CSES Problem Set

General

• Introduction
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• Statistics

Introductory Problems

• Weird Algorithm151165 / 158270
• Missing Number130300 / 136620
• Repetitions113466 / 118077
• Increasing Array106615 / 110461
• Permutations93748 / 96639
• Number Spiral66275 / 72241
• Two Knights50606 / 52208
• Two Sets55047 / 59271
• Bit Strings62940 / 66466
• Trailing Zeros58771 / 62542
• Coin Piles52017 / 56940
• Palindrome Reorder48392 / 51095
• Gray Code32256 / 36282
• Tower of Hanoi29830 / 31036
• Creating Strings40798 / 41872
• Apple Division40940 / 46286
• Chessboard and Queens24651 / 25100
• Raab Game I3951 / 4488
• Mex Grid Construction3808 / 4066
• Knight Moves Grid3796 / 3885
• Grid Coloring I3174 / 3285
• Digit Queries17330 / 20205
• String Reorder2996 / 3489
• Grid Path Description9627 / 12534

Sorting and Searching

• Distinct Numbers73963 / 80037
• Apartments54682 / 60854
• Ferris Wheel52491 / 56709
• Concert Tickets42318 / 49305
• Restaurant Customers42969 / 46418
• Movie Festival41295 / 43752
• Sum of Two Values48232 / 54070
• Maximum Subarray Sum46638 / 48731
• Stick Lengths41551 / 43487
• Missing Coin Sum31251 / 32412
• Collecting Numbers32026 / 34328
• Collecting Numbers II13315 / 17049
• Playlist32078 / 36723
• Towers32487 / 34810
• Traffic Lights25150 / 28177
• Distinct Values Subarrays5832 / 6137
• Distinct Values Subsequences3993 / 4445
• Josephus Problem I19172 / 21157
• Josephus Problem II10346 / 14293
• Nested Ranges Check10972 / 12639
• Nested Ranges Count7424 / 8777
• Room Allocation18887 / 21706
• Factory Machines26898 / 29344
• Tasks and Deadlines21663 / 22135
• Reading Books17576 / 18832
• Sum of Three Values25825 / 28631
• Sum of Four Values16002 / 17857
• Nearest Smaller Values21399 / 22138
• Subarray Sums I28373 / 30279
• Subarray Sums II25737 / 30604
• Subarray Divisibility23486 / 25623
• Distinct Values Subarrays II14098 / 15552
• Array Division22301 / 23488
• Movie Festival II11896 / 14374
• Maximum Subarray Sum II10973 / 13124

Dynamic Programming

• Dice Combinations77292 / 81808
• Minimizing Coins66724 / 71731
• Coin Combinations I60918 / 66005
• Coin Combinations II51465 / 58328
• Removing Digits57299 / 58474
• Grid Paths I53935 / 55494
• Book Shop48123 / 52975
• Array Description35424 / 39394
• Counting Towers21488 / 22793
• Edit Distance35580 / 37566
• Longest Common Subsequence7916 / 8216
• Rectangle Cutting29500 / 32253
• Minimal Grid Path3385 / 6355
• Money Sums34984 / 36328
• Removal Game20672 / 27989
• Two Sets II27574 / 29707
• Mountain Range2391 / 4489
• Increasing Subsequence28172 / 31639
• Projects19396 / 21719
• Elevator Rides12370 / 15608
• Counting Tilings7232 / 7896
• Counting Numbers9917 / 11212
• Increasing Subsequence II3951 / 4595

