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2491 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
1914 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
10704 Bicycles dp graphs greedy implementation shortest paths sortings Statement G Codeforces Round 918 (Div. 4) {1915} PROGRAMMING 123952
790 Group Division constructive algorithms dfs and similar graphs Statement F Good Bye 2023 {1916} PROGRAMMING 2750.0
1174 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
1311 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)
690 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)
4715 Vlad and Trouble at MIT dfs and similar dp flows graphs greedy implementation trees Statement G Codeforces Round 928 (Div. 4) {1926} PROGRAMMING 126132
5697 Microcycle data structures dfs and similar dsu graphs greedy trees Statement F Codeforces Round 923 (Div. 3) {1927} PROGRAMMING 125597
2167 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.
12886 Chat Screenshots combinatorics dfs and similar graphs implementation Statement F Codeforces Round 925 (Div. 3) {1931} PROGRAMMING 125878
1434 Moving Platforms graphs math number theory shortest paths Statement G Codeforces Round 927 (Div. 3) {1932} PROGRAMMING 126196
3042 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
1792 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
310 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
5077 Rudolf and Subway dfs and similar graphs shortest paths Statement G Codeforces Round 933 (Div. 3) {1941} PROGRAMMING 127018
3621 Clique Partition constructive algorithms graphs greedy Statement E Educational Codeforces Round 163 (Rated for Div. 2) {1948} PROGRAMMING Educational Codeforces Round 163 Editorial
21704 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
2901 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
1076 Scooter graphs greedy Statement G European Championship 2024 - Online Mirror (Unrated, ICPC Rules, Teams Preferred) {1949} PROGRAMMING European Championship 2024 (EUC) Editorial
567 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
6464 Shuffling Songs bitmasks dp graphs implementation strings Statement G Codeforces Round 937 (Div. 4) {1950} PROGRAMMING Codeforces Round 937 (Div. 4) Editorial
119 Growing Trees constructive algorithms flows graphs greedy Statement I Codeforces Global Round 25 {1951} PROGRAMMING 4000.0 Codeforces Global Round 25 Editorial
14202 Are You a Robot, Again? expression parsing graphs strings Statement A April Fools Day Contest 2024 {1952} PROGRAMMING April Fools Day Contest 2024 Editorial
759 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
1007 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
17777 Permutation Game brute force dfs and similar games graphs greedy math Statement D Codeforces Round 943 (Div. 3) {1968} PROGRAMMING 129096 1300
920 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
587 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
2997 ±1 2-sat dfs and similar graphs Statement H Codeforces Round 944 (Div. 4) {1971} PROGRAMMING Codeforces Round 944 (Div. 4) Editorial 2100
1046 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
961 Tensor constructive algorithms graphs interactive Statement E Codeforces Round 948 (Div. 2) {1977} PROGRAMMING 2500.0 129858 2600
1649 Large Graph data structures dsu graphs number theory Statement F Codeforces Round 953 (Div. 2) {1978} PROGRAMMING 2500.0 130527
1876 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
452 Kostyanych's Theorem brute force graphs interactive Statement F Codeforces Round 951 (Div. 2) {1979} PROGRAMMING 3000.0 Codeforces Round 951 (Div. 2) Editorial
1799 Yasya and the Mysterious Tree bitmasks data structures dfs and similar graphs strings trees Statement G Codeforces Round 950 (Div. 3) {1980} PROGRAMMING 130135
2250 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
1362 Turtle and Intersected Segments data structures dsu graphs greedy Statement E Codeforces Round 949 (Div. 2) {1981} PROGRAMMING 2500.0 Simplified Chinese Tutorial
7504 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
6965 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
362 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
23718 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
629 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
8097 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
5279 Coloring Game constructive algorithms games graphs greedy interactive Statement E Pinely Round 4 (Div. 1 + Div. 2) {1991} PROGRAMMING 2000.0 Video Tutorial
1665 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
7863 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
422 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
3072 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
4202 Determine Winning Islands in Race data structures dp graphs shortest paths Statement D Codeforces Round 965 (Div. 2) {1998} PROGRAMMING 1500.0 Video Tutorial
3271 Call During the Journey binary search brute force graphs greedy shortest paths Statement G Codeforces Round 966 (Div. 3) {2000} PROGRAMMING 132689
854 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
4761 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
13628 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
