CSES Problem Set

General

• Introduction
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• Statistics

Introductory Problems

• Weird Algorithm145343 / 152233
• Missing Number125209 / 131385
• Repetitions109119 / 113638
• Increasing Array102499 / 106269
• Permutations90082 / 92896
• Number Spiral63691 / 69459
• Two Knights48609 / 50170
• Two Sets52852 / 56951
• Bit Strings60582 / 63990
• Trailing Zeros56592 / 60236
• Coin Piles50083 / 54841
• Palindrome Reorder46425 / 49058
• Gray Code30853 / 34742
• Tower of Hanoi28533 / 29678
• Creating Strings39198 / 40228
• Apple Division39156 / 44333
• Chessboard and Queens23639 / 24073
• Raab Game I3124 / 3575
• Mex Grid Construction2987 / 3201
• Knight Moves Grid3012 / 3081
• Grid Coloring I2483 / 2568
• Digit Queries16706 / 19537
• String Reorder2463 / 2865
• Grid Path Description9321 / 12136

Sorting and Searching

• Distinct Numbers70790 / 76699
• Apartments52444 / 58424
• Ferris Wheel50290 / 54403
• Concert Tickets40493 / 47274
• Restaurant Customers41284 / 44616
• Movie Festival39598 / 41980
• Sum of Two Values46228 / 51873
• Maximum Subarray Sum44847 / 46876
• Stick Lengths40018 / 41912
• Missing Coin Sum29983 / 31106
• Collecting Numbers30756 / 32991
• Collecting Numbers II12696 / 16338
• Playlist30826 / 35362
• Towers31186 / 33447
• Traffic Lights24111 / 27058
• Distinct Values Subarrays4679 / 4935
• Distinct Values Subsequences3241 / 3628
• Josephus Problem I18318 / 20270
• Josephus Problem II9854 / 13638
• Nested Ranges Check10459 / 12090
• Nested Ranges Count7098 / 8398
• Room Allocation18150 / 20900
• Factory Machines25645 / 28034
• Tasks and Deadlines20818 / 21276
• Reading Books16856 / 18064
• Sum of Three Values24648 / 27369
• Sum of Four Values15382 / 17209
• Nearest Smaller Values20589 / 21301
• Subarray Sums I27168 / 29049
• Subarray Sums II24538 / 29288
• Subarray Divisibility22557 / 24654
• Distinct Values Subarrays II13325 / 14767
• Array Division21321 / 22459
• Movie Festival II11343 / 13729
• Maximum Subarray Sum II10487 / 12587

Dynamic Programming

• Dice Combinations74020 / 78369
• Minimizing Coins63978 / 68803
• Coin Combinations I58435 / 63339
• Coin Combinations II49389 / 56036
• Removing Digits55121 / 56274
• Grid Paths I51731 / 53221
• Book Shop46228 / 50974
• Array Description33988 / 37851
• Counting Towers20561 / 21811
• Edit Distance34247 / 36162
• Longest Common Subsequence6407 / 6654
• Rectangle Cutting28470 / 31123
• Minimal Grid Path2726 / 5244
• Money Sums33771 / 35094
• Removal Game19716 / 26995
• Two Sets II26614 / 28705
• Mountain Range1884 / 3696
• Increasing Subsequence27180 / 30555
• Projects18701 / 20990
• Elevator Rides11830 / 14972
• Counting Tilings6891 / 7538
• Counting Numbers9348 / 10594
• Increasing Subsequence II3506 / 4066

