CSES Problem Set

General

• Introduction
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• Statistics

Introductory Problems

• Weird Algorithm145400 / 152292
• Missing Number125289 / 131462
• Repetitions109168 / 113689
• Increasing Array102555 / 106322
• Permutations90115 / 92930
• Number Spiral63714 / 69488
• Two Knights48627 / 50188
• Two Sets52873 / 56971
• Bit Strings60614 / 64019
• Trailing Zeros56620 / 60268
• Coin Piles50118 / 54881
• Palindrome Reorder46450 / 49085
• Gray Code30868 / 34758
• Tower of Hanoi28553 / 29698
• Creating Strings39220 / 40249
• Apple Division39173 / 44350
• Chessboard and Queens23650 / 24084
• Raab Game I3138 / 3588
• Mex Grid Construction3001 / 3214
• Knight Moves Grid3025 / 3094
• Grid Coloring I2492 / 2579
• Digit Queries16717 / 19547
• String Reorder2468 / 2872
• Grid Path Description9323 / 12138

Sorting and Searching

• Distinct Numbers70817 / 76727
• Apartments52466 / 58447
• Ferris Wheel50311 / 54424
• Concert Tickets40513 / 47293
• Restaurant Customers41302 / 44634
• Movie Festival39608 / 41992
• Sum of Two Values46237 / 51882
• Maximum Subarray Sum44859 / 46889
• Stick Lengths40036 / 41930
• Missing Coin Sum30007 / 31129
• Collecting Numbers30771 / 33005
• Collecting Numbers II12700 / 16345
• Playlist30835 / 35370
• Towers31196 / 33460
• Traffic Lights24122 / 27070
• Distinct Values Subarrays4696 / 4951
• Distinct Values Subsequences3255 / 3640
• Josephus Problem I18331 / 20283
• Josephus Problem II9860 / 13648
• Nested Ranges Check10464 / 12094
• Nested Ranges Count7102 / 8403
• Room Allocation18159 / 20911
• Factory Machines25653 / 28043
• Tasks and Deadlines20830 / 21288
• Reading Books16869 / 18076
• Sum of Three Values24658 / 27378
• Sum of Four Values15394 / 17222
• Nearest Smaller Values20607 / 21320
• Subarray Sums I27187 / 29068
• Subarray Sums II24566 / 29317
• Subarray Divisibility22586 / 24687
• Distinct Values Subarrays II13335 / 14777
• Array Division21340 / 22478
• Movie Festival II11348 / 13733
• Maximum Subarray Sum II10493 / 12595

Dynamic Programming

• Dice Combinations74058 / 78408
• Minimizing Coins64005 / 68835
• Coin Combinations I58467 / 63373
• Coin Combinations II49412 / 56057
• Removing Digits55152 / 56303
• Grid Paths I51750 / 53240
• Book Shop46251 / 50997
• Array Description34006 / 37870
• Counting Towers20575 / 21826
• Edit Distance34264 / 36176
• Longest Common Subsequence6423 / 6671
• Rectangle Cutting28476 / 31131
• Minimal Grid Path2737 / 5262
• Money Sums33783 / 35107
• Removal Game19729 / 27007
• Two Sets II26620 / 28712
• Mountain Range1892 / 3711
• Increasing Subsequence27194 / 30567
• Projects18713 / 20998
• Elevator Rides11834 / 14976
• Counting Tilings6891 / 7539
• Counting Numbers9357 / 10603
• Increasing Subsequence II3510 / 4074

