CSES Problem Set

General

• Introduction
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• Statistics

Introductory Problems

• Weird Algorithm151273 / 158384
• Missing Number130401 / 136728
• Repetitions113555 / 118167
• Increasing Array106706 / 110556
• Permutations93824 / 96714
• Number Spiral66327 / 72298
• Two Knights50656 / 52258
• Two Sets55098 / 59321
• Bit Strings62997 / 66523
• Trailing Zeros58817 / 62597
• Coin Piles52069 / 56997
• Palindrome Reorder48440 / 51142
• Gray Code32278 / 36308
• Tower of Hanoi29857 / 31064
• Creating Strings40831 / 41905
• Apple Division40978 / 46321
• Chessboard and Queens24680 / 25129
• Raab Game I3972 / 4508
• Mex Grid Construction3832 / 4089
• Knight Moves Grid3825 / 3915
• Grid Coloring I3192 / 3304
• Digit Queries17352 / 20226
• String Reorder3006 / 3502
• Grid Path Description9636 / 12542

Sorting and Searching

• Distinct Numbers74081 / 80161
• Apartments54781 / 60962
• Ferris Wheel52597 / 56819
• Concert Tickets42399 / 49390
• Restaurant Customers43040 / 46490
• Movie Festival41359 / 43821
• Sum of Two Values48301 / 54143
• Maximum Subarray Sum46705 / 48796
• Stick Lengths41613 / 43549
• Missing Coin Sum31302 / 32463
• Collecting Numbers32077 / 34381
• Collecting Numbers II13343 / 17077
• Playlist32122 / 36769
• Towers32527 / 34851
• Traffic Lights25189 / 28213
• Distinct Values Subarrays5865 / 6174
• Distinct Values Subsequences4015 / 4470
• Josephus Problem I19197 / 21184
• Josephus Problem II10362 / 14314
• Nested Ranges Check10991 / 12656
• Nested Ranges Count7432 / 8787
• Room Allocation18909 / 21729
• Factory Machines26926 / 29372
• Tasks and Deadlines21688 / 22161
• Reading Books17591 / 18846
• Sum of Three Values25861 / 28670
• Sum of Four Values16023 / 17878
• Nearest Smaller Values21426 / 22165
• Subarray Sums I28425 / 30338
• Subarray Sums II25769 / 30639
• Subarray Divisibility23513 / 25653
• Distinct Values Subarrays II14118 / 15572
• Array Division22328 / 23516
• Movie Festival II11904 / 14384
• Maximum Subarray Sum II10992 / 13145

Dynamic Programming

• Dice Combinations77401 / 81919
• Minimizing Coins66819 / 71824
• Coin Combinations I61004 / 66095
• Coin Combinations II51545 / 58414
• Removing Digits57351 / 58525
• Grid Paths I53992 / 55549
• Book Shop48175 / 53027
• Array Description35463 / 39437
• Counting Towers21502 / 22809
• Edit Distance35608 / 37595
• Longest Common Subsequence7940 / 8242
• Rectangle Cutting29526 / 32281
• Minimal Grid Path3399 / 6379
• Money Sums35024 / 36369
• Removal Game20696 / 28013
• Two Sets II27604 / 29739
• Mountain Range2401 / 4505
• Increasing Subsequence28190 / 31663
• Projects19414 / 21738
• Elevator Rides12386 / 15627
• Counting Tilings7237 / 7902
• Counting Numbers9933 / 11229
• Increasing Subsequence II3961 / 4610

