CSES Problem Set

General

• Introduction
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• Statistics

Introductory Problems

• Weird Algorithm145633 / 152531
• Missing Number125554 / 131730
• Repetitions109364 / 113889
• Increasing Array102747 / 106518
• Permutations90270 / 93086
• Number Spiral63819 / 69601
• Two Knights48707 / 50272
• Two Sets52963 / 57069
• Bit Strings60710 / 64115
• Trailing Zeros56723 / 60367
• Coin Piles50201 / 54971
• Palindrome Reorder46541 / 49182
• Gray Code30920 / 34822
• Tower of Hanoi28591 / 29741
• Creating Strings39277 / 40308
• Apple Division39230 / 44413
• Chessboard and Queens23684 / 24117
• Raab Game I3165 / 3619
• Mex Grid Construction3032 / 3246
• Knight Moves Grid3053 / 3122
• Grid Coloring I2520 / 2608
• Digit Queries16745 / 19579
• String Reorder2487 / 2900
• Grid Path Description9335 / 12153

Sorting and Searching

• Distinct Numbers70947 / 76859
• Apartments52551 / 58541
• Ferris Wheel50396 / 54513
• Concert Tickets40578 / 47366
• Restaurant Customers41371 / 44706
• Movie Festival39663 / 42050
• Sum of Two Values46312 / 51963
• Maximum Subarray Sum44939 / 46970
• Stick Lengths40089 / 41987
• Missing Coin Sum30049 / 31173
• Collecting Numbers30820 / 33056
• Collecting Numbers II12724 / 16369
• Playlist30872 / 35417
• Towers31234 / 33504
• Traffic Lights24154 / 27106
• Distinct Values Subarrays4746 / 5001
• Distinct Values Subsequences3286 / 3677
• Josephus Problem I18368 / 20324
• Josephus Problem II9887 / 13684
• Nested Ranges Check10489 / 12116
• Nested Ranges Count7114 / 8417
• Room Allocation18188 / 20940
• Factory Machines25703 / 28094
• Tasks and Deadlines20860 / 21319
• Reading Books16908 / 18118
• Sum of Three Values24701 / 27422
• Sum of Four Values15411 / 17240
• Nearest Smaller Values20636 / 21350
• Subarray Sums I27243 / 29122
• Subarray Sums II24625 / 29381
• Subarray Divisibility22636 / 24737
• Distinct Values Subarrays II13369 / 14808
• Array Division21372 / 22512
• Movie Festival II11371 / 13766
• Maximum Subarray Sum II10514 / 12618

Dynamic Programming

• Dice Combinations74191 / 78550
• Minimizing Coins64125 / 68970
• Coin Combinations I58567 / 63479
• Coin Combinations II49493 / 56151
• Removing Digits55238 / 56389
• Grid Paths I51844 / 53339
• Book Shop46337 / 51088
• Array Description34073 / 37940
• Counting Towers20618 / 21871
• Edit Distance34319 / 36234
• Longest Common Subsequence6499 / 6752
• Rectangle Cutting28529 / 31186
• Minimal Grid Path2770 / 5325
• Money Sums33840 / 35164
• Removal Game19765 / 27046
• Two Sets II26663 / 28758
• Mountain Range1915 / 3741
• Increasing Subsequence27233 / 30612
• Projects18740 / 21026
• Elevator Rides11860 / 15011
• Counting Tilings6906 / 7555
• Counting Numbers9380 / 10628
• Increasing Subsequence II3524 / 4095

