CSES Problem Set

General

• Introduction
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• Statistics

Introductory Problems

• Weird Algorithm147764 / 154752
• Missing Number127494 / 133710
• Repetitions110996 / 115556
• Increasing Array104321 / 108117
• Permutations91676 / 94530
• Number Spiral64834 / 70681
• Two Knights49405 / 50987
• Two Sets53768 / 57919
• Bit Strings61588 / 65044
• Trailing Zeros57530 / 61210
• Coin Piles50908 / 55738
• Palindrome Reorder47350 / 50012
• Gray Code31468 / 35411
• Tower of Hanoi29024 / 30197
• Creating Strings39860 / 40906
• Apple Division39874 / 45113
• Chessboard and Queens24093 / 24528
• Raab Game I3477 / 3970
• Mex Grid Construction3343 / 3572
• Knight Moves Grid3344 / 3422
• Grid Coloring I2765 / 2865
• Digit Queries16971 / 19819
• String Reorder2687 / 3130
• Grid Path Description9459 / 12311

Sorting and Searching

• Distinct Numbers72033 / 77987
• Apartments53361 / 59409
• Ferris Wheel51229 / 55389
• Concert Tickets41309 / 48164
• Restaurant Customers41980 / 45354
• Movie Festival40288 / 42699
• Sum of Two Values47055 / 52770
• Maximum Subarray Sum45563 / 47618
• Stick Lengths40664 / 42581
• Missing Coin Sum30523 / 31657
• Collecting Numbers31291 / 33552
• Collecting Numbers II12961 / 16635
• Playlist31367 / 35956
• Towers31812 / 34091
• Traffic Lights24615 / 27590
• Distinct Values Subarrays5166 / 5439
• Distinct Values Subsequences3570 / 3987
• Josephus Problem I18669 / 20642
• Josephus Problem II10037 / 13906
• Nested Ranges Check10701 / 12340
• Nested Ranges Count7245 / 8569
• Room Allocation18500 / 21282
• Factory Machines26218 / 28636
• Tasks and Deadlines21203 / 21667
• Reading Books17150 / 18379
• Sum of Three Values25123 / 27869
• Sum of Four Values15641 / 17486
• Nearest Smaller Values20932 / 21652
• Subarray Sums I27689 / 29586
• Subarray Sums II25063 / 29868
• Subarray Divisibility23002 / 25114
• Distinct Values Subarrays II13663 / 15110
• Array Division21730 / 22882
• Movie Festival II11574 / 13999
• Maximum Subarray Sum II10700 / 12824

Dynamic Programming

• Dice Combinations75377 / 79795
• Minimizing Coins65139 / 70033
• Coin Combinations I59451 / 64425
• Coin Combinations II50227 / 56971
• Removing Digits56033 / 57195
• Grid Paths I52610 / 54118
• Book Shop47031 / 51814
• Array Description34617 / 38520
• Counting Towers20980 / 22244
• Edit Distance34860 / 36815
• Longest Common Subsequence7069 / 7334
• Rectangle Cutting28942 / 31641
• Minimal Grid Path3016 / 5756
• Money Sums34343 / 35679
• Removal Game20154 / 27447
• Two Sets II27069 / 29179
• Mountain Range2116 / 4067
• Increasing Subsequence27613 / 31025
• Projects19072 / 21372
• Elevator Rides12087 / 15282
• Counting Tilings7044 / 7697
• Counting Numbers9619 / 10887
• Increasing Subsequence II3697 / 4301