Graph Algorithms

• Counting Rooms53102 / 55801
• Labyrinth36718 / 44064
• Building Roads46225 / 47893
• Message Route39793 / 41386
• Building Teams37568 / 39633
• Round Trip29854 / 32548
• Monsters20343 / 24070
• Shortest Routes I32632 / 36051
• Shortest Routes II26595 / 29832
• High Score16115 / 22909
• Flight Discount20866 / 24485
• Cycle Finding14872 / 18297
• Flight Routes14481 / 16180
• Round Trip II16494 / 18548
• Course Schedule21634 / 22878
• Longest Flight Route15196 / 18940
• Game Routes17050 / 18283
• Investigation12634 / 13604
• Planets Queries I11030 / 12932
• Planets Queries II3953 / 5019
• Planets Cycles6742 / 7534
• Road Reparation16575 / 17287
• Road Construction18178 / 18757
• Flight Routes Check14747 / 15996
• Planets and Kingdoms11844 / 12267
• Giant Pizza4888 / 5389
• Coin Collector7673 / 8523
• Mail Delivery6408 / 7020
• De Bruijn Sequence3347 / 3506
• Teleporters Path4848 / 5561
• Hamiltonian Flights7267 / 8301
• Knight's Tour2723 / 3309
• Download Speed4824 / 6505
• Police Chase3843 / 4324
• School Dance4245 / 4491
• Distinct Routes2981 / 3924

Range Queries

• Static Range Sum Queries36842 / 38492
• Static Range Minimum Queries25824 / 27663
• Dynamic Range Sum Queries26796 / 27979
• Dynamic Range Minimum Queries24284 / 24862
• Range Xor Queries25134 / 25473
• Range Update Queries19911 / 21348
• Forest Queries20397 / 21169
• Hotel Queries14400 / 15301
• List Removals11971 / 12600
• Salary Queries8897 / 11273
• Prefix Sum Queries7649 / 8294
• Pizzeria Queries6145 / 6378
• Visible Buildings Queries1308 / 1434
• Range Interval Queries1031 / 1372
• Subarray Sum Queries7340 / 7967
• Subarray Sum Queries II1400 / 1464
• Distinct Values Queries6762 / 8380
• Distinct Values Queries II825 / 951
• Increasing Array Queries2597 / 2984
• Movie Festival Queries1294 / 1440
• Forest Queries II4381 / 4721
• Range Updates and Sums5854 / 6971
• Polynomial Queries4291 / 5038
• Range Queries and Copies3084 / 3304
• Missing Coin Sum Queries646 / 849

Tree Algorithms

• Subordinates30580 / 32708
• Tree Matching17342 / 20210
• Tree Diameter24910 / 26418
• Tree Distances I19022 / 20447
• Tree Distances II15575 / 16244
• Company Queries I17318 / 18234
• Company Queries II16228 / 17020
• Distance Queries14756 / 15837
• Counting Paths9247 / 9806
• Subtree Queries11070 / 11819
• Path Queries8886 / 9415
• Path Queries II3582 / 5411
• Distinct Colors8544 / 9442
• Finding a Centroid6904 / 7194
• Fixed-Length Paths I3298 / 4278
• Fixed-Length Paths II1542 / 2844

Mathematics

• Josephus Queries4711 / 5936
• Exponentiation23999 / 25638
• Exponentiation II17029 / 20428
• Counting Divisors21841 / 24676
• Common Divisors14327 / 16664
• Sum of Divisors8000 / 12026
• Divisor Analysis5444 / 7326
• Prime Multiples6300 / 7370
• Counting Coprime Pairs4093 / 4793
• Next Prime1593 / 1825
• Binomial Coefficients10097 / 11223
• Creating Strings II8538 / 9013
• Distributing Apples8203 / 8826
• Christmas Party6602 / 7099
• Permutation Order749 / 764
• Permutation Rounds911 / 1018
• Bracket Sequences I4542 / 4947
• Bracket Sequences II2358 / 2708
• Counting Necklaces2181 / 2362
• Counting Grids1793 / 1917
• Fibonacci Numbers6989 / 8770
• Throwing Dice3615 / 3932
• Graph Paths I3440 / 3696
• Graph Paths II2877 / 3018
• System of Linear Equations351 / 390
• Sum of Four Squares556 / 641
• Triangle Number Sums467 / 584
• Dice Probability3109 / 3359
• Moving Robots1595 / 1689
• Candy Lottery1411 / 2992
• Inversion Probability343 / 2268
• Stick Game3487 / 3572
• Nim Game I4616 / 4790
• Nim Game II3652 / 3804
• Stair Game2464 / 2682
• Grundy's Game1711 / 2251
• Another Game1938 / 2092

