CSES Problem Set

General

• Introduction
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• Statistics

Introductory Problems

• Weird Algorithm150587 / 157667
• Missing Number129772 / 136085
• Repetitions113020 / 117623
• Increasing Array106204 / 110036
• Permutations93391 / 96271
• Number Spiral65989 / 71938
• Two Knights50384 / 51986
• Two Sets54801 / 59010
• Bit Strings62687 / 66199
• Trailing Zeros58539 / 62292
• Coin Piles51810 / 56716
• Palindrome Reorder48189 / 50884
• Gray Code32094 / 36104
• Tower of Hanoi29674 / 30877
• Creating Strings40631 / 41705
• Apple Division40756 / 46085
• Chessboard and Queens24552 / 24998
• Raab Game I3863 / 4399
• Mex Grid Construction3717 / 3969
• Knight Moves Grid3704 / 3792
• Grid Coloring I3090 / 3195
• Digit Queries17247 / 20117
• String Reorder2938 / 3419
• Grid Path Description9595 / 12491

Sorting and Searching

• Distinct Numbers73484 / 79530
• Apartments54321 / 60469
• Ferris Wheel52155 / 56351
• Concert Tickets42046 / 49005
• Restaurant Customers42721 / 46151
• Movie Festival41052 / 43497
• Sum of Two Values47967 / 53787
• Maximum Subarray Sum46394 / 48487
• Stick Lengths41340 / 43267
• Missing Coin Sum31078 / 32231
• Collecting Numbers31826 / 34125
• Collecting Numbers II13222 / 16939
• Playlist31904 / 36535
• Towers32336 / 34651
• Traffic Lights25031 / 28043
• Distinct Values Subarrays5678 / 5974
• Distinct Values Subsequences3904 / 4351
• Josephus Problem I19076 / 21060
• Josephus Problem II10290 / 14222
• Nested Ranges Check10913 / 12576
• Nested Ranges Count7394 / 8739
• Room Allocation18808 / 21619
• Factory Machines26778 / 29222
• Tasks and Deadlines21564 / 22036
• Reading Books17479 / 18732
• Sum of Three Values25696 / 28486
• Sum of Four Values15925 / 17781
• Nearest Smaller Values21301 / 22037
• Subarray Sums I28239 / 30141
• Subarray Sums II25629 / 30481
• Subarray Divisibility23384 / 25518
• Distinct Values Subarrays II14004 / 15456
• Array Division22192 / 23373
• Movie Festival II11847 / 14305
• Maximum Subarray Sum II10928 / 13071

Dynamic Programming

• Dice Combinations76961 / 81452
• Minimizing Coins66433 / 71435
• Coin Combinations I60633 / 65704
• Coin Combinations II51209 / 58048
• Removing Digits57049 / 58220
• Grid Paths I53704 / 55266
• Book Shop47914 / 52763
• Array Description35277 / 39234
• Counting Towers21390 / 22688
• Edit Distance35412 / 37390
• Longest Common Subsequence7746 / 8039
• Rectangle Cutting29385 / 32123
• Minimal Grid Path3320 / 6249
• Money Sums34839 / 36182
• Removal Game20571 / 27885
• Two Sets II27466 / 29594
• Mountain Range2342 / 4418
• Increasing Subsequence28059 / 31517
• Projects19336 / 21651
• Elevator Rides12315 / 15542
• Counting Tilings7202 / 7864
• Counting Numbers9876 / 11170
• Increasing Subsequence II3902 / 4540

