CSES Problem Set

General

• Introduction
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• Statistics

Introductory Problems

• Weird Algorithm147586 / 154569
• Missing Number127329 / 133537
• Repetitions110871 / 115429
• Increasing Array104200 / 107995
• Permutations91565 / 94419
• Number Spiral64756 / 70598
• Two Knights49339 / 50918
• Two Sets53690 / 57836
• Bit Strings61530 / 64973
• Trailing Zeros57463 / 61138
• Coin Piles50847 / 55676
• Palindrome Reorder47296 / 49957
• Gray Code31417 / 35362
• Tower of Hanoi28978 / 30149
• Creating Strings39820 / 40866
• Apple Division39787 / 45025
• Chessboard and Queens24025 / 24460
• Raab Game I3442 / 3937
• Mex Grid Construction3316 / 3542
• Knight Moves Grid3325 / 3404
• Grid Coloring I2746 / 2845
• Digit Queries16953 / 19800
• String Reorder2677 / 3117
• Grid Path Description9455 / 12304

Sorting and Searching

• Distinct Numbers71950 / 77904
• Apartments53303 / 59343
• Ferris Wheel51165 / 55324
• Concert Tickets41254 / 48106
• Restaurant Customers41934 / 45306
• Movie Festival40232 / 42639
• Sum of Two Values46988 / 52696
• Maximum Subarray Sum45508 / 47561
• Stick Lengths40626 / 42543
• Missing Coin Sum30483 / 31617
• Collecting Numbers31252 / 33513
• Collecting Numbers II12937 / 16614
• Playlist31324 / 35911
• Towers31769 / 34046
• Traffic Lights24585 / 27561
• Distinct Values Subarrays5123 / 5393
• Distinct Values Subsequences3552 / 3968
• Josephus Problem I18643 / 20613
• Josephus Problem II10023 / 13886
• Nested Ranges Check10682 / 12320
• Nested Ranges Count7235 / 8554
• Room Allocation18462 / 21242
• Factory Machines26167 / 28584
• Tasks and Deadlines21171 / 21637
• Reading Books17129 / 18355
• Sum of Three Values25081 / 27828
• Sum of Four Values15624 / 17466
• Nearest Smaller Values20898 / 21619
• Subarray Sums I27648 / 29545
• Subarray Sums II25023 / 29825
• Subarray Divisibility22973 / 25084
• Distinct Values Subarrays II13634 / 15077
• Array Division21698 / 22849
• Movie Festival II11562 / 13986
• Maximum Subarray Sum II10687 / 12803

Dynamic Programming

• Dice Combinations75293 / 79707
• Minimizing Coins65058 / 69949
• Coin Combinations I59369 / 64334
• Coin Combinations II50147 / 56887
• Removing Digits55955 / 57117
• Grid Paths I52543 / 54053
• Book Shop46967 / 51746
• Array Description34571 / 38471
• Counting Towers20946 / 22208
• Edit Distance34818 / 36768
• Longest Common Subsequence7029 / 7293
• Rectangle Cutting28907 / 31606
• Minimal Grid Path2996 / 5720
• Money Sums34302 / 35639
• Removal Game20127 / 27424
• Two Sets II27039 / 29151
• Mountain Range2100 / 4041
• Increasing Subsequence27590 / 30999
• Projects19046 / 21347
• Elevator Rides12069 / 15261
• Counting Tilings7036 / 7688
• Counting Numbers9598 / 10862
• Increasing Subsequence II3678 / 4279

