CSES Problem Set

General

• Introduction
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• Statistics

Introductory Problems

• Weird Algorithm172552 / 180324
• Missing Number149009 / 155797
• Repetitions129566 / 134484
• Increasing Array122090 / 126181
• Permutations107065 / 110167
• Number Spiral75963 / 82421
• Two Knights58577 / 60318
• Two Sets63638 / 68144
• Bit Strings72498 / 76351
• Trailing Zeros67200 / 71311
• Coin Piles59746 / 65041
• Palindrome Reorder55534 / 58459
• Gray Code37844 / 42222
• Tower of Hanoi35260 / 36608
• Creating Strings46822 / 47964
• Apple Division47489 / 53270
• Chessboard and Queens28906 / 29393
• Raab Game I7171 / 8073
• Mex Grid Construction6978 / 7318
• Knight Moves Grid7063 / 7221
• Grid Coloring I5935 / 6146
• Digit Queries20308 / 23321
• String Reorder5318 / 6083
• Grid Path Description11359 / 14581

Sorting and Searching

• Distinct Numbers85671 / 92235
• Apartments64305 / 70803
• Ferris Wheel61882 / 66337
• Concert Tickets49678 / 57353
• Restaurant Customers50518 / 54269
• Movie Festival49089 / 51790
• Sum of Two Values56882 / 63251
• Maximum Subarray Sum54356 / 56617
• Stick Lengths48700 / 50791
• Missing Coin Sum37187 / 38469
• Collecting Numbers38090 / 40588
• Collecting Numbers II16640 / 20790
• Playlist38025 / 43112
• Towers38063 / 40611
• Traffic Lights29589 / 32919
• Distinct Values Subarrays9694 / 10910
• Distinct Values Subsequences7452 / 8128
• Josephus Problem I22966 / 25117
• Josephus Problem II12548 / 17170
• Nested Ranges Check13673 / 15493
• Nested Ranges Count9163 / 10719
• Room Allocation22393 / 25508
• Factory Machines32381 / 35014
• Tasks and Deadlines25912 / 26424
• Reading Books21000 / 22416
• Sum of Three Values30379 / 33412
• Sum of Four Values18958 / 20936
• Nearest Smaller Values25390 / 26213
• Subarray Sums I33672 / 35737
• Subarray Sums II30701 / 36027
• Subarray Divisibility27824 / 30120
• Distinct Values Subarrays II16990 / 18494
• Array Division26322 / 27603
• Movie Festival II14279 / 17044
• Maximum Subarray Sum II13295 / 15691

Dynamic Programming

• Dice Combinations89759 / 94730
• Minimizing Coins77682 / 83158
• Coin Combinations I71059 / 76599
• Coin Combinations II60245 / 67718
• Removing Digits66874 / 68181
• Grid Paths I62890 / 64569
• Book Shop56688 / 61982
• Array Description41925 / 46261
• Counting Towers25970 / 27447
• Edit Distance41822 / 44001
• Longest Common Subsequence13856 / 14331
• Rectangle Cutting34517 / 37525
• Minimal Grid Path6372 / 10701
• Money Sums40728 / 42180
• Removal Game25002 / 32485
• Two Sets II32075 / 34343
• Mountain Range4390 / 7574
• Increasing Subsequence32658 / 36497
• Projects22860 / 25372
• Elevator Rides14883 / 18473
• Counting Tilings8737 / 9455
• Counting Numbers12993 / 14412
• Increasing Subsequence II5767 / 6751