String Algorithms

• Word Combinations5904 / 8575
• String Matching11470 / 15348
• Finding Borders8369 / 9160
• Finding Periods5958 / 6776
• Minimal Rotation2892 / 4410
• Longest Palindrome4375 / 5777
• All Palindromes531 / 606
• Required Substring1660 / 2544
• Palindrome Queries2053 / 2392
• Finding Patterns1917 / 2733
• Counting Patterns1815 / 2256
• Pattern Positions1515 / 1858
• Distinct Substrings1737 / 2074
• Distinct Subsequences1084 / 1156
• Repeating Substring1868 / 2178
• String Functions1627 / 1704
• Inverse Suffix Array173 / 213
• String Transform527 / 643
• Substring Order I1172 / 1314
• Substring Order II777 / 1009
• Substring Distribution1090 / 1186

Geometry

• Point Location Test7327 / 8181
• Line Segment Intersection4356 / 5472
• Polygon Area5032 / 5330
• Point in Polygon2762 / 3538
• Polygon Lattice Points2339 / 2422
• Minimum Euclidean Distance2039 / 2820
• Convex Hull3357 / 4036
• Maximum Manhattan Distances500 / 516
• All Manhattan Distances510 / 556
• Intersection Points1963 / 2116
• Line Segments Trace I279 / 289
• Line Segments Trace II228 / 241
• Lines and Queries I313 / 323
• Lines and Queries II266 / 275
• Area of Rectangles1120 / 1252
• Robot Path293 / 542

Advanced Techniques

• Meet in the Middle6670 / 9303
• Hamming Distance3230 / 3522
• Corner Subgrid Check274 / 433
• Corner Subgrid Count2244 / 2520
• Reachable Nodes2265 / 2437
• Reachability Queries1500 / 1777
• Cut and Paste1512 / 1684
• Substring Reversals1317 / 1436
• Reversals and Sums1326 / 1429
• Necessary Roads1924 / 1976
• Necessary Cities1787 / 1874
• Eulerian Subgraphs788 / 831
• Monster Game I1141 / 1270
• Monster Game II1019 / 1094
• Subarray Squares1387 / 1641
• Houses and Schools761 / 912
• Knuth Division935 / 1056
• Apples and Bananas1057 / 1150
• One Bit Positions841 / 921
• Signal Processing798 / 858
• New Roads Queries2174 / 2644
• Dynamic Connectivity990 / 1117
• Parcel Delivery759 / 843
• Task Assignment898 / 957
• Distinct Routes II575 / 660

Sliding Window Problems

• Sliding Window Sum4086 / 4262
• Sliding Window Minimum3061 / 3510
• Sliding Window Xor3012 / 3051
• Sliding Window Or1325 / 2363
• Sliding Window Distinct Values1940 / 2585
• Sliding Window Mode1766 / 1862
• Sliding Window Mex1578 / 1667
• Sliding Window Median13532 / 15475
• Sliding Window Cost8896 / 10275
• Sliding Window Inversions888 / 951
• Sliding Window Advertisement173 / 279

Interactive Problems

• Hidden Integer1727 / 1787
• Hidden Permutation737 / 877
• K-th Highest Score327 / 393
• Permuted Binary Strings413 / 425
• Colored Chairs365 / 386
• Inversion Sorting215 / 235

Bitwise Operations

• Counting Bits4678 / 6016
• Maximum Xor Subarray2822 / 3190
• Maximum Xor Subset799 / 863
• Number of Subset Xors693 / 709
• K Subset Xors328 / 397
• All Subarray Xors217 / 348
• Xor Pyramid Peak1911 / 2340
• Xor Pyramid Diagonal247 / 281
• Xor Pyramid Row200 / 238
• SOS Bit Problem2017 / 2152
• And Subset Count319 / 325

Construction Problems

• Inverse Inversions1461 / 1558
• Monotone Subsequences900 / 1057
• Third Permutation313 / 367
• Permutation Prime Sums307 / 333
• Chess Tournament1140 / 1318
• Distinct Sums Grid88 / 147
• Filling Trominos232 / 405
• Grid Path Construction118 / 423

