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2466 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
1883 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
10294 Bicycles dp graphs greedy implementation shortest paths sortings Statement G Codeforces Round 918 (Div. 4) {1915} PROGRAMMING 123952
755 Group Division constructive algorithms dfs and similar graphs Statement F Good Bye 2023 {1916} PROGRAMMING 2750.0
1165 Caterpillar on a Tree binary search dfs and similar graphs greedy implementation trees Statement F Codeforces Round 922 (Div. 2) {1918} PROGRAMMING 3000.0 Codeforces Round #922 (Div. 2) Editorial
1294 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)
666 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)
4654 Vlad and Trouble at MIT dfs and similar dp flows graphs greedy implementation trees Statement G Codeforces Round 928 (Div. 4) {1926} PROGRAMMING 126132
5561 Microcycle data structures dfs and similar dsu graphs greedy trees Statement F Codeforces Round 923 (Div. 3) {1927} PROGRAMMING 125597
2147 Sasha and the Happy Tree Cutting bitmasks brute force dp fft graphs greedy trees Statement E Codeforces Round 926 (Div. 2) {1929} PROGRAMMING 2500.0 Codeforces Round #926 (Div. 2) Editorial.
12505 Chat Screenshots combinatorics dfs and similar graphs implementation Statement F Codeforces Round 925 (Div. 3) {1931} PROGRAMMING 125878
1415 Moving Platforms graphs math number theory shortest paths Statement G Codeforces Round 927 (Div. 3) {1932} PROGRAMMING 126196
3012 Turtle Mission: Robot and the Earthquake dfs and similar dp graphs shortest paths Statement F Codeforces Round 929 (Div. 3) {1933} PROGRAMMING Codeforces Round 929 (Div. 3) Editorial
1769 Pokémon Arena data structures graphs shortest paths Statement C Codeforces Round 930 (Div. 1) {1936} PROGRAMMING 1500.0 Codeforces Round 930 (Div. 1, Div. 2) Editorial
308 Evidence Board *special constructive algorithms dfs and similar graphs trees Statement B XVIII Open Olympiad in Informatics - Final Stage, Day 1 (Unrated, Online Mirror, IOI rules) {1939} PROGRAMMING
106 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
44 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
4835 Rudolf and Subway dfs and similar graphs shortest paths Statement G Codeforces Round 933 (Div. 3) {1941} PROGRAMMING 127018
3587 Clique Partition constructive algorithms graphs greedy Statement E Educational Codeforces Round 163 (Rated for Div. 2) {1948} PROGRAMMING Educational Codeforces Round 163 Editorial
21525 Arrow Path dfs and similar graphs shortest paths Statement C Educational Codeforces Round 163 (Rated for Div. 2) {1948} PROGRAMMING Educational Codeforces Round 163 Editorial
2817 Disks dfs and similar geometry graphs Statement I European Championship 2024 - Online Mirror (Unrated, ICPC Rules, Teams Preferred) {1949} PROGRAMMING European Championship 2024 (EUC) Editorial
1067 Scooter graphs greedy Statement G European Championship 2024 - Online Mirror (Unrated, ICPC Rules, Teams Preferred) {1949} PROGRAMMING European Championship 2024 (EUC) Editorial
550 Amanda the Amoeba graphs implementation trees two pointers Statement J European Championship 2024 - Online Mirror (Unrated, ICPC Rules, Teams Preferred) {1949} PROGRAMMING European Championship 2024 (EUC) Editorial
6321 Shuffling Songs bitmasks dp graphs implementation strings Statement G Codeforces Round 937 (Div. 4) {1950} PROGRAMMING Codeforces Round 937 (Div. 4) Editorial
118 Growing Trees constructive algorithms flows graphs greedy Statement I Codeforces Global Round 25 {1951} PROGRAMMING 4000.0 Codeforces Global Round 25 Editorial
14150 Are You a Robot, Again? expression parsing graphs strings Statement A April Fools Day Contest 2024 {1952} PROGRAMMING April Fools Day Contest 2024 Editorial
746 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)
53 Equal Trees *special graphs meet-in-the-middle Statement I Kotlin Heroes: Episode 10 {1958} PROGRAMMING 129483 3100
998 Long Way to be Non-decreasing binary search dfs and similar graphs implementation shortest paths two pointers Statement D Codeforces Round 942 (Div. 1) {1967} PROGRAMMING 1750.0 Tutorial 2800
17667 Permutation Game brute force dfs and similar games graphs greedy math Statement D Codeforces Round 943 (Div. 3) {1968} PROGRAMMING 129096 1300
