CSES Problem Set

General

• Introduction
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• Statistics

Introductory Problems

• Weird Algorithm151096 / 158199
• Missing Number130233 / 136553
• Repetitions113414 / 118024
• Increasing Array106565 / 110407
• Permutations93719 / 96609
• Number Spiral66245 / 72211
• Two Knights50579 / 52180
• Two Sets55026 / 59249
• Bit Strings62907 / 66429
• Trailing Zeros58745 / 62516
• Coin Piles51995 / 56918
• Palindrome Reorder48369 / 51069
• Gray Code32241 / 36266
• Tower of Hanoi29813 / 31020
• Creating Strings40774 / 41848
• Apple Division40917 / 46266
• Chessboard and Queens24635 / 25084
• Raab Game I3941 / 4476
• Mex Grid Construction3802 / 4056
• Knight Moves Grid3789 / 3879
• Grid Coloring I3167 / 3278
• Digit Queries17323 / 20198
• String Reorder2992 / 3482
• Grid Path Description9624 / 12530

Sorting and Searching

• Distinct Numbers73898 / 79971
• Apartments54632 / 60798
• Ferris Wheel52437 / 56652
• Concert Tickets42279 / 49262
• Restaurant Customers42932 / 46381
• Movie Festival41266 / 43717
• Sum of Two Values48200 / 54035
• Maximum Subarray Sum46611 / 48700
• Stick Lengths41525 / 43459
• Missing Coin Sum31223 / 32380
• Collecting Numbers31992 / 34295
• Collecting Numbers II13298 / 17032
• Playlist32050 / 36689
• Towers32460 / 34782
• Traffic Lights25129 / 28152
• Distinct Values Subarrays5805 / 6110
• Distinct Values Subsequences3975 / 4427
• Josephus Problem I19163 / 21145
• Josephus Problem II10343 / 14289
• Nested Ranges Check10961 / 12628
• Nested Ranges Count7417 / 8771
• Room Allocation18878 / 21695
• Factory Machines26882 / 29329
• Tasks and Deadlines21651 / 22123
• Reading Books17563 / 18819
• Sum of Three Values25815 / 28617
• Sum of Four Values15994 / 17849
• Nearest Smaller Values21389 / 22129
• Subarray Sums I28357 / 30263
• Subarray Sums II25722 / 30588
• Subarray Divisibility23473 / 25610
• Distinct Values Subarrays II14089 / 15543
• Array Division22285 / 23474
• Movie Festival II11889 / 14365
• Maximum Subarray Sum II10968 / 13119

Dynamic Programming

• Dice Combinations77245 / 81758
• Minimizing Coins66679 / 71687
• Coin Combinations I60883 / 65969
• Coin Combinations II51431 / 58293
• Removing Digits57267 / 58444
• Grid Paths I53915 / 55475
• Book Shop48101 / 52953
• Array Description35412 / 39381
• Counting Towers21482 / 22787
• Edit Distance35565 / 37549
• Longest Common Subsequence7898 / 8197
• Rectangle Cutting29492 / 32243
• Minimal Grid Path3378 / 6343
• Money Sums34967 / 36311
• Removal Game20666 / 27981
• Two Sets II27560 / 29694
• Mountain Range2387 / 4482
• Increasing Subsequence28160 / 31625
• Projects19390 / 21714
• Elevator Rides12362 / 15598
• Counting Tilings7227 / 7891
• Counting Numbers9914 / 11210
• Increasing Subsequence II3949 / 4592

Graph Algorithms

• Counting Rooms53009 / 55709
• Labyrinth36656 / 44001
• Building Roads46164 / 47831
• Message Route39734 / 41323
• Building Teams37525 / 39590
• Round Trip29816 / 32513
• Monsters20313 / 24036
• Shortest Routes I32589 / 36009
• Shortest Routes II26560 / 29798
• High Score16086 / 22879
• Flight Discount20796 / 24399
• Cycle Finding14813 / 18224
• Flight Routes14457 / 16152
• Round Trip II16469 / 18520
• Course Schedule21604 / 22848
• Longest Flight Route15170 / 18909
• Game Routes17024 / 18257
• Investigation12615 / 13586
• Planets Queries I11011 / 12910
• Planets Queries II3945 / 5005
• Planets Cycles6725 / 7516
• Road Reparation16547 / 17259
• Road Construction18148 / 18726
• Flight Routes Check14727 / 15973
• Planets and Kingdoms11827 / 12250
• Giant Pizza4879 / 5377
• Coin Collector7664 / 8514
• Mail Delivery6401 / 7013
• De Bruijn Sequence3343 / 3502
• Teleporters Path4841 / 5552
• Hamiltonian Flights7260 / 8293
• Knight's Tour2720 / 3305
• Download Speed4812 / 6494
• Police Chase3835 / 4314
• School Dance4238 / 4483
• Distinct Routes2977 / 3916

