CSES Problem Set

General

• Introduction
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• Statistics

Introductory Problems

• Weird Algorithm146255 / 153178
• Missing Number126161 / 132353
• Repetitions109854 / 114397
• Increasing Array103211 / 106991
• Permutations90661 / 93490
• Number Spiral64115 / 69912
• Two Knights48897 / 50463
• Two Sets53182 / 57309
• Bit Strings60967 / 64382
• Trailing Zeros56957 / 60611
• Coin Piles50414 / 55204
• Palindrome Reorder46768 / 49417
• Gray Code31059 / 34977
• Tower of Hanoi28729 / 29885
• Creating Strings39441 / 40476
• Apple Division39413 / 44612
• Chessboard and Queens23780 / 24214
• Raab Game I3245 / 3709
• Mex Grid Construction3118 / 3335
• Knight Moves Grid3141 / 3210
• Grid Coloring I2592 / 2682
• Digit Queries16806 / 19643
• String Reorder2553 / 2972
• Grid Path Description9372 / 12200

Sorting and Searching

• Distinct Numbers71265 / 77181
• Apartments52815 / 58817
• Ferris Wheel50668 / 54800
• Concert Tickets40774 / 47595
• Restaurant Customers41577 / 44929
• Movie Festival39868 / 42269
• Sum of Two Values46533 / 52201
• Maximum Subarray Sum45138 / 47180
• Stick Lengths40289 / 42196
• Missing Coin Sum30188 / 31317
• Collecting Numbers30971 / 33217
• Collecting Numbers II12786 / 16445
• Playlist31014 / 35568
• Towers31386 / 33660
• Traffic Lights24246 / 27208
• Distinct Values Subarrays4857 / 5114
• Distinct Values Subsequences3361 / 3764
• Josephus Problem I18445 / 20406
• Josephus Problem II9924 / 13742
• Nested Ranges Check10542 / 12170
• Nested Ranges Count7149 / 8460
• Room Allocation18268 / 21025
• Factory Machines25829 / 28230
• Tasks and Deadlines20964 / 21428
• Reading Books16975 / 18193
• Sum of Three Values24805 / 27532
• Sum of Four Values15472 / 17306
• Nearest Smaller Values20708 / 21423
• Subarray Sums I27347 / 29230
• Subarray Sums II24724 / 29493
• Subarray Divisibility22739 / 24843
• Distinct Values Subarrays II13442 / 14881
• Array Division21465 / 22613
• Movie Festival II11420 / 13823
• Maximum Subarray Sum II10560 / 12672

Dynamic Programming

• Dice Combinations74523 / 78896
• Minimizing Coins64413 / 69263
• Coin Combinations I58835 / 63750
• Coin Combinations II49720 / 56404
• Removing Digits55480 / 56635
• Grid Paths I52074 / 53578
• Book Shop46551 / 51314
• Array Description34235 / 38120
• Counting Towers20740 / 21996
• Edit Distance34497 / 36427
• Longest Common Subsequence6685 / 6942
• Rectangle Cutting28643 / 31323
• Minimal Grid Path2842 / 5455
• Money Sums33985 / 35318
• Removal Game19876 / 27155
• Two Sets II26772 / 28874
• Mountain Range1974 / 3840
• Increasing Subsequence27333 / 30718
• Projects18832 / 21122
• Elevator Rides11921 / 15085
• Counting Tilings6950 / 7601
• Counting Numbers9452 / 10705
• Increasing Subsequence II3579 / 4166

