CSES Problem Set

General

• Introduction
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• Statistics

Introductory Problems

• Weird Algorithm148658 / 155671
• Missing Number128164 / 134416
• Repetitions111579 / 116150
• Increasing Array104851 / 108649
• Permutations92149 / 95010
• Number Spiral65161 / 71042
• Two Knights49699 / 51284
• Two Sets54040 / 58214
• Bit Strings61913 / 65380
• Trailing Zeros57806 / 61509
• Coin Piles51162 / 56021
• Palindrome Reorder47588 / 50259
• Gray Code31640 / 35592
• Tower of Hanoi29176 / 30354
• Creating Strings40074 / 41126
• Apple Division40143 / 45407
• Chessboard and Queens24213 / 24652
• Raab Game I3574 / 4083
• Mex Grid Construction3437 / 3675
• Knight Moves Grid3437 / 3516
• Grid Coloring I2844 / 2946
• Digit Queries17050 / 19907
• String Reorder2754 / 3214
• Grid Path Description9495 / 12357

Sorting and Searching

• Distinct Numbers72468 / 78448
• Apartments53619 / 59701
• Ferris Wheel51476 / 55646
• Concert Tickets41540 / 48417
• Restaurant Customers42197 / 45583
• Movie Festival40512 / 42930
• Sum of Two Values47335 / 53092
• Maximum Subarray Sum45803 / 47861
• Stick Lengths40854 / 42775
• Missing Coin Sum30683 / 31820
• Collecting Numbers31436 / 33711
• Collecting Numbers II13044 / 16729
• Playlist31563 / 36153
• Towers31980 / 34265
• Traffic Lights24745 / 27736
• Distinct Values Subarrays5308 / 5593
• Distinct Values Subsequences3665 / 4093
• Josephus Problem I18789 / 20773
• Josephus Problem II10101 / 13991
• Nested Ranges Check10753 / 12396
• Nested Ranges Count7280 / 8609
• Room Allocation18584 / 21376
• Factory Machines26368 / 28789
• Tasks and Deadlines21320 / 21784
• Reading Books17248 / 18484
• Sum of Three Values25301 / 28067
• Sum of Four Values15740 / 17589
• Nearest Smaller Values21033 / 21757
• Subarray Sums I27873 / 29773
• Subarray Sums II25247 / 30074
• Subarray Divisibility23114 / 25228
• Distinct Values Subarrays II13795 / 15244
• Array Division21859 / 23015
• Movie Festival II11650 / 14082
• Maximum Subarray Sum II10769 / 12899

Dynamic Programming

• Dice Combinations75805 / 80261
• Minimizing Coins65477 / 70401
• Coin Combinations I59763 / 64751
• Coin Combinations II50502 / 57271
• Removing Digits56320 / 57483
• Grid Paths I52945 / 54466
• Book Shop47289 / 52096
• Array Description34839 / 38751
• Counting Towers21114 / 22386
• Edit Distance35045 / 37007
• Longest Common Subsequence7286 / 7554
• Rectangle Cutting29093 / 31797
• Minimal Grid Path3101 / 5917
• Money Sums34516 / 35850
• Removal Game20289 / 27576
• Two Sets II27199 / 29313
• Mountain Range2175 / 4174
• Increasing Subsequence27750 / 31170
• Projects19153 / 21461
• Elevator Rides12156 / 15357
• Counting Tilings7090 / 7745
• Counting Numbers9680 / 10952
• Increasing Subsequence II3768 / 4383