Graph Algorithms

• Counting Rooms53047 / 55746
• Labyrinth36671 / 44016
• Building Roads46179 / 47848
• Message Route39751 / 41341
• Building Teams37532 / 39597
• Round Trip29828 / 32522
• Monsters20321 / 24047
• Shortest Routes I32608 / 36027
• Shortest Routes II26575 / 29813
• High Score16096 / 22890
• Flight Discount20819 / 24430
• Cycle Finding14829 / 18243
• Flight Routes14466 / 16164
• Round Trip II16474 / 18526
• Course Schedule21613 / 22857
• Longest Flight Route15175 / 18914
• Game Routes17030 / 18264
• Investigation12621 / 13591
• Planets Queries I11014 / 12913
• Planets Queries II3947 / 5011
• Planets Cycles6729 / 7521
• Road Reparation16555 / 17267
• Road Construction18153 / 18732
• Flight Routes Check14733 / 15980
• Planets and Kingdoms11834 / 12258
• Giant Pizza4884 / 5382
• Coin Collector7666 / 8516
• Mail Delivery6405 / 7017
• De Bruijn Sequence3345 / 3504
• Teleporters Path4845 / 5557
• Hamiltonian Flights7263 / 8296
• Knight's Tour2721 / 3307
• Download Speed4816 / 6498
• Police Chase3838 / 4317
• School Dance4241 / 4486
• Distinct Routes2980 / 3920

Range Queries

• Static Range Sum Queries36775 / 38422
• Static Range Minimum Queries25798 / 27635
• Dynamic Range Sum Queries26768 / 27952
• Dynamic Range Minimum Queries24262 / 24841
• Range Xor Queries25108 / 25447
• Range Update Queries19892 / 21330
• Forest Queries20368 / 21140
• Hotel Queries14384 / 15283
• List Removals11961 / 12590
• Salary Queries8882 / 11261
• Prefix Sum Queries7639 / 8284
• Pizzeria Queries6135 / 6367
• Visible Buildings Queries1302 / 1427
• Range Interval Queries1027 / 1367
• Subarray Sum Queries7331 / 7958
• Subarray Sum Queries II1390 / 1456
• Distinct Values Queries6758 / 8378
• Distinct Values Queries II818 / 945
• Increasing Array Queries2595 / 2983
• Movie Festival Queries1294 / 1440
• Forest Queries II4374 / 4714
• Range Updates and Sums5849 / 6965
• Polynomial Queries4284 / 5033
• Range Queries and Copies3080 / 3301
• Missing Coin Sum Queries646 / 849

Tree Algorithms

• Subordinates30559 / 32684
• Tree Matching17336 / 20203
• Tree Diameter24890 / 26397
• Tree Distances I19007 / 20435
• Tree Distances II15556 / 16222
• Company Queries I17305 / 18221
• Company Queries II16215 / 17006
• Distance Queries14747 / 15828
• Counting Paths9236 / 9795
• Subtree Queries11060 / 11808
• Path Queries8873 / 9403
• Path Queries II3571 / 5402
• Distinct Colors8536 / 9434
• Finding a Centroid6893 / 7183
• Fixed-Length Paths I3289 / 4268
• Fixed-Length Paths II1538 / 2840

Mathematics

• Josephus Queries4705 / 5927
• Exponentiation23985 / 25625
• Exponentiation II17017 / 20417
• Counting Divisors21825 / 24658
• Common Divisors14316 / 16652
• Sum of Divisors7994 / 12017
• Divisor Analysis5438 / 7320
• Prime Multiples6295 / 7359
• Counting Coprime Pairs4090 / 4791
• Next Prime1586 / 1819
• Binomial Coefficients10080 / 11204
• Creating Strings II8529 / 9003
• Distributing Apples8192 / 8815
• Christmas Party6594 / 7089
• Permutation Order746 / 761
• Permutation Rounds906 / 1014
• Bracket Sequences I4534 / 4939
• Bracket Sequences II2354 / 2703
• Counting Necklaces2177 / 2358
• Counting Grids1791 / 1915
• Fibonacci Numbers6980 / 8760
• Throwing Dice3611 / 3928
• Graph Paths I3433 / 3690
• Graph Paths II2872 / 3013
• System of Linear Equations351 / 390
• Sum of Four Squares554 / 639
• Triangle Number Sums465 / 582
• Dice Probability3105 / 3355
• Moving Robots1594 / 1688
• Candy Lottery1410 / 2990
• Inversion Probability341 / 2265
• Stick Game3485 / 3570
• Nim Game I4609 / 4783
• Nim Game II3649 / 3801
• Stair Game2463 / 2681
• Grundy's Game1710 / 2250
• Another Game1937 / 2091

