CSES Problem Set

General

• Introduction
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• Statistics

Introductory Problems

• Weird Algorithm145358 / 152248
• Missing Number125233 / 131408
• Repetitions109132 / 113651
• Increasing Array102518 / 106286
• Permutations90087 / 92904
• Number Spiral63697 / 69467
• Two Knights48618 / 50179
• Two Sets52858 / 56959
• Bit Strings60592 / 64003
• Trailing Zeros56603 / 60248
• Coin Piles50092 / 54852
• Palindrome Reorder46434 / 49067
• Gray Code30858 / 34748
• Tower of Hanoi28540 / 29685
• Creating Strings39206 / 40235
• Apple Division39160 / 44337
• Chessboard and Queens23642 / 24076
• Raab Game I3128 / 3579
• Mex Grid Construction2989 / 3203
• Knight Moves Grid3013 / 3082
• Grid Coloring I2485 / 2570
• Digit Queries16711 / 19541
• String Reorder2465 / 2868
• Grid Path Description9322 / 12138

Sorting and Searching

• Distinct Numbers70803 / 76712
• Apartments52455 / 58435
• Ferris Wheel50301 / 54413
• Concert Tickets40501 / 47280
• Restaurant Customers41289 / 44621
• Movie Festival39599 / 41981
• Sum of Two Values46229 / 51873
• Maximum Subarray Sum44849 / 46880
• Stick Lengths40024 / 41917
• Missing Coin Sum29990 / 31113
• Collecting Numbers30759 / 32993
• Collecting Numbers II12697 / 16339
• Playlist30829 / 35365
• Towers31187 / 33449
• Traffic Lights24113 / 27060
• Distinct Values Subarrays4684 / 4942
• Distinct Values Subsequences3245 / 3631
• Josephus Problem I18322 / 20273
• Josephus Problem II9856 / 13642
• Nested Ranges Check10461 / 12092
• Nested Ranges Count7099 / 8400
• Room Allocation18152 / 20902
• Factory Machines25646 / 28035
• Tasks and Deadlines20822 / 21280
• Reading Books16863 / 18071
• Sum of Three Values24651 / 27371
• Sum of Four Values15385 / 17212
• Nearest Smaller Values20598 / 21310
• Subarray Sums I27177 / 29057
• Subarray Sums II24552 / 29302
• Subarray Divisibility22565 / 24663
• Distinct Values Subarrays II13327 / 14769
• Array Division21327 / 22463
• Movie Festival II11344 / 13730
• Maximum Subarray Sum II10488 / 12589

Dynamic Programming

• Dice Combinations74034 / 78385
• Minimizing Coins63983 / 68809
• Coin Combinations I58446 / 63350
• Coin Combinations II49396 / 56041
• Removing Digits55135 / 56286
• Grid Paths I51738 / 53228
• Book Shop46237 / 50983
• Array Description33992 / 37857
• Counting Towers20566 / 21816
• Edit Distance34252 / 36166
• Longest Common Subsequence6412 / 6660
• Rectangle Cutting28472 / 31126
• Minimal Grid Path2730 / 5247
• Money Sums33774 / 35098
• Removal Game19721 / 26999
• Two Sets II26616 / 28707
• Mountain Range1887 / 3700
• Increasing Subsequence27184 / 30558
• Projects18703 / 20992
• Elevator Rides11832 / 14975
• Counting Tilings6891 / 7538
• Counting Numbers9353 / 10599
• Increasing Subsequence II3508 / 4071

