CSES Problem Set

General

• Introduction
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• Statistics

Introductory Problems

• Weird Algorithm150528 / 157604
• Missing Number129724 / 136032
• Repetitions112974 / 117575
• Increasing Array106160 / 109991
• Permutations93352 / 96230
• Number Spiral65959 / 71907
• Two Knights50358 / 51960
• Two Sets54775 / 58982
• Bit Strings62661 / 66170
• Trailing Zeros58514 / 62263
• Coin Piles51788 / 56690
• Palindrome Reorder48167 / 50860
• Gray Code32081 / 36090
• Tower of Hanoi29664 / 30867
• Creating Strings40610 / 41683
• Apple Division40738 / 46064
• Chessboard and Queens24542 / 24988
• Raab Game I3851 / 4387
• Mex Grid Construction3710 / 3959
• Knight Moves Grid3693 / 3781
• Grid Coloring I3082 / 3187
• Digit Queries17241 / 20112
• String Reorder2932 / 3414
• Grid Path Description9591 / 12485

Sorting and Searching

• Distinct Numbers73449 / 79492
• Apartments54296 / 60443
• Ferris Wheel52138 / 56332
• Concert Tickets42028 / 48989
• Restaurant Customers42698 / 46128
• Movie Festival41033 / 43479
• Sum of Two Values47948 / 53765
• Maximum Subarray Sum46378 / 48469
• Stick Lengths41321 / 43249
• Missing Coin Sum31062 / 32213
• Collecting Numbers31808 / 34105
• Collecting Numbers II13218 / 16931
• Playlist31896 / 36523
• Towers32320 / 34635
• Traffic Lights25024 / 28034
• Distinct Values Subarrays5664 / 5960
• Distinct Values Subsequences3894 / 4340
• Josephus Problem I19063 / 21049
• Josephus Problem II10285 / 14214
• Nested Ranges Check10907 / 12570
• Nested Ranges Count7389 / 8733
• Room Allocation18803 / 21611
• Factory Machines26772 / 29217
• Tasks and Deadlines21561 / 22033
• Reading Books17475 / 18727
• Sum of Three Values25677 / 28468
• Sum of Four Values15917 / 17772
• Nearest Smaller Values21296 / 22031
• Subarray Sums I28232 / 30133
• Subarray Sums II25614 / 30462
• Subarray Divisibility23375 / 25509
• Distinct Values Subarrays II14000 / 15449
• Array Division22183 / 23364
• Movie Festival II11839 / 14298
• Maximum Subarray Sum II10924 / 13066

Dynamic Programming

• Dice Combinations76906 / 81388
• Minimizing Coins66390 / 71392
• Coin Combinations I60594 / 65661
• Coin Combinations II51178 / 58015
• Removing Digits57026 / 58196
• Grid Paths I53682 / 55243
• Book Shop47890 / 52739
• Array Description35263 / 39219
• Counting Towers21387 / 22685
• Edit Distance35402 / 37378
• Longest Common Subsequence7731 / 8021
• Rectangle Cutting29377 / 32113
• Minimal Grid Path3314 / 6237
• Money Sums34832 / 36175
• Removal Game20569 / 27881
• Two Sets II27456 / 29586
• Mountain Range2331 / 4403
• Increasing Subsequence28047 / 31505
• Projects19325 / 21642
• Elevator Rides12307 / 15533
• Counting Tilings7193 / 7856
• Counting Numbers9867 / 11159
• Increasing Subsequence II3897 / 4533

