CSES Problem Set

General

• Introduction
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• Statistics

Introductory Problems

• Weird Algorithm149374 / 156423
• Missing Number128711 / 134981
• Repetitions112063 / 116645
• Increasing Array105283 / 109088
• Permutations92516 / 95385
• Number Spiral65405 / 71306
• Two Knights49915 / 51508
• Two Sets54277 / 58463
• Bit Strings62186 / 65675
• Trailing Zeros58035 / 61756
• Coin Piles51380 / 56258
• Palindrome Reorder47788 / 50469
• Gray Code31784 / 35757
• Tower of Hanoi29405 / 30593
• Creating Strings40261 / 41321
• Apple Division40408 / 45698
• Chessboard and Queens24339 / 24780
• Raab Game I3676 / 4190
• Mex Grid Construction3546 / 3786
• Knight Moves Grid3538 / 3620
• Grid Coloring I2921 / 3024
• Digit Queries17124 / 19987
• String Reorder2822 / 3288
• Grid Path Description9526 / 12401

Sorting and Searching

• Distinct Numbers72812 / 78821
• Apartments53890 / 60011
• Ferris Wheel51741 / 55927
• Concert Tickets41720 / 48633
• Restaurant Customers42384 / 45786
• Movie Festival40730 / 43159
• Sum of Two Values47597 / 53380
• Maximum Subarray Sum46026 / 48100
• Stick Lengths41026 / 42955
• Missing Coin Sum30826 / 31973
• Collecting Numbers31563 / 33848
• Collecting Numbers II13101 / 16801
• Playlist31689 / 36292
• Towers32090 / 34392
• Traffic Lights24843 / 27842
• Distinct Values Subarrays5429 / 5713
• Distinct Values Subsequences3750 / 4185
• Josephus Problem I18899 / 20884
• Josephus Problem II10198 / 14094
• Nested Ranges Check10808 / 12453
• Nested Ranges Count7315 / 8650
• Room Allocation18653 / 21450
• Factory Machines26502 / 28934
• Tasks and Deadlines21405 / 21877
• Reading Books17328 / 18567
• Sum of Three Values25431 / 28206
• Sum of Four Values15805 / 17655
• Nearest Smaller Values21120 / 21845
• Subarray Sums I28017 / 29916
• Subarray Sums II25398 / 30231
• Subarray Divisibility23205 / 25330
• Distinct Values Subarrays II13872 / 15321
• Array Division21950 / 23112
• Movie Festival II11705 / 14136
• Maximum Subarray Sum II10824 / 12960

Dynamic Programming

• Dice Combinations76233 / 80696
• Minimizing Coins65827 / 70788
• Coin Combinations I60103 / 65126
• Coin Combinations II50757 / 57566
• Removing Digits56594 / 57760
• Grid Paths I53247 / 54784
• Book Shop47515 / 52345
• Array Description34991 / 38921
• Counting Towers21216 / 22494
• Edit Distance35176 / 37139
• Longest Common Subsequence7440 / 7715
• Rectangle Cutting29198 / 31917
• Minimal Grid Path3164 / 6030
• Money Sums34621 / 35956
• Removal Game20382 / 27660
• Two Sets II27283 / 29400
• Mountain Range2234 / 4263
• Increasing Subsequence27857 / 31297
• Projects19212 / 21524
• Elevator Rides12228 / 15439
• Counting Tilings7124 / 7782
• Counting Numbers9748 / 11029
• Increasing Subsequence II3823 / 4444

