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1160 Interestring graph and Apples dfs and similar dsu graphs Statement E Codeforces Beta Round 9 (Div. 2 Only) {9} PROGRAMMING Codeforces Beta Round #9 tutorial 2300
15461 Roads not only in Berland dsu graphs trees Statement D Codeforces Beta Round 25 (Div. 2 Only) {25} PROGRAMMING Codeforces Beta Round #25 Solution Analysis 1900
3080 Ring Road 2 2-sat dfs and similar dsu graphs Statement D Codeforces Beta Round 27 (Codeforces format, Div. 2) {27} PROGRAMMING Solution of ABC @ Round#27 2300
5502 pSort dfs and similar dsu graphs Statement B Codeforces Beta Round 28 (Codeforces format) {28} PROGRAMMING Codeforces Beta Round #28 (Разбор задач A и B) 1600
612 Two Paths constructive algorithms dsu graphs implementation Statement E Codeforces Beta Round 36 {36} PROGRAMMING Codeforces Beta Round #36 (Problem E solution) 2500
358 Hercule Poirot Problem dsu graphs Statement F School Personal Contest #2 (Winter Computer School 2010/11) - Codeforces Beta Round 43 (ACM-ICPC Rules) {46} PROGRAMMING School Individual Contest #2 (WCS 2010/11) - Codeforces Beta Round #43 (ACM-ICPC Rules). Tasks B, D, E tutorial. 2300
1412 Chessboard Billiard dfs and similar dsu graphs number theory Statement C Codeforces Beta Round 68 {74} PROGRAMMING Solutions for Codeforces Beta Round #68 2100
2134 Gift dsu graphs sortings trees Statement A All-Ukrainian School Olympiad in Informatics {76} PROGRAMMING All-Ukrainian School Olympiad in Informatics: editorial (A,B,C,D,E,F) 2300
398 Pairs dfs and similar dp dsu graphs implementation trees Statement E Yandex.Algorithm Open 2011: Qualification 1 {81} PROGRAMMING 2600
1097 Guard Towers binary search dsu geometry graphs sortings Statement E Yandex.Algorithm 2011: Round 1 {85} PROGRAMMING Яндекс.Алгоритм 2011 - Раунд 1 (Разбор задачи Е "Сторожевые башни") 2600
1052 Beautiful Road dfs and similar dp dsu graphs implementation sortings trees Statement D Codeforces Beta Round 73 (Div. 1 Only) {87} PROGRAMMING CodeForces Beta Round #73 div. 1 analysis (particulary with div. 2) 2300
1010 Ski Base combinatorics dsu graphs Statement C Codeforces Beta Round 75 (Div. 1 Only) {91} PROGRAMMING Analysis Codeforces Beta Round #75 2500
1873 Lucky Country dp dsu graphs Statement E Codeforces Beta Round 77 (Div. 1 Only) {95} PROGRAMMING Codeforces Beta Round #77 - Analysis 2400
429 Leaders dfs and similar dsu graphs trees Statement E Yandex.Algorithm 2011: Finals {97} PROGRAMMING Финал Яндекс.Алгоритм: разбор A-B 2800
10549 Cthulhu dfs and similar dsu graphs Statement B Codeforces Beta Round 80 (Div. 1 Only) {103} PROGRAMMING Tutorial 1600
1358 Clearing Up constructive algorithms dp dsu graphs Statement E Codeforces Round 101 (Div. 2) {141} PROGRAMMING Codeforces Round #101 (Div. 2) Разбор Задач. 2600
3340 Edges in MST dfs and similar dsu graphs sortings Statement D Codeforces Round 111 (Div. 2) {160} PROGRAMMING Codeforces Round #111 (Div. 2) Разбор Задач 2500
3002 Party brute force dfs and similar dsu graphs Statement C2 ABBYY Cup 2.0 - Easy {177} PROGRAMMING 1500
2989 Party dfs and similar dsu graphs Statement C1 ABBYY Cup 2.0 - Easy {177} PROGRAMMING 1500
1730 Counter Attack data structures dsu graphs hashing sortings Statement E Codeforces Round 120 (Div. 2) {190} PROGRAMMING Codeforces Round #120 (Div.2) — editorial 2300
858 Building Forest data structures dsu graphs Statement E Codeforces Round 123 (Div. 2) {195} PROGRAMMING Codeforces Round #123 (Div. 2) Разбор Задач 2200
1202 Opening Portals dsu graphs shortest paths Statement E Codeforces Round 124 (Div. 1) {196} PROGRAMMING Codeforces Round #124 — editorial 2500
875 Trails and Glades constructive algorithms dsu graphs greedy Statement C VK Cup 2012 Finals, Practice Session {209} PROGRAMMING 2400
24216 Ice Skating brute force dfs and similar dsu graphs Statement A Codeforces Round 134 (Div. 1) {217} PROGRAMMING Editorial for Codeforces Round #134 1400
2810 The Road to Berland is Paved With Good Intentions 2-sat dfs and similar dsu graphs Statement E Codeforces Round 141 (Div. 2) {228} PROGRAMMING Codeforces Round #141 (Div. 2) Tutorial 2000
1663 Black and White Tree constructive algorithms dsu graphs greedy trees Statement D Codeforces Round 158 (Div. 2) {260} PROGRAMMING Codeforces Round #158 (Div. 2) Tutorial 2200
940 The Red Button combinatorics dfs and similar dsu graphs greedy Statement E MemSQL start[c]up Round 1 {325} PROGRAMMING Editorial 2700
432 Dima and Kicks brute force dsu graphs implementation Statement E Codeforces Round 208 (Div. 2) {358} PROGRAMMING Codeforces Round #208 (Div. 2) Разбор 2600
1019 Fools and Foolproof Roads data structures dfs and similar dsu graphs greedy Statement D Codeforces Round 212 (Div. 2) {362} PROGRAMMING Codeforces Round #212 (Div. 2). Tutorial. Part 1. 2500