Graph Algorithms

• Counting Rooms52107 / 54768
• Labyrinth36006 / 43251
• Building Roads45451 / 47105
• Message Route39050 / 40618
• Building Teams36925 / 38973
• Round Trip29334 / 32000
• Monsters19971 / 23654
• Shortest Routes I31988 / 35388
• Shortest Routes II26092 / 29297
• High Score15771 / 22510
• Flight Discount20433 / 23996
• Cycle Finding14542 / 17929
• Flight Routes14205 / 15880
• Round Trip II16212 / 18251
• Course Schedule21271 / 22511
• Longest Flight Route14908 / 18623
• Game Routes16770 / 17994
• Investigation12405 / 13357
• Planets Queries I10799 / 12680
• Planets Queries II3855 / 4904
• Planets Cycles6598 / 7381
• Road Reparation16255 / 16952
• Road Construction17813 / 18383
• Flight Routes Check14499 / 15737
• Planets and Kingdoms11661 / 12078
• Giant Pizza4780 / 5273
• Coin Collector7532 / 8379
• Mail Delivery6288 / 6893
• De Bruijn Sequence3287 / 3442
• Teleporters Path4752 / 5464
• Hamiltonian Flights7124 / 8144
• Knight's Tour2654 / 3238
• Download Speed4695 / 6368
• Police Chase3750 / 4226
• School Dance4152 / 4396
• Distinct Routes2912 / 3835

Range Queries

• Static Range Sum Queries36111 / 37730
• Static Range Minimum Queries25348 / 27153
• Dynamic Range Sum Queries26367 / 27535
• Dynamic Range Minimum Queries23874 / 24444
• Range Xor Queries24678 / 25016
• Range Update Queries19531 / 20957
• Forest Queries20016 / 20776
• Hotel Queries14114 / 15009
• List Removals11768 / 12389
• Salary Queries8701 / 11038
• Prefix Sum Queries7443 / 8077
• Pizzeria Queries6006 / 6237
• Visible Buildings Queries1198 / 1317
• Range Interval Queries940 / 1247
• Subarray Sum Queries7197 / 7821
• Subarray Sum Queries II1274 / 1340
• Distinct Values Queries6600 / 8198
• Distinct Values Queries II743 / 866
• Increasing Array Queries2544 / 2921
• Movie Festival Queries1242 / 1382
• Forest Queries II4316 / 4646
• Range Updates and Sums5736 / 6835
• Polynomial Queries4219 / 4951
• Range Queries and Copies3012 / 3230
• Missing Coin Sum Queries612 / 809

Tree Algorithms

• Subordinates30048 / 32157
• Tree Matching17059 / 19910
• Tree Diameter24452 / 25941
• Tree Distances I18695 / 20109
• Tree Distances II15322 / 15978
• Company Queries I16987 / 17881
• Company Queries II15916 / 16704
• Distance Queries14508 / 15581
• Counting Paths9097 / 9653
• Subtree Queries10907 / 11644
• Path Queries8730 / 9253
• Path Queries II3531 / 5290
• Distinct Colors8415 / 9307
• Finding a Centroid6765 / 7050
• Fixed-Length Paths I3196 / 4161
• Fixed-Length Paths II1494 / 2762

Mathematics

• Josephus Queries4596 / 5800
• Exponentiation23589 / 25189
• Exponentiation II16725 / 20077
• Counting Divisors21441 / 24230
• Common Divisors14083 / 16389
• Sum of Divisors7857 / 11832
• Divisor Analysis5349 / 7204
• Prime Multiples6120 / 7170
• Counting Coprime Pairs4001 / 4694
• Next Prime1439 / 1647
• Binomial Coefficients9914 / 11020
• Creating Strings II8362 / 8831
• Distributing Apples8033 / 8648
• Christmas Party6484 / 6971
• Permutation Order670 / 683
• Permutation Rounds786 / 885
• Bracket Sequences I4455 / 4853
• Bracket Sequences II2298 / 2643
• Counting Necklaces2132 / 2312
• Counting Grids1740 / 1858
• Fibonacci Numbers6838 / 8598
• Throwing Dice3546 / 3858
• Graph Paths I3368 / 3618
• Graph Paths II2818 / 2954
• System of Linear Equations316 / 354
• Sum of Four Squares504 / 586
• Triangle Number Sums426 / 536
• Dice Probability3048 / 3292
• Moving Robots1570 / 1662
• Candy Lottery1336 / 2909
• Inversion Probability321 / 2230
• Stick Game3430 / 3512
• Nim Game I4526 / 4697
• Nim Game II3581 / 3730
• Stair Game2424 / 2641
• Grundy's Game1669 / 2203
• Another Game1885 / 2037