Graph Algorithms

• Counting Rooms51013 / 53649
• Labyrinth35221 / 42392
• Building Roads44546 / 46170
• Message Route38252 / 39807
• Building Teams36098 / 38134
• Round Trip28692 / 31316
• Monsters19491 / 23135
• Shortest Routes I31205 / 34578
• Shortest Routes II25464 / 28641
• High Score15328 / 21990
• Flight Discount19942 / 23454
• Cycle Finding14175 / 17520
• Flight Routes13830 / 15461
• Round Trip II15836 / 17843
• Course Schedule20758 / 21994
• Longest Flight Route14510 / 18187
• Game Routes16354 / 17570
• Investigation12107 / 13048
• Planets Queries I10511 / 12370
• Planets Queries II3748 / 4770
• Planets Cycles6442 / 7209
• Road Reparation15818 / 16496
• Road Construction17403 / 17968
• Flight Routes Check14162 / 15385
• Planets and Kingdoms11354 / 11764
• Giant Pizza4628 / 5114
• Coin Collector7314 / 8149
• Mail Delivery6121 / 6718
• De Bruijn Sequence3185 / 3339
• Teleporters Path4612 / 5322
• Hamiltonian Flights6943 / 7943
• Knight's Tour2571 / 3144
• Download Speed4546 / 6195
• Police Chase3643 / 4109
• School Dance4032 / 4273
• Distinct Routes2776 / 3682

Range Queries

• Static Range Sum Queries35148 / 36737
• Static Range Minimum Queries24806 / 26585
• Dynamic Range Sum Queries25797 / 26945
• Dynamic Range Minimum Queries23398 / 23961
• Range Xor Queries24174 / 24505
• Range Update Queries19107 / 20520
• Forest Queries19523 / 20273
• Hotel Queries13806 / 14694
• List Removals11502 / 12121
• Salary Queries8447 / 10757
• Prefix Sum Queries7224 / 7850
• Pizzeria Queries5841 / 6074
• Visible Buildings Queries1044 / 1144
• Range Interval Queries826 / 1089
• Subarray Sum Queries7035 / 7658
• Subarray Sum Queries II1128 / 1164
• Distinct Values Queries6432 / 8016
• Distinct Values Queries II645 / 755
• Increasing Array Queries2474 / 2845
• Movie Festival Queries1176 / 1309
• Forest Queries II4223 / 4552
• Range Updates and Sums5594 / 6687
• Polynomial Queries4123 / 4844
• Range Queries and Copies2929 / 3148
• Missing Coin Sum Queries575 / 766

Tree Algorithms

• Subordinates29367 / 31441
• Tree Matching16637 / 19453
• Tree Diameter23907 / 25377
• Tree Distances I18196 / 19589
• Tree Distances II14942 / 15593
• Company Queries I16574 / 17460
• Company Queries II15521 / 16298
• Distance Queries14137 / 15202
• Counting Paths8799 / 9349
• Subtree Queries10591 / 11318
• Path Queries8417 / 8924
• Path Queries II3392 / 5120
• Distinct Colors8186 / 9063
• Finding a Centroid6581 / 6863
• Fixed-Length Paths I3107 / 4058
• Fixed-Length Paths II1444 / 2689

Mathematics

• Josephus Queries4461 / 5631
• Exponentiation23137 / 24720
• Exponentiation II16397 / 19716
• Counting Divisors20978 / 23724
• Common Divisors13759 / 16029
• Sum of Divisors7665 / 11586
• Divisor Analysis5214 / 7023
• Prime Multiples5931 / 6964
• Counting Coprime Pairs3870 / 4550
• Next Prime1256 / 1446
• Binomial Coefficients9693 / 10777
• Creating Strings II8166 / 8637
• Distributing Apples7851 / 8458
• Christmas Party6313 / 6794
• Permutation Order576 / 585
• Permutation Rounds669 / 747
• Bracket Sequences I4331 / 4726
• Bracket Sequences II2242 / 2582
• Counting Necklaces2075 / 2251
• Counting Grids1688 / 1806
• Fibonacci Numbers6699 / 8436
• Throwing Dice3473 / 3779
• Graph Paths I3288 / 3534
• Graph Paths II2751 / 2886
• System of Linear Equations291 / 314
• Sum of Four Squares441 / 516
• Triangle Number Sums378 / 471
• Dice Probability2983 / 3227
• Moving Robots1536 / 1628
• Candy Lottery1261 / 2827
• Inversion Probability287 / 2178
• Stick Game3338 / 3417
• Nim Game I4401 / 4570
• Nim Game II3486 / 3636
• Stair Game2373 / 2582
• Grundy's Game1624 / 2149
• Another Game1838 / 1986