907 Min-Fund Prison (Medium) brute force dfs and similar dp graphs trees Statement G2 Helvetic Coding Contest 2024 online mirror (teams allowed, unrated) {1970} PROGRAMMING Helvetic Coding Contest 2024 Editorial 2200
574 Min-Fund Prison (Hard) bitmasks dfs and similar dp graphs trees Statement G3 Helvetic Coding Contest 2024 online mirror (teams allowed, unrated) {1970} PROGRAMMING Helvetic Coding Contest 2024 Editorial 2400
2886 ±1 2-sat dfs and similar graphs Statement H Codeforces Round 944 (Div. 4) {1971} PROGRAMMING Codeforces Round 944 (Div. 4) Editorial 2100
1032 Cat, Fox and Swaps graphs math sortings Statement E Codeforces Round 945 (Div. 2) {1973} PROGRAMMING 2250.0 Editorial for Codeforces Round #945 (Div. 2) 2500
951 Tensor constructive algorithms graphs interactive Statement E Codeforces Round 948 (Div. 2) {1977} PROGRAMMING 2500.0 129858 2600
1634 Large Graph data structures dsu graphs number theory Statement F Codeforces Round 953 (Div. 2) {1978} PROGRAMMING 2500.0 130527
1857 Manhattan Triangle binary search constructive algorithms data structures geometry graphs two pointers Statement E Codeforces Round 951 (Div. 2) {1979} PROGRAMMING 2500.0 Codeforces Round 951 (Div. 2) Editorial
451 Kostyanych's Theorem brute force graphs interactive Statement F Codeforces Round 951 (Div. 2) {1979} PROGRAMMING 3000.0 Codeforces Round 951 (Div. 2) Editorial
1775 Yasya and the Mysterious Tree bitmasks data structures dfs and similar graphs strings trees Statement G Codeforces Round 950 (Div. 3) {1980} PROGRAMMING 130135
2217 Turtle and Multiplication constructive algorithms dfs and similar graphs number theory Statement D Codeforces Round 949 (Div. 2) {1981} PROGRAMMING 2000.0 Simplified Chinese Tutorial
1320 Turtle and Intersected Segments data structures dsu graphs greedy Statement E Codeforces Round 949 (Div. 2) {1981} PROGRAMMING 2500.0 Simplified Chinese Tutorial
7413 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
6728 Non-academic Problem combinatorics dfs and similar dsu graphs Statement F Codeforces Round 954 (Div. 3) {1986} PROGRAMMING 130762
255 Spinning Round (Hard Version) dp Statement G2 EPIC Institute of Technology Round Summer 2024 (Div. 1 + Div. 2) {1987} PROGRAMMING 2000.0 EPIC Institute of Technology Round Summer 2024 (Div. 1 + Div. 2) Editorial
361 Spinning Round (Easy Version) dp trees Statement G1 EPIC Institute of Technology Round Summer 2024 (Div. 1 + Div. 2) {1987} PROGRAMMING 3000.0 EPIC Institute of Technology Round Summer 2024 (Div. 1 + Div. 2) Editorial
23605 Substring and Subsequence bitmasks brute force dp graphs greedy hashing strings trees Statement B Educational Codeforces Round 167 (Rated for Div. 2) {1989} PROGRAMMING Educational Codeforces Round 167 Editorial
620 Simultaneous Coloring dfs and similar divide and conquer graphs Statement F Educational Codeforces Round 167 (Rated for Div. 2) {1989} PROGRAMMING Educational Codeforces Round 167 Editorial
7992 Prime XOR Coloring bitmasks constructive algorithms graphs greedy math number theory Statement D Pinely Round 4 (Div. 1 + Div. 2) {1991} PROGRAMMING 1500.0 Video Tutorial
5222 Coloring Game constructive algorithms games graphs greedy interactive Statement E Pinely Round 4 (Div. 1 + Div. 2) {1991} PROGRAMMING 2000.0 Video Tutorial
1624 Stardew Valley constructive algorithms dfs and similar graphs Statement F Codeforces Round 959 sponsored by NEAR (Div. 1 + Div. 2) {1994} PROGRAMMING 2500.0 Video Tutorial
7714 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
417 Let Me Teach You a Lesson (Hard Version) 2-sat bitmasks data structures dp graphs matrices two pointers Statement E2 Codeforces Round 961 (Div. 2) {1995} PROGRAMMING 1500.0 Video Tutorial
3038 Cases bitmasks brute force combinatorics dfs and similar dp graphs greedy strings Statement D Codeforces Round 961 (Div. 2) {1995} PROGRAMMING 2250.0 Video Tutorial
4167 Determine Winning Islands in Race data structures dp graphs shortest paths Statement D Codeforces Round 965 (Div. 2) {1998} PROGRAMMING 1500.0 Video Tutorial
3226 Call During the Journey binary search brute force graphs greedy shortest paths Statement G Codeforces Round 966 (Div. 3) {2000} PROGRAMMING 132689