Graph Algorithms

• Counting Rooms52863 / 55556
• Labyrinth36545 / 43865
• Building Roads46028 / 47690
• Message Route39608 / 41194
• Building Teams37387 / 39445
• Round Trip29713 / 32398
• Monsters20246 / 23963
• Shortest Routes I32458 / 35873
• Shortest Routes II26452 / 29687
• High Score16013 / 22796
• Flight Discount20705 / 24300
• Cycle Finding14739 / 18149
• Flight Routes14399 / 16087
• Round Trip II16411 / 18461
• Course Schedule21525 / 22769
• Longest Flight Route15117 / 18850
• Game Routes16973 / 18204
• Investigation12575 / 13540
• Planets Queries I10961 / 12860
• Planets Queries II3925 / 4983
• Planets Cycles6698 / 7488
• Road Reparation16502 / 17211
• Road Construction18078 / 18656
• Flight Routes Check14680 / 15920
• Planets and Kingdoms11794 / 12217
• Giant Pizza4854 / 5350
• Coin Collector7635 / 8484
• Mail Delivery6376 / 6984
• De Bruijn Sequence3331 / 3487
• Teleporters Path4822 / 5533
• Hamiltonian Flights7231 / 8263
• Knight's Tour2709 / 3293
• Download Speed4789 / 6470
• Police Chase3819 / 4298
• School Dance4222 / 4466
• Distinct Routes2961 / 3898

Range Queries

• Static Range Sum Queries36619 / 38258
• Static Range Minimum Queries25699 / 27525
• Dynamic Range Sum Queries26670 / 27853
• Dynamic Range Minimum Queries24160 / 24738
• Range Xor Queries25007 / 25344
• Range Update Queries19803 / 21241
• Forest Queries20290 / 21059
• Hotel Queries14317 / 15214
• List Removals11904 / 12532
• Salary Queries8834 / 11202
• Prefix Sum Queries7590 / 8235
• Pizzeria Queries6107 / 6337
• Visible Buildings Queries1288 / 1411
• Range Interval Queries1010 / 1345
• Subarray Sum Queries7294 / 7920
• Subarray Sum Queries II1362 / 1429
• Distinct Values Queries6713 / 8322
• Distinct Values Queries II805 / 929
• Increasing Array Queries2578 / 2962
• Movie Festival Queries1284 / 1427
• Forest Queries II4365 / 4702
• Range Updates and Sums5817 / 6929
• Polynomial Queries4267 / 5013
• Range Queries and Copies3065 / 3285
• Missing Coin Sum Queries642 / 843

Tree Algorithms

• Subordinates30439 / 32561
• Tree Matching17253 / 20114
• Tree Diameter24805 / 26305
• Tree Distances I18929 / 20356
• Tree Distances II15491 / 16152
• Company Queries I17214 / 18119
• Company Queries II16147 / 16936
• Distance Queries14678 / 15757
• Counting Paths9197 / 9756
• Subtree Queries11025 / 11769
• Path Queries8839 / 9366
• Path Queries II3552 / 5376
• Distinct Colors8496 / 9394
• Finding a Centroid6866 / 7154
• Fixed-Length Paths I3268 / 4241
• Fixed-Length Paths II1529 / 2823

Mathematics

• Josephus Queries4670 / 5886
• Exponentiation23895 / 25532
• Exponentiation II16947 / 20335
• Counting Divisors21733 / 24558
• Common Divisors14260 / 16592
• Sum of Divisors7945 / 11960
• Divisor Analysis5416 / 7287
• Prime Multiples6258 / 7316
• Counting Coprime Pairs4072 / 4767
• Next Prime1545 / 1764
• Binomial Coefficients10036 / 11156
• Creating Strings II8484 / 8957
• Distributing Apples8152 / 8771
• Christmas Party6568 / 7060
• Permutation Order728 / 740
• Permutation Rounds880 / 984
• Bracket Sequences I4510 / 4911
• Bracket Sequences II2336 / 2685
• Counting Necklaces2167 / 2347
• Counting Grids1780 / 1903
• Fibonacci Numbers6949 / 8721
• Throwing Dice3593 / 3909
• Graph Paths I3421 / 3674
• Graph Paths II2860 / 2998
• System of Linear Equations344 / 383
• Sum of Four Squares543 / 626
• Triangle Number Sums457 / 572
• Dice Probability3088 / 3334
• Moving Robots1588 / 1680
• Candy Lottery1395 / 2973
• Inversion Probability335 / 2257
• Stick Game3470 / 3554
• Nim Game I4589 / 4761
• Nim Game II3631 / 3781
• Stair Game2453 / 2670
• Grundy's Game1702 / 2241
• Another Game1930 / 2083

