CSES Problem Set

General

• Introduction
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• Statistics

Introductory Problems

• Weird Algorithm147665 / 154656
• Missing Number127402 / 133614
• Repetitions110926 / 115484
• Increasing Array104256 / 108051
• Permutations91610 / 94464
• Number Spiral64791 / 70634
• Two Knights49370 / 50952
• Two Sets53723 / 57872
• Bit Strings61557 / 65010
• Trailing Zeros57487 / 61163
• Coin Piles50870 / 55702
• Palindrome Reorder47323 / 49983
• Gray Code31449 / 35391
• Tower of Hanoi29008 / 30179
• Creating Strings39843 / 40891
• Apple Division39831 / 45073
• Chessboard and Queens24060 / 24496
• Raab Game I3454 / 3947
• Mex Grid Construction3325 / 3553
• Knight Moves Grid3332 / 3411
• Grid Coloring I2753 / 2853
• Digit Queries16958 / 19805
• String Reorder2682 / 3123
• Grid Path Description9457 / 12306

Sorting and Searching

• Distinct Numbers71983 / 77935
• Apartments53324 / 59368
• Ferris Wheel51191 / 55352
• Concert Tickets41275 / 48129
• Restaurant Customers41953 / 45324
• Movie Festival40254 / 42664
• Sum of Two Values47011 / 52723
• Maximum Subarray Sum45529 / 47584
• Stick Lengths40641 / 42558
• Missing Coin Sum30499 / 31633
• Collecting Numbers31269 / 33531
• Collecting Numbers II12946 / 16623
• Playlist31343 / 35929
• Towers31785 / 34066
• Traffic Lights24597 / 27571
• Distinct Values Subarrays5141 / 5412
• Distinct Values Subsequences3558 / 3974
• Josephus Problem I18654 / 20627
• Josephus Problem II10027 / 13896
• Nested Ranges Check10693 / 12329
• Nested Ranges Count7240 / 8560
• Room Allocation18478 / 21258
• Factory Machines26186 / 28605
• Tasks and Deadlines21185 / 21649
• Reading Books17137 / 18364
• Sum of Three Values25097 / 27845
• Sum of Four Values15632 / 17475
• Nearest Smaller Values20912 / 21633
• Subarray Sums I27657 / 29552
• Subarray Sums II25033 / 29836
• Subarray Divisibility22979 / 25092
• Distinct Values Subarrays II13645 / 15089
• Array Division21709 / 22861
• Movie Festival II11565 / 13990
• Maximum Subarray Sum II10692 / 12810

Dynamic Programming

• Dice Combinations75318 / 79737
• Minimizing Coins65088 / 69978
• Coin Combinations I59403 / 64369
• Coin Combinations II50176 / 56918
• Removing Digits55973 / 57136
• Grid Paths I52566 / 54074
• Book Shop46989 / 51767
• Array Description34591 / 38495
• Counting Towers20964 / 22228
• Edit Distance34834 / 36786
• Longest Common Subsequence7045 / 7311
• Rectangle Cutting28915 / 31614
• Minimal Grid Path3004 / 5735
• Money Sums34315 / 35651
• Removal Game20138 / 27433
• Two Sets II27046 / 29159
• Mountain Range2108 / 4054
• Increasing Subsequence27598 / 31008
• Projects19059 / 21359
• Elevator Rides12082 / 15275
• Counting Tilings7041 / 7694
• Counting Numbers9612 / 10877
• Increasing Subsequence II3688 / 4292