Graph Algorithms

• Counting Rooms51746 / 54398
• Labyrinth35748 / 42962
• Building Roads45147 / 46789
• Message Route38798 / 40359
• Building Teams36651 / 38701
• Round Trip29136 / 31788
• Monsters19816 / 23486
• Shortest Routes I31762 / 35151
• Shortest Routes II25905 / 29104
• High Score15614 / 22333
• Flight Discount20291 / 23844
• Cycle Finding14424 / 17798
• Flight Routes14094 / 15763
• Round Trip II16083 / 18117
• Course Schedule21087 / 22328
• Longest Flight Route14781 / 18489
• Game Routes16634 / 17856
• Investigation12317 / 13266
• Planets Queries I10703 / 12572
• Planets Queries II3821 / 4857
• Planets Cycles6561 / 7337
• Road Reparation16106 / 16798
• Road Construction17678 / 18247
• Flight Routes Check14394 / 15630
• Planets and Kingdoms11569 / 11984
• Giant Pizza4732 / 5221
• Coin Collector7455 / 8301
• Mail Delivery6237 / 6839
• De Bruijn Sequence3248 / 3402
• Teleporters Path4713 / 5423
• Hamiltonian Flights7061 / 8076
• Knight's Tour2625 / 3207
• Download Speed4650 / 6313
• Police Chase3717 / 4188
• School Dance4122 / 4365
• Distinct Routes2883 / 3803

Range Queries

• Static Range Sum Queries35783 / 37394
• Static Range Minimum Queries25152 / 26952
• Dynamic Range Sum Queries26153 / 27311
• Dynamic Range Minimum Queries23698 / 24264
• Range Xor Queries24500 / 24840
• Range Update Queries19353 / 20777
• Forest Queries19817 / 20574
• Hotel Queries13993 / 14884
• List Removals11651 / 12271
• Salary Queries8605 / 10928
• Prefix Sum Queries7366 / 8001
• Pizzeria Queries5954 / 6186
• Visible Buildings Queries1139 / 1258
• Range Interval Queries893 / 1185
• Subarray Sum Queries7144 / 7767
• Subarray Sum Queries II1202 / 1271
• Distinct Values Queries6538 / 8135
• Distinct Values Queries II696 / 817
• Increasing Array Queries2519 / 2891
• Movie Festival Queries1214 / 1349
• Forest Queries II4287 / 4617
• Range Updates and Sums5688 / 6783
• Polynomial Queries4189 / 4918
• Range Queries and Copies2987 / 3207
• Missing Coin Sum Queries598 / 793

Tree Algorithms

• Subordinates29832 / 31935
• Tree Matching16930 / 19772
• Tree Diameter24281 / 25760
• Tree Distances I18545 / 19957
• Tree Distances II15212 / 15864
• Company Queries I16861 / 17755
• Company Queries II15791 / 16579
• Distance Queries14393 / 15466
• Counting Paths9010 / 9566
• Subtree Queries10815 / 11548
• Path Queries8627 / 9148
• Path Queries II3482 / 5227
• Distinct Colors8340 / 9230
• Finding a Centroid6710 / 6993
• Fixed-Length Paths I3160 / 4124
• Fixed-Length Paths II1473 / 2729

Mathematics

• Josephus Queries4553 / 5746
• Exponentiation23444 / 25034
• Exponentiation II16610 / 19953
• Counting Divisors21291 / 24069
• Common Divisors13975 / 16269
• Sum of Divisors7801 / 11758
• Divisor Analysis5308 / 7151
• Prime Multiples6039 / 7087
• Counting Coprime Pairs3951 / 4638
• Next Prime1371 / 1573
• Binomial Coefficients9837 / 10939
• Creating Strings II8300 / 8770
• Distributing Apples7974 / 8589
• Christmas Party6425 / 6913
• Permutation Order636 / 648
• Permutation Rounds742 / 838
• Bracket Sequences I4414 / 4814
• Bracket Sequences II2280 / 2622
• Counting Necklaces2109 / 2288
• Counting Grids1716 / 1834
• Fibonacci Numbers6791 / 8543
• Throwing Dice3526 / 3836
• Graph Paths I3340 / 3588
• Graph Paths II2796 / 2932
• System of Linear Equations315 / 339
• Sum of Four Squares483 / 560
• Triangle Number Sums411 / 517
• Dice Probability3029 / 3273
• Moving Robots1557 / 1649
• Candy Lottery1319 / 2888
• Inversion Probability307 / 2209
• Stick Game3403 / 3485
• Nim Game I4490 / 4661
• Nim Game II3548 / 3697
• Stair Game2406 / 2620
• Grundy's Game1653 / 2188
• Another Game1868 / 2016