Graph Algorithms

• Counting Rooms50891 / 53522
• Labyrinth35134 / 42291
• Building Roads44456 / 46080
• Message Route38167 / 39722
• Building Teams36014 / 38048
• Round Trip28629 / 31245
• Monsters19441 / 23081
• Shortest Routes I31133 / 34505
• Shortest Routes II25411 / 28593
• High Score15287 / 21949
• Flight Discount19879 / 23392
• Cycle Finding14143 / 17482
• Flight Routes13798 / 15426
• Round Trip II15798 / 17795
• Course Schedule20714 / 21949
• Longest Flight Route14473 / 18144
• Game Routes16324 / 17538
• Investigation12081 / 13022
• Planets Queries I10477 / 12331
• Planets Queries II3737 / 4759
• Planets Cycles6427 / 7195
• Road Reparation15789 / 16466
• Road Construction17370 / 17933
• Flight Routes Check14126 / 15344
• Planets and Kingdoms11326 / 11733
• Giant Pizza4612 / 5099
• Coin Collector7297 / 8130
• Mail Delivery6105 / 6699
• De Bruijn Sequence3174 / 3328
• Teleporters Path4603 / 5314
• Hamiltonian Flights6919 / 7916
• Knight's Tour2565 / 3134
• Download Speed4532 / 6177
• Police Chase3635 / 4100
• School Dance4026 / 4267
• Distinct Routes2766 / 3671

Range Queries

• Static Range Sum Queries35063 / 36649
• Static Range Minimum Queries24750 / 26527
• Dynamic Range Sum Queries25743 / 26892
• Dynamic Range Minimum Queries23357 / 23922
• Range Xor Queries24126 / 24457
• Range Update Queries19064 / 20473
• Forest Queries19475 / 20223
• Hotel Queries13767 / 14657
• List Removals11473 / 12092
• Salary Queries8400 / 10704
• Prefix Sum Queries7209 / 7833
• Pizzeria Queries5824 / 6057
• Visible Buildings Queries1032 / 1128
• Range Interval Queries814 / 1075
• Subarray Sum Queries7021 / 7642
• Subarray Sum Queries II1113 / 1149
• Distinct Values Queries6415 / 7994
• Distinct Values Queries II636 / 742
• Increasing Array Queries2467 / 2835
• Movie Festival Queries1173 / 1305
• Forest Queries II4216 / 4545
• Range Updates and Sums5584 / 6677
• Polynomial Queries4115 / 4834
• Range Queries and Copies2922 / 3141
• Missing Coin Sum Queries573 / 764

Tree Algorithms

• Subordinates29296 / 31367
• Tree Matching16595 / 19410
• Tree Diameter23848 / 25317
• Tree Distances I18120 / 19513
• Tree Distances II14905 / 15553
• Company Queries I16528 / 17412
• Company Queries II15480 / 16255
• Distance Queries14102 / 15165
• Counting Paths8781 / 9332
• Subtree Queries10568 / 11289
• Path Queries8402 / 8907
• Path Queries II3377 / 5103
• Distinct Colors8156 / 9032
• Finding a Centroid6567 / 6847
• Fixed-Length Paths I3100 / 4052
• Fixed-Length Paths II1437 / 2684

Mathematics

• Josephus Queries4448 / 5615
• Exponentiation23096 / 24678
• Exponentiation II16370 / 19683
• Counting Divisors20936 / 23678
• Common Divisors13738 / 16001
• Sum of Divisors7645 / 11563
• Divisor Analysis5208 / 7016
• Prime Multiples5920 / 6950
• Counting Coprime Pairs3860 / 4539
• Next Prime1236 / 1417
• Binomial Coefficients9674 / 10759
• Creating Strings II8152 / 8622
• Distributing Apples7844 / 8449
• Christmas Party6304 / 6785
• Permutation Order572 / 581
• Permutation Rounds660 / 739
• Bracket Sequences I4327 / 4720
• Bracket Sequences II2239 / 2579
• Counting Necklaces2072 / 2248
• Counting Grids1686 / 1803
• Fibonacci Numbers6688 / 8423
• Throwing Dice3468 / 3774
• Graph Paths I3285 / 3531
• Graph Paths II2747 / 2882
• System of Linear Equations289 / 312
• Sum of Four Squares439 / 514
• Triangle Number Sums376 / 467
• Dice Probability2980 / 3223
• Moving Robots1535 / 1627
• Candy Lottery1256 / 2823
• Inversion Probability286 / 2176
• Stick Game3333 / 3412
• Nim Game I4394 / 4563
• Nim Game II3482 / 3632
• Stair Game2371 / 2580
• Grundy's Game1621 / 2144
• Another Game1836 / 1984