Graph Algorithms

• Counting Rooms52402 / 55073
• Labyrinth36217 / 43492
• Building Roads45657 / 47317
• Message Route39246 / 40824
• Building Teams37097 / 39148
• Round Trip29474 / 32144
• Monsters20066 / 23766
• Shortest Routes I32149 / 35555
• Shortest Routes II26201 / 29410
• High Score15846 / 22606
• Flight Discount20528 / 24100
• Cycle Finding14607 / 18006
• Flight Routes14288 / 15967
• Round Trip II16293 / 18343
• Course Schedule21378 / 22619
• Longest Flight Route14980 / 18705
• Game Routes16849 / 18079
• Investigation12462 / 13417
• Planets Queries I10861 / 12751
• Planets Queries II3882 / 4933
• Planets Cycles6636 / 7421
• Road Reparation16365 / 17074
• Road Construction17940 / 18520
• Flight Routes Check14567 / 15804
• Planets and Kingdoms11719 / 12139
• Giant Pizza4812 / 5305
• Coin Collector7577 / 8425
• Mail Delivery6324 / 6930
• De Bruijn Sequence3310 / 3466
• Teleporters Path4784 / 5497
• Hamiltonian Flights7172 / 8198
• Knight's Tour2678 / 3260
• Download Speed4739 / 6417
• Police Chase3787 / 4266
• School Dance4178 / 4422
• Distinct Routes2938 / 3868

Range Queries

• Static Range Sum Queries36354 / 37985
• Static Range Minimum Queries25504 / 27312
• Dynamic Range Sum Queries26497 / 27671
• Dynamic Range Minimum Queries24005 / 24579
• Range Xor Queries24837 / 25175
• Range Update Queries19642 / 21073
• Forest Queries20131 / 20895
• Hotel Queries14195 / 15089
• List Removals11829 / 12451
• Salary Queries8754 / 11104
• Prefix Sum Queries7514 / 8155
• Pizzeria Queries6050 / 6280
• Visible Buildings Queries1233 / 1354
• Range Interval Queries968 / 1282
• Subarray Sum Queries7227 / 7852
• Subarray Sum Queries II1303 / 1369
• Distinct Values Queries6632 / 8231
• Distinct Values Queries II771 / 892
• Increasing Array Queries2561 / 2942
• Movie Festival Queries1260 / 1399
• Forest Queries II4335 / 4667
• Range Updates and Sums5770 / 6875
• Polynomial Queries4239 / 4975
• Range Queries and Copies3029 / 3246
• Missing Coin Sum Queries623 / 820

Tree Algorithms

• Subordinates30178 / 32292
• Tree Matching17130 / 19984
• Tree Diameter24587 / 26082
• Tree Distances I18788 / 20207
• Tree Distances II15382 / 16039
• Company Queries I17075 / 17976
• Company Queries II16010 / 16796
• Distance Queries14564 / 15637
• Counting Paths9134 / 9688
• Subtree Queries10955 / 11695
• Path Queries8776 / 9300
• Path Queries II3552 / 5320
• Distinct Colors8443 / 9339
• Finding a Centroid6806 / 7091
• Fixed-Length Paths I3219 / 4190
• Fixed-Length Paths II1503 / 2785

Mathematics

• Josephus Queries4627 / 5831
• Exponentiation23736 / 25365
• Exponentiation II16831 / 20202
• Counting Divisors21572 / 24374
• Common Divisors14146 / 16465
• Sum of Divisors7901 / 11893
• Divisor Analysis5377 / 7243
• Prime Multiples6186 / 7238
• Counting Coprime Pairs4030 / 4723
• Next Prime1483 / 1696
• Binomial Coefficients9955 / 11067
• Creating Strings II8408 / 8878
• Distributing Apples8073 / 8689
• Christmas Party6521 / 7010
• Permutation Order695 / 708
• Permutation Rounds824 / 927
• Bracket Sequences I4479 / 4877
• Bracket Sequences II2315 / 2663
• Counting Necklaces2150 / 2330
• Counting Grids1760 / 1881
• Fibonacci Numbers6891 / 8655
• Throwing Dice3566 / 3880
• Graph Paths I3390 / 3643
• Graph Paths II2835 / 2972
• System of Linear Equations326 / 365
• Sum of Four Squares520 / 604
• Triangle Number Sums439 / 553
• Dice Probability3060 / 3304
• Moving Robots1580 / 1672
• Candy Lottery1361 / 2940
• Inversion Probability325 / 2240
• Stick Game3441 / 3524
• Nim Game I4553 / 4724
• Nim Game II3601 / 3752
• Stair Game2438 / 2654
• Grundy's Game1686 / 2222
• Another Game1896 / 2048