838 Turtle and Three Sequences data structures dp graphs greedy meet-in-the-middle probabilities two pointers Statement F Codeforces Round 968 (Div. 2) {2003} PROGRAMMING 2500.0 sol-zh.pdf
4714 Turtle and a MEX Problem (Hard Version) dfs and similar dp graphs greedy implementation Statement D2 Codeforces Round 968 (Div. 2) {2003} PROGRAMMING 1250.0 sol-zh.pdf
13523 Colored Portals binary search data structures graphs greedy shortest paths Statement D Educational Codeforces Round 169 (Rated for Div. 2) {2004} PROGRAMMING Educational Codeforces Round 169 Editorial
172 Dora's Paint brute force combinatorics constructive algorithms graphs Statement F Codeforces Round 969 (Div. 1) {2006} PROGRAMMING 3000.0 Tutorial
9758 Iris and Game on the Tree games graphs greedy trees Statement A Codeforces Round 969 (Div. 1) {2006} PROGRAMMING 750.0 Tutorial
23861 Sakurako's Hobby dp dsu graphs math Statement D Codeforces Round 970 (Div. 3) {2008} PROGRAMMING Codeforces Round 970 (Div. 3) Editorial
58 Strange Matrix *special graphs greedy Statement H Kotlin Heroes: Episode 11 {2011} PROGRAMMING Kotlin Heroes 11 — Editorial
9236 Rendez-vous de Marian et Robin graphs shortest paths Statement E Codeforces Round 974 (Div. 3) {2014} PROGRAMMING Discussion stream (With Hints)
7580 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
1964 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
1254 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
725 Digital Village (Extreme Version) data structures dp graphs greedy math Statement E3 Codeforces Round 977 (Div. 2, based on COMPFEST 16 - Final Round) {2021} PROGRAMMING 1000.0 Codeforces Round #977 (Div. 2, based on COMPFEST 16 — Final Round) Editorial
780 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
730 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
1400 C+K+S brute force constructive algorithms dfs and similar graphs greedy hashing math strings Statement C Codeforces Round 980 (Div. 1) {2023} PROGRAMMING 1500.0 135341
7283 Skipping brute force data structures dp graphs greedy shortest paths Statement B Codeforces Round 980 (Div. 1) {2023} PROGRAMMING 1000.0 135341
1084 Choose Your Queries dfs and similar dp graphs greedy trees Statement F Educational Codeforces Round 170 (Rated for Div. 2) {2025} PROGRAMMING Educational Codeforces Round 170 Editorial
2085 Best Subsequence bitmasks dfs and similar flows graph matchings graphs Statement E Educational Codeforces Round 171 (Rated for Div. 2) {2026} PROGRAMMING Educational Codeforces Round 171 Editorial
7140 The Endspeaker (Easy Version) binary search dp graphs greedy implementation two pointers Statement D1 Codeforces Round 982 (Div. 2) {2027} PROGRAMMING 1250.0 Codeforces Round #982 (Div. 2) Editorial
14138 Add Zeros data structures dfs and similar graphs sortings Statement C Codeforces Round 982 (Div. 2) {2027} PROGRAMMING 1250.0 Codeforces Round #982 (Div. 2) Editorial
3824 Alice's Adventures in Cards constructive algorithms data structures dfs and similar dp graphs greedy implementation shortest paths Statement D Codeforces Round 986 (Div. 2) {2028} PROGRAMMING 1750.0 Codeforces Round 986 (Div. 2) Editorial
4010 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
170 Variance Challenge flows graphs greedy Statement I Refact.ai Match 1 (Codeforces Round 985) {2029} PROGRAMMING 5500.0 Refact.ai Match 1 (Codeforces Round 985) Editorial
6338 Genokraken binary search constructive algorithms data structures graphs interactive trees two pointers Statement D Codeforces Round 983 (Div. 2) {2032} PROGRAMMING 1750.0 Codeforces Round 983 (Div. 2) Editorial
9359 Trapped in the Witch's Labyrinth constructive algorithms dfs and similar graphs implementation Statement C Rayan Programming Contest 2024 - Selection (Codeforces Round 989, Div. 1 + Div. 2) {2034} PROGRAMMING 1500.0 Rayan 2024 Selection Round Editorial
2761 Control of Randomness combinatorics dfs and similar graphs greedy math probabilities trees Statement E Codeforces Round 992 (Div. 2) {2040} PROGRAMMING 2250.0 Codeforces Round #992 (Div.2) Editorial
5271 Drunken Maze dfs and similar graphs shortest paths Statement D 2024 ICPC Asia Taichung Regional Contest (Unrated, Online Mirror, ICPC Rules, Preferably Teams) {2041} PROGRAMMING Problem Analysis and Hints (PDF)