3163 Dima and Bacteria dsu graphs shortest paths Statement D Codeforces Round 234 (Div. 2) {400} PROGRAMMING Codeforces Round #234 (Div. 2) — Tutorial 2000
2882 Dungeons and Candies dsu graphs greedy trees Statement C Zepto Code Rush 2014 {436} PROGRAMMING Zepto Code Rush 2014 — solutions A-D 1800
1197 Valera and Swaps constructive algorithms dsu graphs implementation math string suffix structures Statement D Codeforces Round 252 (Div. 2) {441} PROGRAMMING Разбор Codeforces Round #252 (Div. 2) 2300
2612 Information Graph dfs and similar dsu graphs trees Statement E Codeforces Round 266 (Div. 2) {466} PROGRAMMING Editorial Codeforces Round #266 (Div. 2) 2400
9585 New Year Permutation dfs and similar dsu graphs greedy math sortings Statement B Good Bye 2014 {500} PROGRAMMING Tutorial 2 1600
14876 Mr. Kitayuta's Colorful Graph dfs and similar dp dsu graphs Statement B Codeforces Round 286 (Div. 2) {505} PROGRAMMING Tutorial 1500
2527 Mr. Kitayuta's Colorful Graph brute force dfs and similar dsu graphs Statement D Codeforces Round 286 (Div. 1) {506} PROGRAMMING Editorial 2300
1963 Love Triangles dfs and similar dsu graphs Statement C Codeforces Round 309 (Div. 1) {553} PROGRAMMING Codeforces Round #309 Editorial 2300
10199 Minimum spanning tree for each edge data structures dfs and similar dsu graphs trees Statement E Educational Codeforces Round 3 {609} PROGRAMMING Editorial 2100
251 Island Puzzle dfs and similar dsu graphs trees Statement F 8VC Venture Cup 2016 - Final Round {627} PROGRAMMING 8VC Venture Cup 2016 — Final Round Editorial 3400
2174 Table Compression dfs and similar dp dsu graphs greedy Statement C Codeforces Round 345 (Div. 1) {650} PROGRAMMING Codeforces Round #345: editorial 2300
2842 Pursuit For Artifacts dfs and similar dsu graphs trees Statement E Educational Codeforces Round 10 {652} PROGRAMMING Editorial of Educational Codeforces Round 10 2300
1736 Bear and Forgotten Tree 2 dfs and similar dsu graphs trees Statement E IndiaHacks 2016 - Online Edition (Div. 1 + Div. 2) {653} PROGRAMMING IndiaHacks Finals 2016 — Editorial 2400
7984 New Reform data structures dfs and similar dsu graphs greedy Statement E Codeforces Round 346 (Div. 2) {659} PROGRAMMING Editorial for Codeforces Round #346 (Div. 2) 1600
1952 Polycarp and Hay dfs and similar dsu graphs greedy sortings Statement F Codeforces Round 346 (Div. 2) {659} PROGRAMMING Editorial for Codeforces Round #346 (Div. 2) 2100
1047 Dividing Kingdom II brute force data structures dsu graphs sortings Statement D Codeforces Round 360 (Div. 1) {687} PROGRAMMING Codeforces Round #360 Editorial [+ Challenges!] 2500
6172 Fix a Tree constructive algorithms dfs and similar dsu graphs trees Statement B Codeforces Round 363 (Div. 1) {698} PROGRAMMING 46148 1700
7493 Lakes in Berland dfs and similar dsu graphs greedy implementation Statement D Codeforces Round 375 (Div. 2) {723} PROGRAMMING 1600
1744 st-Spanning Tree dsu graphs greedy implementation Statement F Codeforces Round 375 (Div. 2) {723} PROGRAMMING Codeforces Round #375 (Div.2) Editorial 2200
7789 Socks dfs and similar dsu graphs greedy Statement C Codeforces Round 376 (Div. 2) {731} PROGRAMMING 47840 1600
1296 Drivers Dissatisfaction data structures dsu graphs trees Statement F Codeforces Round 378 (Div. 2) {733} PROGRAMMING Codeforces Round #378 (Div. 2) editorial 2500
238 New Year and Snowy Grid dfs and similar dsu graphs interactive Statement H Good Bye 2016 {750} PROGRAMMING Good Bye 2016 — hints and codes 3400
14948 PolandBall and Forest dfs and similar dsu graphs interactive trees Statement C 8VC Venture Cup 2017 - Elimination Round {755} PROGRAMMING 8VC Venture Cup 2017 — Elimination Round [Editorial] 1300
11856 Timofey and a tree dfs and similar dp dsu graphs implementation trees Statement A Codeforces Round 395 (Div. 1) {763} PROGRAMMING Codeforces Round #395 [Editorial] 1600
3894 Mahmoud and a Dictionary data structures dfs and similar dp dsu graphs Statement D Codeforces Round 396 (Div. 2) {766} PROGRAMMING Codeforces round #396 editorial 2000
17686 Bear and Friendship Condition dfs and similar dsu graphs Statement A VK Cup 2017 - Round 1 {771} PROGRAMMING VK Cup 2017 Round 1 and CF Round 405 — Editorial 1500
6167 The Door Problem 2-sat dfs and similar dsu graphs Statement D ICM Technex 2017 and Codeforces Round 400 (Div. 1 + Div. 2, combined) {776} PROGRAMMING ICM Technex 2017 and Codeforces Round #400 (Div. 1 + Div. 2, combined) Editorial 2000
2883 Weird journey combinatorics constructive algorithms dfs and similar dsu graphs Statement B Codeforces Round 407 (Div. 1) {788} PROGRAMMING Codeforces Round #407(Div.1 + Div.2) Editorial 2200
