CSES Problem Set

General

• Introduction
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• Statistics

Introductory Problems

• Weird Algorithm145331 / 152222
• Missing Number125199 / 131373
• Repetitions109112 / 113632
• Increasing Array102491 / 106260
• Permutations90077 / 92891
• Number Spiral63689 / 69456
• Two Knights48608 / 50169
• Two Sets52851 / 56950
• Bit Strings60578 / 63986
• Trailing Zeros56589 / 60233
• Coin Piles50080 / 54837
• Palindrome Reorder46423 / 49056
• Gray Code30851 / 34740
• Tower of Hanoi28526 / 29670
• Creating Strings39196 / 40225
• Apple Division39153 / 44329
• Chessboard and Queens23638 / 24072
• Raab Game I3124 / 3574
• Mex Grid Construction2985 / 3199
• Knight Moves Grid3011 / 3080
• Grid Coloring I2481 / 2566
• Digit Queries16706 / 19536
• String Reorder2463 / 2865
• Grid Path Description9321 / 12135

Sorting and Searching

• Distinct Numbers70782 / 76691
• Apartments52439 / 58419
• Ferris Wheel50288 / 54401
• Concert Tickets40492 / 47273
• Restaurant Customers41284 / 44616
• Movie Festival39594 / 41977
• Sum of Two Values46228 / 51873
• Maximum Subarray Sum44845 / 46875
• Stick Lengths40015 / 41909
• Missing Coin Sum29980 / 31103
• Collecting Numbers30755 / 32989
• Collecting Numbers II12696 / 16338
• Playlist30823 / 35358
• Towers31184 / 33445
• Traffic Lights24111 / 27058
• Distinct Values Subarrays4678 / 4934
• Distinct Values Subsequences3240 / 3627
• Josephus Problem I18317 / 20268
• Josephus Problem II9854 / 13637
• Nested Ranges Check10458 / 12089
• Nested Ranges Count7098 / 8398
• Room Allocation18149 / 20900
• Factory Machines25644 / 28033
• Tasks and Deadlines20816 / 21274
• Reading Books16854 / 18062
• Sum of Three Values24646 / 27366
• Sum of Four Values15381 / 17208
• Nearest Smaller Values20586 / 21298
• Subarray Sums I27165 / 29047
• Subarray Sums II24532 / 29279
• Subarray Divisibility22552 / 24647
• Distinct Values Subarrays II13325 / 14767
• Array Division21320 / 22457
• Movie Festival II11342 / 13729
• Maximum Subarray Sum II10487 / 12587

Dynamic Programming

• Dice Combinations74017 / 78367
• Minimizing Coins63974 / 68799
• Coin Combinations I58433 / 63336
• Coin Combinations II49384 / 56031
• Removing Digits55115 / 56267
• Grid Paths I51728 / 53218
• Book Shop46226 / 50971
• Array Description33984 / 37845
• Counting Towers20561 / 21811
• Edit Distance34246 / 36161
• Longest Common Subsequence6406 / 6653
• Rectangle Cutting28470 / 31123
• Minimal Grid Path2726 / 5244
• Money Sums33768 / 35091
• Removal Game19715 / 26993
• Two Sets II26614 / 28705
• Mountain Range1882 / 3696
• Increasing Subsequence27179 / 30554
• Projects18701 / 20990
• Elevator Rides11830 / 14971
• Counting Tilings6891 / 7538
• Counting Numbers9347 / 10593
• Increasing Subsequence II3506 / 4066