1867 Matrix Transformation bitmasks brute force dfs and similar graphs implementation Statement E Educational Codeforces Round 173 (Rated for Div. 2) {2043} PROGRAMMING Educational Codeforces Round 173 Editorial
4004 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
7638 Medium Demon Problem (easy version) dfs and similar graph matchings graphs Statement G1 Codeforces Round 993 (Div. 4) {2044} PROGRAMMING Codeforces Round 993 (Div. 4) Editorial
2288 Mirror Maze brute force dfs and similar graphs implementation Statement M 2024-2025 ICPC Asia Jakarta Regional Contest (Unrated, Online Mirror, ICPC Rules, Teams Preferred) {2045} PROGRAMMING raRzKDJLPHcUnqTcwvGznwEdKiDWjEkd.pdf 1800
969 X Aura graphs shortest paths Statement G 2024-2025 ICPC Asia Jakarta Regional Contest (Unrated, Online Mirror, ICPC Rules, Teams Preferred) {2045} PROGRAMMING raRzKDJLPHcUnqTcwvGznwEdKiDWjEkd.pdf 2200
558 For the Emperor! flows graphs Statement D Codeforces Round 990 (Div. 1) {2046} PROGRAMMING 2500.0 Разбор Codeforces Round 990 (Div. 2 + Div. 1)
3581 Kevin and Bipartite Graph constructive algorithms graphs greedy Statement E Codeforces Global Round 28 {2048} PROGRAMMING 1750.0 Tutorial
2492 Snakes bitmasks dp graphs Statement G Codeforces Round 995 (Div. 3) {2051} PROGRAMMING 137623
1224 DAG Serialization brute force graphs Statement D 2024-2025 ICPC, NERC, Northern Eurasia Finals (Unrated, Online Mirror, ICPC Rules, Teams Preferred) {2052} PROGRAMMING
403 Managing Cluster dp graphs math trees Statement M 2024-2025 ICPC, NERC, Northern Eurasia Finals (Unrated, Online Mirror, ICPC Rules, Teams Preferred) {2052} PROGRAMMING
155 Incompetent Delivery Guy graphs shortest paths Statement I 2024-2025 ICPC, NERC, Northern Eurasia Finals (Unrated, Online Mirror, ICPC Rules, Teams Preferred) {2052} PROGRAMMING
110 Affectionate Arrays (Hard Version) data structures dp graphs greedy math shortest paths two pointers Statement I2 Good Bye 2024: 2025 is NEAR {2053} PROGRAMMING 2000.0 Good Bye 2024: 2025 is NEAR Editorial
4574 Resourceful Caterpillar Sequence dfs and similar dp games graphs implementation trees Statement E Good Bye 2024: 2025 is NEAR {2053} PROGRAMMING 2000.0 Good Bye 2024: 2025 is NEAR Editorial
18199 Find the Permutation dfs and similar graphs implementation sortings Statement B Codeforces Round 997 (Div. 2) {2056} PROGRAMMING 1250.0 Codeforces Round #997 (Div. 2) Editorial
2674 Another Exercise on Graphs (Easy Version) binary search brute force dp graphs shortest paths Statement E1 Hello 2025 {2057} PROGRAMMING 1000.0
1974 Another Exercise on Graphs (hard version) binary search brute force dsu graphs shortest paths sortings trees Statement E2 Hello 2025 {2057} PROGRAMMING 2000.0
6724 Graph and Graph data structures graphs greedy shortest paths Statement D Codeforces Round 1002 (Div. 2) {2059} PROGRAMMING 2000.0 139094
12679 Graph Composition dfs and similar dsu graphs greedy Statement E Codeforces Round 998 (Div. 3) {2060} PROGRAMMING Codeforces Round 998 (Div. 3) Editorial
525 Kevin and Teams constructive algorithms graphs interactive Statement G IAEPC Preliminary Contest (Codeforces Round 999, Div. 1 + Div. 2) {2061} PROGRAMMING 3000.0 IAEPC Preliminary Contest (Codeforces Round 999, Div. 1 + Div. 2) Editorial
109 Kevin and Stones (Easy Version) flows graph matchings graphs Statement H1 IAEPC Preliminary Contest (Codeforces Round 999, Div. 1 + Div. 2) {2061} PROGRAMMING 3000.0 IAEPC Preliminary Contest (Codeforces Round 999, Div. 1 + Div. 2) Editorial
71 Kevin and Stones (Hard Version) flows graphs Statement H2 IAEPC Preliminary Contest (Codeforces Round 999, Div. 1 + Div. 2) {2061} PROGRAMMING 5000.0 IAEPC Preliminary Contest (Codeforces Round 999, Div. 1 + Div. 2) Editorial
464 The Game (Hard Version) data structures dfs and similar games graphs trees Statement E2 Ethflow Round 1 (Codeforces Round 1001, Div. 1 + Div. 2) {2062} PROGRAMMING 2500.0 Ethflow Round 1 (Codeforces Round 1001, Div. 1 + Div. 2) Editorial
4409 The Game (Easy Version) dfs and similar games graphs trees Statement E1 Ethflow Round 1 (Codeforces Round 1001, Div. 1 + Div. 2) {2062} PROGRAMMING 1500.0 Ethflow Round 1 (Codeforces Round 1001, Div. 1 + Div. 2) Editorial
203 Permutation Factory flows graph matchings graphs Statement G Ethflow Round 1 (Codeforces Round 1001, Div. 1 + Div. 2) {2062} PROGRAMMING 4000.0 Ethflow Round 1 (Codeforces Round 1001, Div. 1 + Div. 2) Editorial