Graph Algorithms

• Counting Rooms62321 / 65262
• Labyrinth44096 / 51987
• Building Roads54596 / 56446
• Message Route47255 / 48998
• Building Teams44642 / 46854
• Round Trip35360 / 38278
• Monsters24921 / 28883
• Shortest Routes I39002 / 42615
• Shortest Routes II31543 / 35097
• High Score20096 / 27293
• Flight Discount25704 / 29637
• Cycle Finding18132 / 21786
• Flight Routes17691 / 19567
• Round Trip II19679 / 21896
• Course Schedule26076 / 27385
• Longest Flight Route18990 / 22971
• Game Routes20756 / 22058
• Investigation15633 / 16700
• Planets Queries I13565 / 15706
• Planets Queries II4931 / 6147
• Planets Cycles8231 / 9112
• Road Reparation20291 / 21091
• Road Construction22136 / 22814
• Flight Routes Check17577 / 18928
• Planets and Kingdoms14294 / 14900
• Giant Pizza6031 / 6586
• Coin Collector9452 / 10358
• Mail Delivery7577 / 8242
• De Bruijn Sequence4018 / 4198
• Teleporters Path5859 / 6610
• Hamiltonian Flights8936 / 10110
• Knight's Tour3371 / 4041
• Download Speed5852 / 7651
• Police Chase4649 / 5172
• School Dance5111 / 5390
• Distinct Routes3621 / 4661

Range Queries

• Static Range Sum Queries43542 / 45471
• Static Range Minimum Queries29939 / 32050
• Dynamic Range Sum Queries31137 / 32470
• Dynamic Range Minimum Queries28156 / 28818
• Range Xor Queries28879 / 29261
• Range Update Queries23213 / 24809
• Forest Queries23923 / 24751
• Hotel Queries16903 / 17854
• List Removals14034 / 14710
• Salary Queries10797 / 13389
• Prefix Sum Queries9067 / 9750
• Pizzeria Queries7283 / 7536
• Visible Buildings Queries2138 / 2323
• Range Interval Queries1624 / 2173
• Subarray Sum Queries8413 / 9085
• Subarray Sum Queries II2389 / 2465
• Distinct Values Queries7970 / 9674
• Distinct Values Queries II1346 / 1531
• Increasing Array Queries3050 / 3475
• Movie Festival Queries1684 / 1854
• Forest Queries II4997 / 5349
• Range Updates and Sums6949 / 8147
• Polynomial Queries5128 / 5994
• Range Queries and Copies3627 / 3865
• Missing Coin Sum Queries838 / 1154

Tree Algorithms

• Subordinates35837 / 38265
• Tree Matching20617 / 23777
• Tree Diameter29276 / 30927
• Tree Distances I22632 / 24223
• Tree Distances II18444 / 19264
• Company Queries I20712 / 21740
• Company Queries II19360 / 20336
• Distance Queries17478 / 18679
• Counting Paths11021 / 11634
• Subtree Queries13019 / 13830
• Path Queries10490 / 11064
• Path Queries II4407 / 6473
• Distinct Colors10083 / 11035
• Finding a Centroid8203 / 8528
• Fixed-Length Paths I4095 / 5156
• Fixed-Length Paths II1982 / 3464

Mathematics

• Josephus Queries5675 / 7088
• Exponentiation27910 / 29697
• Exponentiation II19497 / 23148
• Counting Divisors25580 / 28790
• Common Divisors16447 / 18975
• Sum of Divisors9347 / 13723
• Divisor Analysis6426 / 8518
• Prime Multiples7460 / 8630
• Counting Coprime Pairs4957 / 5717
• Next Prime2543 / 2898
• Binomial Coefficients11957 / 13198
• Creating Strings II9898 / 10419
• Distributing Apples9429 / 10114
• Christmas Party7857 / 8379
• Permutation Order1216 / 1251
• Permutation Rounds1748 / 1934
• Bracket Sequences I5250 / 5697
• Bracket Sequences II2778 / 3163
• Counting Necklaces2544 / 2747
• Counting Grids2132 / 2263
• Fibonacci Numbers7871 / 9789
• Throwing Dice4147 / 4490
• Graph Paths I4022 / 4286
• Graph Paths II3361 / 3517
• System of Linear Equations610 / 664
• Sum of Four Squares908 / 1053
• Triangle Number Sums764 / 917
• Dice Probability3520 / 3779
• Moving Robots1824 / 1923
• Candy Lottery1847 / 3483
• Inversion Probability550 / 2597
• Stick Game4045 / 4141
• Nim Game I5378 / 5574
• Nim Game II4259 / 4423
• Stair Game2888 / 3131
• Grundy's Game2012 / 2638
• Another Game2280 / 2452

