CSES Problem Set

General

• Introduction
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• Statistics

Introductory Problems

• Weird Algorithm154745 / 161958
• Missing Number133508 / 139915
• Repetitions116207 / 120871
• Increasing Array109261 / 113140
• Permutations96097 / 99017
• Number Spiral67942 / 73993
• Two Knights51935 / 53558
• Two Sets56499 / 60790
• Bit Strings64634 / 68218
• Trailing Zeros60208 / 64030
• Coin Piles53308 / 58306
• Palindrome Reorder49594 / 52339
• Gray Code33154 / 37256
• Tower of Hanoi30754 / 31990
• Creating Strings41828 / 42914
• Apple Division41957 / 47391
• Chessboard and Queens25299 / 25754
• Raab Game I4511 / 5100
• Mex Grid Construction4358 / 4625
• Knight Moves Grid4321 / 4421
• Grid Coloring I3628 / 3752
• Digit Queries17788 / 20680
• String Reorder3349 / 3889
• Grid Path Description9894 / 12849

Sorting and Searching

• Distinct Numbers76222 / 82401
• Apartments56655 / 62903
• Ferris Wheel54432 / 58714
• Concert Tickets43702 / 50866
• Restaurant Customers44463 / 47982
• Movie Festival42819 / 45351
• Sum of Two Values49874 / 55805
• Maximum Subarray Sum48123 / 50241
• Stick Lengths42968 / 44944
• Missing Coin Sum32378 / 33557
• Collecting Numbers33232 / 35579
• Collecting Numbers II13908 / 17752
• Playlist33188 / 37880
• Towers33462 / 35842
• Traffic Lights25944 / 29025
• Distinct Values Subarrays5927 / 7055
• Distinct Values Subsequences4639 / 5132
• Josephus Problem I19837 / 21864
• Josephus Problem II10738 / 14816
• Nested Ranges Check11450 / 13159
• Nested Ranges Count7717 / 9115
• Room Allocation19506 / 22369
• Factory Machines27821 / 30296
• Tasks and Deadlines22339 / 22818
• Reading Books18114 / 19398
• Sum of Three Values26577 / 29427
• Sum of Four Values16485 / 18357
• Nearest Smaller Values22087 / 22843
• Subarray Sums I29311 / 31247
• Subarray Sums II26614 / 31565
• Subarray Divisibility24221 / 26377
• Distinct Values Subarrays II14572 / 16031
• Array Division22958 / 24164
• Movie Festival II12267 / 14797
• Maximum Subarray Sum II11341 / 13537

Dynamic Programming

• Dice Combinations79231 / 83804
• Minimizing Coins68437 / 73518
• Coin Combinations I62510 / 67674
• Coin Combinations II52777 / 59736
• Removing Digits58801 / 59991
• Grid Paths I55332 / 56904
• Book Shop49460 / 54390
• Array Description36323 / 40337
• Counting Towers22142 / 23481
• Edit Distance36606 / 38634
• Longest Common Subsequence8917 / 9239
• Rectangle Cutting30232 / 33011
• Minimal Grid Path3793 / 7018
• Money Sums35827 / 37185
• Removal Game21292 / 28629
• Two Sets II28171 / 30335
• Mountain Range2678 / 4934
• Increasing Subsequence28848 / 32391
• Projects19840 / 22180
• Elevator Rides12706 / 16005
• Counting Tilings7429 / 8096
• Counting Numbers10380 / 11706
• Increasing Subsequence II4228 / 4912