String Algorithms

• Word Combinations5722 / 8342
• String Matching11139 / 14955
• Finding Borders8147 / 8917
• Finding Periods5801 / 6596
• Minimal Rotation2817 / 4320
• Longest Palindrome4283 / 5663
• All Palindromes473 / 538
• Required Substring1608 / 2478
• Palindrome Queries2004 / 2339
• Finding Patterns1845 / 2648
• Counting Patterns1742 / 2173
• Pattern Positions1454 / 1785
• Distinct Substrings1664 / 1993
• Distinct Subsequences1041 / 1111
• Repeating Substring1806 / 2113
• String Functions1579 / 1654
• Inverse Suffix Array155 / 183
• String Transform502 / 614
• Substring Order I1130 / 1269
• Substring Order II747 / 970
• Substring Distribution1049 / 1141

Geometry

• Point Location Test7081 / 7923
• Line Segment Intersection4214 / 5316
• Polygon Area4898 / 5195
• Point in Polygon2691 / 3408
• Polygon Lattice Points2275 / 2356
• Minimum Euclidean Distance1971 / 2738
• Convex Hull3232 / 3902
• Maximum Manhattan Distances440 / 452
• All Manhattan Distances446 / 488
• Intersection Points1904 / 2050
• Line Segments Trace I238 / 246
• Line Segments Trace II193 / 204
• Lines and Queries I262 / 270
• Lines and Queries II224 / 232
• Area of Rectangles1081 / 1210
• Robot Path302 / 519

Advanced Techniques

• Meet in the Middle6494 / 9100
• Hamming Distance3173 / 3457
• Corner Subgrid Check234 / 379
• Corner Subgrid Count2196 / 2466
• Reachable Nodes2198 / 2366
• Reachability Queries1461 / 1731
• Cut and Paste1457 / 1623
• Substring Reversals1278 / 1395
• Reversals and Sums1285 / 1387
• Necessary Roads1879 / 1923
• Necessary Cities1745 / 1832
• Eulerian Subgraphs766 / 807
• Monster Game I1111 / 1240
• Monster Game II989 / 1063
• Subarray Squares1322 / 1575
• Houses and Schools738 / 888
• Knuth Division894 / 1014
• Apples and Bananas1003 / 1091
• One Bit Positions807 / 885
• Signal Processing757 / 814
• New Roads Queries2106 / 2567
• Dynamic Connectivity943 / 1068
• Parcel Delivery730 / 810
• Task Assignment853 / 908
• Distinct Routes II551 / 634

Sliding Window Problems

• Sliding Window Sum3518 / 3673
• Sliding Window Minimum2723 / 3112
• Sliding Window Xor2626 / 2658
• Sliding Window Or1121 / 2050
• Sliding Window Distinct Values2196 / 2237
• Sliding Window Mode1529 / 1611
• Sliding Window Mex1365 / 1440
• Sliding Window Median13200 / 15115
• Sliding Window Cost8759 / 10116
• Sliding Window Inversions763 / 819
• Sliding Window Advertisement149 / 241

Interactive Problems

• Hidden Integer1501 / 1553
• Hidden Permutation640 / 773
• K-th Highest Score272 / 330
• Permuted Binary Strings361 / 370
• Colored Chairs311 / 328
• Inversion Sorting183 / 196

Bitwise Operations

• Counting Bits4444 / 5724
• Maximum Xor Subarray2713 / 3056
• Maximum Xor Subset691 / 746
• Number of Subset Xors599 / 610
• K Subset Xors285 / 341
• All Subarray Xors193 / 304
• Xor Pyramid Peak1838 / 2254
• Xor Pyramid Diagonal222 / 252
• Xor Pyramid Row182 / 214
• SOS Bit Problem1907 / 2034
• And Subset Count274 / 278

Construction Problems

• Inverse Inversions1376 / 1465
• Monotone Subsequences831 / 975
• Third Permutation276 / 321
• Permutation Prime Sums271 / 292
• Chess Tournament1104 / 1276
• Distinct Sums Grid73 / 126
• Filling Trominos226 / 392
• Grid Path Construction115 / 417