Graph Algorithms

• Counting Rooms50890 / 53521
• Labyrinth35127 / 42283
• Building Roads44455 / 46079
• Message Route38166 / 39721
• Building Teams36012 / 38046
• Round Trip28625 / 31242
• Monsters19437 / 23078
• Shortest Routes I31129 / 34502
• Shortest Routes II25407 / 28589
• High Score15284 / 21943
• Flight Discount19878 / 23392
• Cycle Finding14143 / 17482
• Flight Routes13796 / 15424
• Round Trip II15798 / 17794
• Course Schedule20713 / 21948
• Longest Flight Route14472 / 18143
• Game Routes16323 / 17537
• Investigation12081 / 13022
• Planets Queries I10476 / 12330
• Planets Queries II3737 / 4758
• Planets Cycles6426 / 7194
• Road Reparation15789 / 16466
• Road Construction17370 / 17933
• Flight Routes Check14125 / 15343
• Planets and Kingdoms11325 / 11732
• Giant Pizza4612 / 5099
• Coin Collector7297 / 8130
• Mail Delivery6105 / 6699
• De Bruijn Sequence3174 / 3328
• Teleporters Path4603 / 5314
• Hamiltonian Flights6919 / 7916
• Knight's Tour2565 / 3134
• Download Speed4532 / 6177
• Police Chase3635 / 4100
• School Dance4026 / 4267
• Distinct Routes2766 / 3671

Range Queries

• Static Range Sum Queries35062 / 36648
• Static Range Minimum Queries24750 / 26527
• Dynamic Range Sum Queries25743 / 26892
• Dynamic Range Minimum Queries23356 / 23921
• Range Xor Queries24125 / 24456
• Range Update Queries19057 / 20468
• Forest Queries19473 / 20221
• Hotel Queries13766 / 14656
• List Removals11470 / 12089
• Salary Queries8398 / 10697
• Prefix Sum Queries7209 / 7833
• Pizzeria Queries5824 / 6057
• Visible Buildings Queries1032 / 1128
• Range Interval Queries814 / 1075
• Subarray Sum Queries7021 / 7642
• Subarray Sum Queries II1113 / 1149
• Distinct Values Queries6414 / 7993
• Distinct Values Queries II636 / 742
• Increasing Array Queries2467 / 2835
• Movie Festival Queries1173 / 1305
• Forest Queries II4216 / 4545
• Range Updates and Sums5582 / 6676
• Polynomial Queries4115 / 4834
• Range Queries and Copies2922 / 3141
• Missing Coin Sum Queries573 / 764

Tree Algorithms

• Subordinates29294 / 31365
• Tree Matching16595 / 19410
• Tree Diameter23845 / 25315
• Tree Distances I18119 / 19511
• Tree Distances II14903 / 15551
• Company Queries I16528 / 17411
• Company Queries II15479 / 16254
• Distance Queries14101 / 15164
• Counting Paths8781 / 9332
• Subtree Queries10568 / 11289
• Path Queries8402 / 8907
• Path Queries II3376 / 5102
• Distinct Colors8155 / 9030
• Finding a Centroid6567 / 6847
• Fixed-Length Paths I3100 / 4052
• Fixed-Length Paths II1437 / 2684

Mathematics

• Josephus Queries4448 / 5615
• Exponentiation23092 / 24674
• Exponentiation II16370 / 19681
• Counting Divisors20935 / 23677
• Common Divisors13737 / 16000
• Sum of Divisors7643 / 11562
• Divisor Analysis5208 / 7016
• Prime Multiples5920 / 6950
• Counting Coprime Pairs3860 / 4539
• Next Prime1235 / 1416
• Binomial Coefficients9674 / 10758
• Creating Strings II8152 / 8622
• Distributing Apples7844 / 8449
• Christmas Party6304 / 6785
• Permutation Order572 / 581
• Permutation Rounds659 / 737
• Bracket Sequences I4327 / 4720
• Bracket Sequences II2239 / 2579
• Counting Necklaces2072 / 2248
• Counting Grids1686 / 1803
• Fibonacci Numbers6688 / 8423
• Throwing Dice3468 / 3774
• Graph Paths I3285 / 3531
• Graph Paths II2747 / 2882
• System of Linear Equations289 / 312
• Sum of Four Squares439 / 514
• Triangle Number Sums376 / 467
• Dice Probability2980 / 3223
• Moving Robots1535 / 1627
• Candy Lottery1256 / 2823
• Inversion Probability286 / 2175
• Stick Game3333 / 3412
• Nim Game I4394 / 4563
• Nim Game II3482 / 3632
• Stair Game2370 / 2579
• Grundy's Game1621 / 2144
• Another Game1836 / 1984

