CSES Problem Set

General

• Introduction
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• Statistics

Introductory Problems

• Weird Algorithm145489 / 152383
• Missing Number125393 / 131567
• Repetitions109239 / 113763
• Increasing Array102629 / 106403
• Permutations90167 / 92983
• Number Spiral63746 / 69522
• Two Knights48657 / 50220
• Two Sets52901 / 57004
• Bit Strings60642 / 64048
• Trailing Zeros56660 / 60303
• Coin Piles50147 / 54911
• Palindrome Reorder46480 / 49119
• Gray Code30888 / 34785
• Tower of Hanoi28570 / 29716
• Creating Strings39240 / 40270
• Apple Division39191 / 44372
• Chessboard and Queens23658 / 24092
• Raab Game I3151 / 3601
• Mex Grid Construction3018 / 3233
• Knight Moves Grid3035 / 3105
• Grid Coloring I2505 / 2594
• Digit Queries16728 / 19561
• String Reorder2478 / 2886
• Grid Path Description9329 / 12144

Sorting and Searching

• Distinct Numbers70865 / 76773
• Apartments52496 / 58483
• Ferris Wheel50342 / 54456
• Concert Tickets40541 / 47320
• Restaurant Customers41324 / 44657
• Movie Festival39627 / 42013
• Sum of Two Values46261 / 51908
• Maximum Subarray Sum44895 / 46926
• Stick Lengths40057 / 41952
• Missing Coin Sum30022 / 31147
• Collecting Numbers30793 / 33029
• Collecting Numbers II12709 / 16354
• Playlist30853 / 35391
• Towers31213 / 33478
• Traffic Lights24133 / 27083
• Distinct Values Subarrays4718 / 4973
• Distinct Values Subsequences3267 / 3653
• Josephus Problem I18344 / 20297
• Josephus Problem II9870 / 13659
• Nested Ranges Check10477 / 12105
• Nested Ranges Count7108 / 8410
• Room Allocation18167 / 20920
• Factory Machines25669 / 28060
• Tasks and Deadlines20839 / 21299
• Reading Books16884 / 18096
• Sum of Three Values24675 / 27395
• Sum of Four Values15401 / 17229
• Nearest Smaller Values20622 / 21334
• Subarray Sums I27209 / 29088
• Subarray Sums II24596 / 29347
• Subarray Divisibility22609 / 24711
• Distinct Values Subarrays II13352 / 14793
• Array Division21352 / 22489
• Movie Festival II11359 / 13750
• Maximum Subarray Sum II10506 / 12608

Dynamic Programming

• Dice Combinations74102 / 78459
• Minimizing Coins64047 / 68883
• Coin Combinations I58513 / 63421
• Coin Combinations II49459 / 56109
• Removing Digits55195 / 56345
• Grid Paths I51792 / 53287
• Book Shop46288 / 51038
• Array Description34036 / 37905
• Counting Towers20596 / 21849
• Edit Distance34289 / 36202
• Longest Common Subsequence6453 / 6702
• Rectangle Cutting28501 / 31161
• Minimal Grid Path2749 / 5287
• Money Sums33807 / 35130
• Removal Game19743 / 27025
• Two Sets II26633 / 28727
• Mountain Range1899 / 3723
• Increasing Subsequence27208 / 30580
• Projects18719 / 21007
• Elevator Rides11842 / 14987
• Counting Tilings6898 / 7547
• Counting Numbers9365 / 10614
• Increasing Subsequence II3515 / 4082