Graph Algorithms

• Counting Rooms51263 / 53900
• Labyrinth35399 / 42587
• Building Roads44729 / 46360
• Message Route38416 / 39976
• Building Teams36269 / 38305
• Round Trip28830 / 31459
• Monsters19606 / 23256
• Shortest Routes I31358 / 34734
• Shortest Routes II25588 / 28767
• High Score15416 / 22095
• Flight Discount20033 / 23562
• Cycle Finding14248 / 17600
• Flight Routes13922 / 15555
• Round Trip II15917 / 17930
• Course Schedule20850 / 22088
• Longest Flight Route14592 / 18281
• Game Routes16444 / 17663
• Investigation12165 / 13107
• Planets Queries I10574 / 12431
• Planets Queries II3767 / 4792
• Planets Cycles6481 / 7251
• Road Reparation15890 / 16572
• Road Construction17490 / 18058
• Flight Routes Check14242 / 15470
• Planets and Kingdoms11423 / 11836
• Giant Pizza4655 / 5143
• Coin Collector7367 / 8206
• Mail Delivery6152 / 6749
• De Bruijn Sequence3205 / 3359
• Teleporters Path4635 / 5341
• Hamiltonian Flights6980 / 7987
• Knight's Tour2589 / 3165
• Download Speed4580 / 6236
• Police Chase3675 / 4145
• School Dance4069 / 4310
• Distinct Routes2812 / 3723

Range Queries

• Static Range Sum Queries35314 / 36907
• Static Range Minimum Queries24915 / 26701
• Dynamic Range Sum Queries25923 / 27076
• Dynamic Range Minimum Queries23500 / 24067
• Range Xor Queries24261 / 24594
• Range Update Queries19189 / 20607
• Forest Queries19614 / 20366
• Hotel Queries13876 / 14764
• List Removals11546 / 12165
• Salary Queries8496 / 10812
• Prefix Sum Queries7264 / 7891
• Pizzeria Queries5868 / 6103
• Visible Buildings Queries1074 / 1176
• Range Interval Queries845 / 1122
• Subarray Sum Queries7066 / 7688
• Subarray Sum Queries II1124 / 1193
• Distinct Values Queries6467 / 8053
• Distinct Values Queries II664 / 777
• Increasing Array Queries2488 / 2859
• Movie Festival Queries1192 / 1325
• Forest Queries II4247 / 4575
• Range Updates and Sums5624 / 6719
• Polynomial Queries4147 / 4870
• Range Queries and Copies2947 / 3166
• Missing Coin Sum Queries582 / 773

Tree Algorithms

• Subordinates29504 / 31588
• Tree Matching16739 / 19566
• Tree Diameter24027 / 25499
• Tree Distances I18318 / 19717
• Tree Distances II15036 / 15690
• Company Queries I16650 / 17540
• Company Queries II15588 / 16367
• Distance Queries14195 / 15263
• Counting Paths8851 / 9402
• Subtree Queries10671 / 11398
• Path Queries8483 / 8996
• Path Queries II3420 / 5152
• Distinct Colors8234 / 9117
• Finding a Centroid6626 / 6908
• Fixed-Length Paths I3127 / 4079
• Fixed-Length Paths II1455 / 2704

Mathematics

• Josephus Queries4481 / 5660
• Exponentiation23225 / 24808
• Exponentiation II16467 / 19793
• Counting Divisors21086 / 23842
• Common Divisors13818 / 16097
• Sum of Divisors7705 / 11640
• Divisor Analysis5238 / 7058
• Prime Multiples5956 / 6995
• Counting Coprime Pairs3896 / 4576
• Next Prime1289 / 1481
• Binomial Coefficients9732 / 10821
• Creating Strings II8193 / 8663
• Distributing Apples7884 / 8494
• Christmas Party6343 / 6826
• Permutation Order601 / 611
• Permutation Rounds691 / 779
• Bracket Sequences I4348 / 4744
• Bracket Sequences II2251 / 2592
• Counting Necklaces2086 / 2262
• Counting Grids1692 / 1810
• Fibonacci Numbers6720 / 8464
• Throwing Dice3484 / 3791
• Graph Paths I3300 / 3547
• Graph Paths II2761 / 2897
• System of Linear Equations301 / 325
• Sum of Four Squares456 / 534
• Triangle Number Sums392 / 490
• Dice Probability2996 / 3240
• Moving Robots1544 / 1637
• Candy Lottery1281 / 2848
• Inversion Probability290 / 2189
• Stick Game3353 / 3432
• Nim Game I4429 / 4597
• Nim Game II3500 / 3650
• Stair Game2378 / 2589
• Grundy's Game1627 / 2154
• Another Game1846 / 1995