Range Queries

• Static Range Sum Queries36760 / 38405
• Static Range Minimum Queries25787 / 27622
• Dynamic Range Sum Queries26761 / 27945
• Dynamic Range Minimum Queries24254 / 24833
• Range Xor Queries25097 / 25436
• Range Update Queries19885 / 21323
• Forest Queries20360 / 21132
• Hotel Queries14379 / 15278
• List Removals11958 / 12587
• Salary Queries8878 / 11256
• Prefix Sum Queries7634 / 8279
• Pizzeria Queries6132 / 6364
• Visible Buildings Queries1302 / 1427
• Range Interval Queries1026 / 1363
• Subarray Sum Queries7330 / 7957
• Subarray Sum Queries II1389 / 1455
• Distinct Values Queries6755 / 8375
• Distinct Values Queries II818 / 945
• Increasing Array Queries2592 / 2980
• Movie Festival Queries1293 / 1439
• Forest Queries II4371 / 4711
• Range Updates and Sums5845 / 6961
• Polynomial Queries4282 / 5032
• Range Queries and Copies3077 / 3298
• Missing Coin Sum Queries644 / 847

Tree Algorithms

• Subordinates30548 / 32674
• Tree Matching17330 / 20197
• Tree Diameter24880 / 26385
• Tree Distances I19002 / 20429
• Tree Distances II15550 / 16215
• Company Queries I17277 / 18185
• Company Queries II16204 / 16996
• Distance Queries14741 / 15822
• Counting Paths9233 / 9792
• Subtree Queries11058 / 11806
• Path Queries8870 / 9399
• Path Queries II3566 / 5397
• Distinct Colors8531 / 9429
• Finding a Centroid6891 / 7181
• Fixed-Length Paths I3286 / 4262
• Fixed-Length Paths II1538 / 2836

Mathematics

• Josephus Queries4699 / 5922
• Exponentiation23974 / 25613
• Exponentiation II17009 / 20407
• Counting Divisors21816 / 24650
• Common Divisors14309 / 16645
• Sum of Divisors7985 / 12009
• Divisor Analysis5436 / 7316
• Prime Multiples6291 / 7353
• Counting Coprime Pairs4086 / 4786
• Next Prime1577 / 1807
• Binomial Coefficients10072 / 11196
• Creating Strings II8520 / 8994
• Distributing Apples8182 / 8804
• Christmas Party6589 / 7084
• Permutation Order744 / 759
• Permutation Rounds904 / 1011
• Bracket Sequences I4531 / 4936
• Bracket Sequences II2354 / 2703
• Counting Necklaces2177 / 2358
• Counting Grids1790 / 1914
• Fibonacci Numbers6977 / 8757
• Throwing Dice3611 / 3928
• Graph Paths I3431 / 3688
• Graph Paths II2871 / 3012
• System of Linear Equations351 / 390
• Sum of Four Squares553 / 637
• Triangle Number Sums462 / 578
• Dice Probability3101 / 3351
• Moving Robots1594 / 1687
• Candy Lottery1409 / 2988
• Inversion Probability341 / 2264
• Stick Game3483 / 3568
• Nim Game I4608 / 4782
• Nim Game II3648 / 3800
• Stair Game2462 / 2680
• Grundy's Game1709 / 2249
• Another Game1936 / 2090

String Algorithms

• Word Combinations5899 / 8567
• String Matching11460 / 15337
• Finding Borders8358 / 9149
• Finding Periods5952 / 6769
• Minimal Rotation2890 / 4407
• Longest Palindrome4371 / 5775
• All Palindromes529 / 604
• Required Substring1659 / 2543
• Palindrome Queries2052 / 2391
• Finding Patterns1913 / 2727
• Counting Patterns1813 / 2254
• Pattern Positions1514 / 1856
• Distinct Substrings1733 / 2071
• 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 Test7319 / 8173
• Line Segment Intersection4352 / 5468
• Polygon Area5026 / 5324
• Point in Polygon2758 / 3535
• Polygon Lattice Points2337 / 2419
• Minimum Euclidean Distance2035 / 2815
• Convex Hull3349 / 4029
• Maximum Manhattan Distances496 / 512
• All Manhattan Distances504 / 550
• Intersection Points1961 / 2113
• Line Segments Trace I276 / 286
• Line Segments Trace II226 / 239
• Lines and Queries I311 / 321
• Lines and Queries II264 / 273
• Area of Rectangles1117 / 1249
• Robot Path292 / 541

Advanced Techniques

• Meet in the Middle6662 / 9294
• Hamming Distance3225 / 3517
• Corner Subgrid Check270 / 428
• Corner Subgrid Count2242 / 2518
• Reachable Nodes2264 / 2435
• Reachability Queries1498 / 1775
• Cut and Paste1512 / 1684
• Substring Reversals1314 / 1433
• Reversals and Sums1323 / 1426
• Necessary Roads1923 / 1975
• Necessary Cities1786 / 1873
• 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 Positions840 / 920
• Signal Processing797 / 857
• New Roads Queries2171 / 2641
• Dynamic Connectivity989 / 1116
• Parcel Delivery756 / 840
• Task Assignment895 / 954
• Distinct Routes II573 / 657