977 Vladik and Entertaining Flags data structures dsu graphs Statement E Codeforces Round 416 (Div. 2) {811} PROGRAMMING Editorial 2600
1697 Bipartite Checking data structures dsu graphs Statement F Educational Codeforces Round 22 {813} PROGRAMMING 52410 2600
2112 Desk Disorder combinatorics dfs and similar dsu graphs trees Statement E MemSQL Start[c]UP 3.0 - Round 1 {859} PROGRAMMING Tutorial 2100
1315 Points, Lines and Ready-made Titles dfs and similar dsu graphs trees Statement E Technocup 2018 - Elimination Round 2 {870} PROGRAMMING Editorial Codeforces Round 440 Div.1+Div.2 (and Technocup 2018 — Elimination Round 2) 2400
1583 Royal Questions dsu graphs greedy Statement F Codeforces Round 441 (Div. 1, by Moscow Team Olympiad) {875} PROGRAMMING Codeforces Round #441. Editorial. 2500
2980 Envy data structures dsu graphs Statement C Codeforces Round 446 (Div. 1) {891} PROGRAMMING Codeforces Round #446 Editorial 2500
1298 Bipartite Segments binary search data structures dfs and similar dsu graphs two pointers Statement C Codeforces Round 453 (Div. 1) {901} PROGRAMMING Codeforces Round #453 (Div. 1 & Div. 2) Editorial 2500
3036 Imbalance Value of a Tree data structures dsu graphs trees Statement F Educational Codeforces Round 36 (Rated for Div. 2) {915} PROGRAMMING 57123 2500
7683 Connected Components? data structures dfs and similar dsu graphs Statement E Educational Codeforces Round 37 (Rated for Div. 2) {920} PROGRAMMING T 2100
1083 Shortest Path Queries bitmasks data structures dsu graphs Statement G Educational Codeforces Round 38 (Rated for Div. 2) {938} PROGRAMMING Educational Codeforces Round 38 — Editorial 2900
8100 Love Rescue dfs and similar dsu graphs greedy strings Statement D Codeforces Round 464 (Div. 2) {939} PROGRAMMING Analysis of Codeforces Round #464 1600
25449 Cyclic Components dfs and similar dsu graphs Statement E Codeforces Round 479 (Div. 3) {977} PROGRAMMING Codeforces Round #479 (Div. 3) Editorial 1500
2710 AND Graph bitmasks dfs and similar dsu graphs Statement C Codeforces Round 485 (Div. 1) {986} PROGRAMMING Codeforces Round #485 Editorial 2300
4381 Chemical table constructive algorithms dfs and similar dsu graphs matrices Statement B Codeforces Round 500 (Div. 1) [based on EJOI] {1012} PROGRAMMING 60920 1900
1008 Mobile Phone Network dfs and similar dsu graphs trees Statement F Codeforces Round 504 (rated, Div. 1 + Div. 2, based on VK Cup 2018 Final) {1023} PROGRAMMING Codeforces Round 504 Editorial 2600
1945 Session in BSU binary search dfs and similar dsu graph matchings graphs Statement F Educational Codeforces Round 49 (Rated for Div. 2) {1027} PROGRAMMING Educational Codeforces Round 49 Editorial 2400
1487 Network Safety dfs and similar dsu graphs math sortings Statement C Codeforces Round 507 (Div. 1, based on Olympiad of Metropolises) {1039} PROGRAMMING 61668 2300
1467 Leaf Sets data structures dfs and similar dsu graphs greedy sortings trees Statement F Codeforces Round 510 (Div. 2) {1042} PROGRAMMING Tutorial 2400
4634 Maximum Distance dsu graphs shortest paths sortings Statement D Avito Cool Challenge 2018 {1081} PROGRAMMING 63888 1800
7440 Make It Connected dsu graphs greedy Statement F Codeforces Round 529 (Div. 3) {1095} PROGRAMMING Codeforces Round #529 (Div. 3) Editorial 2000
3542 MST Unification binary search dsu graphs greedy Statement F Codeforces Round 535 (Div. 3) {1108} PROGRAMMING 64751 2300
1768 Power Tree dfs and similar dp dsu graphs greedy trees Statement D Codeforces Round 543 (Div. 1, based on Technocup 2019 Final Round) {1120} PROGRAMMING Разбор задач финала Технокубка 2019 и Codeforces Round #543 2400
3618 Gourmet choice dfs and similar dp dsu graphs greedy Statement D Codeforces Round 541 (Div. 2) {1131} PROGRAMMING Codeforces Round #541 Editorial 2000
3799 Spanning Tree with One Fixed Degree constructive algorithms dfs and similar dsu graphs greedy Statement F2 Codeforces Round 544 (Div. 3) {1133} PROGRAMMING Codeforces Round #544 (Div. 3) Editorial 2200
16575 Edgy Trees dfs and similar dsu graphs math trees Statement C Codeforces Round 548 (Div. 2) {1139} PROGRAMMING Codeforces Round #548 Editorial 1500
811 Vicky's Delivery Service data structures dsu graphs hashing Statement F Codeforces Round 561 (Div. 2) {1166} PROGRAMMING Codeforces Round #561 (Div. 2) Editorial 2800
25784 News Distribution dfs and similar dsu graphs Statement C Educational Codeforces Round 65 (Rated for Div. 2) {1167} PROGRAMMING 67058 1400
13502 Cover it! dfs and similar dsu graphs shortest paths trees Statement E Codeforces Round 565 (Div. 3) {1176} PROGRAMMING 67598 1700
665 Daleks' Invasion (hard) data structures dsu graphs trees Statement E3 Helvetic Coding Contest 2019 online mirror (teams allowed, unrated) {1184} PROGRAMMING helvetic-coding-contest-2019-editorial.pdf 2500
