CSES Problem Set

General

• Introduction
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• Statistics

Introductory Problems

• Weird Algorithm150351 / 157422
• Missing Number129574 / 135871
• Repetitions112837 / 117434
• Increasing Array106014 / 109839
• Permutations93219 / 96093
• Number Spiral65858 / 71799
• Two Knights50291 / 51892
• Two Sets54694 / 58899
• Bit Strings62579 / 66082
• Trailing Zeros58425 / 62169
• Coin Piles51714 / 56618
• Palindrome Reorder48094 / 50788
• Gray Code32028 / 36030
• Tower of Hanoi29616 / 30818
• Creating Strings40565 / 41639
• Apple Division40683 / 46006
• Chessboard and Queens24508 / 24954
• Raab Game I3827 / 4360
• Mex Grid Construction3690 / 3937
• Knight Moves Grid3673 / 3756
• Grid Coloring I3060 / 3164
• Digit Queries17218 / 20089
• String Reorder2915 / 3393
• Grid Path Description9581 / 12474

Sorting and Searching

• Distinct Numbers73365 / 79394
• Apartments54238 / 60378
• Ferris Wheel52079 / 56269
• Concert Tickets41979 / 48934
• Restaurant Customers42641 / 46064
• Movie Festival40975 / 43417
• Sum of Two Values47890 / 53702
• Maximum Subarray Sum46317 / 48406
• Stick Lengths41262 / 43192
• Missing Coin Sum31017 / 32170
• Collecting Numbers31770 / 34064
• Collecting Numbers II13200 / 16911
• Playlist31866 / 36487
• Towers32282 / 34595
• Traffic Lights24985 / 27992
• Distinct Values Subarrays5623 / 5914
• Distinct Values Subsequences3869 / 4312
• Josephus Problem I19040 / 21026
• Josephus Problem II10270 / 14195
• Nested Ranges Check10889 / 12549
• Nested Ranges Count7380 / 8727
• Room Allocation18766 / 21575
• Factory Machines26730 / 29174
• Tasks and Deadlines21528 / 21999
• Reading Books17443 / 18695
• Sum of Three Values25643 / 28430
• Sum of Four Values15898 / 17754
• Nearest Smaller Values21268 / 22003
• Subarray Sums I28188 / 30090
• Subarray Sums II25587 / 30432
• Subarray Divisibility23354 / 25487
• Distinct Values Subarrays II13977 / 15425
• Array Division22155 / 23335
• Movie Festival II11826 / 14276
• Maximum Subarray Sum II10903 / 13044

Dynamic Programming

• Dice Combinations76794 / 81278
• Minimizing Coins66288 / 71289
• Coin Combinations I60492 / 65550
• Coin Combinations II51107 / 57929
• Removing Digits56945 / 58113
• Grid Paths I53559 / 55106
• Book Shop47832 / 52671
• Array Description35222 / 39180
• Counting Towers21347 / 22642
• Edit Distance35367 / 37336
• Longest Common Subsequence7671 / 7959
• Rectangle Cutting29339 / 32073
• Minimal Grid Path3296 / 6205
• Money Sums34798 / 36137
• Removal Game20542 / 27850
• Two Sets II27413 / 29538
• Mountain Range2314 / 4377
• Increasing Subsequence28017 / 31473
• Projects19307 / 21624
• Elevator Rides12294 / 15515
• Counting Tilings7183 / 7844
• Counting Numbers9858 / 11148
• Increasing Subsequence II3886 / 4520