String Algorithms

• Word Combinations5875 / 8535
• String Matching11419 / 15293
• Finding Borders8337 / 9122
• Finding Periods5940 / 6755
• Minimal Rotation2880 / 4394
• Longest Palindrome4362 / 5765
• All Palindromes526 / 600
• Required Substring1653 / 2535
• Palindrome Queries2048 / 2385
• Finding Patterns1906 / 2720
• Counting Patterns1803 / 2243
• Pattern Positions1506 / 1846
• Distinct Substrings1723 / 2061
• Distinct Subsequences1076 / 1147
• Repeating Substring1859 / 2168
• String Functions1621 / 1697
• Inverse Suffix Array170 / 210
• String Transform524 / 639
• Substring Order I1163 / 1304
• Substring Order II773 / 1003
• Substring Distribution1082 / 1177

Geometry

• Point Location Test7276 / 8127
• Line Segment Intersection4338 / 5450
• Polygon Area5005 / 5303
• Point in Polygon2743 / 3523
• Polygon Lattice Points2330 / 2412
• Minimum Euclidean Distance2023 / 2802
• Convex Hull3333 / 4010
• Maximum Manhattan Distances487 / 502
• All Manhattan Distances494 / 540
• Intersection Points1954 / 2104
• Line Segments Trace I271 / 280
• Line Segments Trace II223 / 235
• Lines and Queries I303 / 312
• Lines and Queries II262 / 270
• Area of Rectangles1115 / 1246
• Robot Path291 / 538

Advanced Techniques

• Meet in the Middle6645 / 9273
• Hamming Distance3221 / 3510
• Corner Subgrid Check262 / 418
• Corner Subgrid Count2234 / 2508
• Reachable Nodes2245 / 2415
• Reachability Queries1489 / 1765
• Cut and Paste1502 / 1673
• Substring Reversals1309 / 1427
• Reversals and Sums1319 / 1421
• Necessary Roads1920 / 1965
• Necessary Cities1780 / 1866
• Eulerian Subgraphs785 / 826
• Monster Game I1138 / 1265
• Monster Game II1016 / 1090
• Subarray Squares1374 / 1627
• Houses and Schools760 / 910
• Knuth Division920 / 1039
• Apples and Bananas1046 / 1137
• One Bit Positions835 / 914
• Signal Processing791 / 849
• New Roads Queries2159 / 2627
• Dynamic Connectivity986 / 1113
• Parcel Delivery754 / 836
• Task Assignment890 / 947
• Distinct Routes II572 / 655

Sliding Window Problems

• Sliding Window Sum3962 / 4139
• Sliding Window Minimum2993 / 3429
• Sliding Window Xor2931 / 2969
• Sliding Window Or1263 / 2276
• Sliding Window Distinct Values1852 / 2496
• Sliding Window Mode1698 / 1793
• Sliding Window Mex1519 / 1604
• Sliding Window Median13459 / 15397
• Sliding Window Cost8861 / 10237
• Sliding Window Inversions857 / 918
• Sliding Window Advertisement167 / 272

Interactive Problems

• Hidden Integer1692 / 1751
• Hidden Permutation721 / 860
• K-th Highest Score318 / 384
• Permuted Binary Strings404 / 415
• Colored Chairs358 / 378
• Inversion Sorting213 / 231

Bitwise Operations

• Counting Bits4623 / 5944
• Maximum Xor Subarray2795 / 3154
• Maximum Xor Subset782 / 843
• Number of Subset Xors676 / 690
• K Subset Xors320 / 388
• All Subarray Xors212 / 340
• Xor Pyramid Peak1895 / 2320
• Xor Pyramid Diagonal243 / 275
• Xor Pyramid Row199 / 234
• SOS Bit Problem2000 / 2133
• And Subset Count315 / 320

Construction Problems

• Inverse Inversions1451 / 1545
• Monotone Subsequences894 / 1050
• Third Permutation309 / 361
• Permutation Prime Sums303 / 328
• Chess Tournament1136 / 1313
• Distinct Sums Grid86 / 144
• Filling Trominos232 / 403
• Grid Path Construction118 / 421