Sliding Window Problems

• Sliding Window Sum4053 / 4233
• Sliding Window Minimum3043 / 3486
• Sliding Window Xor2985 / 3024
• Sliding Window Or1313 / 2345
• Sliding Window Distinct Values1920 / 2563
• Sliding Window Mode1755 / 1851
• Sliding Window Mex1568 / 1655
• Sliding Window Median13520 / 15461
• Sliding Window Cost8880 / 10263
• Sliding Window Inversions885 / 948
• Sliding Window Advertisement173 / 278

Interactive Problems

• Hidden Integer1720 / 1779
• Hidden Permutation732 / 873
• K-th Highest Score326 / 392
• Permuted Binary Strings411 / 422
• Colored Chairs363 / 383
• Inversion Sorting214 / 234

Bitwise Operations

• Counting Bits4660 / 5992
• Maximum Xor Subarray2816 / 3181
• Maximum Xor Subset795 / 860
• Number of Subset Xors689 / 705
• K Subset Xors328 / 397
• All Subarray Xors215 / 346
• Xor Pyramid Peak1907 / 2336
• Xor Pyramid Diagonal247 / 280
• Xor Pyramid Row200 / 238
• SOS Bit Problem2012 / 2147
• And Subset Count319 / 325

Construction Problems

• Inverse Inversions1460 / 1557
• 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 Shops560 / 728
• Prüfer Code1469 / 1586
• Tree Traversals1158 / 1276
• Course Schedule II1828 / 2632
• Acyclic Graph Edges2165 / 2299
• Strongly Connected Edges1505 / 1673
• Even Outdegree Edges1282 / 1508
• Graph Girth3280 / 3747
• Fixed Length Walk Queries284 / 314
• Transfer Speeds Sum334 / 345
• MST Edge Check480 / 516
• MST Edge Set Check180 / 204
• MST Edge Cost299 / 313
• Network Breakdown982 / 1042
• 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 / 132
• Network Renovation910 / 1215
• Forbidden Cities797 / 1045
• Creating Offices397 / 522
• New Flight Routes301 / 816

Counting Problems

• Filled Subgrid Count I444 / 492
• Filled Subgrid Count II227 / 282
• All Letter Subgrid Count I122 / 191
• All Letter Subgrid Count II100 / 125
• Border Subgrid Count I72 / 125
• Border Subgrid Count II76 / 90
• Raab Game II76 / 92
• Empty String1559 / 1906
• Permutation Inversions988 / 1092
• Counting Bishops370 / 414
• Counting Sequences636 / 682
• Grid Paths II724 / 904
• 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 Sum521 / 538
• Distinct Values Splits370 / 391
• Swap Game1994 / 2529
• Beautiful Permutation II342 / 512
• Multiplication Table6422 / 7172
• Bubble Sort Rounds I300 / 344
• Bubble Sort Rounds II173 / 201
• Nearest Campsites I135 / 157
• Nearest Campsites II135 / 146
• Advertisement4165 / 4415
• Special Substrings946 / 1041
• Counting LCM Arrays206 / 225
• Square Subsets168 / 188
• Subarray Sum Constraints241 / 259
• Water Containers Moves126 / 133
• Water Containers Queries158 / 164
• Stack Weights563 / 670
• Maximum Average Subarrays127 / 140
• Subsets with Fixed Average163 / 180
• Two Array Average154 / 174
• Pyramid Array694 / 846
• Permutation Subsequence174 / 178
• Bit Inversions2236 / 2545
• Writing Numbers715 / 773
• 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 I133 / 182
• K Subset Sums II65 / 91
• Increasing Array II757 / 875
• Food Division494 / 598
• Swap Round Sorting399 / 492
• Binary Subsequences277 / 409
• School Excursion1323 / 1406
• Coin Grid831 / 972
• Grid Coloring II102 / 132
• Programmers and Artists473 / 663
• Removing Digits II208 / 456
• Coin Arrangement313 / 421
• Replace with Difference97 / 120
• Grid Puzzle I506 / 556
• Grid Puzzle II482 / 532
• Bit Substrings371 / 451
• Reversal Sorting336 / 410
• Book Shop II1146 / 1316
• GCD Subsets329 / 338
• Minimum Cost Pairs86 / 118
• Same Sum Subsets85 / 166
• Mex Grid Queries814 / 957
• Maximum Building II431 / 531
• Stick Divisions3658 / 4296
• Stick Difference31 / 173
• Coding Company1418 / 1872
• Two Stacks Sorting165 / 523