Graph Algorithms

• Counting Rooms51823 / 54477
• Labyrinth35803 / 43024
• Building Roads45213 / 46864
• Message Route38847 / 40406
• Building Teams36704 / 38750
• Round Trip29183 / 31841
• Monsters19849 / 23519
• Shortest Routes I31826 / 35219
• Shortest Routes II25944 / 29148
• High Score15650 / 22378
• Flight Discount20321 / 23876
• Cycle Finding14450 / 17831
• Flight Routes14118 / 15788
• Round Trip II16115 / 18151
• Course Schedule21119 / 22360
• Longest Flight Route14810 / 18521
• Game Routes16656 / 17880
• Investigation12341 / 13287
• Planets Queries I10724 / 12597
• Planets Queries II3827 / 4866
• Planets Cycles6566 / 7342
• Road Reparation16142 / 16834
• Road Construction17714 / 18282
• Flight Routes Check14414 / 15651
• Planets and Kingdoms11590 / 12006
• Giant Pizza4747 / 5236
• Coin Collector7468 / 8314
• Mail Delivery6246 / 6850
• De Bruijn Sequence3256 / 3410
• Teleporters Path4719 / 5430
• Hamiltonian Flights7082 / 8096
• Knight's Tour2632 / 3215
• Download Speed4662 / 6326
• Police Chase3726 / 4198
• School Dance4128 / 4371
• Distinct Routes2889 / 3810

Range Queries

• Static Range Sum Queries35840 / 37453
• Static Range Minimum Queries25191 / 26992
• Dynamic Range Sum Queries26192 / 27353
• Dynamic Range Minimum Queries23737 / 24304
• Range Xor Queries24538 / 24877
• Range Update Queries19387 / 20812
• Forest Queries19863 / 20621
• Hotel Queries14020 / 14911
• List Removals11673 / 12294
• Salary Queries8629 / 10956
• Prefix Sum Queries7379 / 8014
• Pizzeria Queries5964 / 6196
• Visible Buildings Queries1151 / 1269
• Range Interval Queries897 / 1195
• Subarray Sum Queries7151 / 7775
• Subarray Sum Queries II1207 / 1276
• Distinct Values Queries6553 / 8153
• Distinct Values Queries II701 / 821
• Increasing Array Queries2522 / 2895
• Movie Festival Queries1220 / 1355
• Forest Queries II4293 / 4622
• Range Updates and Sums5704 / 6801
• Polynomial Queries4197 / 4927
• Range Queries and Copies2989 / 3209
• Missing Coin Sum Queries600 / 795

Tree Algorithms

• Subordinates29881 / 31987
• Tree Matching16963 / 19805
• Tree Diameter24315 / 25796
• Tree Distances I18579 / 19991
• Tree Distances II15243 / 15895
• Company Queries I16890 / 17784
• Company Queries II15819 / 16606
• Distance Queries14419 / 15494
• Counting Paths9030 / 9588
• Subtree Queries10841 / 11576
• Path Queries8655 / 9176
• Path Queries II3493 / 5243
• Distinct Colors8359 / 9249
• Finding a Centroid6720 / 7003
• Fixed-Length Paths I3164 / 4128
• Fixed-Length Paths II1475 / 2732

Mathematics

• Josephus Queries4565 / 5760
• Exponentiation23472 / 25062
• Exponentiation II16629 / 19976
• Counting Divisors21328 / 24107
• Common Divisors13997 / 16294
• Sum of Divisors7813 / 11776
• Divisor Analysis5318 / 7160
• Prime Multiples6058 / 7106
• Counting Coprime Pairs3968 / 4655
• Next Prime1386 / 1592
• Binomial Coefficients9851 / 10954
• Creating Strings II8317 / 8787
• Distributing Apples7988 / 8604
• Christmas Party6439 / 6928
• Permutation Order641 / 653
• Permutation Rounds747 / 843
• Bracket Sequences I4425 / 4824
• Bracket Sequences II2285 / 2627
• Counting Necklaces2111 / 2290
• Counting Grids1718 / 1836
• Fibonacci Numbers6798 / 8549
• Throwing Dice3531 / 3841
• Graph Paths I3347 / 3595
• Graph Paths II2803 / 2939
• System of Linear Equations319 / 345
• Sum of Four Squares488 / 565
• Triangle Number Sums414 / 521
• Dice Probability3034 / 3278
• Moving Robots1559 / 1651
• Candy Lottery1322 / 2892
• Inversion Probability311 / 2214
• Stick Game3408 / 3490
• Nim Game I4497 / 4668
• Nim Game II3553 / 3702
• Stair Game2410 / 2624
• Grundy's Game1656 / 2191
• Another Game1871 / 2020