String Algorithms

• Word Combinations5899 / 8570
• String Matching11462 / 15340
• Finding Borders8360 / 9152
• Finding Periods5952 / 6769
• Minimal Rotation2890 / 4407
• Longest Palindrome4372 / 5776
• All Palindromes529 / 604
• Required Substring1659 / 2543
• Palindrome Queries2053 / 2392
• Finding Patterns1916 / 2730
• Counting Patterns1814 / 2255
• Pattern Positions1514 / 1856
• Distinct Substrings1734 / 2072
• Distinct Subsequences1082 / 1154
• Repeating Substring1865 / 2175
• String Functions1626 / 1703
• Inverse Suffix Array173 / 213
• String Transform527 / 643
• Substring Order I1169 / 1311
• Substring Order II777 / 1007
• Substring Distribution1088 / 1184

Geometry

• Point Location Test7323 / 8177
• Line Segment Intersection4354 / 5470
• Polygon Area5031 / 5329
• Point in Polygon2760 / 3537
• Polygon Lattice Points2339 / 2422
• Minimum Euclidean Distance2037 / 2817
• Convex Hull3353 / 4034
• Maximum Manhattan Distances497 / 513
• All Manhattan Distances505 / 552
• Intersection Points1961 / 2113
• Line Segments Trace I276 / 286
• Line Segments Trace II226 / 239
• Lines and Queries I311 / 321
• Lines and Queries II264 / 273
• Area of Rectangles1120 / 1252
• Robot Path292 / 541

Advanced Techniques

• Meet in the Middle6662 / 9294
• Hamming Distance3226 / 3518
• Corner Subgrid Check270 / 428
• Corner Subgrid Count2243 / 2519
• Reachable Nodes2264 / 2435
• Reachability Queries1499 / 1776
• Cut and Paste1512 / 1684
• Substring Reversals1316 / 1435
• Reversals and Sums1325 / 1428
• Necessary Roads1923 / 1975
• Necessary Cities1786 / 1873
• Eulerian Subgraphs788 / 831
• Monster Game I1141 / 1270
• Monster Game II1019 / 1094
• Subarray Squares1382 / 1636
• Houses and Schools761 / 912
• Knuth Division934 / 1055
• Apples and Bananas1057 / 1150
• One Bit Positions841 / 921
• Signal Processing797 / 857
• New Roads Queries2173 / 2643
• Dynamic Connectivity990 / 1117
• Parcel Delivery758 / 842
• Task Assignment896 / 955
• Distinct Routes II574 / 658

Sliding Window Problems

• Sliding Window Sum4066 / 4244
• Sliding Window Minimum3046 / 3492
• Sliding Window Xor2994 / 3033
• Sliding Window Or1313 / 2347
• Sliding Window Distinct Values1925 / 2570
• Sliding Window Mode1760 / 1856
• Sliding Window Mex1569 / 1658
• Sliding Window Median13525 / 15465
• Sliding Window Cost8885 / 10267
• Sliding Window Inversions886 / 949
• Sliding Window Advertisement173 / 278

Interactive Problems

• Hidden Integer1721 / 1780
• Hidden Permutation734 / 874
• K-th Highest Score327 / 393
• Permuted Binary Strings412 / 423
• Colored Chairs364 / 384
• Inversion Sorting215 / 235

Bitwise Operations

• Counting Bits4666 / 6000
• Maximum Xor Subarray2818 / 3184
• Maximum Xor Subset795 / 860
• Number of Subset Xors689 / 705
• K Subset Xors328 / 397
• All Subarray Xors216 / 347
• Xor Pyramid Peak1908 / 2337
• Xor Pyramid Diagonal247 / 280
• Xor Pyramid Row200 / 238
• SOS Bit Problem2014 / 2149
• And Subset Count319 / 325

Construction Problems

• Inverse Inversions1460 / 1557
• Monotone Subsequences899 / 1056
• Third Permutation312 / 366
• Permutation Prime Sums307 / 333
• Chess Tournament1139 / 1317
• Distinct Sums Grid88 / 147
• Filling Trominos232 / 405
• Grid Path Construction118 / 423