Graph Algorithms

• Counting Rooms50917 / 53551
• Labyrinth35150 / 42311
• Building Roads44485 / 46109
• Message Route38185 / 39740
• Building Teams36029 / 38063
• Round Trip28640 / 31257
• Monsters19452 / 23094
• Shortest Routes I31146 / 34520
• Shortest Routes II25428 / 28605
• High Score15298 / 21959
• Flight Discount19890 / 23407
• Cycle Finding14146 / 17488
• Flight Routes13806 / 15433
• Round Trip II15808 / 17809
• Course Schedule20721 / 21956
• Longest Flight Route14479 / 18152
• Game Routes16332 / 17546
• Investigation12087 / 13028
• Planets Queries I10487 / 12342
• Planets Queries II3738 / 4760
• Planets Cycles6430 / 7198
• Road Reparation15800 / 16478
• Road Construction17375 / 17938
• Flight Routes Check14131 / 15349
• Planets and Kingdoms11333 / 11741
• Giant Pizza4616 / 5100
• Coin Collector7301 / 8135
• Mail Delivery6107 / 6702
• De Bruijn Sequence3176 / 3330
• Teleporters Path4605 / 5316
• Hamiltonian Flights6926 / 7923
• Knight's Tour2567 / 3136
• Download Speed4536 / 6182
• Police Chase3637 / 4103
• School Dance4029 / 4270
• Distinct Routes2768 / 3675

Range Queries

• Static Range Sum Queries35078 / 36665
• Static Range Minimum Queries24761 / 26537
• Dynamic Range Sum Queries25751 / 26898
• Dynamic Range Minimum Queries23363 / 23928
• Range Xor Queries24139 / 24470
• Range Update Queries19070 / 20482
• Forest Queries19480 / 20228
• Hotel Queries13772 / 14661
• List Removals11476 / 12094
• Salary Queries8412 / 10719
• Prefix Sum Queries7210 / 7834
• Pizzeria Queries5825 / 6058
• Visible Buildings Queries1036 / 1132
• Range Interval Queries816 / 1078
• Subarray Sum Queries7023 / 7644
• Subarray Sum Queries II1117 / 1153
• Distinct Values Queries6420 / 7999
• Distinct Values Queries II637 / 744
• Increasing Array Queries2469 / 2839
• Movie Festival Queries1175 / 1307
• Forest Queries II4217 / 4547
• Range Updates and Sums5589 / 6682
• Polynomial Queries4116 / 4835
• Range Queries and Copies2923 / 3142
• Missing Coin Sum Queries573 / 764

Tree Algorithms

• Subordinates29308 / 31380
• Tree Matching16600 / 19416
• Tree Diameter23859 / 25328
• Tree Distances I18146 / 19539
• Tree Distances II14915 / 15564
• Company Queries I16540 / 17426
• Company Queries II15486 / 16260
• Distance Queries14104 / 15170
• Counting Paths8788 / 9338
• Subtree Queries10574 / 11296
• Path Queries8404 / 8908
• Path Queries II3382 / 5110
• Distinct Colors8166 / 9043
• Finding a Centroid6571 / 6851
• Fixed-Length Paths I3102 / 4055
• Fixed-Length Paths II1439 / 2685

Mathematics

• Josephus Queries4453 / 5620
• Exponentiation23108 / 24689
• Exponentiation II16379 / 19693
• Counting Divisors20943 / 23686
• Common Divisors13743 / 16010
• Sum of Divisors7652 / 11569
• Divisor Analysis5210 / 7018
• Prime Multiples5923 / 6956
• Counting Coprime Pairs3863 / 4542
• Next Prime1243 / 1427
• Binomial Coefficients9679 / 10763
• Creating Strings II8160 / 8630
• Distributing Apples7847 / 8453
• Christmas Party6306 / 6788
• Permutation Order574 / 583
• Permutation Rounds662 / 742
• Bracket Sequences I4327 / 4720
• Bracket Sequences II2239 / 2579
• Counting Necklaces2072 / 2248
• Counting Grids1686 / 1803
• Fibonacci Numbers6690 / 8425
• Throwing Dice3469 / 3775
• Graph Paths I3286 / 3532
• Graph Paths II2748 / 2883
• System of Linear Equations289 / 312
• Sum of Four Squares439 / 514
• Triangle Number Sums377 / 468
• Dice Probability2981 / 3224
• Moving Robots1535 / 1627
• Candy Lottery1257 / 2824
• Inversion Probability286 / 2177
• Stick Game3335 / 3414
• Nim Game I4396 / 4565
• Nim Game II3483 / 3633
• Stair Game2371 / 2580
• Grundy's Game1622 / 2145
• Another Game1836 / 1984