String Algorithms

• Word Combinations5591 / 8179
• String Matching10914 / 14690
• Finding Borders7975 / 8738
• Finding Periods5690 / 6472
• Minimal Rotation2756 / 4246
• Longest Palindrome4187 / 5557
• All Palindromes424 / 485
• Required Substring1581 / 2447
• Palindrome Queries1973 / 2304
• Finding Patterns1807 / 2600
• Counting Patterns1709 / 2133
• Pattern Positions1429 / 1755
• Distinct Substrings1629 / 1952
• Distinct Subsequences1020 / 1089
• Repeating Substring1772 / 2079
• String Functions1553 / 1629
• Inverse Suffix Array147 / 170
• String Transform494 / 605
• Substring Order I1109 / 1248
• Substring Order II733 / 952
• Substring Distribution1032 / 1124

Geometry

• Point Location Test6940 / 7767
• Line Segment Intersection4146 / 5242
• Polygon Area4826 / 5122
• Point in Polygon2632 / 3344
• Polygon Lattice Points2226 / 2307
• Minimum Euclidean Distance1926 / 2682
• Convex Hull3164 / 3826
• Maximum Manhattan Distances402 / 412
• All Manhattan Distances406 / 445
• Intersection Points1875 / 2018
• Line Segments Trace I219 / 226
• Line Segments Trace II175 / 187
• Lines and Queries I236 / 245
• Lines and Queries II201 / 210
• Area of Rectangles1057 / 1184
• Robot Path293 / 507

Advanced Techniques

• Meet in the Middle6383 / 8965
• Hamming Distance3118 / 3396
• Corner Subgrid Check208 / 350
• Corner Subgrid Count2173 / 2439
• Reachable Nodes2159 / 2324
• Reachability Queries1441 / 1710
• Cut and Paste1436 / 1599
• Substring Reversals1260 / 1377
• Reversals and Sums1268 / 1370
• Necessary Roads1851 / 1895
• Necessary Cities1721 / 1807
• Eulerian Subgraphs757 / 798
• Monster Game I1100 / 1226
• Monster Game II976 / 1050
• Subarray Squares1288 / 1537
• Houses and Schools722 / 864
• Knuth Division878 / 996
• Apples and Bananas968 / 1052
• One Bit Positions784 / 861
• Signal Processing730 / 786
• New Roads Queries2064 / 2521
• Dynamic Connectivity924 / 1048
• Parcel Delivery716 / 797
• Task Assignment837 / 889
• Distinct Routes II547 / 630

Sliding Window Problems

• Sliding Window Sum3172 / 3321
• Sliding Window Minimum2465 / 2813
• Sliding Window Xor2384 / 2415
• Sliding Window Or1005 / 1858
• Sliding Window Distinct Values1992 / 2033
• Sliding Window Mode1392 / 1464
• Sliding Window Mex1241 / 1308
• Sliding Window Median13046 / 14947
• Sliding Window Cost8675 / 10020
• Sliding Window Inversions711 / 760
• Sliding Window Advertisement132 / 212

Interactive Problems

• Hidden Integer1324 / 1364
• Hidden Permutation582 / 691
• K-th Highest Score247 / 302
• Permuted Binary Strings336 / 346
• Colored Chairs292 / 307
• Inversion Sorting170 / 182

Bitwise Operations

• Counting Bits4267 / 5490
• Maximum Xor Subarray2623 / 2946
• Maximum Xor Subset613 / 660
• Number of Subset Xors525 / 536
• K Subset Xors254 / 298
• All Subarray Xors179 / 274
• Xor Pyramid Peak1797 / 2208
• Xor Pyramid Diagonal201 / 227
• Xor Pyramid Row167 / 192
• SOS Bit Problem1855 / 1983
• And Subset Count251 / 255

Construction Problems

• Inverse Inversions1312 / 1399
• Monotone Subsequences798 / 937
• Third Permutation249 / 290
• Permutation Prime Sums244 / 264
• Chess Tournament1085 / 1252
• Distinct Sums Grid67 / 118
• Filling Trominos223 / 386
• Grid Path Construction113 / 412