String Algorithms

• Word Combinations5784 / 8419
• String Matching11253 / 15085
• Finding Borders8230 / 9007
• Finding Periods5857 / 6660
• Minimal Rotation2844 / 4353
• Longest Palindrome4322 / 5708
• All Palindromes495 / 565
• Required Substring1621 / 2498
• Palindrome Queries2015 / 2352
• Finding Patterns1864 / 2672
• Counting Patterns1760 / 2194
• Pattern Positions1470 / 1803
• Distinct Substrings1683 / 2015
• Distinct Subsequences1054 / 1124
• Repeating Substring1821 / 2128
• String Functions1589 / 1665
• Inverse Suffix Array162 / 193
• String Transform508 / 622
• Substring Order I1139 / 1279
• Substring Order II754 / 979
• Substring Distribution1059 / 1151

Geometry

• Point Location Test7155 / 7999
• Line Segment Intersection4253 / 5359
• Polygon Area4929 / 5227
• Point in Polygon2663 / 3431
• Polygon Lattice Points2294 / 2375
• Minimum Euclidean Distance1983 / 2757
• Convex Hull3259 / 3931
• Maximum Manhattan Distances452 / 466
• All Manhattan Distances458 / 504
• Intersection Points1919 / 2068
• Line Segments Trace I247 / 255
• Line Segments Trace II198 / 209
• Lines and Queries I271 / 279
• Lines and Queries II231 / 239
• Area of Rectangles1088 / 1217
• Robot Path284 / 527

Advanced Techniques

• Meet in the Middle6539 / 9156
• Hamming Distance3188 / 3473
• Corner Subgrid Check242 / 390
• Corner Subgrid Count2203 / 2474
• Reachable Nodes2208 / 2374
• Reachability Queries1470 / 1743
• Cut and Paste1472 / 1640
• Substring Reversals1291 / 1408
• Reversals and Sums1298 / 1400
• Necessary Roads1890 / 1934
• Necessary Cities1754 / 1840
• Eulerian Subgraphs771 / 812
• Monster Game I1119 / 1247
• Monster Game II996 / 1071
• Subarray Squares1340 / 1592
• Houses and Schools746 / 896
• Knuth Division904 / 1024
• Apples and Bananas1016 / 1104
• One Bit Positions817 / 895
• Signal Processing764 / 822
• New Roads Queries2125 / 2587
• Dynamic Connectivity958 / 1083
• Parcel Delivery736 / 817
• Task Assignment866 / 921
• Distinct Routes II558 / 641

Sliding Window Problems

• Sliding Window Sum3657 / 3817
• Sliding Window Minimum2822 / 3221
• Sliding Window Xor2739 / 2772
• Sliding Window Or1162 / 2119
• Sliding Window Distinct Values1660 / 2320
• Sliding Window Mode1585 / 1669
• Sliding Window Mex1408 / 1487
• Sliding Window Median13293 / 15219
• Sliding Window Cost8799 / 10164
• Sliding Window Inversions797 / 856
• Sliding Window Advertisement154 / 251

Interactive Problems

• Hidden Integer1562 / 1618
• Hidden Permutation669 / 805
• K-th Highest Score284 / 346
• Permuted Binary Strings375 / 385
• Colored Chairs321 / 339
• Inversion Sorting192 / 205

Bitwise Operations

• Counting Bits4520 / 5811
• Maximum Xor Subarray2738 / 3088
• Maximum Xor Subset724 / 781
• Number of Subset Xors625 / 637
• K Subset Xors296 / 352
• All Subarray Xors198 / 314
• Xor Pyramid Peak1856 / 2276
• Xor Pyramid Diagonal228 / 259
• Xor Pyramid Row187 / 219
• SOS Bit Problem1928 / 2057
• And Subset Count284 / 288

Construction Problems

• Inverse Inversions1406 / 1498
• Monotone Subsequences846 / 996
• Third Permutation286 / 334
• Permutation Prime Sums282 / 304
• Chess Tournament1118 / 1291
• Distinct Sums Grid80 / 134
• Filling Trominos230 / 397
• Grid Path Construction115 / 420