String Algorithms

• Word Combinations5735 / 8359
• String Matching11158 / 14976
• Finding Borders8158 / 8929
• Finding Periods5809 / 6604
• Minimal Rotation2822 / 4328
• Longest Palindrome4291 / 5671
• All Palindromes476 / 542
• Required Substring1608 / 2479
• Palindrome Queries2004 / 2340
• Finding Patterns1849 / 2653
• Counting Patterns1748 / 2180
• Pattern Positions1456 / 1787
• Distinct Substrings1668 / 1998
• Distinct Subsequences1043 / 1113
• Repeating Substring1809 / 2115
• String Functions1581 / 1656
• Inverse Suffix Array155 / 183
• String Transform502 / 614
• Substring Order I1131 / 1270
• Substring Order II749 / 972
• Substring Distribution1050 / 1142

Geometry

• Point Location Test7094 / 7936
• Line Segment Intersection4222 / 5325
• Polygon Area4905 / 5202
• Point in Polygon2693 / 3410
• Polygon Lattice Points2278 / 2359
• Minimum Euclidean Distance1972 / 2739
• Convex Hull3235 / 3904
• Maximum Manhattan Distances441 / 453
• All Manhattan Distances447 / 489
• Intersection Points1907 / 2053
• Line Segments Trace I241 / 249
• Line Segments Trace II195 / 206
• Lines and Queries I264 / 272
• Lines and Queries II225 / 233
• Area of Rectangles1082 / 1212
• Robot Path304 / 522

Advanced Techniques

• Meet in the Middle6502 / 9109
• Hamming Distance3180 / 3465
• Corner Subgrid Check237 / 382
• Corner Subgrid Count2200 / 2470
• Reachable Nodes2199 / 2368
• Reachability Queries1464 / 1735
• Cut and Paste1459 / 1626
• Substring Reversals1280 / 1397
• Reversals and Sums1287 / 1389
• Necessary Roads1883 / 1927
• Necessary Cities1747 / 1834
• Eulerian Subgraphs766 / 807
• Monster Game I1111 / 1240
• Monster Game II989 / 1063
• Subarray Squares1324 / 1577
• Houses and Schools740 / 890
• Knuth Division896 / 1017
• Apples and Bananas1005 / 1093
• One Bit Positions809 / 887
• Signal Processing758 / 815
• New Roads Queries2109 / 2570
• Dynamic Connectivity946 / 1071
• Parcel Delivery730 / 810
• Task Assignment853 / 908
• Distinct Routes II551 / 634

Sliding Window Problems

• Sliding Window Sum3545 / 3702
• Sliding Window Minimum2745 / 3133
• Sliding Window Xor2647 / 2678
• Sliding Window Or1130 / 2062
• Sliding Window Distinct Values2211 / 2252
• Sliding Window Mode1543 / 1625
• Sliding Window Mex1376 / 1452
• Sliding Window Median13210 / 15127
• Sliding Window Cost8765 / 10124
• Sliding Window Inversions776 / 834
• Sliding Window Advertisement150 / 244

Interactive Problems

• Hidden Integer1515 / 1567
• Hidden Permutation643 / 778
• K-th Highest Score272 / 330
• Permuted Binary Strings362 / 371
• Colored Chairs313 / 330
• Inversion Sorting184 / 197

Bitwise Operations

• Counting Bits4460 / 5741
• Maximum Xor Subarray2720 / 3064
• Maximum Xor Subset701 / 756
• Number of Subset Xors607 / 618
• K Subset Xors287 / 344
• All Subarray Xors193 / 306
• Xor Pyramid Peak1844 / 2260
• Xor Pyramid Diagonal224 / 254
• Xor Pyramid Row183 / 215
• SOS Bit Problem1914 / 2041
• And Subset Count278 / 282

Construction Problems

• Inverse Inversions1387 / 1477
• Monotone Subsequences834 / 980
• Third Permutation278 / 325
• Permutation Prime Sums273 / 295
• Chess Tournament1104 / 1276
• Distinct Sums Grid73 / 126
• Filling Trominos226 / 392
• Grid Path Construction115 / 417

