• Dice Probability3100 / 3349
• Moving Robots1594 / 1687
• Candy Lottery1409 / 2988
• Inversion Probability341 / 2263
• Stick Game3483 / 3568
• Nim Game I4605 / 4779
• Nim Game II3646 / 3798
• Stair Game2461 / 2679
• Grundy's Game1707 / 2247
• Another Game1934 / 2088

String Algorithms

• Word Combinations5897 / 8564
• String Matching11458 / 15334
• Finding Borders8357 / 9148
• Finding Periods5952 / 6769
• Minimal Rotation2888 / 4405
• Longest Palindrome4371 / 5775
• All Palindromes529 / 604
• Required Substring1659 / 2543
• Palindrome Queries2052 / 2391
• Finding Patterns1913 / 2727
• Counting Patterns1812 / 2253
• Pattern Positions1513 / 1855
• Distinct Substrings1732 / 2070
• Distinct Subsequences1081 / 1153
• Repeating Substring1865 / 2175
• String Functions1626 / 1703
• Inverse Suffix Array173 / 213
• String Transform527 / 643
• Substring Order I1168 / 1310
• Substring Order II777 / 1007
• Substring Distribution1087 / 1183

Geometry

• Point Location Test7315 / 8168
• Line Segment Intersection4350 / 5467
• Polygon Area5021 / 5320
• Point in Polygon2756 / 3533
• Polygon Lattice Points2335 / 2419
• Minimum Euclidean Distance2033 / 2813
• Convex Hull3346 / 4025
• Maximum Manhattan Distances495 / 511
• All Manhattan Distances501 / 548
• Intersection Points1960 / 2112
• Line Segments Trace I276 / 286
• Line Segments Trace II226 / 239
• Lines and Queries I308 / 318
• Lines and Queries II264 / 273
• Area of Rectangles1117 / 1249
• Robot Path292 / 541

Advanced Techniques

• Meet in the Middle6661 / 9292
• Hamming Distance3225 / 3517
• Corner Subgrid Check268 / 426
• Corner Subgrid Count2240 / 2515
• Reachable Nodes2263 / 2434
• Reachability Queries1498 / 1775
• Cut and Paste1512 / 1684
• Substring Reversals1314 / 1433
• Reversals and Sums1323 / 1426
• Necessary Roads1921 / 1973
• Necessary Cities1785 / 1872
• Eulerian Subgraphs788 / 831
• Monster Game I1141 / 1270
• Monster Game II1019 / 1094
• Subarray Squares1382 / 1636
• Houses and Schools761 / 912
• Knuth Division933 / 1054
• Apples and Bananas1055 / 1148
• One Bit Positions838 / 918
• Signal Processing795 / 855
• New Roads Queries2171 / 2641
• Dynamic Connectivity989 / 1116
• Parcel Delivery756 / 839
• Task Assignment895 / 954
• Distinct Routes II573 / 657

Sliding Window Problems

• Sliding Window Sum4042 / 4222
• Sliding Window Minimum3039 / 3480
• Sliding Window Xor2979 / 3018
• Sliding Window Or1311 / 2341
• Sliding Window Distinct Values1913 / 2558
• Sliding Window Mode1750 / 1846
• Sliding Window Mex1567 / 1654
• Sliding Window Median13516 / 15458
• Sliding Window Cost8879 / 10261
• Sliding Window Inversions883 / 946
• Sliding Window Advertisement172 / 277

Interactive Problems

• Hidden Integer1719 / 1778
• Hidden Permutation731 / 873
• K-th Highest Score325 / 391
• Permuted Binary Strings410 / 421
• Colored Chairs362 / 383
• Inversion Sorting214 / 233

Bitwise Operations

• Counting Bits4655 / 5986
• Maximum Xor Subarray2811 / 3175
• Maximum Xor Subset792 / 857
• Number of Subset Xors686 / 702
• K Subset Xors326 / 395
• All Subarray Xors214 / 345
• Xor Pyramid Peak1907 / 2336
• Xor Pyramid Diagonal247 / 280
• Xor Pyramid Row200 / 238
• SOS Bit Problem2010 / 2146
• And Subset Count319 / 325

Construction Problems

• Inverse Inversions1458 / 1555
• Monotone Subsequences899 / 1056
• Third Permutation312 / 366
• Permutation Prime Sums307 / 333
• Chess Tournament1139 / 1317
• Distinct Sums Grid88 / 147
• Filling Trominos232 / 405
• Grid Path Construction118 / 423