Graph Algorithms

• Counting Rooms54332 / 57072
• Labyrinth37618 / 45080
• Building Roads47305 / 49012
• Message Route40735 / 42350
• Building Teams38539 / 40629
• Round Trip30600 / 33317
• Monsters20892 / 24657
• Shortest Routes I33422 / 36868
• Shortest Routes II27223 / 30507
• High Score16588 / 23422
• Flight Discount21441 / 25078
• Cycle Finding15292 / 18751
• Flight Routes14857 / 16574
• Round Trip II16893 / 18957
• Course Schedule22163 / 23411
• Longest Flight Route15626 / 19399
• Game Routes17487 / 18726
• Investigation12974 / 13944
• Planets Queries I11356 / 13281
• Planets Queries II4100 / 5193
• Planets Cycles6949 / 7764
• Road Reparation17018 / 17739
• Road Construction18664 / 19243
• Flight Routes Check15118 / 16385
• Planets and Kingdoms12055 / 12552
• Giant Pizza5047 / 5550
• Coin Collector7887 / 8743
• Mail Delivery6578 / 7195
• De Bruijn Sequence3451 / 3613
• Teleporters Path4995 / 5713
• Hamiltonian Flights7518 / 8579
• Knight's Tour2825 / 3417
• Download Speed4958 / 6651
• Police Chase3972 / 4453
• School Dance4359 / 4607
• Distinct Routes3083 / 4034

Range Queries

• Static Range Sum Queries37920 / 39606
• Static Range Minimum Queries26400 / 28262
• Dynamic Range Sum Queries27393 / 28594
• Dynamic Range Minimum Queries24814 / 25396
• Range Xor Queries25677 / 26018
• Range Update Queries20381 / 21839
• Forest Queries20948 / 21733
• Hotel Queries14795 / 15699
• List Removals12270 / 12906
• Salary Queries9209 / 11609
• Prefix Sum Queries7871 / 8522
• Pizzeria Queries6328 / 6563
• Visible Buildings Queries1454 / 1593
• Range Interval Queries1131 / 1510
• Subarray Sum Queries7521 / 8152
• Subarray Sum Queries II1578 / 1642
• Distinct Values Queries6953 / 8581
• Distinct Values Queries II914 / 1050
• Increasing Array Queries2667 / 3057
• Movie Festival Queries1356 / 1509
• Forest Queries II4474 / 4816
• Range Updates and Sums6013 / 7137
• Polynomial Queries4403 / 5160
• Range Queries and Copies3170 / 3392
• Missing Coin Sum Queries679 / 901

Tree Algorithms

• Subordinates31294 / 33459
• Tree Matching17776 / 20683
• Tree Diameter25516 / 27039
• Tree Distances I19513 / 20958
• Tree Distances II15986 / 16666
• Company Queries I17751 / 18669
• Company Queries II16691 / 17497
• Distance Queries15119 / 16213
• Counting Paths9482 / 10054
• Subtree Queries11352 / 12114
• Path Queries9117 / 9662
• Path Queries II3670 / 5567
• Distinct Colors8750 / 9658
• Finding a Centroid7078 / 7367
• Fixed-Length Paths I3380 / 4378
• Fixed-Length Paths II1592 / 2908

Mathematics

• Josephus Queries4872 / 6140
• Exponentiation24780 / 26466
• Exponentiation II17432 / 20882
• Counting Divisors22452 / 25332
• Common Divisors14682 / 17040
• Sum of Divisors8205 / 12281
• Divisor Analysis5607 / 7520
• Prime Multiples6498 / 7587
• Counting Coprime Pairs4235 / 4941
• Next Prime1758 / 2017
• Binomial Coefficients10459 / 11597
• Creating Strings II8783 / 9266
• Distributing Apples8431 / 9063
• Christmas Party6852 / 7347
• Permutation Order832 / 850
• Permutation Rounds1052 / 1166
• Bracket Sequences I4643 / 5055
• Bracket Sequences II2426 / 2780
• Counting Necklaces2236 / 2421
• Counting Grids1842 / 1966
• Fibonacci Numbers7111 / 8912
• Throwing Dice3692 / 4016
• Graph Paths I3506 / 3761
• Graph Paths II2928 / 3070
• System of Linear Equations390 / 434
• Sum of Four Squares590 / 707
• Triangle Number Sums514 / 635
• Dice Probability3173 / 3421
• Moving Robots1627 / 1722
• Candy Lottery1478 / 3063
• Inversion Probability378 / 2310
• Stick Game3579 / 3666
• Nim Game I4744 / 4924
• Nim Game II3758 / 3910
• Stair Game2540 / 2765
• Grundy's Game1757 / 2313
• Another Game1989 / 2144