String Algorithms

• Word Combinations5594 / 8182
• String Matching10922 / 14699
• Finding Borders7981 / 8744
• Finding Periods5694 / 6477
• Minimal Rotation2758 / 4250
• Longest Palindrome4191 / 5561
• All Palindromes424 / 485
• Required Substring1582 / 2449
• Palindrome Queries1973 / 2305
• Finding Patterns1809 / 2601
• Counting Patterns1709 / 2133
• Pattern Positions1431 / 1757
• Distinct Substrings1632 / 1956
• Distinct Subsequences1020 / 1089
• Repeating Substring1774 / 2080
• String Functions1554 / 1630
• Inverse Suffix Array147 / 170
• String Transform494 / 605
• Substring Order I1110 / 1248
• Substring Order II733 / 953
• Substring Distribution1033 / 1125

Geometry

• Point Location Test6947 / 7775
• Line Segment Intersection4150 / 5247
• Polygon Area4833 / 5129
• Point in Polygon2638 / 3350
• Polygon Lattice Points2231 / 2312
• Minimum Euclidean Distance1929 / 2686
• Convex Hull3166 / 3828
• Maximum Manhattan Distances403 / 413
• All Manhattan Distances407 / 446
• Intersection Points1876 / 2019
• Line Segments Trace I220 / 228
• Line Segments Trace II176 / 188
• Lines and Queries I238 / 247
• Lines and Queries II203 / 212
• Area of Rectangles1060 / 1188
• Robot Path293 / 509

Advanced Techniques

• Meet in the Middle6388 / 8973
• Hamming Distance3120 / 3398
• Corner Subgrid Check208 / 351
• Corner Subgrid Count2174 / 2440
• Reachable Nodes2162 / 2327
• Reachability Queries1442 / 1711
• Cut and Paste1436 / 1599
• Substring Reversals1260 / 1377
• Reversals and Sums1268 / 1370
• Necessary Roads1852 / 1896
• Necessary Cities1721 / 1807
• Eulerian Subgraphs757 / 798
• Monster Game I1101 / 1227
• Monster Game II977 / 1051
• Subarray Squares1289 / 1538
• Houses and Schools722 / 864
• Knuth Division879 / 997
• Apples and Bananas968 / 1052
• One Bit Positions784 / 861
• Signal Processing732 / 788
• New Roads Queries2068 / 2525
• Dynamic Connectivity926 / 1050
• Parcel Delivery717 / 798
• Task Assignment838 / 890
• Distinct Routes II548 / 631

Sliding Window Problems

• Sliding Window Sum3184 / 3333
• Sliding Window Minimum2473 / 2822
• Sliding Window Xor2390 / 2422
• Sliding Window Or1010 / 1864
• Sliding Window Distinct Values1998 / 2039
• Sliding Window Mode1396 / 1470
• Sliding Window Mex1243 / 1310
• Sliding Window Median13052 / 14954
• Sliding Window Cost8679 / 10024
• Sliding Window Inversions712 / 762
• Sliding Window Advertisement134 / 215

Interactive Problems

• Hidden Integer1330 / 1370
• Hidden Permutation585 / 695
• K-th Highest Score249 / 305
• Permuted Binary Strings337 / 347
• Colored Chairs293 / 308
• Inversion Sorting170 / 182

Bitwise Operations

• Counting Bits4273 / 5497
• Maximum Xor Subarray2626 / 2950
• Maximum Xor Subset615 / 662
• Number of Subset Xors527 / 538
• K Subset Xors256 / 301
• All Subarray Xors179 / 275
• Xor Pyramid Peak1800 / 2211
• Xor Pyramid Diagonal202 / 228
• Xor Pyramid Row168 / 193
• SOS Bit Problem1855 / 1983
• And Subset Count251 / 255

Construction Problems

• Inverse Inversions1312 / 1399
• Monotone Subsequences798 / 937
• Third Permutation249 / 290
• Permutation Prime Sums244 / 264
• Chess Tournament1085 / 1252
• Distinct Sums Grid67 / 118
• Filling Trominos223 / 386
• Grid Path Construction113 / 412