String Algorithms

• Word Combinations5808 / 8451
• String Matching11312 / 15159
• Finding Borders8275 / 9056
• Finding Periods5892 / 6697
• Minimal Rotation2858 / 4369
• Longest Palindrome4336 / 5731
• All Palindromes506 / 576
• Required Substring1638 / 2518
• Palindrome Queries2031 / 2367
• Finding Patterns1879 / 2691
• Counting Patterns1772 / 2208
• Pattern Positions1480 / 1817
• Distinct Substrings1698 / 2030
• Distinct Subsequences1065 / 1135
• Repeating Substring1836 / 2144
• String Functions1602 / 1678
• Inverse Suffix Array168 / 200
• String Transform512 / 626
• Substring Order I1149 / 1289
• Substring Order II759 / 987
• Substring Distribution1068 / 1160

Geometry

• Point Location Test7204 / 8052
• Line Segment Intersection4282 / 5392
• Polygon Area4954 / 5253
• Point in Polygon2691 / 3463
• Polygon Lattice Points2307 / 2388
• Minimum Euclidean Distance1998 / 2772
• Convex Hull3284 / 3957
• Maximum Manhattan Distances459 / 473
• All Manhattan Distances470 / 514
• Intersection Points1930 / 2078
• Line Segments Trace I256 / 265
• Line Segments Trace II208 / 220
• Lines and Queries I285 / 293
• Lines and Queries II242 / 250
• Area of Rectangles1102 / 1232
• Robot Path285 / 529

Advanced Techniques

• Meet in the Middle6577 / 9202
• Hamming Distance3199 / 3485
• Corner Subgrid Check249 / 397
• Corner Subgrid Count2210 / 2483
• Reachable Nodes2221 / 2389
• Reachability Queries1477 / 1752
• Cut and Paste1480 / 1648
• Substring Reversals1297 / 1414
• Reversals and Sums1306 / 1408
• Necessary Roads1899 / 1945
• Necessary Cities1759 / 1845
• Eulerian Subgraphs774 / 815
• Monster Game I1125 / 1253
• Monster Game II1002 / 1076
• Subarray Squares1353 / 1605
• Houses and Schools749 / 899
• Knuth Division911 / 1030
• Apples and Bananas1026 / 1116
• One Bit Positions821 / 901
• Signal Processing774 / 832
• New Roads Queries2134 / 2599
• Dynamic Connectivity969 / 1094
• Parcel Delivery746 / 828
• Task Assignment874 / 931
• Distinct Routes II565 / 648

Sliding Window Problems

• Sliding Window Sum3758 / 3922
• Sliding Window Minimum2873 / 3286
• Sliding Window Xor2797 / 2831
• Sliding Window Or1190 / 2156
• Sliding Window Distinct Values1725 / 2373
• Sliding Window Mode1619 / 1706
• Sliding Window Mex1445 / 1524
• Sliding Window Median13368 / 15297
• Sliding Window Cost8829 / 10205
• Sliding Window Inversions818 / 877
• Sliding Window Advertisement159 / 258

Interactive Problems

• Hidden Integer1610 / 1670
• Hidden Permutation688 / 826
• K-th Highest Score294 / 356
• Permuted Binary Strings385 / 396
• Colored Chairs336 / 355
• Inversion Sorting202 / 217

Bitwise Operations

• Counting Bits4557 / 5861
• Maximum Xor Subarray2753 / 3106
• Maximum Xor Subset741 / 799
• Number of Subset Xors641 / 653
• K Subset Xors301 / 361
• All Subarray Xors203 / 323
• Xor Pyramid Peak1871 / 2292
• Xor Pyramid Diagonal232 / 263
• Xor Pyramid Row189 / 223
• SOS Bit Problem1947 / 2078
• And Subset Count293 / 297

Construction Problems

• Inverse Inversions1416 / 1508
• Monotone Subsequences855 / 1007
• Third Permutation295 / 345
• Permutation Prime Sums287 / 311
• Chess Tournament1125 / 1299
• Distinct Sums Grid81 / 136
• Filling Trominos232 / 400
• Grid Path Construction117 / 421