String Algorithms

• Word Combinations6942 / 9839
• String Matching13298 / 17570
• Finding Borders9768 / 10629
• Finding Periods6979 / 7862
• Minimal Rotation3467 / 5087
• Longest Palindrome5119 / 6655
• All Palindromes887 / 993
• Required Substring1966 / 2923
• Palindrome Queries2409 / 2782
• Finding Patterns2269 / 3141
• Counting Patterns2151 / 2628
• Pattern Positions1815 / 2184
• Distinct Substrings2035 / 2408
• Distinct Subsequences1303 / 1380
• Repeating Substring2209 / 2533
• String Functions1942 / 2035
• Inverse Suffix Array353 / 404
• String Transform664 / 789
• Substring Order I1394 / 1542
• Substring Order II942 / 1210
• Substring Distribution1296 / 1402

Geometry

• Point Location Test8381 / 9303
• Line Segment Intersection4979 / 6195
• Polygon Area5715 / 6030
• Point in Polygon3192 / 4017
• Polygon Lattice Points2589 / 2772
• Minimum Euclidean Distance2292 / 3207
• Convex Hull3828 / 4542
• Maximum Manhattan Distances790 / 822
• All Manhattan Distances818 / 900
• Intersection Points2264 / 2437
• Line Segments Trace I439 / 453
• Line Segments Trace II365 / 384
• Lines and Queries I485 / 508
• Lines and Queries II431 / 451
• Area of Rectangles1318 / 1469
• Robot Path361 / 662

Advanced Techniques

• Meet in the Middle7779 / 10553
• Hamming Distance3570 / 3902
• Corner Subgrid Check280 / 655
• Corner Subgrid Count2462 / 2794
• Reachable Nodes2553 / 2738
• Reachability Queries1715 / 2010
• Cut and Paste1751 / 1935
• Substring Reversals1544 / 1670
• Reversals and Sums1569 / 1677
• Necessary Roads2257 / 2315
• Necessary Cities2100 / 2193
• Eulerian Subgraphs899 / 948
• Monster Game I1347 / 1493
• Monster Game II1186 / 1266
• Subarray Squares1682 / 1953
• Houses and Schools913 / 1079
• Knuth Division1092 / 1226
• Apples and Bananas1259 / 1363
• One Bit Positions962 / 1046
• Signal Processing934 / 998
• New Roads Queries2540 / 3056
• Dynamic Connectivity1165 / 1306
• Parcel Delivery904 / 991
• Task Assignment1044 / 1131
• Distinct Routes II688 / 779

Sliding Window Problems

• Sliding Window Sum7434 / 7679
• Sliding Window Minimum5562 / 6330
• Sliding Window Xor5468 / 5544
• Sliding Window Or2457 / 4092
• Sliding Window Distinct Values3847 / 4538
• Sliding Window Mode3023 / 3202
• Sliding Window Mex2859 / 3009
• Sliding Window Median14990 / 17047
• Sliding Window Cost9797 / 11262
• Sliding Window Inversions1547 / 1639
• Sliding Window Advertisement303 / 478

Interactive Problems

• Hidden Integer2737 / 2855
• Hidden Permutation1222 / 1414
• K-th Highest Score556 / 669
• Permuted Binary Strings658 / 676
• Colored Chairs616 / 653
• Inversion Sorting359 / 404

Bitwise Operations

• Counting Bits5954 / 7653
• Maximum Xor Subarray3535 / 4036
• Maximum Xor Subset1267 / 1389
• Number of Subset Xors1114 / 1136
• K Subset Xors574 / 675
• All Subarray Xors345 / 543
• Xor Pyramid Peak2342 / 2818
• Xor Pyramid Diagonal390 / 439
• Xor Pyramid Row338 / 394
• SOS Bit Problem2471 / 2617
• And Subset Count555 / 578

Construction Problems

• Inverse Inversions1973 / 2105
• Monotone Subsequences1195 / 1412
• Third Permutation514 / 635
• Permutation Prime Sums518 / 557
• Chess Tournament1348 / 1556
• Distinct Sums Grid183 / 271
• Filling Trominos295 / 507
• Grid Path Construction161 / 483

