CSES Problem Set

General

• Introduction
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• Statistics

Introductory Problems

• Weird Algorithm150033 / 157103
• Missing Number129281 / 135580
• Repetitions112580 / 117173
• Increasing Array105743 / 109561
• Permutations92974 / 95848
• Number Spiral65703 / 71632
• Two Knights50161 / 51759
• Two Sets54532 / 58732
• Bit Strings62441 / 65938
• Trailing Zeros58296 / 62029
• Coin Piles51605 / 56496
• Palindrome Reorder47993 / 50686
• Gray Code31947 / 35941
• Tower of Hanoi29553 / 30746
• Creating Strings40467 / 41533
• Apple Division40592 / 45902
• Chessboard and Queens24455 / 24899
• Raab Game I3775 / 4302
• Mex Grid Construction3642 / 3889
• Knight Moves Grid3633 / 3715
• Grid Coloring I3020 / 3123
• Digit Queries17190 / 20059
• String Reorder2886 / 3363
• Grid Path Description9562 / 12452

Sorting and Searching

• Distinct Numbers73183 / 79206
• Apartments54118 / 60244
• Ferris Wheel51967 / 56159
• Concert Tickets41905 / 48844
• Restaurant Customers42559 / 45971
• Movie Festival40900 / 43342
• Sum of Two Values47790 / 53593
• Maximum Subarray Sum46203 / 48284
• Stick Lengths41169 / 43098
• Missing Coin Sum30950 / 32101
• Collecting Numbers31697 / 33987
• Collecting Numbers II13164 / 16870
• Playlist31800 / 36415
• Towers32204 / 34514
• Traffic Lights24934 / 27939
• Distinct Values Subarrays5550 / 5836
• Distinct Values Subsequences3832 / 4275
• Josephus Problem I19003 / 20989
• Josephus Problem II10251 / 14167
• Nested Ranges Check10859 / 12510
• Nested Ranges Count7357 / 8696
• Room Allocation18729 / 21535
• Factory Machines26662 / 29100
• Tasks and Deadlines21483 / 21954
• Reading Books17408 / 18657
• Sum of Three Values25584 / 28364
• Sum of Four Values15862 / 17714
• Nearest Smaller Values21198 / 21930
• Subarray Sums I28131 / 30031
• Subarray Sums II25514 / 30354
• Subarray Divisibility23293 / 25423
• Distinct Values Subarrays II13936 / 15383
• Array Division22041 / 23210
• Movie Festival II11769 / 14213
• Maximum Subarray Sum II10876 / 13013

Dynamic Programming

• Dice Combinations76563 / 81038
• Minimizing Coins66103 / 71077
• Coin Combinations I60343 / 65395
• Coin Combinations II50968 / 57798
• Removing Digits56822 / 57988
• Grid Paths I53443 / 54986
• Book Shop47716 / 52547
• Array Description35111 / 39055
• Counting Towers21297 / 22582
• Edit Distance35285 / 37250
• Longest Common Subsequence7592 / 7874
• Rectangle Cutting29288 / 32015
• Minimal Grid Path3258 / 6152
• Money Sums34728 / 36068
• Removal Game20465 / 27741
• Two Sets II27362 / 29481
• Mountain Range2293 / 4344
• Increasing Subsequence27954 / 31399
• Projects19268 / 21584
• Elevator Rides12272 / 15489
• Counting Tilings7171 / 7830
• Counting Numbers9829 / 11119
• Increasing Subsequence II3868 / 4502

