CSES Problem Set

General

• Introduction
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• Statistics

Introductory Problems

• Weird Algorithm150169 / 157238
• Missing Number129405 / 135707
• Repetitions112700 / 117295
• Increasing Array105870 / 109690
• Permutations93083 / 95959
• Number Spiral65775 / 71711
• Two Knights50227 / 51829
• Two Sets54600 / 58800
• Bit Strings62507 / 66006
• Trailing Zeros58358 / 62097
• Coin Piles51652 / 56550
• Palindrome Reorder48032 / 50727
• Gray Code31983 / 35981
• Tower of Hanoi29580 / 30778
• Creating Strings40509 / 41578
• Apple Division40638 / 45954
• Chessboard and Queens24480 / 24925
• Raab Game I3797 / 4326
• Mex Grid Construction3662 / 3909
• Knight Moves Grid3649 / 3732
• Grid Coloring I3040 / 3143
• Digit Queries17200 / 20070
• String Reorder2902 / 3380
• Grid Path Description9573 / 12464

Sorting and Searching

• Distinct Numbers73254 / 79282
• Apartments54169 / 60303
• Ferris Wheel52021 / 56210
• Concert Tickets41937 / 48880
• Restaurant Customers42601 / 46015
• Movie Festival40934 / 43372
• Sum of Two Values47846 / 53655
• Maximum Subarray Sum46267 / 48354
• Stick Lengths41213 / 43144
• Missing Coin Sum30982 / 32134
• Collecting Numbers31730 / 34023
• Collecting Numbers II13184 / 16891
• Playlist31829 / 36448
• Towers32229 / 34543
• Traffic Lights24957 / 27967
• Distinct Values Subarrays5584 / 5871
• Distinct Values Subsequences3850 / 4293
• Josephus Problem I19023 / 21009
• Josephus Problem II10261 / 14179
• Nested Ranges Check10872 / 12524
• Nested Ranges Count7366 / 8710
• Room Allocation18748 / 21554
• Factory Machines26689 / 29129
• Tasks and Deadlines21505 / 21976
• Reading Books17427 / 18679
• Sum of Three Values25610 / 28397
• Sum of Four Values15872 / 17725
• Nearest Smaller Values21218 / 21950
• Subarray Sums I28150 / 30054
• Subarray Sums II25542 / 30383
• Subarray Divisibility23315 / 25446
• Distinct Values Subarrays II13957 / 15406
• Array Division22090 / 23266
• Movie Festival II11803 / 14249
• Maximum Subarray Sum II10884 / 13022

Dynamic Programming

• Dice Combinations76636 / 81111
• Minimizing Coins66169 / 71143
• Coin Combinations I60408 / 65462
• Coin Combinations II51029 / 57859
• Removing Digits56870 / 58036
• Grid Paths I53493 / 55039
• Book Shop47756 / 52590
• Array Description35150 / 39099
• Counting Towers21315 / 22601
• Edit Distance35319 / 37287
• Longest Common Subsequence7614 / 7899
• Rectangle Cutting29310 / 32039
• Minimal Grid Path3274 / 6172
• Money Sums34744 / 36085
• Removal Game20494 / 27786
• Two Sets II27382 / 29501
• Mountain Range2304 / 4356
• Increasing Subsequence27975 / 31422
• Projects19285 / 21604
• Elevator Rides12284 / 15501
• Counting Tilings7176 / 7838
• Counting Numbers9840 / 11133
• Increasing Subsequence II3878 / 4511