Advanced Graph Problems

• Nearest Shops873 / 1119
• Prüfer Code1680 / 1803
• Tree Traversals1382 / 1514
• Course Schedule II2259 / 3176
• Acyclic Graph Edges2406 / 2547
• Strongly Connected Edges1726 / 2012
• Even Outdegree Edges1525 / 1771
• Graph Girth3844 / 4339
• Fixed Length Walk Queries437 / 486
• Transfer Speeds Sum501 / 516
• MST Edge Check809 / 878
• MST Edge Set Check301 / 339
• MST Edge Cost484 / 506
• Network Breakdown1310 / 1424
• Tree Coin Collecting I429 / 463
• Tree Coin Collecting II244 / 279
• Tree Isomorphism I1201 / 1417
• Tree Isomorphism II992 / 1137
• Flight Route Requests562 / 694
• Critical Cities483 / 726
• Visiting Cities746 / 978
• Graph Coloring273 / 319
• Bus Companies319 / 329
• Split into Two Paths128 / 220
• Network Renovation1018 / 1338
• Forbidden Cities940 / 1221
• Creating Offices463 / 602
• New Flight Routes390 / 1007

Counting Problems

• Filled Subgrid Count I722 / 810
• Filled Subgrid Count II395 / 485
• All Letter Subgrid Count I225 / 326
• All Letter Subgrid Count II165 / 214
• Border Subgrid Count I119 / 203
• Border Subgrid Count II130 / 151
• Raab Game II135 / 154
• Empty String1867 / 2261
• Permutation Inversions1110 / 1225
• Counting Bishops435 / 484
• Counting Sequences743 / 798
• Grid Paths II832 / 1044
• Counting Permutations963 / 1087
• Grid Completion249 / 315
• Counting Reorders287 / 400
• Tournament Graph Distribution134 / 143
• Collecting Numbers Distribution140 / 147
• Functional Graph Distribution270 / 331

Additional Problems I

• Shortest Subsequence3209 / 4203
• Distinct Values Sum809 / 833
• Distinct Values Splits570 / 610
• Swap Game2220 / 2841
• Beautiful Permutation II703 / 1083
• Multiplication Table7584 / 8429
• Bubble Sort Rounds I517 / 586
• Bubble Sort Rounds II352 / 392
• Nearest Campsites I225 / 262
• Nearest Campsites II219 / 235
• Advertisement4813 / 5093
• Special Substrings1061 / 1164
• Counting LCM Arrays344 / 375
• Square Subsets264 / 290
• Subarray Sum Constraints529 / 563
• Water Containers Moves212 / 225
• Water Containers Queries247 / 260
• Stack Weights635 / 760
• Maximum Average Subarrays206 / 226
• Subsets with Fixed Average247 / 270
• Two Array Average253 / 282
• Pyramid Array836 / 1007
• Permutation Subsequence294 / 305
• Bit Inversions2515 / 2833
• Writing Numbers795 / 859
• Letter Pair Move Game224 / 311
• Maximum Building I2241 / 2340
• Sorting Methods827 / 883
• Cyclic Array1336 / 1510
• List of Sums529 / 686

Additional Problems II

• Bouncing Ball Steps290 / 321
• Bouncing Ball Cycle120 / 166
• Knight Moves Queries149 / 178
• K Subset Sums I233 / 297
• K Subset Sums II143 / 179
• Increasing Array II885 / 1009
• Food Division563 / 673
• Swap Round Sorting441 / 546
• Binary Subsequences312 / 451
• School Excursion1506 / 1592
• Coin Grid983 / 1147
• Grid Coloring II162 / 210
• Programmers and Artists551 / 767
• Removing Digits II239 / 508
• Coin Arrangement366 / 484
• Replace with Difference157 / 187
• Grid Puzzle I590 / 647
• Grid Puzzle II573 / 627
• Bit Substrings436 / 527
• Reversal Sorting385 / 464
• Book Shop II1388 / 1579
• GCD Subsets484 / 500
• Minimum Cost Pairs165 / 210
• Same Sum Subsets146 / 282
• Mex Grid Queries908 / 1062
• Maximum Building II479 / 589
• Stick Divisions4082 / 4764
• Stick Difference91 / 310
• Coding Company1626 / 2123
• Two Stacks Sorting199 / 622