Graph Algorithms

• Counting Rooms52644 / 55329
• Labyrinth36401 / 43696
• Building Roads45855 / 47515
• Message Route39444 / 41029
• Building Teams37260 / 39316
• Round Trip29611 / 32290
• Monsters20174 / 23891
• Shortest Routes I32324 / 35735
• Shortest Routes II26354 / 29578
• High Score15936 / 22715
• Flight Discount20620 / 24204
• Cycle Finding14688 / 18092
• Flight Routes14354 / 16035
• Round Trip II16357 / 18405
• Course Schedule21453 / 22694
• Longest Flight Route15050 / 18779
• Game Routes16913 / 18143
• Investigation12521 / 13479
• Planets Queries I10901 / 12797
• Planets Queries II3904 / 4960
• Planets Cycles6668 / 7452
• Road Reparation16440 / 17151
• Road Construction18006 / 18586
• Flight Routes Check14625 / 15865
• Planets and Kingdoms11768 / 12188
• Giant Pizza4833 / 5328
• Coin Collector7608 / 8457
• Mail Delivery6353 / 6961
• De Bruijn Sequence3322 / 3478
• Teleporters Path4804 / 5516
• Hamiltonian Flights7202 / 8228
• Knight's Tour2695 / 3279
• Download Speed4759 / 6440
• Police Chase3799 / 4276
• School Dance4193 / 4437
• Distinct Routes2945 / 3880

Range Queries

• Static Range Sum Queries36502 / 38140
• Static Range Minimum Queries25602 / 27422
• Dynamic Range Sum Queries26590 / 27773
• Dynamic Range Minimum Queries24085 / 24661
• Range Xor Queries24924 / 25263
• Range Update Queries19728 / 21164
• Forest Queries20218 / 20985
• Hotel Queries14252 / 15145
• List Removals11874 / 12497
• Salary Queries8797 / 11160
• Prefix Sum Queries7557 / 8199
• Pizzeria Queries6084 / 6314
• Visible Buildings Queries1272 / 1395
• Range Interval Queries999 / 1328
• Subarray Sum Queries7259 / 7885
• Subarray Sum Queries II1340 / 1407
• Distinct Values Queries6679 / 8283
• Distinct Values Queries II790 / 916
• Increasing Array Queries2568 / 2950
• Movie Festival Queries1273 / 1415
• Forest Queries II4350 / 4686
• Range Updates and Sums5790 / 6900
• Polynomial Queries4255 / 4995
• Range Queries and Copies3046 / 3264
• Missing Coin Sum Queries630 / 831

Tree Algorithms

• Subordinates30321 / 32439
• Tree Matching17200 / 20057
• Tree Diameter24703 / 26199
• Tree Distances I18874 / 20295
• Tree Distances II15457 / 16118
• Company Queries I17167 / 18071
• Company Queries II16093 / 16881
• Distance Queries14632 / 15708
• Counting Paths9167 / 9724
• Subtree Queries10996 / 11738
• Path Queries8813 / 9339
• Path Queries II3529 / 5353
• Distinct Colors8478 / 9375
• Finding a Centroid6846 / 7134
• Fixed-Length Paths I3248 / 4220
• Fixed-Length Paths II1517 / 2804

Mathematics

• Josephus Queries4653 / 5863
• Exponentiation23814 / 25453
• Exponentiation II16892 / 20271
• Counting Divisors21670 / 24483
• Common Divisors14225 / 16547
• Sum of Divisors7929 / 11931
• Divisor Analysis5394 / 7264
• Prime Multiples6223 / 7275
• Counting Coprime Pairs4048 / 4743
• Next Prime1519 / 1736
• Binomial Coefficients9997 / 11112
• Creating Strings II8445 / 8919
• Distributing Apples8106 / 8725
• Christmas Party6542 / 7032
• Permutation Order712 / 724
• Permutation Rounds852 / 957
• Bracket Sequences I4493 / 4893
• Bracket Sequences II2327 / 2675
• Counting Necklaces2158 / 2338
• Counting Grids1770 / 1893
• Fibonacci Numbers6928 / 8694
• Throwing Dice3581 / 3895
• Graph Paths I3410 / 3662
• Graph Paths II2853 / 2991
• System of Linear Equations339 / 377
• Sum of Four Squares532 / 615
• Triangle Number Sums445 / 561
• Dice Probability3078 / 3322
• Moving Robots1583 / 1675
• Candy Lottery1381 / 2957
• Inversion Probability328 / 2245
• Stick Game3460 / 3543
• Nim Game I4567 / 4739
• Nim Game II3614 / 3765
• Stair Game2442 / 2659
• Grundy's Game1689 / 2225
• Another Game1922 / 2075