Graph Algorithms

• Counting Rooms52710 / 55395
• Labyrinth36431 / 43729
• Building Roads45890 / 47549
• Message Route39495 / 41079
• Building Teams37295 / 39348
• Round Trip29627 / 32305
• Monsters20190 / 23906
• Shortest Routes I32354 / 35767
• Shortest Routes II26377 / 29600
• High Score15954 / 22735
• Flight Discount20642 / 24229
• Cycle Finding14697 / 18103
• Flight Routes14368 / 16051
• Round Trip II16371 / 18418
• Course Schedule21467 / 22710
• Longest Flight Route15061 / 18789
• Game Routes16922 / 18153
• Investigation12535 / 13495
• Planets Queries I10911 / 12806
• Planets Queries II3908 / 4963
• Planets Cycles6674 / 7460
• Road Reparation16454 / 17165
• Road Construction18021 / 18601
• Flight Routes Check14638 / 15878
• Planets and Kingdoms11773 / 12194
• Giant Pizza4838 / 5334
• Coin Collector7616 / 8464
• Mail Delivery6356 / 6964
• De Bruijn Sequence3324 / 3480
• Teleporters Path4809 / 5520
• Hamiltonian Flights7209 / 8236
• Knight's Tour2697 / 3281
• Download Speed4763 / 6444
• Police Chase3803 / 4281
• School Dance4197 / 4441
• Distinct Routes2946 / 3882

Range Queries

• Static Range Sum Queries36532 / 38170
• Static Range Minimum Queries25624 / 27444
• Dynamic Range Sum Queries26616 / 27799
• Dynamic Range Minimum Queries24107 / 24683
• Range Xor Queries24951 / 25289
• Range Update Queries19745 / 21180
• Forest Queries20241 / 21008
• Hotel Queries14275 / 15169
• List Removals11881 / 12505
• Salary Queries8809 / 11175
• Prefix Sum Queries7567 / 8211
• Pizzeria Queries6087 / 6317
• Visible Buildings Queries1279 / 1402
• Range Interval Queries1001 / 1332
• Subarray Sum Queries7274 / 7900
• Subarray Sum Queries II1348 / 1415
• Distinct Values Queries6687 / 8293
• Distinct Values Queries II797 / 922
• Increasing Array Queries2570 / 2952
• Movie Festival Queries1277 / 1419
• Forest Queries II4353 / 4689
• Range Updates and Sums5796 / 6904
• Polynomial Queries4257 / 4999
• Range Queries and Copies3052 / 3272
• Missing Coin Sum Queries634 / 835

Tree Algorithms

• Subordinates30344 / 32460
• Tree Matching17213 / 20070
• Tree Diameter24740 / 26238
• Tree Distances I18890 / 20312
• Tree Distances II15469 / 16130
• Company Queries I17178 / 18081
• Company Queries II16112 / 16900
• Distance Queries14647 / 15725
• Counting Paths9179 / 9735
• Subtree Queries11003 / 11745
• Path Queries8818 / 9344
• Path Queries II3538 / 5362
• Distinct Colors8485 / 9381
• Finding a Centroid6851 / 7139
• Fixed-Length Paths I3252 / 4225
• Fixed-Length Paths II1519 / 2808

Mathematics

• Josephus Queries4661 / 5872
• Exponentiation23834 / 25471
• Exponentiation II16904 / 20286
• Counting Divisors21690 / 24504
• Common Divisors14234 / 16559
• Sum of Divisors7939 / 11943
• Divisor Analysis5397 / 7270
• Prime Multiples6240 / 7293
• Counting Coprime Pairs4056 / 4750
• Next Prime1526 / 1743
• Binomial Coefficients10006 / 11122
• Creating Strings II8452 / 8926
• Distributing Apples8116 / 8734
• Christmas Party6546 / 7037
• Permutation Order715 / 727
• Permutation Rounds858 / 963
• Bracket Sequences I4496 / 4897
• Bracket Sequences II2327 / 2675
• Counting Necklaces2159 / 2339
• Counting Grids1772 / 1895
• Fibonacci Numbers6930 / 8696
• Throwing Dice3582 / 3896
• Graph Paths I3414 / 3666
• Graph Paths II2856 / 2994
• System of Linear Equations339 / 377
• Sum of Four Squares534 / 617
• Triangle Number Sums447 / 563
• Dice Probability3080 / 3326
• Moving Robots1583 / 1675
• Candy Lottery1383 / 2961
• Inversion Probability328 / 2247
• Stick Game3461 / 3544
• Nim Game I4573 / 4745
• Nim Game II3617 / 3768
• Stair Game2443 / 2660
• Grundy's Game1693 / 2229
• Another Game1923 / 2076