Advanced Graph Problems

• Nearest Shops534 / 697
• Prüfer Code1440 / 1556
• Tree Traversals1139 / 1252
• Course Schedule II1795 / 2581
• Acyclic Graph Edges2118 / 2252
• Strongly Connected Edges1473 / 1634
• Even Outdegree Edges1257 / 1480
• Graph Girth3220 / 3686
• Fixed Length Walk Queries266 / 292
• Transfer Speeds Sum311 / 320
• MST Edge Check452 / 485
• MST Edge Set Check169 / 191
• MST Edge Cost286 / 299
• Network Breakdown971 / 1030
• Tree Coin Collecting I241 / 267
• Tree Coin Collecting II124 / 146
• Tree Isomorphism I1032 / 1241
• Tree Isomorphism II838 / 980
• Flight Route Requests459 / 562
• Critical Cities389 / 604
• Visiting Cities646 / 858
• Graph Coloring170 / 198
• Bus Companies194 / 200
• Split into Two Paths65 / 120
• Network Renovation901 / 1205
• Forbidden Cities782 / 1024
• Creating Offices388 / 510
• New Flight Routes296 / 802

Counting Problems

• Filled Subgrid Count I412 / 454
• Filled Subgrid Count II208 / 257
• All Letter Subgrid Count I110 / 175
• All Letter Subgrid Count II94 / 114
• Border Subgrid Count I71 / 122
• Border Subgrid Count II71 / 82
• Raab Game II74 / 88
• Empty String1536 / 1877
• Permutation Inversions977 / 1078
• Counting Bishops366 / 409
• Counting Sequences628 / 673
• Grid Paths II717 / 895
• Counting Permutations843 / 954
• Grid Completion213 / 269
• Counting Reorders223 / 328
• Tournament Graph Distribution82 / 86
• Collecting Numbers Distribution86 / 93
• Functional Graph Distribution229 / 283

Additional Problems I

• Shortest Subsequence2874 / 3811
• Distinct Values Sum491 / 505
• Distinct Values Splits342 / 362
• Swap Game1957 / 2489
• Beautiful Permutation II302 / 455
• Multiplication Table6314 / 7053
• Bubble Sort Rounds I272 / 311
• Bubble Sort Rounds II153 / 180
• Nearest Campsites I122 / 140
• Nearest Campsites II121 / 130
• Advertisement4104 / 4350
• Special Substrings930 / 1021
• Counting LCM Arrays192 / 208
• Square Subsets154 / 173
• Subarray Sum Constraints207 / 223
• Water Containers Moves116 / 123
• Water Containers Queries144 / 151
• Stack Weights558 / 662
• Maximum Average Subarrays115 / 127
• Subsets with Fixed Average150 / 165
• Two Array Average142 / 159
• Pyramid Array676 / 824
• Permutation Subsequence160 / 163
• Bit Inversions2208 / 2515
• Writing Numbers706 / 763
• Letter Pair Move Game189 / 268
• Maximum Building I1972 / 2057
• Sorting Methods733 / 785
• Cyclic Array1115 / 1271
• List of Sums451 / 594

Additional Problems II

• Bouncing Ball Steps163 / 179
• Bouncing Ball Cycle65 / 92
• Knight Moves Queries87 / 106
• K Subset Sums I125 / 171
• K Subset Sums II62 / 85
• Increasing Array II746 / 862
• Food Division499 / 591
• Swap Round Sorting396 / 488
• Binary Subsequences275 / 405
• School Excursion1305 / 1385
• Coin Grid820 / 960
• Grid Coloring II98 / 126
• Programmers and Artists466 / 652
• Removing Digits II208 / 455
• Coin Arrangement308 / 416
• Replace with Difference90 / 111
• Grid Puzzle I503 / 551
• Grid Puzzle II471 / 519
• Bit Substrings367 / 446
• Reversal Sorting335 / 407
• Book Shop II1128 / 1295
• GCD Subsets315 / 323
• Minimum Cost Pairs73 / 103
• Same Sum Subsets82 / 153
• Mex Grid Queries807 / 946
• Maximum Building II427 / 525
• Stick Divisions3623 / 4256
• Stick Difference30 / 166
• Coding Company1391 / 1838
• Two Stacks Sorting163 / 514