String Algorithms

• Word Combinations5840 / 8486
• String Matching11368 / 15224
• Finding Borders8314 / 9098
• Finding Periods5921 / 6733
• Minimal Rotation2865 / 4380
• Longest Palindrome4349 / 5751
• All Palindromes519 / 589
• Required Substring1646 / 2526
• Palindrome Queries2037 / 2374
• Finding Patterns1894 / 2706
• Counting Patterns1790 / 2230
• Pattern Positions1496 / 1834
• Distinct Substrings1713 / 2047
• Distinct Subsequences1074 / 1144
• Repeating Substring1851 / 2158
• String Functions1613 / 1689
• Inverse Suffix Array172 / 204
• String Transform521 / 634
• Substring Order I1159 / 1299
• Substring Order II766 / 996
• Substring Distribution1076 / 1168

Geometry

• Point Location Test7247 / 8095
• Line Segment Intersection4315 / 5425
• Polygon Area4979 / 5277
• Point in Polygon2722 / 3501
• Polygon Lattice Points2319 / 2400
• Minimum Euclidean Distance2011 / 2789
• Convex Hull3301 / 3979
• Maximum Manhattan Distances473 / 488
• All Manhattan Distances482 / 528
• Intersection Points1942 / 2090
• Line Segments Trace I264 / 273
• Line Segments Trace II216 / 228
• Lines and Queries I295 / 304
• Lines and Queries II255 / 263
• Area of Rectangles1110 / 1240
• Robot Path286 / 532

Advanced Techniques

• Meet in the Middle6621 / 9247
• Hamming Distance3213 / 3500
• Corner Subgrid Check255 / 411
• Corner Subgrid Count2219 / 2494
• Reachable Nodes2231 / 2400
• Reachability Queries1482 / 1757
• Cut and Paste1491 / 1661
• Substring Reversals1303 / 1420
• Reversals and Sums1313 / 1415
• Necessary Roads1914 / 1959
• Necessary Cities1777 / 1863
• Eulerian Subgraphs780 / 821
• Monster Game I1133 / 1260
• Monster Game II1011 / 1085
• Subarray Squares1362 / 1615
• Houses and Schools755 / 905
• Knuth Division917 / 1036
• Apples and Bananas1036 / 1125
• One Bit Positions830 / 910
• Signal Processing784 / 842
• New Roads Queries2146 / 2612
• Dynamic Connectivity978 / 1104
• Parcel Delivery751 / 833
• Task Assignment884 / 941
• Distinct Routes II569 / 652

Sliding Window Problems

• Sliding Window Sum3838 / 4007
• Sliding Window Minimum2930 / 3354
• Sliding Window Xor2868 / 2904
• Sliding Window Or1216 / 2198
• Sliding Window Distinct Values1779 / 2423
• Sliding Window Mode1648 / 1737
• Sliding Window Mex1470 / 1552
• Sliding Window Median13413 / 15345
• Sliding Window Cost8846 / 10224
• Sliding Window Inversions843 / 903
• Sliding Window Advertisement164 / 266

Interactive Problems

• Hidden Integer1639 / 1698
• Hidden Permutation709 / 846
• K-th Highest Score308 / 374
• Permuted Binary Strings394 / 405
• Colored Chairs346 / 365
• Inversion Sorting209 / 226

Bitwise Operations

• Counting Bits4596 / 5907
• Maximum Xor Subarray2775 / 3132
• Maximum Xor Subset766 / 826
• Number of Subset Xors662 / 676
• K Subset Xors314 / 378
• All Subarray Xors209 / 332
• Xor Pyramid Peak1887 / 2310
• Xor Pyramid Diagonal239 / 270
• Xor Pyramid Row192 / 227
• SOS Bit Problem1987 / 2119
• And Subset Count306 / 310

Construction Problems

• Inverse Inversions1436 / 1529
• Monotone Subsequences885 / 1039
• Third Permutation304 / 353
• Permutation Prime Sums296 / 320
• Chess Tournament1132 / 1307
• Distinct Sums Grid83 / 140
• Filling Trominos232 / 402
• Grid Path Construction118 / 421