Advanced Graph Problems

• Nearest Shops512 / 668
• Prüfer Code1426 / 1541
• Tree Traversals1123 / 1237
• Course Schedule II1761 / 2534
• Acyclic Graph Edges2102 / 2233
• Strongly Connected Edges1460 / 1620
• Even Outdegree Edges1247 / 1469
• Graph Girth3177 / 3639
• Fixed Length Walk Queries261 / 286
• Transfer Speeds Sum299 / 307
• MST Edge Check390 / 417
• MST Edge Set Check162 / 183
• MST Edge Cost268 / 281
• Network Breakdown953 / 1012
• Tree Coin Collecting I230 / 253
• Tree Coin Collecting II121 / 139
• Tree Isomorphism I1025 / 1233
• Tree Isomorphism II824 / 967
• Flight Route Requests455 / 556
• Critical Cities385 / 597
• Visiting Cities641 / 849
• Graph Coloring157 / 183
• Bus Companies188 / 192
• Split into Two Paths62 / 113
• Network Renovation891 / 1192
• Forbidden Cities769 / 1007
• Creating Offices384 / 503
• New Flight Routes293 / 794

Counting Problems

• Filled Subgrid Count I390 / 432
• Filled Subgrid Count II195 / 237
• All Letter Subgrid Count I100 / 163
• All Letter Subgrid Count II90 / 104
• Border Subgrid Count I67 / 114
• Border Subgrid Count II68 / 78
• Raab Game II72 / 84
• Empty String1516 / 1851
• Permutation Inversions965 / 1065
• Counting Bishops362 / 405
• Counting Sequences620 / 665
• Grid Paths II707 / 881
• Counting Permutations834 / 945
• Grid Completion210 / 266
• Counting Reorders221 / 326
• Tournament Graph Distribution79 / 82
• Collecting Numbers Distribution82 / 85
• Functional Graph Distribution226 / 280

Additional Problems I

• Shortest Subsequence2857 / 3790
• Distinct Values Sum464 / 477
• Distinct Values Splits321 / 340
• Swap Game1949 / 2477
• Beautiful Permutation II279 / 410
• Multiplication Table6244 / 6979
• Bubble Sort Rounds I253 / 291
• Bubble Sort Rounds II140 / 165
• Nearest Campsites I112 / 128
• Nearest Campsites II112 / 120
• Advertisement4052 / 4293
• Special Substrings922 / 1010
• Counting LCM Arrays180 / 194
• Square Subsets144 / 161
• Subarray Sum Constraints187 / 200
• Water Containers Moves107 / 114
• Water Containers Queries135 / 141
• Stack Weights549 / 651
• Maximum Average Subarrays108 / 119
• Subsets with Fixed Average143 / 155
• Two Array Average136 / 153
• Pyramid Array668 / 814
• Permutation Subsequence153 / 156
• Bit Inversions2192 / 2500
• Writing Numbers702 / 759
• Letter Pair Move Game187 / 266
• Maximum Building I1960 / 2045
• Sorting Methods729 / 781
• Cyclic Array1103 / 1257
• List of Sums445 / 584

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 Excursion1293 / 1373
• Coin Grid806 / 946
• Grid Coloring II90 / 113
• Programmers and Artists459 / 645
• Removing Digits II204 / 452
• Coin Arrangement306 / 413
• Replace with Difference89 / 106
• Grid Puzzle I499 / 547
• Grid Puzzle II462 / 510
• Bit Substrings360 / 439
• Reversal Sorting332 / 404
• Book Shop II1108 / 1275
• GCD Subsets295 / 302
• Minimum Cost Pairs68 / 92
• Same Sum Subsets77 / 140
• Mex Grid Queries800 / 939
• Maximum Building II421 / 516
• Stick Divisions3594 / 4222
• Stick Difference27 / 151
• Coding Company1374 / 1818
• Two Stacks Sorting160 / 506