String Algorithms

• Word Combinations5849 / 8497
• String Matching11381 / 15239
• Finding Borders8319 / 9103
• Finding Periods5924 / 6738
• Minimal Rotation2871 / 4385
• Longest Palindrome4350 / 5752
• All Palindromes521 / 593
• Required Substring1647 / 2526
• Palindrome Queries2040 / 2376
• Finding Patterns1898 / 2710
• Counting Patterns1793 / 2232
• Pattern Positions1499 / 1838
• Distinct Substrings1714 / 2049
• Distinct Subsequences1074 / 1144
• Repeating Substring1853 / 2160
• String Functions1616 / 1692
• Inverse Suffix Array172 / 206
• String Transform521 / 636
• Substring Order I1159 / 1299
• Substring Order II770 / 999
• Substring Distribution1079 / 1173

Geometry

• Point Location Test7254 / 8101
• Line Segment Intersection4319 / 5430
• Polygon Area4985 / 5283
• Point in Polygon2728 / 3507
• Polygon Lattice Points2321 / 2402
• Minimum Euclidean Distance2013 / 2791
• Convex Hull3305 / 3983
• Maximum Manhattan Distances474 / 489
• All Manhattan Distances484 / 530
• Intersection Points1945 / 2095
• Line Segments Trace I264 / 273
• Line Segments Trace II216 / 228
• Lines and Queries I296 / 305
• Lines and Queries II255 / 263
• Area of Rectangles1113 / 1243
• Robot Path289 / 535

Advanced Techniques

• Meet in the Middle6625 / 9250
• Hamming Distance3215 / 3502
• Corner Subgrid Check259 / 413
• Corner Subgrid Count2229 / 2505
• Reachable Nodes2236 / 2405
• Reachability Queries1487 / 1762
• Cut and Paste1495 / 1665
• Substring Reversals1307 / 1424
• Reversals and Sums1317 / 1419
• Necessary Roads1916 / 1961
• Necessary Cities1778 / 1864
• Eulerian Subgraphs782 / 823
• Monster Game I1135 / 1262
• Monster Game II1013 / 1087
• Subarray Squares1365 / 1618
• Houses and Schools756 / 906
• Knuth Division917 / 1036
• Apples and Bananas1039 / 1128
• One Bit Positions830 / 910
• Signal Processing786 / 844
• New Roads Queries2148 / 2614
• Dynamic Connectivity979 / 1106
• Parcel Delivery751 / 834
• Task Assignment885 / 942
• Distinct Routes II569 / 652

Sliding Window Problems

• Sliding Window Sum3861 / 4030
• Sliding Window Minimum2943 / 3372
• Sliding Window Xor2888 / 2924
• Sliding Window Or1222 / 2215
• Sliding Window Distinct Values1793 / 2435
• Sliding Window Mode1660 / 1749
• Sliding Window Mex1479 / 1561
• Sliding Window Median13422 / 15354
• Sliding Window Cost8848 / 10226
• Sliding Window Inversions847 / 907
• Sliding Window Advertisement165 / 267

Interactive Problems

• Hidden Integer1649 / 1708
• Hidden Permutation711 / 848
• K-th Highest Score311 / 377
• Permuted Binary Strings396 / 407
• Colored Chairs347 / 366
• Inversion Sorting209 / 226

Bitwise Operations

• Counting Bits4605 / 5920
• Maximum Xor Subarray2779 / 3137
• Maximum Xor Subset770 / 831
• Number of Subset Xors665 / 679
• K Subset Xors315 / 381
• All Subarray Xors210 / 338
• Xor Pyramid Peak1887 / 2312
• Xor Pyramid Diagonal239 / 271
• Xor Pyramid Row192 / 228
• SOS Bit Problem1990 / 2123
• And Subset Count309 / 313

Construction Problems

• Inverse Inversions1436 / 1529
• Monotone Subsequences885 / 1040
• Third Permutation304 / 353
• Permutation Prime Sums297 / 321
• Chess Tournament1132 / 1307
• Distinct Sums Grid84 / 142
• Filling Trominos232 / 402
• Grid Path Construction118 / 421