Advanced Graph Problems

• Nearest Shops544 / 708
• Prüfer Code1451 / 1567
• Tree Traversals1144 / 1258
• Course Schedule II1808 / 2597
• Acyclic Graph Edges2152 / 2286
• Strongly Connected Edges1483 / 1646
• Even Outdegree Edges1267 / 1491
• Graph Girth3249 / 3715
• Fixed Length Walk Queries271 / 299
• Transfer Speeds Sum323 / 333
• MST Edge Check464 / 499
• MST Edge Set Check174 / 198
• MST Edge Cost290 / 303
• Network Breakdown977 / 1036
• Tree Coin Collecting I244 / 272
• Tree Coin Collecting II127 / 149
• Tree Isomorphism I1036 / 1245
• Tree Isomorphism II842 / 984
• Flight Route Requests463 / 567
• Critical Cities393 / 610
• Visiting Cities652 / 867
• Graph Coloring174 / 203
• Bus Companies199 / 205
• Split into Two Paths66 / 127
• Network Renovation907 / 1210
• Forbidden Cities794 / 1040
• Creating Offices393 / 515
• New Flight Routes298 / 809

Counting Problems

• Filled Subgrid Count I423 / 466
• Filled Subgrid Count II218 / 269
• All Letter Subgrid Count I115 / 179
• All Letter Subgrid Count II96 / 117
• Border Subgrid Count I71 / 123
• Border Subgrid Count II74 / 86
• Raab Game II76 / 91
• Empty String1544 / 1888
• Permutation Inversions982 / 1084
• Counting Bishops367 / 410
• Counting Sequences631 / 676
• Grid Paths II719 / 897
• Counting Permutations847 / 958
• Grid Completion214 / 270
• Counting Reorders224 / 329
• Tournament Graph Distribution83 / 87
• Collecting Numbers Distribution87 / 95
• Functional Graph Distribution230 / 284

Additional Problems I

• Shortest Subsequence2909 / 3849
• Distinct Values Sum501 / 517
• Distinct Values Splits351 / 371
• Swap Game1977 / 2511
• Beautiful Permutation II318 / 477
• Multiplication Table6358 / 7103
• Bubble Sort Rounds I287 / 328
• Bubble Sort Rounds II160 / 188
• Nearest Campsites I127 / 147
• Nearest Campsites II126 / 135
• Advertisement4128 / 4374
• Special Substrings934 / 1026
• Counting LCM Arrays200 / 218
• Square Subsets161 / 179
• Subarray Sum Constraints219 / 236
• Water Containers Moves119 / 126
• Water Containers Queries148 / 155
• Stack Weights560 / 664
• Maximum Average Subarrays119 / 131
• Subsets with Fixed Average155 / 171
• Two Array Average149 / 166
• Pyramid Array680 / 829
• Permutation Subsequence166 / 169
• Bit Inversions2222 / 2530
• Writing Numbers710 / 767
• Letter Pair Move Game190 / 268
• Maximum Building I1982 / 2067
• Sorting Methods735 / 788
• Cyclic Array1119 / 1276
• List of Sums452 / 595

Additional Problems II

• Bouncing Ball Steps167 / 183
• Bouncing Ball Cycle66 / 94
• Knight Moves Queries90 / 111
• K Subset Sums I127 / 174
• K Subset Sums II64 / 87
• Increasing Array II753 / 869
• Food Division502 / 594
• Swap Round Sorting398 / 490
• Binary Subsequences275 / 406
• School Excursion1315 / 1396
• Coin Grid824 / 964
• Grid Coloring II101 / 129
• Programmers and Artists466 / 653
• Removing Digits II208 / 455
• Coin Arrangement309 / 417
• Replace with Difference92 / 113
• Grid Puzzle I505 / 554
• Grid Puzzle II477 / 525
• Bit Substrings368 / 447
• Reversal Sorting335 / 407
• Book Shop II1137 / 1304
• GCD Subsets322 / 330
• Minimum Cost Pairs78 / 108
• Same Sum Subsets84 / 157
• Mex Grid Queries810 / 949
• Maximum Building II429 / 527
• Stick Divisions3629 / 4261
• Stick Difference31 / 166
• Coding Company1399 / 1845
• Two Stacks Sorting163 / 518