Advanced Graph Problems

• Nearest Shops511 / 667
• Prüfer Code1424 / 1539
• Tree Traversals1121 / 1236
• Course Schedule II1754 / 2527
• Acyclic Graph Edges2098 / 2230
• Strongly Connected Edges1458 / 1617
• Even Outdegree Edges1245 / 1467
• Graph Girth3168 / 3632
• Fixed Length Walk Queries261 / 286
• Transfer Speeds Sum299 / 307
• MST Edge Check380 / 407
• MST Edge Set Check162 / 183
• MST Edge Cost267 / 280
• Network Breakdown952 / 1011
• Tree Coin Collecting I230 / 252
• Tree Coin Collecting II121 / 139
• Tree Isomorphism I1024 / 1232
• Tree Isomorphism II823 / 967
• Flight Route Requests455 / 555
• Critical Cities384 / 595
• Visiting Cities641 / 849
• Graph Coloring157 / 183
• Bus Companies188 / 192
• Split into Two Paths62 / 112
• Network Renovation891 / 1191
• Forbidden Cities768 / 1007
• Creating Offices384 / 503
• New Flight Routes293 / 792

Counting Problems

• Filled Subgrid Count I385 / 428
• Filled Subgrid Count II193 / 234
• All Letter Subgrid Count I100 / 162
• All Letter Subgrid Count II90 / 104
• Border Subgrid Count I67 / 114
• Border Subgrid Count II68 / 78
• Raab Game II72 / 84
• Empty String1512 / 1845
• Permutation Inversions965 / 1064
• Counting Bishops362 / 405
• Counting Sequences619 / 664
• Grid Paths II707 / 881
• Counting Permutations834 / 945
• Grid Completion210 / 265
• Counting Reorders221 / 326
• Tournament Graph Distribution79 / 82
• Collecting Numbers Distribution81 / 84
• Functional Graph Distribution225 / 279

Additional Problems I

• Shortest Subsequence2854 / 3786
• Distinct Values Sum460 / 473
• Distinct Values Splits316 / 335
• Swap Game1947 / 2475
• Beautiful Permutation II271 / 402
• Multiplication Table6228 / 6961
• Bubble Sort Rounds I248 / 285
• Bubble Sort Rounds II137 / 162
• Nearest Campsites I112 / 128
• Nearest Campsites II112 / 120
• Advertisement4047 / 4287
• Special Substrings922 / 1010
• Counting LCM Arrays178 / 191
• Square Subsets144 / 161
• Subarray Sum Constraints183 / 197
• Water Containers Moves107 / 114
• Water Containers Queries135 / 141
• Stack Weights549 / 651
• Maximum Average Subarrays108 / 119
• Subsets with Fixed Average141 / 153
• Two Array Average135 / 152
• Pyramid Array668 / 812
• Permutation Subsequence152 / 155
• Bit Inversions2190 / 2498
• Writing Numbers702 / 759
• Letter Pair Move Game187 / 266
• Maximum Building I1956 / 2041
• Sorting Methods729 / 781
• Cyclic Array1099 / 1253
• List of Sums444 / 583

Additional Problems II

• Bouncing Ball Steps159 / 174
• Bouncing Ball Cycle63 / 86
• Knight Moves Queries86 / 103
• K Subset Sums I118 / 157
• K Subset Sums II61 / 83
• Increasing Array II742 / 858
• Food Division498 / 590
• Swap Round Sorting393 / 485
• Binary Subsequences273 / 401
• School Excursion1289 / 1369
• Coin Grid805 / 945
• Grid Coloring II90 / 113
• Programmers and Artists459 / 645
• Removing Digits II204 / 452
• Coin Arrangement306 / 413
• Replace with Difference88 / 105
• Grid Puzzle I499 / 547
• Grid Puzzle II462 / 510
• Bit Substrings360 / 439
• Reversal Sorting332 / 404
• Book Shop II1107 / 1274
• GCD Subsets292 / 299
• Minimum Cost Pairs68 / 92
• Same Sum Subsets77 / 140
• Mex Grid Queries799 / 938
• Maximum Building II419 / 515
• Stick Divisions3591 / 4219
• Stick Difference26 / 150
• Coding Company1373 / 1816
• Two Stacks Sorting160 / 505