181 Dora's Paint brute force combinatorics constructive algorithms graphs Statement F Codeforces Round 969 (Div. 1) {2006} PROGRAMMING 3000.0 Tutorial
9934 Iris and Game on the Tree games graphs greedy trees Statement A Codeforces Round 969 (Div. 1) {2006} PROGRAMMING 750.0 Tutorial
24023 Sakurako's Hobby dp dsu graphs math Statement D Codeforces Round 970 (Div. 3) {2008} PROGRAMMING Codeforces Round 970 (Div. 3) Editorial
59 Strange Matrix *special graphs greedy Statement H Kotlin Heroes: Episode 11 {2011} PROGRAMMING Kotlin Heroes 11 — Editorial
9595 Rendez-vous de Marian et Robin graphs shortest paths Statement E Codeforces Round 974 (Div. 3) {2014} PROGRAMMING Discussion stream (With Hints)
7645 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
1982 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
1271 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
736 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
795 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
746 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
1409 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
7378 Skipping brute force data structures dp graphs greedy shortest paths Statement B Codeforces Round 980 (Div. 1) {2023} PROGRAMMING 1000.0 135341
1095 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
2142 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
7210 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
14307 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
3863 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
4061 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
180 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
6385 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
9443 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
2842 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
5492 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)
1879 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
4075 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
7721 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
2345 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
993 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
570 For the Emperor! flows graphs Statement D Codeforces Round 990 (Div. 1) {2046} PROGRAMMING 2500.0 Разбор Codeforces Round 990 (Div. 2 + Div. 1)
3606 Kevin and Bipartite Graph constructive algorithms graphs greedy Statement E Codeforces Global Round 28 {2048} PROGRAMMING 1750.0 Tutorial
2534 Snakes bitmasks dp graphs Statement G Codeforces Round 995 (Div. 3) {2051} PROGRAMMING 137623
1254 DAG Serialization brute force graphs Statement D 2024-2025 ICPC, NERC, Northern Eurasia Finals (Unrated, Online Mirror, ICPC Rules, Teams Preferred) {2052} PROGRAMMING
424 Managing Cluster dp graphs math trees Statement M 2024-2025 ICPC, NERC, Northern Eurasia Finals (Unrated, Online Mirror, ICPC Rules, Teams Preferred) {2052} PROGRAMMING
171 Incompetent Delivery Guy graphs shortest paths Statement I 2024-2025 ICPC, NERC, Northern Eurasia Finals (Unrated, Online Mirror, ICPC Rules, Teams Preferred) {2052} PROGRAMMING
111 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
4614 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
18299 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
2715 Another Exercise on Graphs (Easy Version) binary search brute force dp graphs shortest paths Statement E1 Hello 2025 {2057} PROGRAMMING 1000.0
2030 Another Exercise on Graphs (hard version) binary search brute force dsu graphs shortest paths sortings trees Statement E2 Hello 2025 {2057} PROGRAMMING 2000.0
6818 Graph and Graph data structures graphs greedy shortest paths Statement D Codeforces Round 1002 (Div. 2) {2059} PROGRAMMING 2000.0 139094
13051 Graph Composition dfs and similar dsu graphs greedy Statement E Codeforces Round 998 (Div. 3) {2060} PROGRAMMING Codeforces Round 998 (Div. 3) Editorial
563 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
111 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
81 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
475 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
4443 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
212 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
15432 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
7449 Skibidus and Slay data structures dfs and similar graphs greedy trees Statement F Codeforces Round 1003 (Div. 4) {2065} PROGRAMMING Video Tutorial
7447 Object Identification graphs implementation interactive Statement A Codeforces Round 1004 (Div. 1) {2066} PROGRAMMING 750.0 139415
1045 Condorcet Elections constructive algorithms graphs probabilities Statement A European Championship 2025 - Online Mirror (Unrated, ICPC Rules, Teams Preferred) {2068} PROGRAMMING 140239
390 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
244 Amusement Park Rides flows graphs Statement K European Championship 2025 - Online Mirror (Unrated, ICPC Rules, Teams Preferred) {2068} PROGRAMMING 140239
73 Pinball graphs shortest paths Statement I European Championship 2025 - Online Mirror (Unrated, ICPC Rules, Teams Preferred) {2068} PROGRAMMING 140239
833 Graph Inclusion data structures divide and conquer dsu Statement F Educational Codeforces Round 174 (Rated for Div. 2) {2069} PROGRAMMING 139774
152 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