String Algorithms

• Word Combinations5591 / 8178
• String Matching10913 / 14689
• Finding Borders7975 / 8738
• Finding Periods5690 / 6472
• Minimal Rotation2756 / 4246
• Longest Palindrome4187 / 5557
• All Palindromes424 / 485
• Required Substring1581 / 2447
• Palindrome Queries1973 / 2304
• Finding Patterns1807 / 2600
• Counting Patterns1709 / 2133
• Pattern Positions1429 / 1755
• Distinct Substrings1629 / 1952
• Distinct Subsequences1020 / 1089
• Repeating Substring1770 / 2077
• String Functions1553 / 1629
• Inverse Suffix Array147 / 170
• String Transform494 / 605
• Substring Order I1109 / 1248
• Substring Order II733 / 952
• Substring Distribution1032 / 1124

Geometry

• Point Location Test6940 / 7766
• Line Segment Intersection4146 / 5242
• Polygon Area4826 / 5122
• Point in Polygon2632 / 3344
• Polygon Lattice Points2226 / 2307
• Minimum Euclidean Distance1926 / 2682
• Convex Hull3164 / 3826
• Maximum Manhattan Distances401 / 411
• All Manhattan Distances405 / 444
• Intersection Points1874 / 2017
• Line Segments Trace I219 / 226
• Line Segments Trace II175 / 187
• Lines and Queries I236 / 245
• Lines and Queries II201 / 210
• Area of Rectangles1057 / 1184
• Robot Path293 / 507

Advanced Techniques

• Meet in the Middle6382 / 8965
• Hamming Distance3118 / 3396
• Corner Subgrid Check208 / 350
• Corner Subgrid Count2173 / 2439
• Reachable Nodes2159 / 2324
• Reachability Queries1441 / 1710
• Cut and Paste1436 / 1599
• Substring Reversals1259 / 1376
• Reversals and Sums1267 / 1369
• Necessary Roads1851 / 1895
• Necessary Cities1721 / 1807
• Eulerian Subgraphs757 / 798
• Monster Game I1100 / 1226
• Monster Game II976 / 1050
• Subarray Squares1288 / 1537
• Houses and Schools722 / 864
• Knuth Division878 / 996
• Apples and Bananas968 / 1052
• One Bit Positions784 / 861
• Signal Processing730 / 786
• New Roads Queries2064 / 2521
• Dynamic Connectivity924 / 1048
• Parcel Delivery716 / 797
• Task Assignment837 / 889
• Distinct Routes II547 / 630

Sliding Window Problems

• Sliding Window Sum3170 / 3319
• Sliding Window Minimum2464 / 2811
• Sliding Window Xor2383 / 2413
• Sliding Window Or1005 / 1856
• Sliding Window Distinct Values1990 / 2031
• Sliding Window Mode1392 / 1464
• Sliding Window Mex1241 / 1308
• Sliding Window Median13045 / 14946
• Sliding Window Cost8675 / 10020
• Sliding Window Inversions709 / 759
• Sliding Window Advertisement132 / 212

Interactive Problems

• Hidden Integer1324 / 1364
• Hidden Permutation582 / 691
• K-th Highest Score247 / 302
• Permuted Binary Strings335 / 345
• Colored Chairs292 / 307
• Inversion Sorting169 / 181