10701 Cow and Snacks dfs and similar dsu graphs Statement D Codeforces Round 584 - Dasha Code Championship - Elimination Round (rated, open for everyone, Div. 1 + Div. 2) {1209} PROGRAMMING 69791 1700
9447 Path Queries divide and conquer dsu graphs sortings trees Statement G Codeforces Round 582 (Div. 3) {1213} PROGRAMMING Codeforces Round #582 (Div. 3) Editorial 2000
3013 Unstable String Sort data structures dfs and similar dsu graphs greedy implementation strings Statement F Codeforces Round 582 (Div. 3) {1213} PROGRAMMING Codeforces Round #582 (Div. 3) Editorial 2400
716 Forced Online Queries Problem data structures divide and conquer dsu graphs trees Statement F Educational Codeforces Round 72 (Rated for Div. 2) {1217} PROGRAMMING Educational Codeforces Round 72 Editorial 2800
2999 Tourism dfs and similar dp dsu graphs greedy trees Statement E Codeforces Round 586 (Div. 1 + Div. 2) {1220} PROGRAMMING Codeforces Round #586 Editorial 2200
9213 0-1 MST dfs and similar dsu graphs sortings Statement B Codeforces Round 599 (Div. 1) {1242} PROGRAMMING Codeforces Round #599 Editorial 1900
9533 Shichikuji and Power Grid dsu graphs greedy shortest paths trees Statement D Codeforces Round 597 (Div. 2) {1245} PROGRAMMING Codeforces Round #597 (Div. 2) Editorial 1900
10229 Harmonious Graph constructive algorithms dfs and similar dsu graphs greedy sortings Statement D Codeforces Round 600 (Div. 2) {1253} PROGRAMMING Editorial 1700
2244 Cheap Robot binary search dsu graphs shortest paths trees Statement F Codeforces Round 600 (Div. 2) {1253} PROGRAMMING Editorial 2600
15973 Secret Passwords dfs and similar dsu graphs Statement D Codeforces Round 603 (Div. 2) {1263} PROGRAMMING Codeforces Round #603 (Div. 2) Editorial 1500
5647 Two Fairs combinatorics dfs and similar dsu graphs Statement B Codeforces Round 606 (Div. 1, based on Technocup 2020 Elimination Round 4) {1276} PROGRAMMING Technocup 2020 — Elimination Round 4 + Codeforces Round 606: Editorial 1900
4321 Segment Tree data structures dsu graphs trees Statement D Educational Codeforces Round 78 (Rated for Div. 2) {1278} PROGRAMMING Educational Codeforces Round 78 Editorial 2100
2005 Prefix Enlightenment dfs and similar dsu graphs Statement C Codeforces Round 616 (Div. 1) {1290} PROGRAMMING 1750.0 Codeforces Round #616 Editorial 2400
1372 Kuroni and Antihype bitmasks dp dsu graphs Statement G Ozon Tech Challenge 2020 (Div.1 + Div.2, Rated, T-shirts + prizes!) {1305} PROGRAMMING 3250.0 Ozon Tech Challenge 2020 Editorial 3300
2412 Robots on a Grid data structures dfs and similar dsu graphs greedy matrices Statement F Codeforces Round 634 (Div. 3) {1335} PROGRAMMING 75993 2600
6348 Monopole Magnets constructive algorithms dfs and similar dsu graphs Statement B Codeforces Round 639 (Div. 1) {1344} PROGRAMMING 1000.0 Codeforces Round #639 Editorial 2000
1831 Johnny and Megan's Necklace binary search bitmasks constructive algorithms dfs and similar dsu graphs Statement C Codeforces Round 647 (Div. 1) - Thanks, Algo Muse! {1361} PROGRAMMING 2000.0 Codeforces Round #647 Editorial 2500
20700 Solve The Maze constructive algorithms dfs and similar dsu graphs greedy implementation shortest paths Statement D Codeforces Round 648 (Div. 2) {1365} PROGRAMMING 1500.0 Editorial — Codeforces Round #648 1700
11246 String Transformation 1 dsu graphs greedy sortings strings trees Statement A Codeforces Round 659 (Div. 1) {1383} PROGRAMMING 1000.0 Codeforces Round #659 Editorial
1809 Columns Swaps 2-sat dfs and similar dsu graphs implementation Statement G Codeforces Round 656 (Div. 3) {1385} PROGRAMMING Codeforces Round #656 (Div. 3) Editorial 2300
1293 Clusterization Counting combinatorics dp dsu fft graphs Statement G Grakn Forces 2020 {1408} PROGRAMMING 3000.0 Grakn Forces -- Editorial
2177 Avoid Rainbow Cycles dsu graphs greedy sortings Statement E Grakn Forces 2020 {1408} PROGRAMMING 2500.0 Grakn Forces -- Editorial
8568 Peaceful Rooks dfs and similar dsu graphs Statement C Technocup 2021 - Elimination Round 3 {1411} PROGRAMMING 1750.0 Technocup 2021 Elimination Round 3 and Round #692 (Div. 1 + Div. 2) Editorial
2697 Graph and Queries data structures dfs and similar dsu graphs trees Statement D Codeforces Round 673 (Div. 1) {1416} PROGRAMMING 2000.0 Codeforces Round #673 Editorial 2600
561 Rain of Fire binary search dfs and similar dsu graphs implementation sortings Statement F Codeforces Round 671 (Div. 2) {1419} PROGRAMMING 3000.0 Codeforces Round #671 Editorial
625 Virus data structures dsu graphs Statement H Bubble Cup 13 - Finals [Online Mirror, unrated, Div. 1] {1423} PROGRAMMING FinalsEditorial2020.pdf