15097 Remove Exactly Two brute force data structures dp graphs greedy sortings trees Statement C Codeforces Round 1000 (Div. 2) {2063} PROGRAMMING 1500.0 Codeforces Round 1000 (Div. 2) — Editorial
7335 Skibidus and Slay data structures dfs and similar graphs greedy trees Statement F Codeforces Round 1003 (Div. 4) {2065} PROGRAMMING Video Tutorial
7367 Object Identification graphs implementation interactive Statement A Codeforces Round 1004 (Div. 1) {2066} PROGRAMMING 750.0 139415
1020 Condorcet Elections constructive algorithms graphs probabilities Statement A European Championship 2025 - Online Mirror (Unrated, ICPC Rules, Teams Preferred) {2068} PROGRAMMING 140239
384 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
211 Amusement Park Rides flows graphs Statement K European Championship 2025 - Online Mirror (Unrated, ICPC Rules, Teams Preferred) {2068} PROGRAMMING 140239
67 Pinball graphs shortest paths Statement I European Championship 2025 - Online Mirror (Unrated, ICPC Rules, Teams Preferred) {2068} PROGRAMMING 140239
823 Graph Inclusion data structures divide and conquer dsu Statement F Educational Codeforces Round 174 (Rated for Div. 2) {2069} PROGRAMMING 139774
142 RGB Walking bitmasks chinese remainder theorem dfs and similar graphs number theory Statement G Codeforces Round 1008 (Div. 1) {2077} PROGRAMMING 3000.0 Codeforces Round 1008 (Div. 1, Div. 2) Editorial
18600 Vicious Labyrinth constructive algorithms graphs greedy implementation math Statement B Codeforces Round 1008 (Div. 2) {2078} PROGRAMMING 750.0 Codeforces Round 1008 (Div. 1, Div. 2) Editorial
46 Strong Connectivity Strikes Back *special constructive algorithms graphs Statement A XIX Open Olympiad in Informatics - Final Stage, Day 2 (Unrated, Online Mirror, IOI rules) {2080} PROGRAMMING
1228 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
16556 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
1560 Gleb and Boating brute force constructive algorithms data structures dp graphs greedy math shortest paths Statement G Codeforces Round 1013 (Div. 3) {2091} PROGRAMMING Codeforces Round 1013 (Div. 3) Editorial
3903 She knows... combinatorics constructive algorithms graphs math Statement E Codeforces Round 1014 (Div. 2) {2092} PROGRAMMING 2250.0 Codeforces Round #1014 (Div. 2) Editorial
1982 Baggage Claim combinatorics dsu graphs math trees Statement B Codeforces Round 1021 (Div. 1) {2097} PROGRAMMING 1000.0 142316
2011 Kia Bakes a Cake data structures dp graphs greedy Statement E Codeforces Round 1024 (Div. 1) {2101} PROGRAMMING 3250.0 142788
4060 Local Construction constructive algorithms dfs and similar graphs implementation two pointers Statement D Codeforces Round 1019 (Div. 2) {2103} PROGRAMMING 2000.0 142149
921 Spruce Dispute constructive algorithms dfs and similar graphs implementation shortest paths trees Statement E Codeforces Round 1022 (Div. 2) {2108} PROGRAMMING 2750.0 Codeforces Round 1022 Editorial
15144 Neo's Escape data structures dsu graphs greedy implementation Statement C Codeforces Round 1022 (Div. 2) {2108} PROGRAMMING 1500.0 Codeforces Round 1022 Editorial
284 Penguin Steps binary search dfs and similar flows graphs shortest paths Statement F Codeforces Round 1025 (Div. 2) {2109} PROGRAMMING 3000.0 Codeforces Round 1025 (Div. 2) Editorial
5845 D/D/D dfs and similar graphs greedy shortest paths Statement D Codeforces Round 1025 (Div. 2) {2109} PROGRAMMING 1750.0 Codeforces Round 1025 (Div. 2) Editorial
8846 Fewer Batteries binary search dfs and similar dp graphs greedy Statement D Codeforces Round 1026 (Div. 2) {2110} PROGRAMMING 2000.0 Codeforces Round 1026 (Div. 2) Editorial
2805 Melody dfs and similar graphs Statement E Codeforces Round 1026 (Div. 2) {2110} PROGRAMMING 2250.0 Codeforces Round 1026 (Div. 2) Editorial
3454 Tree Colorings combinatorics dp graphs math trees Statement E Educational Codeforces Round 180 (Rated for Div. 2) {2112} PROGRAMMING Educational Codeforces Round 180 — Editorial
663 Variables and Operations graphs greedy shortest paths Statement F Educational Codeforces Round 180 (Rated for Div. 2) {2112} PROGRAMMING Educational Codeforces Round 180 — Editorial
430 From Kazan with Love brute force graphs trees Statement E Codeforces Round 1031 (Div. 2) {2113} PROGRAMMING 2500.0 Codeforces Round #1031 Editorial