Graph Algorithms

• Counting Rooms51783 / 54435
• Labyrinth35774 / 42988
• Building Roads45177 / 46820
• Message Route38819 / 40379
• Building Teams36673 / 38722
• Round Trip29154 / 31805
• Monsters19831 / 23500
• Shortest Routes I31779 / 35172
• Shortest Routes II25922 / 29121
• High Score15626 / 22347
• Flight Discount20304 / 23856
• Cycle Finding14434 / 17813
• Flight Routes14102 / 15773
• Round Trip II16098 / 18132
• Course Schedule21096 / 22336
• Longest Flight Route14788 / 18498
• Game Routes16643 / 17867
• Investigation12327 / 13275
• Planets Queries I10712 / 12582
• Planets Queries II3822 / 4859
• Planets Cycles6563 / 7339
• Road Reparation16116 / 16807
• Road Construction17691 / 18260
• Flight Routes Check14402 / 15638
• Planets and Kingdoms11577 / 11992
• Giant Pizza4739 / 5229
• Coin Collector7461 / 8307
• Mail Delivery6240 / 6843
• De Bruijn Sequence3252 / 3406
• Teleporters Path4716 / 5426
• Hamiltonian Flights7072 / 8085
• Knight's Tour2627 / 3210
• Download Speed4657 / 6319
• Police Chase3721 / 4193
• School Dance4124 / 4367
• Distinct Routes2884 / 3805

Range Queries

• Static Range Sum Queries35805 / 37418
• Static Range Minimum Queries25167 / 26967
• Dynamic Range Sum Queries26171 / 27330
• Dynamic Range Minimum Queries23717 / 24283
• Range Xor Queries24518 / 24857
• Range Update Queries19364 / 20787
• Forest Queries19835 / 20592
• Hotel Queries14002 / 14893
• List Removals11661 / 12281
• Salary Queries8615 / 10938
• Prefix Sum Queries7370 / 8005
• Pizzeria Queries5956 / 6188
• Visible Buildings Queries1142 / 1260
• Range Interval Queries893 / 1186
• Subarray Sum Queries7148 / 7771
• Subarray Sum Queries II1204 / 1273
• Distinct Values Queries6545 / 8145
• Distinct Values Queries II696 / 817
• Increasing Array Queries2520 / 2893
• Movie Festival Queries1215 / 1350
• Forest Queries II4289 / 4619
• Range Updates and Sums5696 / 6790
• Polynomial Queries4194 / 4923
• Range Queries and Copies2988 / 3208
• Missing Coin Sum Queries599 / 794

Tree Algorithms

• Subordinates29851 / 31955
• Tree Matching16942 / 19783
• Tree Diameter24295 / 25775
• Tree Distances I18559 / 19970
• Tree Distances II15228 / 15880
• Company Queries I16872 / 17767
• Company Queries II15801 / 16589
• Distance Queries14404 / 15477
• Counting Paths9016 / 9572
• Subtree Queries10826 / 11561
• Path Queries8641 / 9162
• Path Queries II3486 / 5232
• Distinct Colors8347 / 9236
• Finding a Centroid6715 / 6998
• Fixed-Length Paths I3162 / 4126
• Fixed-Length Paths II1474 / 2730

Mathematics

• Josephus Queries4559 / 5753
• Exponentiation23455 / 25045
• Exponentiation II16621 / 19964
• Counting Divisors21300 / 24078
• Common Divisors13987 / 16283
• Sum of Divisors7808 / 11766
• Divisor Analysis5315 / 7156
• Prime Multiples6048 / 7096
• Counting Coprime Pairs3958 / 4645
• Next Prime1378 / 1581
• Binomial Coefficients9843 / 10945
• Creating Strings II8308 / 8778
• Distributing Apples7981 / 8596
• Christmas Party6430 / 6919
• Permutation Order638 / 650
• Permutation Rounds744 / 840
• Bracket Sequences I4422 / 4821
• Bracket Sequences II2284 / 2626
• Counting Necklaces2111 / 2290
• Counting Grids1718 / 1836
• Fibonacci Numbers6795 / 8546
• Throwing Dice3528 / 3838
• Graph Paths I3343 / 3591
• Graph Paths II2799 / 2935
• System of Linear Equations317 / 342
• Sum of Four Squares486 / 563
• Triangle Number Sums412 / 519
• Dice Probability3031 / 3275
• Moving Robots1558 / 1650
• Candy Lottery1320 / 2891
• Inversion Probability307 / 2211
• Stick Game3406 / 3488
• Nim Game I4493 / 4664
• Nim Game II3550 / 3699
• Stair Game2408 / 2622
• Grundy's Game1653 / 2188
• Another Game1869 / 2017