1851 Team-Building 2-sat dfs and similar dsu graphs Statement C Codeforces Round 680 (Div. 1, based on Moscow Team Olympiad) {1444} PROGRAMMING 1500.0 Codeforces Round #680 Editorial
6601 Number of Simple Paths combinatorics data structures dfs and similar dsu graphs trees Statement E Codeforces Round 686 (Div. 3) {1454} PROGRAMMING Codeforces Round #686 (Div. 3) Editorial
1729 Plan of Lectures dfs and similar dsu graphs Statement E Educational Codeforces Round 100 (Rated for Div. 2) {1463} PROGRAMMING Educational Codeforces Round 100 Editorial
3057 Euclid's nightmare dfs and similar dsu graphs math Statement F Good Bye 2020 {1466} PROGRAMMING 1750.0 Good Bye 2020 Editorial
5862 Road Reform dsu graphs greedy Statement J 2020-2021 ICPC, NERC, Southern and Volga Russian Regional Contest (Online Mirror, ICPC Rules) {1468} PROGRAMMING 2020-2021 ICPC, NERC, Southern and Volga Russian Regional Contest (Online Mirror, ICPC Rules) — Tutorials
4178 Strange Housing constructive algorithms dfs and similar dsu graph matchings graphs Statement D Codeforces Round 694 (Div. 1) {1470} PROGRAMMING 1500.0 86464
1723 Complete the MST data structures dfs and similar dsu graphs greedy math Statement C Codeforces Round 715 (Div. 1) {1508} PROGRAMMING 1500.0 Codeforces Round #715 Editorial
6451 GCD and MST constructive algorithms data structures dsu graphs implementation number theory sortings Statement D Divide by Zero 2021 and Codeforces Round 714 (Div. 2) {1513} PROGRAMMING 2000.0 Divide by Zero 2021 and Codeforces Round #714 (Div. 2) Editorial
2070 Phoenix and Earthquake constructive algorithms dfs and similar dsu graphs greedy trees Statement F Codeforces Global Round 14 {1515} PROGRAMMING 3250.0 Editorial
13770 Little Alawn's Puzzle combinatorics dfs and similar dp dsu graphs math Statement C Codeforces LATOKEN Round 1 (Div. 1 + Div. 2) {1534} PROGRAMMING 1250.0 Codeforces LATOKEN Round 1 (Div. 1 + Div. 2) Editorial
2805 Figure Fixing constructive algorithms dfs and similar dsu graphs math Statement F Codeforces Round 726 (Div. 2) {1537} PROGRAMMING 2000.0 Codeforces Round #726 (Div.2) Editorial
895 Jumping Around data structures divide and conquer dp dsu graphs shortest paths trees Statement F Educational Codeforces Round 111 (Rated for Div. 2) {1550} PROGRAMMING Educational Codeforces Round 111 Editorial
1211 Common Divisor Graph binary search dsu graphs math number theory Statement G Harbour.Space Scholarship Contest 2021-2022 (open for everyone, rated, Div. 1 + Div. 2) {1553} PROGRAMMING 3000.0 Harbour.Space Scholarship Contest 2021-2022 (Div. 1 + Div. 2) Editorial
1044 Good Graph data structures dsu graphs trees Statement F Educational Codeforces Round 112 (Rated for Div. 2) {1555} PROGRAMMING 93389 2700
15976 Mocha and Diana (Easy Version) brute force constructive algorithms dsu graphs greedy trees Statement D1 Codeforces Round 738 (Div. 2) {1559} PROGRAMMING 1500.0 Tutorial (en) 1400
3049 Mocha and Diana (Hard Version) brute force constructive algorithms dfs and similar dsu graphs greedy trees two pointers Statement D2 Codeforces Round 738 (Div. 2) {1559} PROGRAMMING 1500.0 Tutorial (en) 2500
740 Occurrences combinatorics dp dsu fft graphs Statement F Educational Codeforces Round 114 (Rated for Div. 2) {1574} PROGRAMMING 95188
9328 The Number of Imposters constructive algorithms dfs and similar dp dsu graphs Statement D Codeforces Round 747 (Div. 2) {1594} PROGRAMMING 1750.0 95525 1700
8374 Social Network dsu graphs greedy implementation trees Statement D Deltix Round, Autumn 2021 (open for everyone, rated, Div. 1 + Div. 2) {1609} PROGRAMMING 2000.0 Deltix Round, Autumn 2021. Editorial 1600
1737 Spanning Tree Queries binary search data structures dsu graphs implementation math sortings Statement E Educational Codeforces Round 122 (Rated for Div. 2) {1633} PROGRAMMING 99539
2722 Cars constructive algorithms dfs and similar dsu graphs greedy sortings Statement E Codeforces Round 772 (Div. 2) {1635} PROGRAMMING 2250.0 Codeforces Round #772 Editorial
15902 Inversion Graph dsu graphs math Statement C Codeforces Round 771 (Div. 2) {1638} PROGRAMMING 1250.0 Codeforces Round #771 Editorial
504 Air Reform data structures dfs and similar divide and conquer dsu graphs implementation trees Statement E Codeforces Round 775 (Div. 1, based on Moscow Open Olympiad in Informatics) {1648} PROGRAMMING 2500.0 Codeforces Round #775 Editorial
1964 AND-MEX Walk bitmasks brute force data structures dfs and similar dsu graphs greedy Statement E Codeforces Round 782 (Div. 2) {1659} PROGRAMMING 2250.0 Codeforces Round #782 (Div. 2) Editorial
10979 Where is the Pizza? data structures dfs and similar dsu graphs implementation math Statement C Codeforces Round 788 (Div. 2) {1670} PROGRAMMING 1750.0 Tutorial 1400