Advanced Graph Problems

• Nearest Shops527 / 688
• Prüfer Code1434 / 1549
• Tree Traversals1131 / 1244
• Course Schedule II1780 / 2566
• Acyclic Graph Edges2112 / 2245
• Strongly Connected Edges1466 / 1627
• Even Outdegree Edges1250 / 1473
• Graph Girth3192 / 3656
• Fixed Length Walk Queries264 / 289
• Transfer Speeds Sum305 / 314
• MST Edge Check418 / 449
• MST Edge Set Check165 / 187
• MST Edge Cost279 / 291
• Network Breakdown958 / 1017
• Tree Coin Collecting I235 / 260
• Tree Coin Collecting II123 / 143
• Tree Isomorphism I1030 / 1239
• Tree Isomorphism II833 / 976
• Flight Route Requests457 / 560
• Critical Cities388 / 602
• Visiting Cities645 / 857
• Graph Coloring163 / 191
• Bus Companies191 / 197
• Split into Two Paths65 / 118
• Network Renovation898 / 1199
• Forbidden Cities774 / 1014
• Creating Offices384 / 505
• New Flight Routes295 / 799

Counting Problems

• Filled Subgrid Count I401 / 442
• Filled Subgrid Count II199 / 245
• All Letter Subgrid Count I103 / 165
• All Letter Subgrid Count II94 / 111
• Border Subgrid Count I69 / 119
• Border Subgrid Count II69 / 79
• Raab Game II72 / 85
• Empty String1527 / 1864
• Permutation Inversions972 / 1073
• Counting Bishops363 / 406
• Counting Sequences624 / 669
• Grid Paths II712 / 888
• Counting Permutations840 / 951
• Grid Completion211 / 267
• Counting Reorders222 / 327
• Tournament Graph Distribution80 / 83
• Collecting Numbers Distribution83 / 89
• Functional Graph Distribution227 / 281

Additional Problems I

• Shortest Subsequence2863 / 3797
• Distinct Values Sum480 / 493
• Distinct Values Splits333 / 353
• Swap Game1952 / 2483
• Beautiful Permutation II290 / 436
• Multiplication Table6285 / 7022
• Bubble Sort Rounds I263 / 302
• Bubble Sort Rounds II146 / 171
• Nearest Campsites I116 / 133
• Nearest Campsites II115 / 123
• Advertisement4076 / 4320
• Special Substrings924 / 1013
• Counting LCM Arrays184 / 199
• Square Subsets149 / 167
• Subarray Sum Constraints197 / 212
• Water Containers Moves111 / 118
• Water Containers Queries139 / 145
• Stack Weights554 / 655
• Maximum Average Subarrays111 / 123
• Subsets with Fixed Average144 / 160
• Two Array Average137 / 154
• Pyramid Array673 / 819
• Permutation Subsequence155 / 158
• Bit Inversions2198 / 2506
• Writing Numbers703 / 760
• Letter Pair Move Game188 / 267
• Maximum Building I1965 / 2050
• Sorting Methods730 / 782
• Cyclic Array1108 / 1263
• List of Sums446 / 589

Additional Problems II

• Bouncing Ball Steps160 / 176
• Bouncing Ball Cycle64 / 89
• Knight Moves Queries86 / 104
• K Subset Sums I121 / 162
• K Subset Sums II61 / 83
• Increasing Array II745 / 861
• Food Division498 / 590
• Swap Round Sorting394 / 486
• Binary Subsequences274 / 403
• School Excursion1299 / 1379
• Coin Grid814 / 954
• Grid Coloring II95 / 120
• Programmers and Artists465 / 650
• Removing Digits II206 / 453
• Coin Arrangement306 / 414
• Replace with Difference89 / 107
• Grid Puzzle I501 / 549
• Grid Puzzle II465 / 513
• Bit Substrings364 / 443
• Reversal Sorting334 / 406
• Book Shop II1114 / 1280
• GCD Subsets302 / 310
• Minimum Cost Pairs71 / 95
• Same Sum Subsets79 / 146
• Mex Grid Queries801 / 940
• Maximum Building II425 / 522
• Stick Divisions3609 / 4240
• Stick Difference27 / 153
• Coding Company1383 / 1829
• Two Stacks Sorting161 / 510