String Algorithms

• Word Combinations6055 / 8771
• String Matching11721 / 15653
• Finding Borders8556 / 9361
• Finding Periods6077 / 6904
• Minimal Rotation2958 / 4490
• Longest Palindrome4472 / 5929
• All Palindromes576 / 657
• Required Substring1696 / 2590
• Palindrome Queries2087 / 2429
• Finding Patterns1949 / 2772
• Counting Patterns1843 / 2290
• Pattern Positions1543 / 1888
• Distinct Substrings1761 / 2103
• Distinct Subsequences1104 / 1177
• Repeating Substring1900 / 2210
• String Functions1654 / 1733
• Inverse Suffix Array193 / 233
• String Transform536 / 653
• Substring Order I1193 / 1335
• Substring Order II792 / 1028
• Substring Distribution1110 / 1206

Geometry

• Point Location Test7505 / 8367
• Line Segment Intersection4458 / 5586
• Polygon Area5152 / 5451
• Point in Polygon2839 / 3626
• Polygon Lattice Points2401 / 2483
• Minimum Euclidean Distance2002 / 2875
• Convex Hull3438 / 4117
• Maximum Manhattan Distances545 / 562
• All Manhattan Distances541 / 591
• Intersection Points2010 / 2169
• Line Segments Trace I298 / 307
• Line Segments Trace II244 / 257
• Lines and Queries I336 / 348
• Lines and Queries II288 / 298
• Area of Rectangles1161 / 1296
• Robot Path307 / 565

Advanced Techniques

• Meet in the Middle6808 / 9457
• Hamming Distance3275 / 3569
• Corner Subgrid Check295 / 461
• Corner Subgrid Count2271 / 2549
• Reachable Nodes2309 / 2485
• Reachability Queries1529 / 1807
• Cut and Paste1537 / 1714
• Substring Reversals1347 / 1467
• Reversals and Sums1356 / 1459
• Necessary Roads1975 / 2027
• Necessary Cities1822 / 1909
• Eulerian Subgraphs804 / 847
• Monster Game I1164 / 1295
• Monster Game II1038 / 1113
• Subarray Squares1419 / 1677
• Houses and Schools783 / 937
• Knuth Division959 / 1082
• Apples and Bananas1086 / 1181
• One Bit Positions861 / 941
• Signal Processing819 / 878
• New Roads Queries2215 / 2692
• Dynamic Connectivity1012 / 1141
• Parcel Delivery783 / 866
• Task Assignment923 / 982
• Distinct Routes II591 / 676

Sliding Window Problems

• Sliding Window Sum4670 / 4856
• Sliding Window Minimum3468 / 3974
• Sliding Window Xor3418 / 3462
• Sliding Window Or1517 / 2657
• Sliding Window Distinct Values2258 / 2898
• Sliding Window Mode1972 / 2079
• Sliding Window Mex1787 / 1885
• Sliding Window Median13779 / 15739
• Sliding Window Cost9041 / 10440
• Sliding Window Inversions1015 / 1084
• Sliding Window Advertisement200 / 319

Interactive Problems

• Hidden Integer1906 / 1971
• Hidden Permutation810 / 956
• K-th Highest Score354 / 434
• Permuted Binary Strings443 / 455
• Colored Chairs399 / 420
• Inversion Sorting229 / 252

Bitwise Operations

• Counting Bits4875 / 6290
• Maximum Xor Subarray2914 / 3307
• Maximum Xor Subset866 / 949
• Number of Subset Xors764 / 781
• K Subset Xors373 / 444
• All Subarray Xors241 / 391
• Xor Pyramid Peak1993 / 2431
• Xor Pyramid Diagonal273 / 308
• Xor Pyramid Row223 / 268
• SOS Bit Problem2095 / 2230
• And Subset Count354 / 365

Construction Problems

• Inverse Inversions1542 / 1642
• Monotone Subsequences944 / 1109
• Third Permutation343 / 409
• Permutation Prime Sums346 / 373
• Chess Tournament1183 / 1365
• Distinct Sums Grid103 / 165
• Filling Trominos233 / 417
• Grid Path Construction119 / 427