992 Two Arrays constructive algorithms dfs and similar graphs math Statement F Codeforces Round 1031 (Div. 2) {2113} PROGRAMMING 3000.0 Codeforces Round #1031 Editorial
5009 Gellyfish and Camellia Japonica constructive algorithms dfs and similar dp graphs greedy Statement B Codeforces Round 1028 (Div. 1) {2115} PROGRAMMING 1250.0 Codeforces Round 1028 (Div.1, Div.2) Editorial
315 Gellyfish and Mayflower dp graphs Statement E Codeforces Round 1028 (Div. 1) {2115} PROGRAMMING 3000.0 Codeforces Round 1028 (Div.1, Div.2) Editorial
5347 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
2568 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
8633 Red Light, Green Light (Easy version) brute force dfs and similar dp graphs implementation Statement D1 Codeforces Round 1030 (Div. 2) {2118} PROGRAMMING 1250.0 Codeforces Round 1030 (Div. 2) Editorial
298 Shifts and Swaps graphs hashing strings Statement F Codeforces Round 1030 (Div. 2) {2118} PROGRAMMING 3500.0 Codeforces Round 1030 (Div. 2) Editorial
503 Superb Graphs 2-sat graphs Statement F Codeforces Round 1033 (Div. 2) and CodeNite 2025 {2120} PROGRAMMING 3000.0 Codeforces Round 1033 (Div. 2) and CodeNite 2025 Editorial
113 Eulerian Line Graph graphs greedy math Statement G Codeforces Round 1033 (Div. 2) and CodeNite 2025 {2120} PROGRAMMING 4000.0 Codeforces Round 1033 (Div. 2) and CodeNite 2025 Editorial
2761 Traffic Lights brute force dp graphs shortest paths Statement D Order Capital Round 1 (Codeforces Round 1038, Div. 1 + Div. 2) {2122} PROGRAMMING 2000.0 Order Capital Round 1 (Codeforces Round 1038, Div. 1 + Div. 2) Editorial
4424 1-1-1, Free Tree! data structures dfs and similar graphs trees Statement F Codeforces Round 1037 (Div. 3) {2126} PROGRAMMING 144845
126 Inter Active (Hard Version) binary search bitmasks constructive algorithms graphs implementation interactive math probabilities Statement G2 Atto Round 1 (Codeforces Round 1041, Div. 1 + Div. 2) {2127} PROGRAMMING 2750.0 Atto Round 1 (Codeforces Round 1041, Div. 1 + Div. 2) Editorial
1915 23 Rises Again brute force data structures dfs and similar dp flows graphs implementation probabilities trees Statement H Atto Round 1 (Codeforces Round 1041, Div. 1 + Div. 2) {2127} PROGRAMMING 4000.0 Atto Round 1 (Codeforces Round 1041, Div. 1 + Div. 2) Editorial
7488 Root was Built by Love, Broken by Destiny combinatorics dfs and similar graphs trees Statement D Atto Round 1 (Codeforces Round 1041, Div. 1 + Div. 2) {2127} PROGRAMMING 2000.0 Atto Round 1 (Codeforces Round 1041, Div. 1 + Div. 2) Editorial
403 Strict Triangle graphs shortest paths Statement F Codeforces Round 1039 (Div. 2) {2128} PROGRAMMING 4000.0 Codeforces Round #1039 — Editorial
559 Induced Subgraph Queries data structures graphs sortings Statement E Codeforces Round 1040 (Div. 1) {2129} PROGRAMMING 3000.0 Codeforces Round 1040 (Div. 1, Div. 2) Editorial
909 Sea, You & copriMe brute force combinatorics constructive algorithms graphs greedy math number theory Statement H Codeforces Round 1042 (Div. 3) {2131} PROGRAMMING Codeforces Round 1042 (Div. 3) Editorial
14866 Arboris Contractio graphs greedy trees Statement D Codeforces Round 1042 (Div. 3) {2131} PROGRAMMING Codeforces Round 1042 (Div. 3) Editorial
2869 Rada and the Chamomile Valley dfs and similar graphs shortest paths Statement F Codeforces Round 1043 (Div. 3) {2132} PROGRAMMING Codeforces Round 1043 (Div. 3) Editorial
13358 The Nether graphs interactive Statement C Codeforces Round 1044 (Div. 2) {2133} PROGRAMMING 1750.0 Codeforces Round 1044 (Div. 2) Editorial
5334 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
2005 Cry Me a River dfs and similar dp games graphs Statement G Codeforces Round 1047 (Div. 3) {2137} PROGRAMMING Codeforces Round 1047 (Div. 3) Editorial
5690 Maple and Tree Beauty (Easy Version) dfs and similar dp graphs trees Statement C1 Codeforces Round 1048 (Div. 1) {2138} PROGRAMMING 1250.0 Codeforces Round 1048 (Div. 1, Div. 2) Editorial
85 Merging Vertices in a Graph *special dfs and similar dsu graphs Statement H Kotlin Heroes: Episode 13 {2141} PROGRAMMING Kotlin Heroes 13 Editorial
14904 Max Tree dfs and similar graphs greedy Statement C Codeforces Round 1051 (Div. 2) {2143} PROGRAMMING 1500.0 Codeforces Round 1051 (Div. 2) Editorial