Graph Algorithms

• Counting Rooms50901 / 53534
• Labyrinth35138 / 42298
• Building Roads44464 / 46088
• Message Route38169 / 39723
• Building Teams36018 / 38053
• Round Trip28632 / 31248
• Monsters19442 / 23083
• Shortest Routes I31138 / 34512
• Shortest Routes II25415 / 28596
• High Score15291 / 21951
• Flight Discount19881 / 23396
• Cycle Finding14144 / 17485
• Flight Routes13800 / 15427
• Round Trip II15800 / 17798
• Course Schedule20715 / 21951
• Longest Flight Route14475 / 18146
• Game Routes16327 / 17541
• Investigation12081 / 13022
• Planets Queries I10480 / 12336
• Planets Queries II3738 / 4759
• Planets Cycles6427 / 7195
• Road Reparation15793 / 16470
• Road Construction17373 / 17936
• Flight Routes Check14129 / 15347
• Planets and Kingdoms11328 / 11736
• Giant Pizza4613 / 5099
• Coin Collector7299 / 8132
• Mail Delivery6105 / 6700
• De Bruijn Sequence3174 / 3328
• Teleporters Path4603 / 5314
• Hamiltonian Flights6920 / 7917
• Knight's Tour2565 / 3134
• Download Speed4533 / 6178
• Police Chase3635 / 4100
• School Dance4026 / 4267
• Distinct Routes2767 / 3673

Range Queries

• Static Range Sum Queries35068 / 36655
• Static Range Minimum Queries24754 / 26531
• Dynamic Range Sum Queries25744 / 26893
• Dynamic Range Minimum Queries23358 / 23923
• Range Xor Queries24131 / 24462
• Range Update Queries19066 / 20477
• Forest Queries19477 / 20225
• Hotel Queries13772 / 14661
• List Removals11475 / 12093
• Salary Queries8409 / 10712
• Prefix Sum Queries7210 / 7834
• Pizzeria Queries5824 / 6057
• Visible Buildings Queries1032 / 1128
• Range Interval Queries814 / 1075
• Subarray Sum Queries7022 / 7643
• Subarray Sum Queries II1116 / 1152
• Distinct Values Queries6418 / 7997
• Distinct Values Queries II636 / 742
• Increasing Array Queries2467 / 2835
• Movie Festival Queries1173 / 1305
• Forest Queries II4217 / 4546
• Range Updates and Sums5584 / 6677
• Polynomial Queries4115 / 4834
• Range Queries and Copies2923 / 3142
• Missing Coin Sum Queries573 / 764

Tree Algorithms

• Subordinates29302 / 31374
• Tree Matching16597 / 19412
• Tree Diameter23850 / 25319
• Tree Distances I18122 / 19516
• Tree Distances II14908 / 15556
• Company Queries I16534 / 17417
• Company Queries II15483 / 16257
• Distance Queries14103 / 15167
• Counting Paths8783 / 9334
• Subtree Queries10570 / 11291
• Path Queries8402 / 8907
• Path Queries II3378 / 5104
• Distinct Colors8159 / 9036
• Finding a Centroid6570 / 6850
• Fixed-Length Paths I3101 / 4053
• Fixed-Length Paths II1438 / 2685

Mathematics

• Josephus Queries4450 / 5617
• Exponentiation23101 / 24683
• Exponentiation II16373 / 19686
• Counting Divisors20939 / 23681
• Common Divisors13740 / 16005
• Sum of Divisors7648 / 11565
• Divisor Analysis5208 / 7016
• Prime Multiples5920 / 6950
• Counting Coprime Pairs3861 / 4540
• Next Prime1237 / 1418
• Binomial Coefficients9676 / 10760
• Creating Strings II8153 / 8623
• Distributing Apples7844 / 8449
• Christmas Party6305 / 6787
• Permutation Order572 / 581
• Permutation Rounds662 / 740
• 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 Lottery1257 / 2824
• Inversion Probability286 / 2176
• Stick Game3334 / 3413
• Nim Game I4395 / 4564
• Nim Game II3483 / 3633
• Stair Game2371 / 2580
• Grundy's Game1621 / 2144
• Another Game1836 / 1984