Graph Algorithms

• Counting Rooms52843 / 55537
• Labyrinth36534 / 43850
• Building Roads46013 / 47676
• Message Route39592 / 41179
• Building Teams37377 / 39434
• Round Trip29698 / 32382
• Monsters20238 / 23955
• Shortest Routes I32453 / 35864
• Shortest Routes II26449 / 29683
• High Score16008 / 22789
• Flight Discount20701 / 24294
• Cycle Finding14735 / 18144
• Flight Routes14394 / 16082
• Round Trip II16405 / 18452
• Course Schedule21517 / 22761
• Longest Flight Route15112 / 18845
• Game Routes16964 / 18195
• Investigation12567 / 13532
• Planets Queries I10957 / 12857
• Planets Queries II3923 / 4981
• Planets Cycles6697 / 7485
• Road Reparation16497 / 17206
• Road Construction18069 / 18649
• Flight Routes Check14673 / 15913
• Planets and Kingdoms11790 / 12213
• Giant Pizza4851 / 5347
• Coin Collector7630 / 8478
• Mail Delivery6373 / 6981
• De Bruijn Sequence3329 / 3485
• Teleporters Path4820 / 5531
• Hamiltonian Flights7228 / 8259
• Knight's Tour2706 / 3290
• Download Speed4786 / 6466
• Police Chase3818 / 4297
• School Dance4221 / 4465
• Distinct Routes2959 / 3896

Range Queries

• Static Range Sum Queries36600 / 38236
• Static Range Minimum Queries25690 / 27514
• Dynamic Range Sum Queries26666 / 27849
• Dynamic Range Minimum Queries24155 / 24733
• Range Xor Queries24999 / 25336
• Range Update Queries19791 / 21229
• Forest Queries20284 / 21052
• Hotel Queries14312 / 15210
• List Removals11899 / 12527
• Salary Queries8832 / 11200
• Prefix Sum Queries7587 / 8232
• Pizzeria Queries6105 / 6335
• Visible Buildings Queries1286 / 1409
• Range Interval Queries1009 / 1344
• Subarray Sum Queries7290 / 7916
• Subarray Sum Queries II1360 / 1427
• Distinct Values Queries6711 / 8319
• Distinct Values Queries II804 / 929
• Increasing Array Queries2576 / 2960
• Movie Festival Queries1282 / 1425
• Forest Queries II4364 / 4701
• Range Updates and Sums5815 / 6928
• Polynomial Queries4265 / 5010
• Range Queries and Copies3065 / 3285
• Missing Coin Sum Queries641 / 842

Tree Algorithms

• Subordinates30421 / 32540
• Tree Matching17242 / 20101
• Tree Diameter24793 / 26293
• Tree Distances I18920 / 20344
• Tree Distances II15489 / 16150
• Company Queries I17211 / 18116
• Company Queries II16146 / 16935
• Distance Queries14674 / 15753
• Counting Paths9195 / 9753
• Subtree Queries11022 / 11767
• Path Queries8837 / 9364
• Path Queries II3550 / 5376
• Distinct Colors8495 / 9393
• Finding a Centroid6865 / 7153
• Fixed-Length Paths I3265 / 4237
• Fixed-Length Paths II1528 / 2821

Mathematics

• Josephus Queries4669 / 5884
• Exponentiation23888 / 25525
• Exponentiation II16943 / 20330
• Counting Divisors21730 / 24552
• Common Divisors14258 / 16590
• Sum of Divisors7945 / 11960
• Divisor Analysis5415 / 7286
• Prime Multiples6256 / 7312
• Counting Coprime Pairs4070 / 4765
• Next Prime1542 / 1759
• Binomial Coefficients10030 / 11149
• Creating Strings II8477 / 8949
• Distributing Apples8145 / 8765
• Christmas Party6564 / 7056
• Permutation Order726 / 738
• Permutation Rounds878 / 981
• Bracket Sequences I4506 / 4907
• Bracket Sequences II2333 / 2681
• Counting Necklaces2166 / 2346
• Counting Grids1779 / 1902
• Fibonacci Numbers6946 / 8716
• Throwing Dice3592 / 3908
• Graph Paths I3420 / 3673
• Graph Paths II2859 / 2997
• System of Linear Equations343 / 382
• Sum of Four Squares540 / 623
• Triangle Number Sums454 / 570
• Dice Probability3087 / 3333
• Moving Robots1587 / 1679
• Candy Lottery1394 / 2972
• Inversion Probability334 / 2255
• Stick Game3469 / 3552
• Nim Game I4588 / 4760
• Nim Game II3631 / 3781
• Stair Game2453 / 2670
• Grundy's Game1700 / 2240
• Another Game1929 / 2082