String Algorithms

• Word Combinations5648 / 8254
• String Matching11003 / 14795
• Finding Borders8048 / 8812
• Finding Periods5735 / 6525
• Minimal Rotation2779 / 4272
• Longest Palindrome4221 / 5594
• All Palindromes441 / 504
• Required Substring1589 / 2457
• Palindrome Queries1985 / 2319
• Finding Patterns1823 / 2619
• Counting Patterns1720 / 2150
• Pattern Positions1443 / 1770
• Distinct Substrings1646 / 1973
• Distinct Subsequences1031 / 1101
• Repeating Substring1789 / 2096
• String Functions1562 / 1637
• Inverse Suffix Array149 / 175
• String Transform498 / 609
• Substring Order I1119 / 1257
• Substring Order II738 / 962
• Substring Distribution1038 / 1130

Geometry

• Point Location Test6999 / 7834
• Line Segment Intersection4180 / 5274
• Polygon Area4864 / 5161
• Point in Polygon2663 / 3379
• Polygon Lattice Points2253 / 2334
• Minimum Euclidean Distance1952 / 2715
• Convex Hull3194 / 3857
• Maximum Manhattan Distances428 / 439
• All Manhattan Distances424 / 469
• Intersection Points1884 / 2027
• Line Segments Trace I230 / 237
• Line Segments Trace II186 / 197
• Lines and Queries I252 / 260
• Lines and Queries II216 / 224
• Area of Rectangles1068 / 1197
• Robot Path296 / 513

Advanced Techniques

• Meet in the Middle6433 / 9021
• Hamming Distance3144 / 3424
• Corner Subgrid Check223 / 365
• Corner Subgrid Count2181 / 2451
• Reachable Nodes2175 / 2342
• Reachability Queries1451 / 1720
• Cut and Paste1440 / 1604
• Substring Reversals1264 / 1381
• Reversals and Sums1271 / 1373
• Necessary Roads1864 / 1908
• Necessary Cities1731 / 1817
• Eulerian Subgraphs760 / 801
• Monster Game I1105 / 1233
• Monster Game II980 / 1054
• Subarray Squares1299 / 1549
• Houses and Schools726 / 870
• Knuth Division883 / 1002
• Apples and Bananas976 / 1061
• One Bit Positions789 / 866
• Signal Processing737 / 793
• New Roads Queries2076 / 2536
• Dynamic Connectivity930 / 1054
• Parcel Delivery721 / 800
• Task Assignment842 / 895
• Distinct Routes II548 / 631

Sliding Window Problems

• Sliding Window Sum3318 / 3469
• Sliding Window Minimum2583 / 2946
• Sliding Window Xor2485 / 2516
• Sliding Window Or1057 / 1951
• Sliding Window Distinct Values2075 / 2116
• Sliding Window Mode1454 / 1533
• Sliding Window Mex1286 / 1357
• Sliding Window Median13105 / 15009
• Sliding Window Cost8706 / 10053
• Sliding Window Inversions731 / 783
• Sliding Window Advertisement142 / 225

Interactive Problems

• Hidden Integer1395 / 1440
• Hidden Permutation605 / 724
• K-th Highest Score260 / 317
• Permuted Binary Strings346 / 356
• Colored Chairs298 / 314
• Inversion Sorting175 / 187

Bitwise Operations

• Counting Bits4347 / 5597
• Maximum Xor Subarray2653 / 2983
• Maximum Xor Subset650 / 701
• Number of Subset Xors561 / 572
• K Subset Xors272 / 321
• All Subarray Xors184 / 289
• Xor Pyramid Peak1814 / 2227
• Xor Pyramid Diagonal214 / 243
• Xor Pyramid Row173 / 204
• SOS Bit Problem1880 / 2007
• And Subset Count265 / 269

Construction Problems

• Inverse Inversions1342 / 1431
• Monotone Subsequences811 / 950
• Third Permutation260 / 302
• Permutation Prime Sums254 / 275
• Chess Tournament1092 / 1260
• Distinct Sums Grid69 / 123
• Filling Trominos226 / 388
• Grid Path Construction114 / 414