String Algorithms

• Word Combinations5728 / 8352
• String Matching11147 / 14965
• Finding Borders8151 / 8922
• Finding Periods5803 / 6598
• Minimal Rotation2818 / 4322
• Longest Palindrome4287 / 5666
• All Palindromes475 / 540
• Required Substring1608 / 2478
• Palindrome Queries2004 / 2340
• Finding Patterns1847 / 2649
• Counting Patterns1745 / 2177
• Pattern Positions1455 / 1786
• Distinct Substrings1666 / 1996
• Distinct Subsequences1042 / 1112
• Repeating Substring1807 / 2113
• String Functions1579 / 1654
• Inverse Suffix Array155 / 183
• String Transform502 / 614
• Substring Order I1130 / 1269
• Substring Order II748 / 971
• Substring Distribution1050 / 1142

Geometry

• Point Location Test7085 / 7927
• Line Segment Intersection4218 / 5320
• Polygon Area4901 / 5198
• Point in Polygon2692 / 3409
• Polygon Lattice Points2276 / 2357
• Minimum Euclidean Distance1971 / 2738
• Convex Hull3234 / 3904
• Maximum Manhattan Distances440 / 452
• All Manhattan Distances446 / 488
• Intersection Points1904 / 2050
• Line Segments Trace I239 / 247
• Line Segments Trace II194 / 205
• Lines and Queries I262 / 270
• Lines and Queries II224 / 232
• Area of Rectangles1082 / 1211
• Robot Path302 / 521

Advanced Techniques

• Meet in the Middle6498 / 9104
• Hamming Distance3177 / 3461
• Corner Subgrid Check235 / 380
• Corner Subgrid Count2196 / 2466
• Reachable Nodes2198 / 2366
• Reachability Queries1463 / 1734
• Cut and Paste1458 / 1625
• Substring Reversals1280 / 1397
• Reversals and Sums1287 / 1389
• Necessary Roads1880 / 1924
• Necessary Cities1745 / 1832
• Eulerian Subgraphs766 / 807
• Monster Game I1111 / 1240
• Monster Game II989 / 1063
• Subarray Squares1323 / 1576
• Houses and Schools739 / 889
• Knuth Division894 / 1014
• Apples and Bananas1004 / 1092
• One Bit Positions808 / 886
• Signal Processing758 / 815
• New Roads Queries2106 / 2567
• Dynamic Connectivity944 / 1069
• Parcel Delivery730 / 810
• Task Assignment853 / 908
• Distinct Routes II551 / 634

Sliding Window Problems

• Sliding Window Sum3530 / 3687
• Sliding Window Minimum2734 / 3123
• Sliding Window Xor2636 / 2667
• Sliding Window Or1123 / 2056
• Sliding Window Distinct Values2202 / 2243
• Sliding Window Mode1537 / 1619
• Sliding Window Mex1371 / 1448
• Sliding Window Median13204 / 15121
• Sliding Window Cost8762 / 10120
• Sliding Window Inversions765 / 822
• Sliding Window Advertisement150 / 243

Interactive Problems

• Hidden Integer1505 / 1557
• Hidden Permutation641 / 775
• K-th Highest Score272 / 330
• Permuted Binary Strings361 / 370
• Colored Chairs313 / 330
• Inversion Sorting183 / 196

Bitwise Operations

• Counting Bits4448 / 5730
• Maximum Xor Subarray2715 / 3058
• Maximum Xor Subset693 / 748
• Number of Subset Xors601 / 612
• K Subset Xors285 / 341
• All Subarray Xors193 / 304
• Xor Pyramid Peak1840 / 2256
• Xor Pyramid Diagonal222 / 252
• Xor Pyramid Row182 / 214
• SOS Bit Problem1908 / 2035
• And Subset Count274 / 278