Graph Algorithms

• Counting Rooms52756 / 55448
• Labyrinth36472 / 43783
• Building Roads45936 / 47598
• Message Route39536 / 41122
• Building Teams37326 / 39380
• Round Trip29664 / 32343
• Monsters20212 / 23928
• Shortest Routes I32419 / 35830
• Shortest Routes II26411 / 29642
• High Score15975 / 22757
• Flight Discount20671 / 24264
• Cycle Finding14706 / 18114
• Flight Routes14380 / 16064
• Round Trip II16385 / 18432
• Course Schedule21496 / 22740
• Longest Flight Route15087 / 18815
• Game Routes16946 / 18178
• Investigation12547 / 13510
• Planets Queries I10938 / 12835
• Planets Queries II3917 / 4972
• Planets Cycles6688 / 7474
• Road Reparation16470 / 17180
• Road Construction18042 / 18622
• Flight Routes Check14652 / 15892
• Planets and Kingdoms11779 / 12200
• Giant Pizza4840 / 5335
• Coin Collector7624 / 8472
• Mail Delivery6367 / 6974
• De Bruijn Sequence3326 / 3482
• Teleporters Path4815 / 5526
• Hamiltonian Flights7220 / 8250
• Knight's Tour2701 / 3285
• Download Speed4777 / 6456
• Police Chase3812 / 4291
• School Dance4212 / 4456
• Distinct Routes2952 / 3889

Range Queries

• Static Range Sum Queries36567 / 38206
• Static Range Minimum Queries25648 / 27468
• Dynamic Range Sum Queries26640 / 27823
• Dynamic Range Minimum Queries24125 / 24703
• Range Xor Queries24968 / 25305
• Range Update Queries19766 / 21203
• Forest Queries20262 / 21030
• Hotel Queries14294 / 15190
• List Removals11892 / 12520
• Salary Queries8817 / 11186
• Prefix Sum Queries7575 / 8220
• Pizzeria Queries6093 / 6323
• Visible Buildings Queries1281 / 1404
• Range Interval Queries1003 / 1337
• Subarray Sum Queries7280 / 7906
• Subarray Sum Queries II1349 / 1416
• Distinct Values Queries6698 / 8306
• Distinct Values Queries II799 / 924
• Increasing Array Queries2574 / 2957
• Movie Festival Queries1278 / 1421
• Forest Queries II4356 / 4693
• Range Updates and Sums5801 / 6913
• Polynomial Queries4258 / 5002
• Range Queries and Copies3057 / 3277
• Missing Coin Sum Queries639 / 841

Tree Algorithms

• Subordinates30382 / 32498
• Tree Matching17230 / 20086
• Tree Diameter24765 / 26265
• Tree Distances I18902 / 20325
• Tree Distances II15478 / 16139
• Company Queries I17197 / 18100
• Company Queries II16129 / 16918
• Distance Queries14662 / 15740
• Counting Paths9187 / 9744
• Subtree Queries11015 / 11758
• Path Queries8826 / 9352
• Path Queries II3541 / 5368
• Distinct Colors8488 / 9385
• Finding a Centroid6858 / 7146
• Fixed-Length Paths I3257 / 4230
• Fixed-Length Paths II1521 / 2810

Mathematics

• Josephus Queries4665 / 5878
• Exponentiation23858 / 25496
• Exponentiation II16922 / 20308
• Counting Divisors21706 / 24526
• Common Divisors14245 / 16571
• Sum of Divisors7941 / 11950
• Divisor Analysis5407 / 7276
• Prime Multiples6249 / 7303
• Counting Coprime Pairs4063 / 4758
• Next Prime1534 / 1752
• Binomial Coefficients10016 / 11133
• Creating Strings II8464 / 8938
• Distributing Apples8134 / 8752
• Christmas Party6554 / 7046
• Permutation Order723 / 735
• Permutation Rounds868 / 971
• Bracket Sequences I4503 / 4904
• Bracket Sequences II2331 / 2679
• Counting Necklaces2162 / 2342
• Counting Grids1775 / 1898
• Fibonacci Numbers6938 / 8705
• Throwing Dice3585 / 3900
• Graph Paths I3416 / 3668
• Graph Paths II2858 / 2996
• System of Linear Equations340 / 378
• Sum of Four Squares537 / 620
• Triangle Number Sums449 / 564
• Dice Probability3083 / 3329
• Moving Robots1585 / 1677
• Candy Lottery1390 / 2969
• Inversion Probability331 / 2251
• Stick Game3466 / 3549
• Nim Game I4585 / 4757
• Nim Game II3629 / 3779
• Stair Game2451 / 2668
• Grundy's Game1698 / 2238
• Another Game1928 / 2081