Advanced Graph Problems

• Nearest Shops562 / 729
• Prüfer Code1471 / 1587
• Tree Traversals1159 / 1276
• Course Schedule II1833 / 2638
• Acyclic Graph Edges2167 / 2301
• Strongly Connected Edges1509 / 1677
• Even Outdegree Edges1286 / 1511
• Graph Girth3283 / 3750
• Fixed Length Walk Queries286 / 316
• Transfer Speeds Sum335 / 346
• MST Edge Check480 / 516
• MST Edge Set Check181 / 205
• MST Edge Cost299 / 313
• Network Breakdown984 / 1044
• Tree Coin Collecting I254 / 283
• Tree Coin Collecting II131 / 155
• Tree Isomorphism I1044 / 1256
• Tree Isomorphism II848 / 992
• Flight Route Requests465 / 570
• Critical Cities396 / 613
• Visiting Cities656 / 873
• Graph Coloring182 / 215
• Bus Companies206 / 214
• Split into Two Paths69 / 133
• Network Renovation910 / 1216
• Forbidden Cities797 / 1046
• Creating Offices402 / 526
• New Flight Routes302 / 816

Counting Problems

• Filled Subgrid Count I451 / 499
• Filled Subgrid Count II229 / 286
• All Letter Subgrid Count I126 / 194
• All Letter Subgrid Count II101 / 127
• Border Subgrid Count I74 / 127
• Border Subgrid Count II76 / 90
• Raab Game II76 / 92
• Empty String1560 / 1908
• Permutation Inversions989 / 1093
• Counting Bishops370 / 414
• Counting Sequences636 / 682
• Grid Paths II726 / 907
• Counting Permutations851 / 964
• Grid Completion215 / 272
• Counting Reorders225 / 331
• Tournament Graph Distribution85 / 90
• Collecting Numbers Distribution90 / 99
• Functional Graph Distribution231 / 286

Additional Problems I

• Shortest Subsequence2922 / 3864
• Distinct Values Sum522 / 539
• Distinct Values Splits371 / 392
• Swap Game1995 / 2530
• Beautiful Permutation II344 / 518
• Multiplication Table6431 / 7183
• Bubble Sort Rounds I304 / 348
• Bubble Sort Rounds II176 / 204
• Nearest Campsites I135 / 157
• Nearest Campsites II135 / 146
• Advertisement4171 / 4423
• Special Substrings946 / 1041
• Counting LCM Arrays207 / 226
• Square Subsets170 / 190
• Subarray Sum Constraints244 / 263
• Water Containers Moves126 / 133
• Water Containers Queries158 / 164
• Stack Weights564 / 671
• Maximum Average Subarrays127 / 141
• Subsets with Fixed Average163 / 180
• Two Array Average155 / 175
• Pyramid Array695 / 848
• Permutation Subsequence174 / 178
• Bit Inversions2243 / 2552
• Writing Numbers716 / 774
• Letter Pair Move Game191 / 270
• Maximum Building I1994 / 2082
• Sorting Methods745 / 799
• Cyclic Array1132 / 1290
• List of Sums459 / 605

Additional Problems II

• Bouncing Ball Steps173 / 190
• Bouncing Ball Cycle67 / 98
• Knight Moves Queries96 / 118
• K Subset Sums I133 / 182
• K Subset Sums II65 / 91
• Increasing Array II757 / 875
• Food Division494 / 598
• Swap Round Sorting399 / 492
• Binary Subsequences278 / 410
• School Excursion1324 / 1407
• Coin Grid833 / 974
• Grid Coloring II103 / 133
• Programmers and Artists473 / 663
• Removing Digits II208 / 456
• Coin Arrangement313 / 421
• Replace with Difference97 / 120
• Grid Puzzle I506 / 556
• Grid Puzzle II483 / 533
• Bit Substrings372 / 452
• Reversal Sorting336 / 410
• Book Shop II1148 / 1319
• GCD Subsets329 / 338
• Minimum Cost Pairs86 / 118
• Same Sum Subsets86 / 166
• Mex Grid Queries814 / 957
• Maximum Building II432 / 532
• Stick Divisions3661 / 4299
• Stick Difference31 / 173
• Coding Company1422 / 1874
• Two Stacks Sorting165 / 525