String Algorithms

• Word Combinations5592 / 8179
• String Matching10916 / 14692
• Finding Borders7976 / 8739
• Finding Periods5691 / 6473
• Minimal Rotation2757 / 4247
• Longest Palindrome4189 / 5559
• All Palindromes424 / 485
• Required Substring1581 / 2447
• Palindrome Queries1973 / 2304
• Finding Patterns1809 / 2601
• Counting Patterns1709 / 2133
• Pattern Positions1429 / 1755
• Distinct Substrings1630 / 1954
• Distinct Subsequences1020 / 1089
• Repeating Substring1772 / 2079
• String Functions1554 / 1630
• Inverse Suffix Array147 / 170
• String Transform494 / 605
• Substring Order I1109 / 1248
• Substring Order II733 / 952
• Substring Distribution1032 / 1124

Geometry

• Point Location Test6943 / 7771
• Line Segment Intersection4146 / 5242
• Polygon Area4827 / 5123
• Point in Polygon2632 / 3346
• 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 I220 / 227
• Line Segments Trace II176 / 188
• Lines and Queries I237 / 246
• Lines and Queries II202 / 211
• Area of Rectangles1059 / 1186
• Robot Path293 / 508

Advanced Techniques

• Meet in the Middle6383 / 8966
• Hamming Distance3119 / 3397
• Corner Subgrid Check208 / 351
• Corner Subgrid Count2174 / 2440
• Reachable Nodes2161 / 2326
• Reachability Queries1442 / 1711
• 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 Sum3173 / 3322
• Sliding Window Minimum2466 / 2813
• Sliding Window Xor2384 / 2415
• Sliding Window Or1006 / 1859
• Sliding Window Distinct Values1994 / 2035
• Sliding Window Mode1394 / 1466
• Sliding Window Mex1241 / 1309
• Sliding Window Median13049 / 14949
• Sliding Window Cost8676 / 10021
• Sliding Window Inversions711 / 760
• Sliding Window Advertisement133 / 214

Interactive Problems

• Hidden Integer1327 / 1367
• Hidden Permutation582 / 692
• K-th Highest Score247 / 303
• Permuted Binary Strings336 / 346
• Colored Chairs292 / 307
• Inversion Sorting170 / 182

Bitwise Operations

• Counting Bits4271 / 5496
• Maximum Xor Subarray2624 / 2948
• Maximum Xor Subset614 / 661
• Number of Subset Xors525 / 536
• K Subset Xors255 / 300
• All Subarray Xors179 / 275
• Xor Pyramid Peak1799 / 2210
• 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 Check146 / 167
• 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 I339 / 375
• Filled Subgrid Count II174 / 211
• All Letter Subgrid Count I83 / 139
• All Letter Subgrid Count II67 / 83
• Border Subgrid Count I60 / 106
• Border Subgrid Count II63 / 73
• Raab Game II62 / 74
• Empty String1489 / 1817
• Permutation Inversions945 / 1037
• Counting Bishops356 / 399
• Counting Sequences607 / 653
• Grid Paths II699 / 871
• Counting Permutations820 / 929
• Grid Completion205 / 260
• Counting Reorders215 / 315
• Tournament Graph Distribution68 / 71
• Collecting Numbers Distribution73 / 75
• Functional Graph Distribution220 / 275

Additional Problems I

• Shortest Subsequence2817 / 3744
• Distinct Values Sum417 / 429
• Distinct Values Splits288 / 307
• Swap Game1912 / 2432
• Beautiful Permutation II220 / 322
• Multiplication Table6096 / 6821
• 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 Numbers695 / 752
• Letter Pair Move Game182 / 261
• Maximum Building I1935 / 2020
• Sorting Methods724 / 776
• Cyclic Array1085 / 1239
• List of Sums438 / 571

Additional Problems II

• Bouncing Ball Steps142 / 156
• 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 Artists449 / 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 II1086 / 1250
• GCD Subsets266 / 274
• Minimum Cost Pairs61 / 83
• Same Sum Subsets66 / 123
• Mex Grid Queries787 / 927
• Maximum Building II412 / 507
• Stick Divisions3559 / 4183
• Stick Difference24 / 138
• Coding Company1352 / 1787
• Two Stacks Sorting157 / 496