Advanced Graph Problems

• Nearest Shops467 / 607
• Prüfer Code1397 / 1511
• Tree Traversals1096 / 1209
• Course Schedule II1713 / 2466
• Acyclic Graph Edges2063 / 2193
• Strongly Connected Edges1433 / 1589
• Even Outdegree Edges1224 / 1444
• Graph Girth3127 / 3587
• Fixed Length Walk Queries243 / 263
• Transfer Speeds Sum277 / 284
• MST Edge Check348 / 375
• MST Edge Set Check146 / 167
• MST Edge Cost251 / 262
• Network Breakdown930 / 989
• Tree Coin Collecting I205 / 228
• Tree Coin Collecting II108 / 124
• Tree Isomorphism I1006 / 1204
• Tree Isomorphism II815 / 957
• Flight Route Requests444 / 540
• Critical Cities381 / 587
• Visiting Cities628 / 836
• Graph Coloring135 / 161
• Bus Companies169 / 172
• Split into Two Paths58 / 104
• Network Renovation880 / 1177
• Forbidden Cities749 / 987
• Creating Offices385 / 499
• New Flight Routes285 / 767

Counting Problems

• Filled Subgrid Count I340 / 376
• Filled Subgrid Count II174 / 212
• All Letter Subgrid Count I85 / 140
• All Letter Subgrid Count II67 / 84
• Border Subgrid Count I60 / 106
• Border Subgrid Count II63 / 73
• Raab Game II62 / 74
• Empty String1489 / 1817
• Permutation Inversions945 / 1039
• Counting Bishops356 / 399
• Counting Sequences607 / 653
• Grid Paths II699 / 872
• Counting Permutations822 / 931
• Grid Completion205 / 260
• Counting Reorders215 / 315
• Tournament Graph Distribution68 / 71
• Collecting Numbers Distribution73 / 75
• Functional Graph Distribution220 / 275

Additional Problems I

• Shortest Subsequence2818 / 3745
• Distinct Values Sum418 / 430
• Distinct Values Splits289 / 308
• Swap Game1914 / 2434
• Beautiful Permutation II220 / 323
• Multiplication Table6097 / 6823
• Bubble Sort Rounds I220 / 254
• Bubble Sort Rounds II117 / 137
• Nearest Campsites I98 / 115
• Nearest Campsites II95 / 105
• Advertisement3993 / 4230
• Special Substrings908 / 994
• Counting LCM Arrays167 / 179
• Square Subsets131 / 147
• Subarray Sum Constraints154 / 165
• Water Containers Moves95 / 105
• Water Containers Queries125 / 130
• Stack Weights541 / 644
• Maximum Average Subarrays97 / 108
• Subsets with Fixed Average129 / 138
• Two Array Average119 / 136
• Pyramid Array663 / 804
• Permutation Subsequence140 / 144
• Bit Inversions2161 / 2469
• Writing Numbers697 / 754
• Letter Pair Move Game183 / 262
• Maximum Building I1937 / 2022
• Sorting Methods726 / 778
• Cyclic Array1089 / 1243
• List of Sums440 / 573

Additional Problems II

• Bouncing Ball Steps142 / 156
• Bouncing Ball Cycle56 / 76
• Knight Moves Queries80 / 96
• K Subset Sums I100 / 138
• K Subset Sums II52 / 73
• Increasing Array II736 / 851
• Food Division494 / 584
• Swap Round Sorting389 / 480
• Binary Subsequences266 / 393
• School Excursion1269 / 1349
• Coin Grid790 / 929
• Grid Coloring II83 / 105
• Programmers and Artists449 / 634
• Removing Digits II196 / 444
• Coin Arrangement300 / 409
• Replace with Difference77 / 94
• Grid Puzzle I486 / 533
• Grid Puzzle II446 / 490
• Bit Substrings349 / 428
• Reversal Sorting325 / 397
• Book Shop II1086 / 1251
• GCD Subsets266 / 274
• Minimum Cost Pairs61 / 83
• Same Sum Subsets66 / 123
• Mex Grid Queries788 / 928
• Maximum Building II413 / 508
• Stick Divisions3560 / 4184
• Stick Difference24 / 138
• Coding Company1353 / 1787
• Two Stacks Sorting157 / 497