String Algorithms

• Word Combinations5603 / 8198
• String Matching10947 / 14725
• Finding Borders7999 / 8763
• Finding Periods5706 / 6493
• Minimal Rotation2762 / 4254
• Longest Palindrome4199 / 5572
• All Palindromes427 / 488
• Required Substring1582 / 2449
• Palindrome Queries1976 / 2308
• Finding Patterns1812 / 2605
• Counting Patterns1711 / 2137
• Pattern Positions1435 / 1759
• Distinct Substrings1634 / 1961
• Distinct Subsequences1024 / 1093
• Repeating Substring1777 / 2084
• String Functions1557 / 1633
• Inverse Suffix Array148 / 171
• String Transform495 / 606
• Substring Order I1111 / 1249
• Substring Order II733 / 954
• Substring Distribution1034 / 1126

Geometry

• Point Location Test6959 / 7792
• Line Segment Intersection4160 / 5254
• Polygon Area4838 / 5136
• Point in Polygon2644 / 3358
• Polygon Lattice Points2234 / 2315
• Minimum Euclidean Distance1933 / 2688
• Convex Hull3173 / 3835
• Maximum Manhattan Distances408 / 419
• All Manhattan Distances410 / 450
• Intersection Points1878 / 2021
• Line Segments Trace I223 / 231
• Line Segments Trace II179 / 190
• Lines and Queries I240 / 249
• Lines and Queries II205 / 214
• Area of Rectangles1062 / 1190
• Robot Path295 / 510

Advanced Techniques

• Meet in the Middle6401 / 8987
• Hamming Distance3126 / 3404
• Corner Subgrid Check211 / 355
• Corner Subgrid Count2177 / 2444
• Reachable Nodes2166 / 2332
• Reachability Queries1444 / 1713
• Cut and Paste1437 / 1600
• Substring Reversals1262 / 1379
• Reversals and Sums1270 / 1372
• Necessary Roads1855 / 1899
• Necessary Cities1724 / 1810
• Eulerian Subgraphs758 / 799
• Monster Game I1101 / 1227
• Monster Game II977 / 1051
• Subarray Squares1294 / 1543
• Houses and Schools723 / 865
• Knuth Division881 / 999
• Apples and Bananas968 / 1052
• One Bit Positions784 / 861
• Signal Processing733 / 789
• New Roads Queries2069 / 2529
• Dynamic Connectivity927 / 1051
• Parcel Delivery719 / 800
• Task Assignment839 / 891
• Distinct Routes II548 / 631

Sliding Window Problems

• Sliding Window Sum3224 / 3374
• Sliding Window Minimum2507 / 2858
• Sliding Window Xor2415 / 2447
• Sliding Window Or1023 / 1885
• Sliding Window Distinct Values2025 / 2066
• Sliding Window Mode1415 / 1494
• Sliding Window Mex1256 / 1325
• Sliding Window Median13068 / 14971
• Sliding Window Cost8684 / 10032
• Sliding Window Inversions716 / 767
• Sliding Window Advertisement138 / 218

Interactive Problems

• Hidden Integer1343 / 1385
• Hidden Permutation589 / 702
• K-th Highest Score253 / 309
• Permuted Binary Strings340 / 351
• Colored Chairs296 / 312
• Inversion Sorting171 / 182

Bitwise Operations

• Counting Bits4296 / 5527
• Maximum Xor Subarray2635 / 2961
• Maximum Xor Subset630 / 680
• Number of Subset Xors536 / 548
• K Subset Xors260 / 307
• All Subarray Xors181 / 279
• Xor Pyramid Peak1801 / 2212
• Xor Pyramid Diagonal207 / 233
• Xor Pyramid Row171 / 198
• SOS Bit Problem1858 / 1986
• And Subset Count255 / 259

Construction Problems

• Inverse Inversions1316 / 1402
• Monotone Subsequences801 / 939
• Third Permutation253 / 293
• Permutation Prime Sums248 / 268
• Chess Tournament1086 / 1253
• Distinct Sums Grid69 / 120
• Filling Trominos226 / 388
• Grid Path Construction113 / 412