18727 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
49 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
1252 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
16703 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
1660 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
3943 She knows... combinatorics constructive algorithms graphs math Statement E Codeforces Round 1014 (Div. 2) {2092} PROGRAMMING 2250.0 Codeforces Round #1014 (Div. 2) Editorial
2002 Baggage Claim combinatorics dsu graphs math trees Statement B Codeforces Round 1021 (Div. 1) {2097} PROGRAMMING 1000.0 142316
3174 Kia Bakes a Cake data structures dp graphs greedy Statement E Codeforces Round 1024 (Div. 1) {2101} PROGRAMMING 3250.0 142788
4099 Local Construction constructive algorithms dfs and similar graphs implementation two pointers Statement D Codeforces Round 1019 (Div. 2) {2103} PROGRAMMING 2000.0 142149
944 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
15338 Neo's Escape data structures dsu graphs greedy implementation Statement C Codeforces Round 1022 (Div. 2) {2108} PROGRAMMING 1500.0 Codeforces Round 1022 Editorial
293 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
5961 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
8935 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
2861 Melody dfs and similar graphs Statement E Codeforces Round 1026 (Div. 2) {2110} PROGRAMMING 2250.0 Codeforces Round 1026 (Div. 2) Editorial
3490 Tree Colorings combinatorics dp graphs math trees Statement E Educational Codeforces Round 180 (Rated for Div. 2) {2112} PROGRAMMING Educational Codeforces Round 180 — Editorial
671 Variables and Operations graphs greedy shortest paths Statement F Educational Codeforces Round 180 (Rated for Div. 2) {2112} PROGRAMMING Educational Codeforces Round 180 — Editorial
435 From Kazan with Love brute force graphs trees Statement E Codeforces Round 1031 (Div. 2) {2113} PROGRAMMING 2500.0 Codeforces Round #1031 Editorial
1006 Two Arrays constructive algorithms dfs and similar graphs math Statement F Codeforces Round 1031 (Div. 2) {2113} PROGRAMMING 3000.0 Codeforces Round #1031 Editorial
5835 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
485 Gellyfish and Mayflower dp graphs Statement E Codeforces Round 1028 (Div. 1) {2115} PROGRAMMING 3000.0 Codeforces Round 1028 (Div.1, Div.2) Editorial
5494 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
2592 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
8704 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
303 Shifts and Swaps graphs hashing strings Statement F Codeforces Round 1030 (Div. 2) {2118} PROGRAMMING 3500.0 Codeforces Round 1030 (Div. 2) Editorial
508 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
117 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
3075 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
4475 1-1-1, Free Tree! data structures dfs and similar graphs trees Statement F Codeforces Round 1037 (Div. 3) {2126} PROGRAMMING 144845
147 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
2693 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
8313 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
410 Strict Triangle graphs shortest paths Statement F Codeforces Round 1039 (Div. 2) {2128} PROGRAMMING 4000.0 Codeforces Round #1039 — Editorial
655 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
932 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
15076 Arboris Contractio graphs greedy trees Statement D Codeforces Round 1042 (Div. 3) {2131} PROGRAMMING Codeforces Round 1042 (Div. 3) Editorial
2989 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
13474 The Nether graphs interactive Statement C Codeforces Round 1044 (Div. 2) {2133} PROGRAMMING 1750.0 Codeforces Round 1044 (Div. 2) Editorial
6431 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
2058 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
5771 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
15157 Max Tree dfs and similar graphs greedy Statement C Codeforces Round 1051 (Div. 2) {2143} PROGRAMMING 1500.0 Codeforces Round 1051 (Div. 2) Editorial
1078 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
12268 Rabbits 2-sat dp graphs greedy implementation Statement C Codeforces Global Round 29 (Div. 1 + Div. 2) {2147} PROGRAMMING 1500.0
501 Maxflow GCD Coloring flows graphs Statement H Codeforces Global Round 29 (Div. 1 + Div. 2) {2147} PROGRAMMING 5500.0
249 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)
4703 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
2565 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
5163 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
18068 Abraham's Great Escape constructive algorithms graphs Statement B Codeforces Round 1056 (Div. 2) {2155} PROGRAMMING 1000.0 Codeforces Round 1056 (Div. 2) Editorial
759 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
308 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
472 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
687 Sink data structures dsu dsu graphs graphs Statement E Codeforces Round 1067 (Div. 2) {2158} PROGRAMMING 2750.0 Codeforces Round 1067 (Div. 2) Editorial
3422 Twin Polynomials combinatorics graph matchings graphs math Statement C Codeforces Round 1058 (Div. 1) {2159} PROGRAMMING 1500.0 Codeforces Round 1058 Editorial