Graph Algorithms

• Counting Rooms50956 / 53590
• Labyrinth35173 / 42344
• Building Roads44511 / 46135
• Message Route38209 / 39765
• Building Teams36061 / 38096
• Round Trip28658 / 31277
• Monsters19468 / 23111
• Shortest Routes I31175 / 34548
• Shortest Routes II25440 / 28618
• High Score15313 / 21973
• Flight Discount19907 / 23423
• Cycle Finding14161 / 17502
• Flight Routes13815 / 15445
• Round Trip II15818 / 17821
• Course Schedule20738 / 21975
• Longest Flight Route14488 / 18160
• Game Routes16341 / 17555
• Investigation12097 / 13038
• Planets Queries I10500 / 12357
• Planets Queries II3741 / 4762
• Planets Cycles6435 / 7203
• Road Reparation15811 / 16489
• Road Construction17389 / 17952
• Flight Routes Check14140 / 15360
• Planets and Kingdoms11342 / 11751
• Giant Pizza4622 / 5107
• Coin Collector7307 / 8141
• Mail Delivery6112 / 6708
• De Bruijn Sequence3181 / 3335
• Teleporters Path4607 / 5318
• Hamiltonian Flights6933 / 7931
• Knight's Tour2569 / 3138
• Download Speed4541 / 6188
• Police Chase3640 / 4106
• School Dance4032 / 4273
• Distinct Routes2773 / 3678

Range Queries

• Static Range Sum Queries35107 / 36697
• Static Range Minimum Queries24781 / 26558
• Dynamic Range Sum Queries25774 / 26923
• Dynamic Range Minimum Queries23378 / 23942
• Range Xor Queries24157 / 24488
• Range Update Queries19082 / 20498
• Forest Queries19507 / 20258
• Hotel Queries13785 / 14673
• List Removals11488 / 12106
• Salary Queries8430 / 10739
• Prefix Sum Queries7216 / 7842
• Pizzeria Queries5831 / 6065
• Visible Buildings Queries1039 / 1138
• Range Interval Queries820 / 1083
• Subarray Sum Queries7027 / 7649
• Subarray Sum Queries II1120 / 1156
• Distinct Values Queries6427 / 8011
• Distinct Values Queries II640 / 750
• Increasing Array Queries2471 / 2842
• Movie Festival Queries1175 / 1309
• Forest Queries II4220 / 4549
• Range Updates and Sums5590 / 6683
• Polynomial Queries4119 / 4838
• Range Queries and Copies2924 / 3143
• Missing Coin Sum Queries574 / 765

Tree Algorithms

• Subordinates29327 / 31400
• Tree Matching16614 / 19429
• Tree Diameter23871 / 25340
• Tree Distances I18169 / 19561
• Tree Distances II14928 / 15578
• Company Queries I16555 / 17441
• Company Queries II15501 / 16276
• Distance Queries14121 / 15186
• Counting Paths8793 / 9342
• Subtree Queries10581 / 11304
• Path Queries8408 / 8913
• Path Queries II3386 / 5112
• Distinct Colors8172 / 9051
• Finding a Centroid6575 / 6856
• Fixed-Length Paths I3103 / 4055
• Fixed-Length Paths II1442 / 2688

Mathematics

• Josephus Queries4458 / 5626
• Exponentiation23119 / 24700
• Exponentiation II16388 / 19705
• Counting Divisors20959 / 23706
• Common Divisors13750 / 16016
• Sum of Divisors7655 / 11577
• Divisor Analysis5211 / 7019
• Prime Multiples5925 / 6958
• Counting Coprime Pairs3868 / 4548
• Next Prime1250 / 1436
• Binomial Coefficients9680 / 10765
• Creating Strings II8160 / 8631
• Distributing Apples7847 / 8453
• Christmas Party6308 / 6789
• Permutation Order574 / 583
• Permutation Rounds664 / 744
• Bracket Sequences I4330 / 4724
• Bracket Sequences II2240 / 2580
• Counting Necklaces2072 / 2248
• Counting Grids1687 / 1804
• Fibonacci Numbers6692 / 8428
• Throwing Dice3470 / 3776
• Graph Paths I3286 / 3532
• Graph Paths II2748 / 2883
• System of Linear Equations289 / 312
• Sum of Four Squares439 / 514
• Triangle Number Sums377 / 469
• Dice Probability2981 / 3224
• Moving Robots1535 / 1627
• Candy Lottery1259 / 2825
• Inversion Probability287 / 2177
• Stick Game3336 / 3415
• Nim Game I4397 / 4566
• Nim Game II3483 / 3633
• Stair Game2371 / 2580
• Grundy's Game1622 / 2147
• Another Game1836 / 1984