Bitwise Operations

• Counting Bits4267 / 5490
• Maximum Xor Subarray2623 / 2946
• Maximum Xor Subset612 / 659
• Number of Subset Xors524 / 535
• K Subset Xors254 / 297
• All Subarray Xors179 / 274
• Xor Pyramid Peak1797 / 2208
• Xor Pyramid Diagonal201 / 227
• Xor Pyramid Row167 / 192
• 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 Shops465 / 605
• Prüfer Code1395 / 1509
• Tree Traversals1096 / 1209
• Course Schedule II1712 / 2465
• Acyclic Graph Edges2063 / 2193
• Strongly Connected Edges1432 / 1589
• Even Outdegree Edges1224 / 1444
• Graph Girth3127 / 3587
• Fixed Length Walk Queries243 / 263
• Transfer Speeds Sum277 / 284
• MST Edge Check348 / 374
• MST Edge Set Check145 / 166
• MST Edge Cost251 / 262
• Network Breakdown930 / 988
• Tree Coin Collecting I205 / 228
• Tree Coin Collecting II108 / 124
• Tree Isomorphism I1005 / 1203
• Tree Isomorphism II814 / 956
• Flight Route Requests443 / 539
• Critical Cities380 / 586
• Visiting Cities627 / 835
• Graph Coloring135 / 160
• Bus Companies169 / 172
• Split into Two Paths59 / 104
• Network Renovation879 / 1176
• Forbidden Cities748 / 986
• Creating Offices384 / 498
• New Flight Routes285 / 766

Counting Problems

• Filled Subgrid Count I337 / 373
• Filled Subgrid Count II173 / 210
• All Letter Subgrid Count I83 / 139
• All Letter Subgrid Count II67 / 81
• Border Subgrid Count I60 / 106
• Border Subgrid Count II63 / 73
• Raab Game II62 / 74
• Empty String1488 / 1816
• Permutation Inversions944 / 1036
• Counting Bishops354 / 397
• Counting Sequences606 / 652
• Grid Paths II698 / 870
• Counting Permutations819 / 928
• Grid Completion204 / 259
• Counting Reorders214 / 314
• Tournament Graph Distribution68 / 71
• Collecting Numbers Distribution73 / 75
• Functional Graph Distribution219 / 274

Additional Problems I

• Shortest Subsequence2816 / 3743
• Distinct Values Sum416 / 428
• Distinct Values Splits287 / 306
• Swap Game1911 / 2431
• Beautiful Permutation II220 / 321
• Multiplication Table6094 / 6819
• Bubble Sort Rounds I219 / 253
• Bubble Sort Rounds II117 / 137
• Nearest Campsites I98 / 115
• Nearest Campsites II95 / 105
• Advertisement3988 / 4225
• Special Substrings905 / 991
• Counting LCM Arrays165 / 177
• Square Subsets129 / 145
• Subarray Sum Constraints151 / 162
• Water Containers Moves95 / 105
• Water Containers Queries125 / 130
• Stack Weights539 / 642
• Maximum Average Subarrays97 / 108
• Subsets with Fixed Average128 / 137
• Two Array Average117 / 134
• Pyramid Array661 / 801
• Permutation Subsequence139 / 143
• Bit Inversions2158 / 2466
• Writing Numbers694 / 751
• Letter Pair Move Game182 / 261
• Maximum Building I1934 / 2019
• Sorting Methods724 / 776
• Cyclic Array1085 / 1239
• List of Sums438 / 571

Additional Problems II

• Bouncing Ball Steps142 / 155
• 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 Grid789 / 928
• Grid Coloring II83 / 105
• Programmers and Artists448 / 633
• Removing Digits II196 / 444
• Coin Arrangement299 / 408
• Replace with Difference77 / 94
• Grid Puzzle I486 / 533
• Grid Puzzle II446 / 490
• Bit Substrings348 / 427
• Reversal Sorting325 / 397
• Book Shop II1085 / 1249
• GCD Subsets266 / 274
• Minimum Cost Pairs60 / 83
• Same Sum Subsets66 / 123
• Mex Grid Queries787 / 927
• Maximum Building II412 / 507
• Stick Divisions3559 / 4183
• Stick Difference24 / 138
• Coding Company1352 / 1786
• Two Stacks Sorting156 / 495