Advanced Graph Problems

• Nearest Shops481 / 624
• Prüfer Code1406 / 1520
• Tree Traversals1104 / 1218
• Course Schedule II1722 / 2482
• Acyclic Graph Edges2073 / 2205
• Strongly Connected Edges1443 / 1601
• Even Outdegree Edges1234 / 1454
• Graph Girth3135 / 3595
• Fixed Length Walk Queries249 / 271
• Transfer Speeds Sum284 / 291
• MST Edge Check358 / 384
• MST Edge Set Check153 / 175
• MST Edge Cost255 / 266
• Network Breakdown933 / 992
• Tree Coin Collecting I211 / 234
• Tree Coin Collecting II111 / 130
• Tree Isomorphism I1011 / 1213
• Tree Isomorphism II818 / 961
• Flight Route Requests449 / 548
• Critical Cities383 / 589
• Visiting Cities634 / 842
• Graph Coloring150 / 174
• Bus Companies176 / 179
• Split into Two Paths61 / 109
• Network Renovation883 / 1180
• Forbidden Cities754 / 993
• Creating Offices386 / 500
• New Flight Routes290 / 774

Counting Problems

• Filled Subgrid Count I358 / 397
• Filled Subgrid Count II184 / 221
• All Letter Subgrid Count I95 / 152
• All Letter Subgrid Count II83 / 97
• Border Subgrid Count I62 / 107
• Border Subgrid Count II66 / 76
• Raab Game II67 / 81
• Empty String1495 / 1825
• Permutation Inversions951 / 1047
• Counting Bishops359 / 401
• Counting Sequences610 / 656
• Grid Paths II702 / 875
• Counting Permutations828 / 938
• Grid Completion208 / 263
• Counting Reorders218 / 320
• Tournament Graph Distribution75 / 78
• Collecting Numbers Distribution78 / 81
• Functional Graph Distribution221 / 276

Additional Problems I

• Shortest Subsequence2831 / 3759
• Distinct Values Sum433 / 445
• Distinct Values Splits301 / 320
• Swap Game1924 / 2446
• Beautiful Permutation II241 / 358
• Multiplication Table6140 / 6870
• Bubble Sort Rounds I229 / 265
• Bubble Sort Rounds II126 / 147
• Nearest Campsites I106 / 123
• Nearest Campsites II106 / 115
• Advertisement4024 / 4261
• Special Substrings918 / 1006
• Counting LCM Arrays171 / 183
• Square Subsets136 / 154
• Subarray Sum Constraints170 / 182
• Water Containers Moves99 / 109
• Water Containers Queries129 / 135
• Stack Weights544 / 647
• Maximum Average Subarrays102 / 113
• Subsets with Fixed Average132 / 143
• Two Array Average130 / 147
• Pyramid Array665 / 806
• Permutation Subsequence144 / 148
• Bit Inversions2171 / 2479
• Writing Numbers698 / 755
• Letter Pair Move Game184 / 263
• Maximum Building I1945 / 2030
• Sorting Methods725 / 777
• Cyclic Array1090 / 1243
• List of Sums442 / 577

Additional Problems II

• Bouncing Ball Steps149 / 163
• Bouncing Ball Cycle58 / 79
• Knight Moves Queries82 / 98
• K Subset Sums I112 / 150
• K Subset Sums II57 / 80
• Increasing Array II738 / 853
• Food Division496 / 586
• Swap Round Sorting391 / 483
• Binary Subsequences271 / 399
• School Excursion1275 / 1355
• Coin Grid797 / 937
• Grid Coloring II86 / 108
• Programmers and Artists454 / 640
• Removing Digits II198 / 445
• Coin Arrangement305 / 412
• Replace with Difference83 / 100
• Grid Puzzle I491 / 538
• Grid Puzzle II452 / 497
• Bit Substrings354 / 433
• Reversal Sorting329 / 401
• Book Shop II1093 / 1258
• GCD Subsets277 / 285
• Minimum Cost Pairs64 / 88
• Same Sum Subsets71 / 131
• Mex Grid Queries792 / 932
• Maximum Building II414 / 509
• Stick Divisions3575 / 4199
• Stick Difference24 / 141
• Coding Company1361 / 1801
• Two Stacks Sorting158 / 501