Advanced Graph Problems

• Nearest Shops604 / 782
• Prüfer Code1502 / 1618
• Tree Traversals1189 / 1309
• Course Schedule II1885 / 2704
• Acyclic Graph Edges2202 / 2338
• Strongly Connected Edges1556 / 1728
• Even Outdegree Edges1320 / 1546
• Graph Girth3362 / 3833
• Fixed Length Walk Queries314 / 344
• Transfer Speeds Sum364 / 375
• MST Edge Check522 / 565
• MST Edge Set Check195 / 224
• MST Edge Cost326 / 340
• Network Breakdown1010 / 1072
• Tree Coin Collecting I279 / 308
• Tree Coin Collecting II148 / 175
• Tree Isomorphism I1071 / 1284
• Tree Isomorphism II876 / 1018
• Flight Route Requests480 / 589
• Critical Cities403 / 626
• Visiting Cities665 / 884
• Graph Coloring202 / 238
• Bus Companies230 / 238
• Split into Two Paths77 / 146
• Network Renovation925 / 1234
• Forbidden Cities821 / 1073
• Creating Offices407 / 531
• New Flight Routes310 / 835

Counting Problems

• Filled Subgrid Count I486 / 542
• Filled Subgrid Count II259 / 320
• All Letter Subgrid Count I141 / 221
• All Letter Subgrid Count II109 / 139
• Border Subgrid Count I81 / 140
• Border Subgrid Count II83 / 100
• Raab Game II87 / 103
• Empty String1604 / 1960
• Permutation Inversions1006 / 1112
• Counting Bishops377 / 422
• Counting Sequences636 / 692
• Grid Paths II736 / 921
• Counting Permutations862 / 976
• Grid Completion218 / 277
• Counting Reorders230 / 337
• Tournament Graph Distribution91 / 96
• Collecting Numbers Distribution97 / 106
• Functional Graph Distribution235 / 291

Additional Problems I

• Shortest Subsequence2961 / 3908
• Distinct Values Sum570 / 589
• Distinct Values Splits407 / 432
• Swap Game2039 / 2581
• Beautiful Permutation II403 / 608
• Multiplication Table6626 / 7390
• Bubble Sort Rounds I338 / 384
• Bubble Sort Rounds II215 / 246
• Nearest Campsites I151 / 177
• Nearest Campsites II150 / 161
• Advertisement4254 / 4507
• Special Substrings964 / 1059
• Counting LCM Arrays225 / 247
• Square Subsets189 / 211
• Subarray Sum Constraints297 / 319
• Water Containers Moves140 / 148
• Water Containers Queries174 / 181
• Stack Weights576 / 685
• Maximum Average Subarrays144 / 160
• Subsets with Fixed Average176 / 193
• Two Array Average168 / 189
• Pyramid Array720 / 876
• Permutation Subsequence193 / 197
• Bit Inversions2284 / 2592
• Writing Numbers725 / 783
• Letter Pair Move Game196 / 275
• Maximum Building I2030 / 2120
• Sorting Methods755 / 809
• Cyclic Array1160 / 1320
• List of Sums471 / 617

Additional Problems II

• Bouncing Ball Steps191 / 212
• Bouncing Ball Cycle76 / 111
• Knight Moves Queries100 / 123
• K Subset Sums I154 / 203
• K Subset Sums II80 / 111
• Increasing Array II777 / 895
• Food Division505 / 611
• Swap Round Sorting403 / 498
• Binary Subsequences285 / 419
• School Excursion1351 / 1433
• Coin Grid856 / 1001
• Grid Coloring II114 / 152
• Programmers and Artists484 / 680
• Removing Digits II211 / 465
• Coin Arrangement321 / 433
• Replace with Difference109 / 131
• Grid Puzzle I519 / 572
• Grid Puzzle II494 / 547
• Bit Substrings379 / 462
• Reversal Sorting345 / 420
• Book Shop II1191 / 1366
• GCD Subsets356 / 365
• Minimum Cost Pairs92 / 130
• Same Sum Subsets100 / 183
• Mex Grid Queries826 / 971
• Maximum Building II437 / 539
• Stick Divisions3736 / 4390
• Stick Difference39 / 196
• Coding Company1453 / 1907
• Two Stacks Sorting171 / 547