Advanced Graph Problems

• Nearest Shops465 / 605
• Prüfer Code1395 / 1509
• Tree Traversals1096 / 1209
• Course Schedule II1712 / 2465
• Acyclic Graph Edges2063 / 2193
• Strongly Connected Edges1432 / 1589
• Even Outdegree Edges1224 / 1444
• Graph Girth3127 / 3587
• Fixed Length Walk Queries243 / 263
• Transfer Speeds Sum277 / 284
• MST Edge Check348 / 374
• MST Edge Set Check145 / 166
• MST Edge Cost251 / 262
• Network Breakdown930 / 989
• Tree Coin Collecting I205 / 228
• Tree Coin Collecting II108 / 124
• Tree Isomorphism I1006 / 1204
• Tree Isomorphism II815 / 957
• Flight Route Requests444 / 540
• Critical Cities381 / 587
• Visiting Cities628 / 836
• Graph Coloring135 / 160
• Bus Companies169 / 172
• Split into Two Paths59 / 104
• Network Renovation880 / 1177
• Forbidden Cities749 / 987
• Creating Offices385 / 499
• New Flight Routes285 / 766

Counting Problems

• Filled Subgrid Count I338 / 374
• Filled Subgrid Count II174 / 211
• All Letter Subgrid Count I83 / 139
• All Letter Subgrid Count II67 / 81
• Border Subgrid Count I60 / 106
• Border Subgrid Count II63 / 73
• Raab Game II62 / 74
• Empty String1489 / 1817
• Permutation Inversions945 / 1037
• Counting Bishops355 / 398
• Counting Sequences607 / 653
• Grid Paths II699 / 871
• Counting Permutations820 / 929
• Grid Completion205 / 260
• Counting Reorders214 / 314
• Tournament Graph Distribution68 / 71
• Collecting Numbers Distribution73 / 75
• Functional Graph Distribution220 / 275

Additional Problems I

• Shortest Subsequence2816 / 3743
• Distinct Values Sum416 / 428
• Distinct Values Splits287 / 306
• Swap Game1911 / 2431
• Beautiful Permutation II220 / 321
• Multiplication Table6094 / 6819
• Bubble Sort Rounds I219 / 253
• Bubble Sort Rounds II117 / 137
• Nearest Campsites I98 / 115
• Nearest Campsites II95 / 105
• Advertisement3989 / 4226
• Special Substrings905 / 991
• Counting LCM Arrays165 / 177
• Square Subsets130 / 146
• Subarray Sum Constraints152 / 163
• Water Containers Moves95 / 105
• Water Containers Queries125 / 130
• Stack Weights539 / 642
• Maximum Average Subarrays97 / 108
• Subsets with Fixed Average128 / 137
• Two Array Average118 / 134
• Pyramid Array661 / 801
• Permutation Subsequence139 / 143
• Bit Inversions2158 / 2466
• Writing Numbers694 / 751
• Letter Pair Move Game182 / 261
• Maximum Building I1934 / 2020
• Sorting Methods724 / 776
• Cyclic Array1085 / 1239
• List of Sums438 / 571

Additional Problems II

• Bouncing Ball Steps142 / 155
• Bouncing Ball Cycle56 / 76
• Knight Moves Queries80 / 96
• K Subset Sums I100 / 138
• K Subset Sums II52 / 73
• Increasing Array II736 / 851
• Food Division494 / 584
• Swap Round Sorting389 / 480
• Binary Subsequences266 / 393
• School Excursion1269 / 1349
• Coin Grid789 / 928
• Grid Coloring II83 / 105
• Programmers and Artists448 / 634
• Removing Digits II196 / 444
• Coin Arrangement299 / 408
• Replace with Difference77 / 94
• Grid Puzzle I486 / 533
• Grid Puzzle II446 / 490
• Bit Substrings348 / 427
• Reversal Sorting325 / 397
• Book Shop II1085 / 1249
• GCD Subsets266 / 274
• Minimum Cost Pairs60 / 83
• Same Sum Subsets66 / 123
• Mex Grid Queries787 / 927
• Maximum Building II412 / 507
• Stick Divisions3559 / 4183
• Stick Difference24 / 138
• Coding Company1352 / 1786
• Two Stacks Sorting156 / 495