Advanced Graph Problems

• Nearest Shops552 / 717
• Prüfer Code1464 / 1580
• Tree Traversals1151 / 1266
• Course Schedule II1816 / 2613
• Acyclic Graph Edges2157 / 2290
• Strongly Connected Edges1499 / 1664
• Even Outdegree Edges1275 / 1499
• Graph Girth3268 / 3733
• Fixed Length Walk Queries274 / 303
• Transfer Speeds Sum324 / 334
• MST Edge Check469 / 504
• MST Edge Set Check178 / 202
• MST Edge Cost292 / 305
• Network Breakdown980 / 1039
• Tree Coin Collecting I248 / 276
• Tree Coin Collecting II128 / 151
• Tree Isomorphism I1038 / 1246
• Tree Isomorphism II843 / 985
• Flight Route Requests464 / 568
• Critical Cities394 / 611
• Visiting Cities654 / 869
• Graph Coloring176 / 207
• Bus Companies202 / 208
• Split into Two Paths68 / 129
• Network Renovation907 / 1211
• Forbidden Cities797 / 1044
• Creating Offices397 / 519
• New Flight Routes299 / 812

Counting Problems

• Filled Subgrid Count I432 / 478
• Filled Subgrid Count II223 / 276
• All Letter Subgrid Count I118 / 185
• All Letter Subgrid Count II98 / 121
• Border Subgrid Count I72 / 124
• Border Subgrid Count II76 / 89
• Raab Game II76 / 91
• Empty String1552 / 1898
• Permutation Inversions983 / 1086
• Counting Bishops367 / 410
• Counting Sequences633 / 678
• Grid Paths II723 / 902
• Counting Permutations848 / 960
• Grid Completion214 / 270
• Counting Reorders225 / 330
• Tournament Graph Distribution83 / 87
• Collecting Numbers Distribution89 / 97
• Functional Graph Distribution230 / 284

Additional Problems I

• Shortest Subsequence2912 / 3852
• Distinct Values Sum513 / 529
• Distinct Values Splits360 / 380
• Swap Game1987 / 2520
• Beautiful Permutation II327 / 488
• Multiplication Table6396 / 7142
• Bubble Sort Rounds I291 / 335
• Bubble Sort Rounds II166 / 193
• Nearest Campsites I130 / 150
• Nearest Campsites II130 / 139
• Advertisement4150 / 4398
• Special Substrings938 / 1030
• Counting LCM Arrays205 / 223
• Square Subsets167 / 187
• Subarray Sum Constraints233 / 250
• Water Containers Moves122 / 129
• Water Containers Queries153 / 159
• Stack Weights562 / 667
• Maximum Average Subarrays122 / 134
• Subsets with Fixed Average160 / 175
• Two Array Average152 / 171
• Pyramid Array686 / 837
• Permutation Subsequence172 / 175
• Bit Inversions2231 / 2539
• Writing Numbers713 / 770
• Letter Pair Move Game191 / 269
• Maximum Building I1990 / 2076
• Sorting Methods740 / 793
• Cyclic Array1126 / 1283
• List of Sums457 / 600

Additional Problems II

• Bouncing Ball Steps169 / 185
• Bouncing Ball Cycle66 / 94
• Knight Moves Queries93 / 114
• K Subset Sums I130 / 177
• K Subset Sums II66 / 90
• Increasing Array II757 / 873
• Food Division503 / 597
• Swap Round Sorting399 / 491
• Binary Subsequences276 / 407
• School Excursion1319 / 1401
• Coin Grid828 / 968
• Grid Coloring II102 / 131
• Programmers and Artists467 / 654
• Removing Digits II208 / 455
• Coin Arrangement312 / 419
• Replace with Difference94 / 115
• Grid Puzzle I506 / 555
• Grid Puzzle II480 / 528
• Bit Substrings369 / 448
• Reversal Sorting335 / 408
• Book Shop II1143 / 1311
• GCD Subsets324 / 332
• Minimum Cost Pairs84 / 114
• Same Sum Subsets84 / 161
• Mex Grid Queries813 / 954
• Maximum Building II430 / 529
• Stick Divisions3652 / 4287
• Stick Difference31 / 170
• Coding Company1408 / 1856
• Two Stacks Sorting163 / 518