4075 Tokitsukaze and Two Colorful Tapes constructive algorithms dfs and similar dsu graphs greedy Statement C Codeforces Round 789 (Div. 1) {1677} PROGRAMMING 1250.0 Tutorial
896 Lenient Vertex Cover data structures dfs and similar divide and conquer dsu graphs Statement F Educational Codeforces Round 128 (Rated for Div. 2) {1680} PROGRAMMING 102852
4134 Railway System constructive algorithms dsu graphs greedy interactive sortings Statement B Codeforces Round 796 (Div. 1) {1687} PROGRAMMING 750.0 Editorial of Codeforces Round 796
1358 ANDfinity bitmasks brute force constructive algorithms dfs and similar dsu graphs Statement E Codeforces Round 798 (Div. 2) {1689} PROGRAMMING 2500.0 Editorial for Codeforces Round #798 (Div. 2)
2092 Number of Groups data structures dfs and similar dsu graphs greedy sortings Statement E CodeCraft-22 and Codeforces Round 795 (Div. 2) {1691} PROGRAMMING 2250.0 Editorial for CodeCraft-22 and Codeforces Round #795 (Div. 2)
1128 Tree Recovery bitmasks brute force constructive algorithms dfs and similar dsu graphs trees Statement F Codeforces Global Round 21 {1696} PROGRAMMING 2500.0 Editorial of Codeforces Global Round 21
1449 Coloring brute force combinatorics constructive algorithms dfs and similar dp dsu graphs implementation Statement E Educational Codeforces Round 130 (Rated for Div. 2) {1697} PROGRAMMING 103835
17733 Split Into Two Sets dfs and similar dsu graph matchings graphs Statement E Codeforces Round 805 (Div. 3) {1702} PROGRAMMING 104763
1895 DFS Trees data structures dfs and similar dsu graphs greedy trees Statement C Codeforces Round 808 (Div. 1) {1707} PROGRAMMING 1250.0 104930
295 Imitating the Key Tree combinatorics dsu trees Statement I COMPFEST 14 - Preliminary Online Mirror (Unrated, ICPC Rules, Teams Preferred) {1725} PROGRAMMING Tutorial
13393 Jatayu's Balanced Bracket Sequence data structures dsu graphs Statement C Codeforces Round 819 (Div. 1 + Div. 2) and Grimoire of Code Annual Contest 2022 {1726} PROGRAMMING 1500.0 Codeforces Round #819 (Div. 1 + Div. 2) and Grimoire of Code Annual Contest 2022 Editorial
10907 Phase Shift dfs and similar dsu graphs greedy strings Statement C Codeforces Round 824 (Div. 2) {1735} PROGRAMMING 1250.0 Codeforces Round #824 — editorial
3741 Permutation Addicts constructive algorithms dfs and similar dsu graphs trees Statement D Codeforces Global Round 22 {1738} PROGRAMMING 2000.0 Editorial of Codeforces Global Round <strong>22</strong>
1373 Connectivity Addicts constructive algorithms dsu graphs greedy interactive shortest paths sortings trees Statement F Codeforces Global Round 22 {1738} PROGRAMMING 2750.0 Editorial of Codeforces Global Round <strong>22</strong>
1008 Tick, Tock 2-sat combinatorics dfs and similar dsu graphs Statement E Codeforces Round 836 (Div. 2) {1758} PROGRAMMING 2250.0 Codeforces Round #836 (Div. 2) Editorial
8960 Lucky Permutation dfs and similar dsu graphs greedy Statement D Codeforces Round 842 (Div. 2) {1768} PROGRAMMING 1750.0 Codeforces Round #842 (Div. 2) Editorial
4389 Koxia and Game data structures dfs and similar dsu games graph matchings graphs implementation Statement D Good Bye 2022: 2023 is NEAR {1770} PROGRAMMING 1500.0 Good Bye 2022 -- Editorial
2326 Edge Reverse binary search dfs and similar dsu graphs Statement E Codeforces Round 845 (Div. 2) and ByteRace 2023 {1777} PROGRAMMING 2250.0 Codeforces Round #845 (Div. 2) and ByteRace 2023 Editorial
3812 Game on Axis combinatorics dsu graphs implementation Statement D TypeDB Forces 2023 (Div. 1 + Div. 2, Rated, Prizes!) {1787} PROGRAMMING 2000.0 TypeDB Forces 2023 (Div. 1 + Div. 2, Rated, Prizes!) Editorial
1146 XOR, Tree, and Queries constructive algorithms dfs and similar dsu graphs trees Statement F Codeforces Round 851 (Div. 2) {1788} PROGRAMMING 3000.0 Codeforces Round #851 (Div. 2) Editorial
15228 Unforgivable Curse (hard version) brute force constructive algorithms constructive algorithms dsu graphs greedy Statement E2 Codeforces Round 855 (Div. 3) {1800} PROGRAMMING Codeforces Round 855 (Div. 3) Editorial
15546 Unforgivable Curse (easy version) brute force constructive algorithms dsu graphs greedy Statement E1 Codeforces Round 855 (Div. 3) {1800} PROGRAMMING Codeforces Round 855 (Div. 3) Editorial
1904 There Should Be a Lot of Maximums data structures dfs and similar dsu graphs trees Statement E Codeforces Round 862 (Div. 2) {1805} PROGRAMMING 2250.0 Editorial of Codeforces Round #862 (Div. 2)
3897 Monsters brute force data structures dfs and similar dsu graphs implementation trees Statement E CodeTON Round 4 (Div. 1 + Div. 2, Rated, Prizes!) {1810} PROGRAMMING 2000.0 Editorial of CodeTON Round 4 (Div. 1 + Div. 2, Rated, Prizes!)