Advanced Graph Problems

• Nearest Shops560 / 728
• Prüfer Code1469 / 1586
• Tree Traversals1159 / 1276
• Course Schedule II1830 / 2635
• Acyclic Graph Edges2166 / 2300
• Strongly Connected Edges1505 / 1673
• Even Outdegree Edges1283 / 1508
• Graph Girth3280 / 3747
• Fixed Length Walk Queries285 / 315
• Transfer Speeds Sum335 / 346
• MST Edge Check480 / 516
• MST Edge Set Check180 / 204
• MST Edge Cost299 / 313
• Network Breakdown982 / 1042
• Tree Coin Collecting I252 / 281
• Tree Coin Collecting II130 / 154
• Tree Isomorphism I1043 / 1255
• Tree Isomorphism II848 / 991
• Flight Route Requests464 / 570
• Critical Cities395 / 612
• Visiting Cities655 / 871
• Graph Coloring180 / 213
• Bus Companies204 / 212
• Split into Two Paths68 / 132
• Network Renovation910 / 1215
• Forbidden Cities797 / 1045
• Creating Offices397 / 523
• New Flight Routes302 / 816

Counting Problems

• Filled Subgrid Count I449 / 497
• Filled Subgrid Count II228 / 285
• All Letter Subgrid Count I123 / 193
• All Letter Subgrid Count II100 / 125
• Border Subgrid Count I72 / 125
• Border Subgrid Count II76 / 90
• Raab Game II76 / 92
• Empty String1559 / 1907
• Permutation Inversions988 / 1092
• Counting Bishops370 / 414
• Counting Sequences636 / 682
• Grid Paths II725 / 905
• Counting Permutations850 / 963
• Grid Completion215 / 272
• Counting Reorders225 / 331
• Tournament Graph Distribution84 / 89
• Collecting Numbers Distribution90 / 99
• Functional Graph Distribution230 / 285

Additional Problems I

• Shortest Subsequence2920 / 3863
• Distinct Values Sum521 / 538
• Distinct Values Splits370 / 391
• Swap Game1994 / 2529
• Beautiful Permutation II343 / 514
• Multiplication Table6425 / 7175
• Bubble Sort Rounds I303 / 347
• Bubble Sort Rounds II175 / 203
• Nearest Campsites I135 / 157
• Nearest Campsites II135 / 146
• Advertisement4168 / 4420
• Special Substrings946 / 1041
• Counting LCM Arrays206 / 225
• Square Subsets168 / 188
• Subarray Sum Constraints242 / 260
• Water Containers Moves126 / 133
• Water Containers Queries158 / 164
• Stack Weights564 / 671
• Maximum Average Subarrays127 / 141
• Subsets with Fixed Average163 / 180
• Two Array Average155 / 175
• Pyramid Array695 / 848
• Permutation Subsequence174 / 178
• Bit Inversions2236 / 2545
• Writing Numbers716 / 774
• Letter Pair Move Game191 / 270
• Maximum Building I1993 / 2081
• Sorting Methods743 / 797
• Cyclic Array1128 / 1286
• List of Sums459 / 604

Additional Problems II

• Bouncing Ball Steps173 / 190
• Bouncing Ball Cycle67 / 98
• Knight Moves Queries96 / 118
• K Subset Sums I133 / 182
• K Subset Sums II65 / 91
• Increasing Array II757 / 875
• Food Division494 / 598
• Swap Round Sorting399 / 492
• Binary Subsequences277 / 409
• School Excursion1323 / 1406
• Coin Grid831 / 972
• Grid Coloring II102 / 132
• Programmers and Artists473 / 663
• Removing Digits II208 / 456
• Coin Arrangement313 / 421
• Replace with Difference97 / 120
• Grid Puzzle I506 / 556
• Grid Puzzle II482 / 532
• Bit Substrings372 / 452
• Reversal Sorting336 / 410
• Book Shop II1147 / 1318
• GCD Subsets329 / 338
• Minimum Cost Pairs86 / 118
• Same Sum Subsets85 / 166
• Mex Grid Queries814 / 957
• Maximum Building II432 / 532
• Stick Divisions3658 / 4296
• Stick Difference31 / 173
• Coding Company1421 / 1873
• Two Stacks Sorting165 / 524