1061 Long Journey dfs and similar dp graphs matrices number theory shortest paths Statement F Educational Codeforces Round 183 (Rated for Div. 2) {2145} PROGRAMMING Educational Codeforces Round 183 Editorial
11298 Rabbits 2-sat dp graphs greedy implementation Statement C Codeforces Global Round 29 (Div. 1 + Div. 2) {2147} PROGRAMMING 1500.0
283 Maxflow GCD Coloring flows graphs Statement H Codeforces Global Round 29 (Div. 1 + Div. 2) {2147} PROGRAMMING 5500.0
223 Cycle Closing constructive algorithms graphs trees Statement F Codeforces Round 1053 (Div. 1) {2150} PROGRAMMING 3250.0 Editorial of Codeforces Round 1053 (Div. 1, Div. 2)
3895 Monotone Subsequence brute force constructive algorithms dp graphs interactive math Statement E Squarepoint Challenge (Codeforces Round 1055, Div. 1 + Div. 2) {2152} PROGRAMMING 3000.0 Squarepoint Challenge (Codeforces Round 1055, Div. 1 + Div. 2) Editorial
1755 Victorious Coloring (Easy Version) dp graphs Statement H1 Squarepoint Challenge (Codeforces Round 1055, Div. 1 + Div. 2) {2152} PROGRAMMING 4000.0 Squarepoint Challenge (Codeforces Round 1055, Div. 1 + Div. 2) Editorial
5047 Catshock constructive algorithms dfs and similar graphs trees Statement D Codeforces Round 1060 (Div. 2) {2154} PROGRAMMING 1750.0 Codeforces Round 1060 (Div. 2) Editorial
17750 Abraham's Great Escape constructive algorithms graphs Statement B Codeforces Round 1056 (Div. 2) {2155} PROGRAMMING 1000.0 Codeforces Round 1056 (Div. 2) Editorial
744 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
287 Distinct GCDs (Hard Version) combinatorics constructive algorithms graphs graphs graphs math number theory number theory Statement F2 Codeforces Round 1067 (Div. 2) {2158} PROGRAMMING 1000.0 Codeforces Round 1067 (Div. 2) Editorial
450 Distinct GCDs (Easy Version) constructive algorithms constructive algorithms graphs graphs number theory number theory Statement F1 Codeforces Round 1067 (Div. 2) {2158} PROGRAMMING 2500.0 Codeforces Round 1067 (Div. 2) Editorial
665 Sink data structures dsu dsu graphs graphs Statement E Codeforces Round 1067 (Div. 2) {2158} PROGRAMMING 2750.0 Codeforces Round 1067 (Div. 2) Editorial
2653 Twin Polynomials combinatorics graph matchings graphs math Statement C Codeforces Round 1058 (Div. 1) {2159} PROGRAMMING 1500.0 Codeforces Round 1058 Editorial
2864 Locked Out binary search data structures dp graphs greedy implementation two pointers Statement D Pinely Round 5 (Div. 1 + Div. 2) {2161} PROGRAMMING 2250.0
368 SubMST combinatorics graphs trees Statement F Pinely Round 5 (Div. 1 + Div. 2) {2161} PROGRAMMING 3250.0
3575 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
15854 Cyclic Merging brute force constructive algorithms graphs greedy trees Statement A Codeforces Round 1064 (Div. 1) {2165} PROGRAMMING 500.0 148452
912 Intercepting Butterflies bitmasks constructive algorithms graphs interactive Statement C Testing Round 20 (Unrated, Communication Problems) {2168} PROGRAMMING Testing Round 20 Editorial (officially unofficial)
6069 Fibonacci Paths data structures dp geometry graphs sortings Statement D Codeforces Round 1070 (Div. 2) {2176} PROGRAMMING 2000.0 Codeforces Round 1070 (Div.2) Editorial
6975 Xmas or Hysteria constructive algorithms graphs greedy implementation Statement D Good Bye 2025 {2178} PROGRAMMING 1750.0
2881 Blackslex and Another RGB Walking graphs interactive number theory Statement F Codeforces Round 1071 (Div. 3) {2179} PROGRAMMING Codeforces Round 1071 (Div. 3) Editorial
167 Cacti Classification binary search interactive math Statement C 2025-2026 ICPC, NERC, Northern Eurasia Finals (Unrated, Online Mirror, ICPC Rules, Teams Preferred) {2181} PROGRAMMING Tutorial
4214 Cherry Tree dfs and similar dp graphs trees Statement F Codeforces Round 1072 (Div. 3) {2184} PROGRAMMING Codeforces Round 1072 (Div. 3) Editorial
1479 Jerry and Tom data structures dfs and similar games graphs greedy trees Statement C Codeforces Round 1077 (Div. 1) {2187} PROGRAMMING 1750.0 Codeforces Round 1077 (Div. 1, Div. 2) Editorial
105 Maximize Determinant graphs Statement G Codeforces Round 1073 (Div. 1) {2190} PROGRAMMING 3750.0 Codeforces Round 1073 (Div. 1, Div. 2) Editorial