2933 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
386 SubMST combinatorics graphs trees Statement F Pinely Round 5 (Div. 1 + Div. 2) {2161} PROGRAMMING 3250.0
4774 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
16870 Cyclic Merging brute force constructive algorithms graphs greedy trees Statement A Codeforces Round 1064 (Div. 1) {2165} PROGRAMMING 500.0 148452
932 Intercepting Butterflies bitmasks constructive algorithms graphs interactive Statement C Testing Round 20 (Unrated, Communication Problems) {2168} PROGRAMMING Testing Round 20 Editorial (officially unofficial)
6240 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
7076 Xmas or Hysteria constructive algorithms graphs greedy implementation Statement D Good Bye 2025 {2178} PROGRAMMING 1750.0
2963 Blackslex and Another RGB Walking graphs interactive number theory Statement F Codeforces Round 1071 (Div. 3) {2179} PROGRAMMING Codeforces Round 1071 (Div. 3) Editorial
177 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
4402 Cherry Tree dfs and similar dp graphs trees Statement F Codeforces Round 1072 (Div. 3) {2184} PROGRAMMING Codeforces Round 1072 (Div. 3) Editorial
1518 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
110 Maximize Determinant graphs Statement G Codeforces Round 1073 (Div. 1) {2190} PROGRAMMING 3750.0 Codeforces Round 1073 (Div. 1, Div. 2) Editorial
2338 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
2948 The Turtle Strikes Back dp graphs greedy Statement E Codeforces Round 1078 (Div. 2) {2194} PROGRAMMING 2500.0 Codeforces Round #1078 Editorial
1214 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
3011 Parabola Independence dp graphs math Statement F Codeforces Round 1080 (Div. 3) {2195} PROGRAMMING Codeforces Round 1080 (Div. 3) Editorial
3985 Interactive Graph (Simple Version) combinatorics dfs and similar dp graphs interactive Statement C1 Codeforces Round 1079 (Div. 1) {2196} PROGRAMMING 750.0 Tutorial
2820 Interactive Graph (Hard Version) combinatorics dfs and similar dp graphs interactive Statement C2 Codeforces Round 1079 (Div. 1) {2196} PROGRAMMING 750.0 Tutorial
125 Indivisible constructive algorithms graphs Statement F Codeforces Round 1079 (Div. 1) {2196} PROGRAMMING 3500.0 Tutorial
10318 Alternating Path dfs and similar graphs Statement D Educational Codeforces Round 188 (Rated for Div. 2) {2204} PROGRAMMING Educational Codeforces Round 188 Editorial
618 Grid Path dp graphs matrices Statement G Educational Codeforces Round 188 (Rated for Div. 2) {2204} PROGRAMMING Educational Codeforces Round 188 Editorial
746 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
332 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
4927 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
2142 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
902 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
233 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
756 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
384 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
279 Simple Problem graphs number theory Statement G Educational Codeforces Round 189 (Rated for Div. 2) {2225} PROGRAMMING Tutorial
2070 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
5520 Good Schedule dp graphs greedy two pointers Statement D Educational Codeforces Round 190 (Rated for Div. 2) {2230} PROGRAMMING Educational Codeforces Round 190 — Editorial
1215 Graph Cutting dfs and similar dp trees Statement E Codeforces Round 1099 (Div. 2) {2231} PROGRAMMING 2500.0
435 Shortest GCD Paths dp graphs math number theory shortest paths Statement F Educational Codeforces Round 191 (Rated for Div. 2) {2233} PROGRAMMING 154371
2134 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
474 Infinite Work combinatorics graphs greedy math Statement F Codeforces Round 1106 (Div. 2) {2238} PROGRAMMING 2750.0 Codeforces Round 1106 (Div. 2) Editorial
686 Hunting the Beast combinatorics dp graphs Statement D Codeforces Round 1105 (Div. 1) {2239} PROGRAMMING 2000.0 Codeforces Round 1105 (Div. 1, Div. 2) Editorial
6630 Fair and Square combinatorics dp graphs math number theory trees Statement E Codeforces Round 1107 (Div. 3) {2241} PROGRAMMING Codeforces Round 1107 (Div. 3) Editorial
190 Even Simple Path constructive algorithms graphs shortest paths Statement F Codeforces Round 1112 (Div. 1) {2249} PROGRAMMING 3500.0 Codeforces Round 1112 (Div. 1, Div. 2) Editorial
486 4-beauty bitmasks dp graphs math Statement F Educational Codeforces Round 193 (Rated for Div. 2) {2253} PROGRAMMING 155813
1356 Diameter Intersections brute force dfs and similar fft graphs trees Statement E Educational Codeforces Round 193 (Rated for Div. 2) {2253} PROGRAMMING 155813
11444 Spying on the Beaver dfs and similar dsu graphs trees Statement C Codeforces Round 1117 (Div. 2) {2257} PROGRAMMING 1250.0 Codeforces Round 1117 (Div. 2) Editorial
217 Plus Minus Tree dfs and similar dp graphs trees Statement F Codeforces Round 1118 (Div. 2) {2258} PROGRAMMING 3000.0 Codeforces Round 1118 (Div. 2) Editorial
690 Treasure Map Destruction (Counting Version) 2-sat combinatorics dfs and similar dp graphs math Statement H Codeforces Round 1119 (Div. 3) {2259} PROGRAMMING
396 Edge Three-Coloring bitmasks brute force dfs and similar dsu graphs trees Statement F Educational Codeforces Round 194 (Rated for Div. 2) {2260} PROGRAMMING