String Algorithms

• Word Combinations5861 / 8514
• String Matching11396 / 15258
• Finding Borders8325 / 9110
• Finding Periods5931 / 6744
• Minimal Rotation2875 / 4389
• Longest Palindrome4353 / 5755
• All Palindromes523 / 596
• Required Substring1649 / 2528
• Palindrome Queries2044 / 2381
• Finding Patterns1904 / 2715
• Counting Patterns1799 / 2239
• Pattern Positions1501 / 1841
• Distinct Substrings1716 / 2052
• Distinct Subsequences1075 / 1145
• Repeating Substring1856 / 2163
• String Functions1617 / 1693
• Inverse Suffix Array174 / 208
• String Transform522 / 637
• Substring Order I1162 / 1303
• Substring Order II772 / 1001
• Substring Distribution1081 / 1175

Geometry

• Point Location Test7264 / 8113
• Line Segment Intersection4325 / 5435
• Polygon Area4992 / 5290
• Point in Polygon2732 / 3510
• Polygon Lattice Points2324 / 2405
• Minimum Euclidean Distance2017 / 2795
• Convex Hull3313 / 3991
• Maximum Manhattan Distances483 / 498
• All Manhattan Distances492 / 538
• Intersection Points1950 / 2099
• Line Segments Trace I267 / 276
• Line Segments Trace II219 / 231
• Lines and Queries I299 / 308
• Lines and Queries II258 / 266
• Area of Rectangles1114 / 1245
• Robot Path290 / 537

Advanced Techniques

• Meet in the Middle6635 / 9260
• Hamming Distance3219 / 3506
• Corner Subgrid Check260 / 414
• Corner Subgrid Count2231 / 2506
• Reachable Nodes2241 / 2411
• Reachability Queries1487 / 1762
• Cut and Paste1497 / 1668
• Substring Reversals1309 / 1426
• Reversals and Sums1318 / 1420
• Necessary Roads1916 / 1961
• Necessary Cities1778 / 1864
• Eulerian Subgraphs784 / 825
• Monster Game I1136 / 1263
• Monster Game II1015 / 1089
• Subarray Squares1367 / 1621
• Houses and Schools759 / 909
• Knuth Division918 / 1037
• Apples and Bananas1043 / 1134
• One Bit Positions834 / 913
• Signal Processing790 / 848
• New Roads Queries2153 / 2619
• Dynamic Connectivity980 / 1107
• Parcel Delivery753 / 835
• Task Assignment889 / 946
• Distinct Routes II569 / 652

Sliding Window Problems

• Sliding Window Sum3898 / 4068
• Sliding Window Minimum2959 / 3387
• Sliding Window Xor2902 / 2938
• Sliding Window Or1238 / 2240
• Sliding Window Distinct Values1815 / 2457
• Sliding Window Mode1675 / 1766
• Sliding Window Mex1496 / 1580
• Sliding Window Median13435 / 15372
• Sliding Window Cost8852 / 10230
• Sliding Window Inversions852 / 912
• Sliding Window Advertisement167 / 270

Interactive Problems

• Hidden Integer1656 / 1715
• Hidden Permutation715 / 852
• K-th Highest Score315 / 381
• Permuted Binary Strings398 / 409
• Colored Chairs351 / 370
• Inversion Sorting210 / 228

Bitwise Operations

• Counting Bits4609 / 5926
• Maximum Xor Subarray2784 / 3142
• Maximum Xor Subset774 / 835
• Number of Subset Xors671 / 685
• K Subset Xors317 / 384
• All Subarray Xors211 / 339
• Xor Pyramid Peak1890 / 2315
• Xor Pyramid Diagonal240 / 272
• Xor Pyramid Row193 / 229
• SOS Bit Problem1994 / 2127
• And Subset Count311 / 316

Construction Problems

• Inverse Inversions1445 / 1538
• Monotone Subsequences889 / 1046
• Third Permutation305 / 358
• Permutation Prime Sums298 / 323
• Chess Tournament1133 / 1310
• Distinct Sums Grid84 / 142
• Filling Trominos232 / 402
• Grid Path Construction118 / 421