String Algorithms

• Word Combinations5595 / 8185
• String Matching10930 / 14707
• Finding Borders7985 / 8748
• Finding Periods5700 / 6483
• Minimal Rotation2761 / 4251
• Longest Palindrome4195 / 5566
• All Palindromes424 / 485
• Required Substring1582 / 2449
• Palindrome Queries1974 / 2306
• Finding Patterns1811 / 2605
• Counting Patterns1711 / 2136
• Pattern Positions1435 / 1759
• Distinct Substrings1634 / 1959
• Distinct Subsequences1024 / 1093
• Repeating Substring1775 / 2082
• String Functions1556 / 1632
• Inverse Suffix Array148 / 171
• String Transform495 / 606
• Substring Order I1110 / 1248
• Substring Order II733 / 953
• Substring Distribution1033 / 1125

Geometry

• Point Location Test6950 / 7780
• Line Segment Intersection4153 / 5248
• Polygon Area4835 / 5131
• Point in Polygon2640 / 3352
• Polygon Lattice Points2231 / 2312
• Minimum Euclidean Distance1931 / 2687
• Convex Hull3169 / 3831
• Maximum Manhattan Distances404 / 415
• All Manhattan Distances408 / 447
• Intersection Points1877 / 2020
• Line Segments Trace I223 / 230
• Line Segments Trace II179 / 190
• Lines and Queries I239 / 248
• Lines and Queries II204 / 213
• Area of Rectangles1062 / 1190
• Robot Path295 / 510

Advanced Techniques

• Meet in the Middle6390 / 8975
• Hamming Distance3123 / 3401
• Corner Subgrid Check210 / 353
• Corner Subgrid Count2175 / 2442
• Reachable Nodes2165 / 2330
• Reachability Queries1444 / 1712
• Cut and Paste1436 / 1599
• Substring Reversals1261 / 1378
• Reversals and Sums1269 / 1371
• Necessary Roads1852 / 1896
• Necessary Cities1721 / 1807
• Eulerian Subgraphs757 / 798
• Monster Game I1101 / 1227
• Monster Game II977 / 1051
• Subarray Squares1291 / 1540
• Houses and Schools722 / 864
• Knuth Division879 / 997
• Apples and Bananas968 / 1052
• One Bit Positions784 / 861
• Signal Processing733 / 789
• New Roads Queries2068 / 2526
• Dynamic Connectivity926 / 1050
• Parcel Delivery717 / 798
• Task Assignment838 / 890
• Distinct Routes II548 / 631

Sliding Window Problems

• Sliding Window Sum3199 / 3349
• Sliding Window Minimum2489 / 2836
• Sliding Window Xor2399 / 2431
• Sliding Window Or1017 / 1876
• Sliding Window Distinct Values2010 / 2051
• Sliding Window Mode1406 / 1482
• Sliding Window Mex1247 / 1314
• Sliding Window Median13059 / 14959
• Sliding Window Cost8680 / 10025
• Sliding Window Inversions713 / 763
• Sliding Window Advertisement137 / 217

Interactive Problems

• Hidden Integer1335 / 1377
• Hidden Permutation587 / 699
• K-th Highest Score253 / 309
• Permuted Binary Strings340 / 351
• Colored Chairs295 / 310
• Inversion Sorting171 / 182

Bitwise Operations

• Counting Bits4280 / 5506
• Maximum Xor Subarray2630 / 2954
• Maximum Xor Subset619 / 667
• Number of Subset Xors529 / 541
• K Subset Xors257 / 303
• All Subarray Xors180 / 276
• Xor Pyramid Peak1801 / 2212
• Xor Pyramid Diagonal205 / 231
• Xor Pyramid Row169 / 195
• SOS Bit Problem1856 / 1984
• And Subset Count253 / 257

Construction Problems

• Inverse Inversions1314 / 1400
• Monotone Subsequences799 / 937
• Third Permutation251 / 292
• Permutation Prime Sums246 / 266
• Chess Tournament1085 / 1252
• Distinct Sums Grid68 / 119
• Filling Trominos224 / 387
• Grid Path Construction113 / 412