Advanced Graph Problems

• Nearest Shops546 / 710
• Prüfer Code1453 / 1569
• Tree Traversals1145 / 1260
• Course Schedule II1809 / 2599
• Acyclic Graph Edges2152 / 2286
• Strongly Connected Edges1487 / 1650
• Even Outdegree Edges1268 / 1492
• Graph Girth3255 / 3721
• Fixed Length Walk Queries271 / 299
• Transfer Speeds Sum323 / 333
• MST Edge Check465 / 500
• MST Edge Set Check175 / 199
• MST Edge Cost290 / 303
• Network Breakdown977 / 1036
• Tree Coin Collecting I246 / 274
• Tree Coin Collecting II127 / 150
• Tree Isomorphism I1036 / 1245
• Tree Isomorphism II842 / 984
• Flight Route Requests463 / 568
• Critical Cities393 / 610
• Visiting Cities652 / 867
• Graph Coloring175 / 205
• Bus Companies200 / 206
• Split into Two Paths66 / 127
• Network Renovation907 / 1210
• Forbidden Cities794 / 1040
• Creating Offices395 / 517
• New Flight Routes298 / 809

Counting Problems

• Filled Subgrid Count I423 / 467
• Filled Subgrid Count II218 / 269
• All Letter Subgrid Count I116 / 180
• All Letter Subgrid Count II96 / 118
• Border Subgrid Count I72 / 124
• Border Subgrid Count II74 / 86
• Raab Game II76 / 91
• Empty String1545 / 1890
• Permutation Inversions982 / 1085
• Counting Bishops367 / 410
• Counting Sequences632 / 677
• Grid Paths II720 / 898
• Counting Permutations847 / 958
• Grid Completion214 / 270
• Counting Reorders225 / 330
• Tournament Graph Distribution83 / 87
• Collecting Numbers Distribution87 / 95
• Functional Graph Distribution230 / 284

Additional Problems I

• Shortest Subsequence2910 / 3850
• Distinct Values Sum505 / 521
• Distinct Values Splits354 / 374
• Swap Game1980 / 2514
• Beautiful Permutation II319 / 478
• Multiplication Table6370 / 7116
• Bubble Sort Rounds I287 / 329
• Bubble Sort Rounds II161 / 188
• Nearest Campsites I128 / 148
• Nearest Campsites II127 / 136
• Advertisement4132 / 4378
• Special Substrings936 / 1028
• Counting LCM Arrays202 / 220
• Square Subsets165 / 183
• Subarray Sum Constraints224 / 240
• Water Containers Moves120 / 127
• Water Containers Queries150 / 156
• Stack Weights561 / 665
• Maximum Average Subarrays120 / 132
• Subsets with Fixed Average156 / 172
• Two Array Average149 / 167
• Pyramid Array682 / 832
• Permutation Subsequence168 / 171
• Bit Inversions2222 / 2530
• Writing Numbers711 / 768
• Letter Pair Move Game190 / 268
• Maximum Building I1984 / 2069
• Sorting Methods737 / 790
• Cyclic Array1121 / 1278
• List of Sums453 / 596

Additional Problems II

• Bouncing Ball Steps168 / 184
• Bouncing Ball Cycle66 / 94
• Knight Moves Queries91 / 112
• K Subset Sums I128 / 175
• K Subset Sums II65 / 89
• Increasing Array II756 / 872
• Food Division502 / 594
• Swap Round Sorting398 / 490
• Binary Subsequences275 / 406
• School Excursion1315 / 1396
• Coin Grid824 / 964
• Grid Coloring II101 / 130
• Programmers and Artists466 / 653
• Removing Digits II208 / 455
• Coin Arrangement309 / 417
• Replace with Difference93 / 114
• Grid Puzzle I505 / 554
• Grid Puzzle II477 / 525
• Bit Substrings368 / 447
• Reversal Sorting335 / 407
• Book Shop II1138 / 1306
• GCD Subsets323 / 331
• Minimum Cost Pairs79 / 109
• Same Sum Subsets84 / 158
• Mex Grid Queries811 / 951
• Maximum Building II429 / 527
• Stick Divisions3631 / 4264
• Stick Difference31 / 166
• Coding Company1400 / 1846
• Two Stacks Sorting163 / 518