String Algorithms

• Word Combinations5872 / 8530
• String Matching11413 / 15285
• Finding Borders8334 / 9118
• Finding Periods5938 / 6752
• Minimal Rotation2880 / 4394
• Longest Palindrome4358 / 5761
• All Palindromes525 / 599
• Required Substring1651 / 2532
• Palindrome Queries2047 / 2384
• Finding Patterns1905 / 2718
• Counting Patterns1803 / 2242
• Pattern Positions1505 / 1845
• Distinct Substrings1719 / 2057
• Distinct Subsequences1076 / 1146
• Repeating Substring1858 / 2167
• String Functions1621 / 1697
• Inverse Suffix Array169 / 210
• String Transform524 / 639
• Substring Order I1163 / 1304
• Substring Order II773 / 1002
• Substring Distribution1082 / 1176

Geometry

• Point Location Test7274 / 8125
• Line Segment Intersection4336 / 5448
• Polygon Area5003 / 5301
• Point in Polygon2740 / 3520
• Polygon Lattice Points2327 / 2410
• Minimum Euclidean Distance2021 / 2800
• Convex Hull3330 / 4006
• Maximum Manhattan Distances487 / 502
• All Manhattan Distances494 / 540
• Intersection Points1954 / 2104
• Line Segments Trace I271 / 280
• Line Segments Trace II223 / 235
• Lines and Queries I303 / 312
• Lines and Queries II262 / 270
• Area of Rectangles1115 / 1246
• Robot Path290 / 538

Advanced Techniques

• Meet in the Middle6639 / 9265
• Hamming Distance3220 / 3509
• Corner Subgrid Check260 / 415
• Corner Subgrid Count2232 / 2507
• Reachable Nodes2244 / 2414
• Reachability Queries1488 / 1764
• Cut and Paste1499 / 1671
• Substring Reversals1309 / 1427
• Reversals and Sums1319 / 1421
• Necessary Roads1918 / 1963
• Necessary Cities1779 / 1865
• Eulerian Subgraphs784 / 825
• Monster Game I1136 / 1263
• Monster Game II1015 / 1089
• Subarray Squares1373 / 1627
• Houses and Schools759 / 909
• Knuth Division919 / 1038
• Apples and Bananas1046 / 1137
• One Bit Positions835 / 914
• Signal Processing791 / 849
• New Roads Queries2159 / 2627
• Dynamic Connectivity984 / 1111
• Parcel Delivery754 / 836
• Task Assignment890 / 947
• Distinct Routes II571 / 654

Sliding Window Problems

• Sliding Window Sum3954 / 4130
• Sliding Window Minimum2983 / 3419
• Sliding Window Xor2927 / 2965
• Sliding Window Or1258 / 2270
• Sliding Window Distinct Values1845 / 2490
• Sliding Window Mode1690 / 1783
• Sliding Window Mex1513 / 1599
• Sliding Window Median13452 / 15389
• Sliding Window Cost8858 / 10234
• Sliding Window Inversions857 / 917
• Sliding Window Advertisement167 / 272

Interactive Problems

• Hidden Integer1688 / 1746
• Hidden Permutation720 / 858
• K-th Highest Score318 / 384
• Permuted Binary Strings402 / 413
• Colored Chairs355 / 375
• Inversion Sorting212 / 230

Bitwise Operations

• Counting Bits4620 / 5941
• Maximum Xor Subarray2793 / 3152
• Maximum Xor Subset780 / 841
• Number of Subset Xors674 / 688
• K Subset Xors319 / 386
• All Subarray Xors212 / 340
• Xor Pyramid Peak1895 / 2320
• Xor Pyramid Diagonal243 / 275
• Xor Pyramid Row198 / 233
• SOS Bit Problem1999 / 2132
• And Subset Count314 / 319

Construction Problems

• Inverse Inversions1451 / 1545
• Monotone Subsequences894 / 1050
• Third Permutation309 / 361
• Permutation Prime Sums302 / 327
• Chess Tournament1136 / 1313
• Distinct Sums Grid86 / 144
• Filling Trominos232 / 403
• Grid Path Construction118 / 421