Advanced Graph Problems

• Nearest Shops548 / 714
• Prüfer Code1457 / 1573
• Tree Traversals1147 / 1262
• Course Schedule II1812 / 2605
• Acyclic Graph Edges2153 / 2287
• Strongly Connected Edges1494 / 1657
• Even Outdegree Edges1272 / 1496
• Graph Girth3260 / 3725
• Fixed Length Walk Queries272 / 300
• Transfer Speeds Sum324 / 334
• MST Edge Check467 / 502
• MST Edge Set Check177 / 201
• MST Edge Cost291 / 304
• Network Breakdown980 / 1039
• Tree Coin Collecting I247 / 275
• Tree Coin Collecting II128 / 151
• Tree Isomorphism I1037 / 1246
• Tree Isomorphism II842 / 984
• Flight Route Requests464 / 568
• Critical Cities393 / 610
• Visiting Cities653 / 868
• Graph Coloring176 / 207
• Bus Companies202 / 208
• Split into Two Paths66 / 127
• Network Renovation907 / 1211
• Forbidden Cities795 / 1042
• Creating Offices396 / 517
• New Flight Routes299 / 811

Counting Problems

• Filled Subgrid Count I428 / 473
• Filled Subgrid Count II222 / 273
• All Letter Subgrid Count I117 / 181
• All Letter Subgrid Count II96 / 119
• Border Subgrid Count I72 / 124
• Border Subgrid Count II75 / 87
• Raab Game II76 / 91
• Empty String1549 / 1894
• Permutation Inversions983 / 1086
• Counting Bishops367 / 410
• Counting Sequences633 / 678
• Grid Paths II722 / 901
• Counting Permutations847 / 959
• Grid Completion214 / 270
• Counting Reorders225 / 330
• Tournament Graph Distribution83 / 87
• Collecting Numbers Distribution88 / 96
• Functional Graph Distribution230 / 284

Additional Problems I

• Shortest Subsequence2911 / 3850
• Distinct Values Sum509 / 525
• Distinct Values Splits357 / 377
• Swap Game1983 / 2517
• Beautiful Permutation II324 / 484
• Multiplication Table6385 / 7130
• Bubble Sort Rounds I289 / 333
• Bubble Sort Rounds II163 / 190
• Nearest Campsites I128 / 148
• Nearest Campsites II127 / 136
• Advertisement4143 / 4391
• Special Substrings937 / 1029
• Counting LCM Arrays204 / 222
• Square Subsets165 / 185
• Subarray Sum Constraints227 / 243
• Water Containers Moves120 / 127
• Water Containers Queries150 / 156
• Stack Weights562 / 666
• Maximum Average Subarrays121 / 133
• Subsets with Fixed Average157 / 173
• Two Array Average151 / 169
• Pyramid Array686 / 836
• Permutation Subsequence170 / 173
• Bit Inversions2228 / 2536
• Writing Numbers712 / 769
• Letter Pair Move Game190 / 268
• Maximum Building I1987 / 2073
• Sorting Methods738 / 791
• Cyclic Array1122 / 1279
• List of Sums454 / 597

Additional Problems II

• Bouncing Ball Steps168 / 184
• Bouncing Ball Cycle66 / 94
• Knight Moves Queries92 / 113
• K Subset Sums I128 / 175
• K Subset Sums II65 / 89
• Increasing Array II756 / 872
• Food Division503 / 596
• Swap Round Sorting398 / 490
• Binary Subsequences275 / 406
• School Excursion1317 / 1398
• Coin Grid824 / 964
• Grid Coloring II101 / 130
• Programmers and Artists466 / 653
• Removing Digits II208 / 455
• Coin Arrangement311 / 418
• Replace with Difference93 / 114
• Grid Puzzle I505 / 554
• Grid Puzzle II478 / 526
• Bit Substrings368 / 447
• Reversal Sorting335 / 407
• Book Shop II1139 / 1307
• GCD Subsets324 / 332
• Minimum Cost Pairs80 / 110
• Same Sum Subsets84 / 159
• Mex Grid Queries811 / 951
• Maximum Building II430 / 528
• Stick Divisions3646 / 4281
• Stick Difference31 / 167
• Coding Company1404 / 1851
• Two Stacks Sorting163 / 518