Advanced Graph Problems

• Nearest Shops468 / 609
• Prüfer Code1397 / 1511
• Tree Traversals1097 / 1210
• Course Schedule II1714 / 2466
• Acyclic Graph Edges2064 / 2194
• Strongly Connected Edges1434 / 1590
• Even Outdegree Edges1224 / 1444
• Graph Girth3127 / 3588
• Fixed Length Walk Queries243 / 263
• Transfer Speeds Sum277 / 284
• MST Edge Check351 / 377
• MST Edge Set Check147 / 168
• MST Edge Cost251 / 262
• Network Breakdown931 / 990
• Tree Coin Collecting I207 / 230
• Tree Coin Collecting II109 / 125
• Tree Isomorphism I1006 / 1204
• Tree Isomorphism II815 / 958
• Flight Route Requests445 / 542
• Critical Cities381 / 587
• Visiting Cities628 / 836
• Graph Coloring136 / 162
• Bus Companies171 / 174
• Split into Two Paths59 / 105
• Network Renovation880 / 1177
• Forbidden Cities749 / 987
• Creating Offices385 / 499
• New Flight Routes285 / 768

Counting Problems

• Filled Subgrid Count I342 / 378
• Filled Subgrid Count II176 / 214
• All Letter Subgrid Count I86 / 142
• All Letter Subgrid Count II79 / 94
• Border Subgrid Count I61 / 107
• Border Subgrid Count II64 / 74
• Raab Game II63 / 75
• Empty String1490 / 1818
• Permutation Inversions946 / 1040
• Counting Bishops356 / 399
• Counting Sequences607 / 653
• Grid Paths II699 / 872
• Counting Permutations822 / 932
• Grid Completion205 / 260
• Counting Reorders216 / 316
• Tournament Graph Distribution70 / 73
• Collecting Numbers Distribution74 / 76
• Functional Graph Distribution220 / 275

Additional Problems I

• Shortest Subsequence2820 / 3748
• Distinct Values Sum419 / 431
• Distinct Values Splits289 / 308
• Swap Game1916 / 2436
• Beautiful Permutation II220 / 323
• Multiplication Table6101 / 6826
• Bubble Sort Rounds I221 / 255
• Bubble Sort Rounds II118 / 138
• Nearest Campsites I99 / 116
• Nearest Campsites II96 / 106
• Advertisement4001 / 4237
• Special Substrings908 / 994
• Counting LCM Arrays167 / 179
• Square Subsets131 / 147
• Subarray Sum Constraints156 / 167
• Water Containers Moves95 / 105
• Water Containers Queries125 / 130
• Stack Weights541 / 644
• Maximum Average Subarrays97 / 108
• Subsets with Fixed Average129 / 138
• Two Array Average120 / 136
• Pyramid Array664 / 805
• Permutation Subsequence140 / 144
• Bit Inversions2162 / 2471
• Writing Numbers697 / 754
• Letter Pair Move Game183 / 262
• Maximum Building I1937 / 2022
• Sorting Methods726 / 778
• Cyclic Array1089 / 1243
• List of Sums440 / 573

Additional Problems II

• Bouncing Ball Steps144 / 158
• Bouncing Ball Cycle57 / 77
• Knight Moves Queries80 / 96
• K Subset Sums I101 / 139
• K Subset Sums II53 / 74
• Increasing Array II737 / 852
• Food Division496 / 586
• Swap Round Sorting390 / 481
• Binary Subsequences268 / 395
• School Excursion1270 / 1350
• Coin Grid791 / 930
• Grid Coloring II84 / 106
• Programmers and Artists452 / 637
• Removing Digits II196 / 444
• Coin Arrangement301 / 410
• Replace with Difference78 / 95
• Grid Puzzle I488 / 535
• Grid Puzzle II449 / 493
• Bit Substrings350 / 429
• Reversal Sorting328 / 400
• Book Shop II1088 / 1252
• GCD Subsets267 / 275
• Minimum Cost Pairs61 / 83
• Same Sum Subsets66 / 124
• Mex Grid Queries790 / 930
• Maximum Building II414 / 509
• Stick Divisions3563 / 4187
• Stick Difference24 / 139
• Coding Company1355 / 1790
• Two Stacks Sorting157 / 497