2157 Is It Flower? dfs and similar dsu graphs implementation Statement F Codeforces Round 863 (Div. 3) {1811} PROGRAMMING 114788
26464 The Lakes dfs and similar dsu graphs implementation Statement E Codeforces Round 871 (Div. 4) {1829} PROGRAMMING Codeforces Round 871 (Div. 4) Editorial 1100
18256 Round Dance dsu graphs shortest paths Statement E Codeforces Round 874 (Div. 3) {1833} PROGRAMMING 116636
2152 Great Grids constructive algorithms dfs and similar dsu graphs math Statement E Codeforces Round 884 (Div. 1 + Div. 2) {1844} PROGRAMMING 2000.0 Codeforces Round #884 (Div. 1 + Div. 2) Editorial
4019 Vlad and the Mountains data structures dsu graphs implementation sortings trees two pointers Statement G Codeforces Round 888 (Div. 3) {1851} PROGRAMMING 118667
5451 Counting Graphs combinatorics divide and conquer dsu graphs greedy sortings Statement G Codeforces Round 891 (Div. 3) {1857} PROGRAMMING 119134
7520 Selling a Menagerie dfs and similar dsu graphs implementation math Statement F Codeforces Round 895 (Div. 3) {1872} PROGRAMMING Codeforces Round 895 (Div. 3) Editorial
9472 Mad City dfs and similar dsu graphs shortest paths Statement H Codeforces Round 898 (Div. 4) {1873} PROGRAMMING 120634
1048 Lexichromatography combinatorics dfs and similar dsu graphs two pointers Statement D Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round) {1876} PROGRAMMING 1750.0 Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round) Editorial
2386 Light Bulbs (Easy Version) brute force combinatorics dfs and similar dp dsu graphs math Statement G1 Codeforces Round 916 (Div. 3) {1914} PROGRAMMING Codeforces Round 916 (Div. 3) Editorial
1806 Light Bulbs (Hard Version) combinatorics data structures dfs and similar dp dsu graphs hashing Statement G2 Codeforces Round 916 (Div. 3) {1914} PROGRAMMING Codeforces Round 916 (Div. 3) Editorial
1192 Smooth Sailing (Easy Version) binary search data structures dfs and similar dsu graphs Statement F1 Codeforces Round 919 (Div. 2) {1920} PROGRAMMING 2500.0 Editorial for Codeforces Round #919 (Div. 2)
642 Smooth Sailing (Hard Version) binary search data structures dsu graphs trees Statement F2 Codeforces Round 919 (Div. 2) {1920} PROGRAMMING 2500.0 Editorial for Codeforces Round #919 (Div. 2)
5362 Microcycle data structures dfs and similar dsu graphs greedy trees Statement F Codeforces Round 923 (Div. 3) {1927} PROGRAMMING 125597
105 Parallel Universes *special constructive algorithms dfs and similar dsu graphs Statement A XVIII Open Olympiad in Informatics - Final Stage, Day 2 (Unrated, Online Mirror, IOI rules) {1940} PROGRAMMING
43 Burenka and Pether *special data structures dfs and similar divide and conquer dsu graphs sortings trees Statement C XVIII Open Olympiad in Informatics - Final Stage, Day 2 (Unrated, Online Mirror, IOI rules) {1940} PROGRAMMING
481 Nene and the Passing Game constructive algorithms data structures dsu graphs sortings Statement F Codeforces Round 939 (Div. 2) {1956} PROGRAMMING 2500.0 [Editorial] Codeforces Round 939 (Div. 2)
1569 Large Graph data structures dsu graphs number theory Statement F Codeforces Round 953 (Div. 2) {1978} PROGRAMMING 2500.0 130527
1215 Turtle and Intersected Segments data structures dsu graphs greedy Statement E Codeforces Round 949 (Div. 2) {1981} PROGRAMMING 2500.0 Simplified Chinese Tutorial
7210 Maximize the Largest Component (Easy Version) brute force data structures dfs and similar dsu graphs implementation Statement H1 Codeforces Round 952 (Div. 4) {1985} PROGRAMMING Codeforces Round 952 (Div. 4) Editorial
6393 Non-academic Problem combinatorics dfs and similar dsu graphs Statement F Codeforces Round 954 (Div. 3) {1986} PROGRAMMING 130762
7351 Funny Game constructive algorithms dsu graphs greedy math number theory Statement D Codeforces Round 959 sponsored by NEAR (Div. 1 + Div. 2) {1994} PROGRAMMING 2000.0 Video Tutorial
23371 Sakurako's Hobby dp dsu graphs math Statement D Codeforces Round 970 (Div. 3) {2008} PROGRAMMING Codeforces Round 970 (Div. 3) Editorial
7393 Connect the Dots brute force dfs and similar dp dsu graphs math trees Statement D Codeforces Round 976 (Div. 2) and Divide By Zero 9.0 {2020} PROGRAMMING 1500.0 Tutorial for Codeforces Round 976 (Div. 2) and Divide By Zero 9.0