Advanced Graph Problems

• Nearest Shops471 / 612
• Prüfer Code1397 / 1511
• Tree Traversals1097 / 1210
• Course Schedule II1714 / 2466
• Acyclic Graph Edges2064 / 2194
• Strongly Connected Edges1434 / 1590
• Even Outdegree Edges1226 / 1446
• Graph Girth3127 / 3588
• Fixed Length Walk Queries244 / 264
• Transfer Speeds Sum277 / 284
• MST Edge Check351 / 377
• MST Edge Set Check148 / 169
• MST Edge Cost251 / 262
• Network Breakdown931 / 990
• Tree Coin Collecting I207 / 230
• Tree Coin Collecting II110 / 127
• Tree Isomorphism I1006 / 1205
• Tree Isomorphism II815 / 958
• Flight Route Requests446 / 543
• Critical Cities381 / 587
• Visiting Cities628 / 836
• Graph Coloring138 / 164
• Bus Companies171 / 174
• Split into Two Paths59 / 105
• Network Renovation880 / 1177
• Forbidden Cities750 / 989
• Creating Offices385 / 499
• New Flight Routes286 / 769

Counting Problems

• Filled Subgrid Count I344 / 381
• Filled Subgrid Count II176 / 214
• All Letter Subgrid Count I86 / 142
• All Letter Subgrid Count II79 / 94
• Border Subgrid Count I61 / 107
• Border Subgrid Count II64 / 74
• Raab Game II64 / 76
• Empty String1490 / 1818
• Permutation Inversions949 / 1045
• Counting Bishops356 / 399
• Counting Sequences607 / 653
• Grid Paths II699 / 872
• Counting Permutations823 / 933
• Grid Completion205 / 260
• Counting Reorders216 / 317
• Tournament Graph Distribution70 / 73
• Collecting Numbers Distribution74 / 76
• Functional Graph Distribution220 / 275

Additional Problems I

• Shortest Subsequence2822 / 3750
• Distinct Values Sum420 / 432
• Distinct Values Splits290 / 310
• Swap Game1916 / 2437
• Beautiful Permutation II222 / 330
• Multiplication Table6108 / 6834
• Bubble Sort Rounds I222 / 256
• Bubble Sort Rounds II119 / 139
• Nearest Campsites I99 / 117
• Nearest Campsites II97 / 107
• Advertisement4003 / 4239
• Special Substrings908 / 994
• Counting LCM Arrays167 / 179
• Square Subsets133 / 149
• Subarray Sum Constraints162 / 174
• Water Containers Moves97 / 107
• Water Containers Queries126 / 131
• Stack Weights541 / 644
• Maximum Average Subarrays99 / 110
• Subsets with Fixed Average130 / 139
• Two Array Average121 / 140
• Pyramid Array665 / 807
• Permutation Subsequence141 / 145
• Bit Inversions2162 / 2471
• Writing Numbers698 / 755
• Letter Pair Move Game183 / 262
• Maximum Building I1938 / 2023
• Sorting Methods726 / 778
• Cyclic Array1089 / 1243
• List of Sums440 / 573

Additional Problems II

• Bouncing Ball Steps145 / 158
• Bouncing Ball Cycle58 / 78
• Knight Moves Queries80 / 96
• K Subset Sums I103 / 141
• K Subset Sums II54 / 75
• Increasing Array II738 / 853
• Food Division497 / 587
• Swap Round Sorting391 / 482
• Binary Subsequences270 / 397
• School Excursion1271 / 1351
• Coin Grid792 / 931
• Grid Coloring II84 / 106
• Programmers and Artists453 / 638
• Removing Digits II198 / 446
• Coin Arrangement305 / 413
• Replace with Difference81 / 98
• Grid Puzzle I490 / 537
• Grid Puzzle II451 / 496
• Bit Substrings352 / 431
• Reversal Sorting330 / 402
• Book Shop II1089 / 1253
• GCD Subsets273 / 281
• Minimum Cost Pairs62 / 86
• Same Sum Subsets66 / 125
• Mex Grid Queries791 / 931
• Maximum Building II415 / 510
• Stick Divisions3565 / 4189
• Stick Difference24 / 139
• Coding Company1356 / 1792
• Two Stacks Sorting157 / 497