Advanced Graph Problems

• Nearest Shops558 / 725
• Prüfer Code1468 / 1585
• Tree Traversals1157 / 1274
• Course Schedule II1828 / 2630
• Acyclic Graph Edges2164 / 2298
• Strongly Connected Edges1505 / 1673
• Even Outdegree Edges1281 / 1506
• Graph Girth3278 / 3745
• Fixed Length Walk Queries283 / 313
• Transfer Speeds Sum333 / 344
• MST Edge Check477 / 513
• MST Edge Set Check179 / 203
• MST Edge Cost297 / 312
• Network Breakdown981 / 1041
• Tree Coin Collecting I250 / 279
• Tree Coin Collecting II128 / 152
• Tree Isomorphism I1042 / 1254
• Tree Isomorphism II847 / 990
• Flight Route Requests464 / 569
• Critical Cities395 / 612
• Visiting Cities655 / 871
• Graph Coloring179 / 212
• Bus Companies203 / 211
• Split into Two Paths68 / 131
• Network Renovation910 / 1215
• Forbidden Cities797 / 1045
• Creating Offices397 / 522
• New Flight Routes301 / 815

Counting Problems

• Filled Subgrid Count I442 / 490
• Filled Subgrid Count II227 / 281
• All Letter Subgrid Count I121 / 190
• All Letter Subgrid Count II100 / 125
• Border Subgrid Count I72 / 125
• Border Subgrid Count II76 / 90
• Raab Game II76 / 92
• Empty String1558 / 1905
• Permutation Inversions986 / 1090
• Counting Bishops369 / 413
• Counting Sequences636 / 682
• Grid Paths II723 / 903
• Counting Permutations850 / 963
• Grid Completion214 / 271
• Counting Reorders225 / 331
• Tournament Graph Distribution84 / 89
• Collecting Numbers Distribution90 / 99
• Functional Graph Distribution230 / 285

Additional Problems I

• Shortest Subsequence2919 / 3862
• Distinct Values Sum520 / 537
• Distinct Values Splits370 / 391
• Swap Game1993 / 2528
• Beautiful Permutation II340 / 510
• Multiplication Table6420 / 7168
• Bubble Sort Rounds I300 / 344
• Bubble Sort Rounds II172 / 200
• Nearest Campsites I135 / 157
• Nearest Campsites II135 / 146
• Advertisement4162 / 4412
• Special Substrings945 / 1040
• Counting LCM Arrays206 / 225
• Square Subsets168 / 188
• Subarray Sum Constraints241 / 259
• Water Containers Moves124 / 131
• Water Containers Queries157 / 164
• Stack Weights563 / 670
• Maximum Average Subarrays127 / 140
• Subsets with Fixed Average163 / 180
• Two Array Average154 / 174
• Pyramid Array694 / 846
• Permutation Subsequence173 / 177
• Bit Inversions2234 / 2543
• Writing Numbers714 / 772
• Letter Pair Move Game191 / 270
• Maximum Building I1993 / 2081
• Sorting Methods743 / 797
• Cyclic Array1128 / 1286
• List of Sums459 / 604

Additional Problems II

• Bouncing Ball Steps173 / 190
• Bouncing Ball Cycle67 / 98
• Knight Moves Queries96 / 118
• K Subset Sums I132 / 181
• K Subset Sums II65 / 91
• Increasing Array II757 / 875
• Food Division494 / 598
• Swap Round Sorting399 / 492
• Binary Subsequences277 / 409
• School Excursion1321 / 1404
• Coin Grid831 / 972
• Grid Coloring II102 / 132
• Programmers and Artists471 / 661
• Removing Digits II208 / 456
• Coin Arrangement313 / 421
• Replace with Difference96 / 119
• Grid Puzzle I506 / 556
• Grid Puzzle II482 / 532
• Bit Substrings371 / 451
• Reversal Sorting336 / 409
• Book Shop II1146 / 1316
• GCD Subsets327 / 336
• Minimum Cost Pairs85 / 117
• Same Sum Subsets85 / 165
• Mex Grid Queries814 / 957
• Maximum Building II431 / 531
• Stick Divisions3657 / 4295
• Stick Difference31 / 173
• Coding Company1418 / 1871
• Two Stacks Sorting165 / 523