Advanced Graph Problems

• Nearest Shops551 / 716
• Prüfer Code1462 / 1578
• Tree Traversals1149 / 1264
• Course Schedule II1814 / 2609
• Acyclic Graph Edges2155 / 2288
• Strongly Connected Edges1498 / 1663
• Even Outdegree Edges1274 / 1498
• Graph Girth3265 / 3730
• Fixed Length Walk Queries273 / 302
• Transfer Speeds Sum324 / 334
• MST Edge Check468 / 503
• MST Edge Set Check177 / 201
• MST Edge Cost292 / 305
• Network Breakdown980 / 1039
• Tree Coin Collecting I248 / 276
• Tree Coin Collecting II128 / 151
• Tree Isomorphism I1037 / 1246
• Tree Isomorphism II842 / 984
• Flight Route Requests464 / 568
• Critical Cities393 / 610
• Visiting Cities654 / 869
• Graph Coloring176 / 207
• Bus Companies202 / 208
• Split into Two Paths66 / 127
• Network Renovation907 / 1211
• Forbidden Cities796 / 1043
• Creating Offices396 / 518
• New Flight Routes299 / 812

Counting Problems

• Filled Subgrid Count I431 / 476
• Filled Subgrid Count II223 / 276
• All Letter Subgrid Count I118 / 185
• All Letter Subgrid Count II98 / 121
• Border Subgrid Count I72 / 124
• Border Subgrid Count II75 / 87
• Raab Game II76 / 91
• Empty String1551 / 1896
• Permutation Inversions983 / 1086
• Counting Bishops367 / 410
• Counting Sequences633 / 678
• Grid Paths II723 / 902
• Counting Permutations848 / 960
• Grid Completion214 / 270
• Counting Reorders225 / 330
• Tournament Graph Distribution83 / 87
• Collecting Numbers Distribution89 / 97
• Functional Graph Distribution230 / 284

Additional Problems I

• Shortest Subsequence2911 / 3851
• Distinct Values Sum512 / 528
• Distinct Values Splits360 / 380
• Swap Game1986 / 2520
• Beautiful Permutation II327 / 488
• Multiplication Table6394 / 7140
• Bubble Sort Rounds I291 / 335
• Bubble Sort Rounds II165 / 192
• Nearest Campsites I130 / 150
• Nearest Campsites II130 / 139
• Advertisement4149 / 4397
• Special Substrings938 / 1030
• Counting LCM Arrays205 / 223
• Square Subsets167 / 187
• Subarray Sum Constraints231 / 248
• Water Containers Moves122 / 129
• Water Containers Queries153 / 159
• Stack Weights562 / 667
• Maximum Average Subarrays122 / 134
• Subsets with Fixed Average159 / 175
• Two Array Average152 / 171
• Pyramid Array686 / 837
• Permutation Subsequence172 / 175
• Bit Inversions2231 / 2539
• Writing Numbers713 / 770
• Letter Pair Move Game191 / 269
• Maximum Building I1990 / 2076
• Sorting Methods740 / 793
• Cyclic Array1125 / 1282
• List of Sums456 / 599

Additional Problems II

• Bouncing Ball Steps169 / 185
• Bouncing Ball Cycle66 / 94
• Knight Moves Queries93 / 114
• K Subset Sums I130 / 177
• K Subset Sums II66 / 90
• Increasing Array II757 / 873
• Food Division503 / 596
• Swap Round Sorting399 / 491
• Binary Subsequences275 / 406
• School Excursion1318 / 1400
• Coin Grid828 / 968
• Grid Coloring II102 / 131
• Programmers and Artists466 / 653
• Removing Digits II208 / 455
• Coin Arrangement311 / 418
• Replace with Difference93 / 114
• Grid Puzzle I506 / 555
• Grid Puzzle II480 / 528
• Bit Substrings368 / 447
• Reversal Sorting335 / 408
• Book Shop II1141 / 1309
• GCD Subsets324 / 332
• Minimum Cost Pairs82 / 113
• Same Sum Subsets84 / 160
• Mex Grid Queries813 / 954
• Maximum Building II430 / 529
• Stick Divisions3652 / 4287
• Stick Difference31 / 170
• Coding Company1406 / 1854
• Two Stacks Sorting163 / 518