1919 Digital Village (Easy Version) brute force data structures dp dsu graphs greedy implementation math shortest paths trees Statement E1 Codeforces Round 977 (Div. 2, based on COMPFEST 16 - Final Round) {2021} PROGRAMMING 1750.0 Codeforces Round #977 (Div. 2, based on COMPFEST 16 — Final Round) Editorial
1198 Digital Village (Hard Version) data structures dp dsu graphs math trees Statement E2 Codeforces Round 977 (Div. 2, based on COMPFEST 16 - Final Round) {2021} PROGRAMMING 750.0 Codeforces Round #977 (Div. 2, based on COMPFEST 16 — Final Round) Editorial
755 Billetes MX (Easy Version) 2-sat binary search combinatorics dfs and similar dsu graphs Statement E1 Codeforces Round 978 (Div. 2) {2022} PROGRAMMING 2250.0 Codeforces Round 978 (Div 2) Editorial
704 Billetes MX (Hard Version) binary search combinatorics dfs and similar dsu graphs Statement E2 Codeforces Round 978 (Div. 2) {2022} PROGRAMMING 1000.0 Codeforces Round 978 (Div 2) Editorial
3908 Cool Graph constructive algorithms data structures dfs and similar dsu graphs trees Statement D Refact.ai Match 1 (Codeforces Round 985) {2029} PROGRAMMING 2250.0 Refact.ai Match 1 (Codeforces Round 985) Editorial
3799 Medium Demon Problem (hard version) dfs and similar dp dsu graphs implementation trees Statement G2 Codeforces Round 993 (Div. 4) {2044} PROGRAMMING Codeforces Round 993 (Div. 4) Editorial
1906 Another Exercise on Graphs (hard version) binary search brute force dsu graphs shortest paths sortings trees Statement E2 Hello 2025 {2057} PROGRAMMING 2000.0
12173 Graph Composition dfs and similar dsu graphs greedy Statement E Codeforces Round 998 (Div. 3) {2060} PROGRAMMING Codeforces Round 998 (Div. 3) Editorial
362 Porto Vs. Benfica data structures dfs and similar dsu graphs shortest paths Statement E European Championship 2025 - Online Mirror (Unrated, ICPC Rules, Teams Preferred) {2068} PROGRAMMING 140239
1171 MST in Modulo Graph constructive algorithms dsu graphs greedy math number theory sortings Statement D Codeforces Round 1010 (Div. 1, Unrated) {2081} PROGRAMMING 1750.0 Codeforces Round 1010 (Div. 1, Div. 2, based on Zhili Cup 2025) Editorial
16049 Disappearing Permutation dfs and similar dsu graphs greedy implementation Statement C Educational Codeforces Round 177 (Rated for Div. 2) {2086} PROGRAMMING Educational Codeforces Round 177 Editorial
1890 Baggage Claim combinatorics dsu graphs math trees Statement B Codeforces Round 1021 (Div. 1) {2097} PROGRAMMING 1000.0 142316
14572 Neo's Escape data structures dsu graphs greedy implementation Statement C Codeforces Round 1022 (Div. 2) {2108} PROGRAMMING 1500.0 Codeforces Round 1022 Editorial
5118 Omg Graph brute force dsu graphs greedy shortest paths sortings Statement G Codeforces Round 1029 (Div. 3) {2117} PROGRAMMING Codeforces Round 1029 (Div. 3) Editorial
2482 Red Light, Green Light (Hard version) binary search dfs and similar dp dsu graphs implementation number theory Statement D2 Codeforces Round 1030 (Div. 2) {2118} PROGRAMMING 1000.0 Codeforces Round 1030 (Div. 2) Editorial
3860 By the Assignment bitmasks dfs and similar dsu graphs Statement C Codeforces Round 1046 (Div. 1) {2135} PROGRAMMING 1750.0 Codeforces Round 1046 (Div. 1, Div. 2) Editorial
83 Merging Vertices in a Graph *special dfs and similar dsu graphs Statement H Kotlin Heroes: Episode 13 {2141} PROGRAMMING Kotlin Heroes 13 Editorial
628 Juan's Colorful Tree data structures data structures dfs and similar dfs and similar dsu graphs graphs trees Statement F Codeforces Round 1056 (Div. 2) {2155} PROGRAMMING 3000.0 Codeforces Round 1056 (Div. 2) Editorial
612 Sink data structures dsu dsu graphs graphs Statement E Codeforces Round 1067 (Div. 2) {2158} PROGRAMMING 2750.0 Codeforces Round 1067 (Div. 2) Editorial
1566 Journey dfs and similar dsu graphs greedy Statement E Codeforces Global Round 30 (Div. 1 + Div. 2) {2164} PROGRAMMING 2250.0 Codeforces Global Round 30 Editorial
617 Simons and Reconstructing His Roads constructive algorithms data structures dsu graphs meet-in-the-middle Statement F Codeforces Round 1083 (Div. 2) {2205} PROGRAMMING 2750.0 Tutorial
4055 Tree Orientation (Easy Version) constructive algorithms dfs and similar dsu graphs greedy trees Statement D1 Codeforces Round 1086 (Div. 2) {2208} PROGRAMMING 1250.0 Tutorial
1754 Tree Orientation (Hard Version) data structures dfs and similar dsu graphs greedy matrices sortings trees Statement D2 Codeforces Round 1086 (Div. 2) {2208} PROGRAMMING 1250.0 Tutorial