Construction Problems

• Inverse Inversions1381 / 1471
• Monotone Subsequences832 / 978
• Third Permutation276 / 322
• Permutation Prime Sums272 / 293
• Chess Tournament1104 / 1276
• Distinct Sums Grid73 / 126
• Filling Trominos226 / 392
• Grid Path Construction115 / 417

Advanced Graph Problems

• Nearest Shops511 / 667
• Prüfer Code1424 / 1539
• Tree Traversals1122 / 1237
• Course Schedule II1757 / 2529
• Acyclic Graph Edges2099 / 2231
• Strongly Connected Edges1459 / 1618
• Even Outdegree Edges1246 / 1468
• Graph Girth3172 / 3634
• Fixed Length Walk Queries261 / 286
• Transfer Speeds Sum299 / 307
• MST Edge Check385 / 412
• MST Edge Set Check162 / 183
• MST Edge Cost268 / 281
• Network Breakdown952 / 1011
• Tree Coin Collecting I230 / 253
• Tree Coin Collecting II121 / 139
• Tree Isomorphism I1024 / 1232
• Tree Isomorphism II823 / 967
• Flight Route Requests455 / 555
• Critical Cities384 / 595
• Visiting Cities641 / 849
• Graph Coloring157 / 183
• Bus Companies188 / 192
• Split into Two Paths62 / 112
• Network Renovation891 / 1191
• Forbidden Cities768 / 1007
• Creating Offices384 / 503
• New Flight Routes293 / 792

Counting Problems

• Filled Subgrid Count I386 / 429
• Filled Subgrid Count II194 / 235
• All Letter Subgrid Count I100 / 162
• All Letter Subgrid Count II90 / 104
• Border Subgrid Count I67 / 114
• Border Subgrid Count II68 / 78
• Raab Game II72 / 84
• Empty String1514 / 1847
• Permutation Inversions965 / 1064
• Counting Bishops362 / 405
• Counting Sequences619 / 664
• Grid Paths II707 / 881
• Counting Permutations834 / 945
• Grid Completion210 / 265
• Counting Reorders221 / 326
• Tournament Graph Distribution79 / 82
• Collecting Numbers Distribution82 / 85
• Functional Graph Distribution225 / 279

Additional Problems I

• Shortest Subsequence2856 / 3788
• Distinct Values Sum463 / 476
• Distinct Values Splits321 / 340
• Swap Game1948 / 2476
• Beautiful Permutation II275 / 406
• Multiplication Table6232 / 6965
• Bubble Sort Rounds I250 / 289
• Bubble Sort Rounds II139 / 164
• Nearest Campsites I112 / 128
• Nearest Campsites II112 / 120
• Advertisement4050 / 4290
• Special Substrings922 / 1010
• Counting LCM Arrays179 / 192
• Square Subsets144 / 161
• Subarray Sum Constraints183 / 197
• Water Containers Moves107 / 114
• Water Containers Queries135 / 141
• Stack Weights549 / 651
• Maximum Average Subarrays108 / 119
• Subsets with Fixed Average142 / 154
• Two Array Average135 / 152
• Pyramid Array668 / 813
• Permutation Subsequence152 / 155
• Bit Inversions2191 / 2499
• Writing Numbers702 / 759
• Letter Pair Move Game187 / 266
• Maximum Building I1957 / 2042
• Sorting Methods729 / 781
• Cyclic Array1100 / 1254
• 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 Excursion1292 / 1372
• Coin Grid806 / 946
• Grid Coloring II90 / 113
• Programmers and Artists459 / 645
• Removing Digits II204 / 452
• Coin Arrangement306 / 413
• Replace with Difference88 / 105
• Grid Puzzle I499 / 547
• Grid Puzzle II462 / 510
• Bit Substrings360 / 439
• Reversal Sorting332 / 404
• Book Shop II1107 / 1274
• GCD Subsets293 / 300
• Minimum Cost Pairs68 / 92
• Same Sum Subsets77 / 140
• Mex Grid Queries800 / 939
• Maximum Building II421 / 516
• Stick Divisions3591 / 4219
• Stick Difference27 / 150
• Coding Company1374 / 1817
• Two Stacks Sorting160 / 505