2274 Swap to Rearrange constructive algorithms dfs and similar graph matchings graphs greedy strings Statement E Codeforces Round 1081 (Div. 2) {2192} PROGRAMMING 2250.0 Codeforces Round 1081 (Div. 2) Editorial
2840 The Turtle Strikes Back dp graphs greedy Statement E Codeforces Round 1078 (Div. 2) {2194} PROGRAMMING 2500.0 Codeforces Round #1078 Editorial
1151 Idiot First Search and Queries binary search data structures graphs trees Statement G Codeforces Round 1080 (Div. 3) {2195} PROGRAMMING Codeforces Round 1080 (Div. 3) Editorial
2917 Parabola Independence dp graphs math Statement F Codeforces Round 1080 (Div. 3) {2195} PROGRAMMING Codeforces Round 1080 (Div. 3) Editorial
3881 Interactive Graph (Simple Version) combinatorics dfs and similar dp graphs interactive Statement C1 Codeforces Round 1079 (Div. 1) {2196} PROGRAMMING 750.0 Tutorial
2721 Interactive Graph (Hard Version) combinatorics dfs and similar dp graphs interactive Statement C2 Codeforces Round 1079 (Div. 1) {2196} PROGRAMMING 750.0 Tutorial
117 Indivisible constructive algorithms graphs Statement F Codeforces Round 1079 (Div. 1) {2196} PROGRAMMING 3500.0 Tutorial
9966 Alternating Path dfs and similar graphs Statement D Educational Codeforces Round 188 (Rated for Div. 2) {2204} PROGRAMMING Educational Codeforces Round 188 Editorial
496 Grid Path dp graphs matrices Statement G Educational Codeforces Round 188 (Rated for Div. 2) {2204} PROGRAMMING Educational Codeforces Round 188 Editorial
714 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
315 Hanabi data structures dp flows graph matchings graphs greedy Statement F Codeforces Round 1085 (Div. 1 + Div. 2) {2207} PROGRAMMING 3250.0 Codeforces Round 1085 (Div. 1 + Div. 2) Editorial
4750 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
2073 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
817 Oriented Journey bitmasks communication constructive algorithms graphs hashing interactive trees Statement C Codeforces Round 1092 (Unrated, Div. 1, Based on THUPC 2026 — Finals) {2215} PROGRAMMING 1750.0 152930
215 Statistics on Tree binary search brute force dfs and similar divide and conquer graphs trees Statement G Spectral::Cup 2026 Round 1 (Codeforces Round 1094, Div. 1 + Div. 2) {2222} PROGRAMMING 3500.0 Spectral::Cup 2026 Round 1 (Codeforces Round 1094, Div. 1 + Div. 2) Editorial
716 Building Tree divide and conquer dsu graphs implementation Statement F Spectral::Cup 2026 Round 1 (Codeforces Round 1094, Div. 1 + Div. 2) {2222} PROGRAMMING 3000.0 Spectral::Cup 2026 Round 1 (Codeforces Round 1094, Div. 1 + Div. 2) Editorial
357 Zhily and Cycle graphs greedy Statement D Codeforces Round 1097 (Div. 1, Based on Zhili Cup 2026) {2223} PROGRAMMING 2500.0 Codeforces Round 1097 (Div. 1, Div2, Based on Zhili Cup 2026) Tutorial
269 Simple Problem graphs number theory Statement G Educational Codeforces Round 189 (Rated for Div. 2) {2225} PROGRAMMING Tutorial
1965 Deconstruction Tree combinatorics data structures dp graphs trees Statement E Spectral::Cup 2026 Round 2 (Codeforces Round 1100, Div. 1 + Div. 2) {2229} PROGRAMMING 2500.0 Spectral::Cup 2026 Round 2 (Codeforces Round 1100, Div. 1 + Div. 2) Editorial
5174 Good Schedule dp graphs greedy two pointers Statement D Educational Codeforces Round 190 (Rated for Div. 2) {2230} PROGRAMMING Educational Codeforces Round 190 — Editorial
1139 Graph Cutting dfs and similar dp trees Statement E Codeforces Round 1099 (Div. 2) {2231} PROGRAMMING 2500.0
382 Shortest GCD Paths dp graphs math number theory shortest paths Statement F Educational Codeforces Round 191 (Rated for Div. 2) {2233} PROGRAMMING
1993 Permutation Commutation constructive algorithms graphs greedy Statement E Order Capital Round 2 (Codeforces Round 1104, Div. 1 + Div. 2) {2237} PROGRAMMING 2250.0 Order Capital Round 2 (Codeforces Round 1104, Div. 1 + Div. 2) Editorial
403 Infinite Work combinatorics graphs greedy math Statement F Codeforces Round 1106 (Div. 2) {2238} PROGRAMMING 2750.0
599 Hunting the Beast combinatorics dp graphs Statement D Codeforces Round 1105 (Div. 1) {2239} PROGRAMMING 2000.0
5738 Fair and Square combinatorics dp graphs math number theory trees Statement E Codeforces Round 1107 (Div. 3) {2241} PROGRAMMING
33 Even Simple Path constructive algorithms graphs shortest paths Statement F Codeforces Round 1112 (Div. 1) {2249} PROGRAMMING 3500.0