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2385 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
1805 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
9594 Bicycles dp graphs greedy implementation shortest paths sortings Statement G Codeforces Round 918 (Div. 4) {1915} PROGRAMMING 123952
707 Group Division constructive algorithms dfs and similar graphs Statement F Good Bye 2023 {1916} PROGRAMMING 2750.0
1095 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
1190 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)
641 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)
4506 Vlad and Trouble at MIT dfs and similar dp flows graphs greedy implementation trees Statement G Codeforces Round 928 (Div. 4) {1926} PROGRAMMING 126132
5360 Microcycle data structures dfs and similar dsu graphs greedy trees Statement F Codeforces Round 923 (Div. 3) {1927} PROGRAMMING 125597
2065 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.
11921 Chat Screenshots combinatorics dfs and similar graphs implementation Statement F Codeforces Round 925 (Div. 3) {1931} PROGRAMMING 125878
1341 Moving Platforms graphs math number theory shortest paths Statement G Codeforces Round 927 (Div. 3) {1932} PROGRAMMING 126196
2940 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
1719 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
304 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
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
4615 Rudolf and Subway dfs and similar graphs shortest paths Statement G Codeforces Round 933 (Div. 3) {1941} PROGRAMMING 127018
3508 Clique Partition constructive algorithms graphs greedy Statement E Educational Codeforces Round 163 (Rated for Div. 2) {1948} PROGRAMMING Educational Codeforces Round 163 Editorial
21034 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
2745 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
1040 Scooter graphs greedy Statement G European Championship 2024 - Online Mirror (Unrated, ICPC Rules, Teams Preferred) {1949} PROGRAMMING European Championship 2024 (EUC) Editorial
533 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
6039 Shuffling Songs bitmasks dp graphs implementation strings Statement G Codeforces Round 937 (Div. 4) {1950} PROGRAMMING Codeforces Round 937 (Div. 4) Editorial
103 Growing Trees constructive algorithms flows graphs greedy Statement I Codeforces Global Round 25 {1951} PROGRAMMING 4000.0 Codeforces Global Round 25 Editorial
14088 Are You a Robot, Again? expression parsing graphs strings Statement A April Fools Day Contest 2024 {1952} PROGRAMMING April Fools Day Contest 2024 Editorial
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)
50 Equal Trees *special graphs meet-in-the-middle Statement I Kotlin Heroes: Episode 10 {1958} PROGRAMMING 129483 3100
971 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
17364 Permutation Game brute force dfs and similar games graphs greedy math Statement D Codeforces Round 943 (Div. 3) {1968} PROGRAMMING 129096 1300
867 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
538 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
2709 ±1 2-sat dfs and similar graphs Statement H Codeforces Round 944 (Div. 4) {1971} PROGRAMMING Codeforces Round 944 (Div. 4) Editorial 2100
988 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
933 Tensor constructive algorithms graphs interactive Statement E Codeforces Round 948 (Div. 2) {1977} PROGRAMMING 2500.0 129858 2600
1569 Large Graph data structures dsu graphs number theory Statement F Codeforces Round 953 (Div. 2) {1978} PROGRAMMING 2500.0 130527
1801 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
436 Kostyanych's Theorem brute force graphs interactive Statement F Codeforces Round 951 (Div. 2) {1979} PROGRAMMING 3000.0 Codeforces Round 951 (Div. 2) Editorial
1689 Yasya and the Mysterious Tree bitmasks data structures dfs and similar graphs strings trees Statement G Codeforces Round 950 (Div. 3) {1980} PROGRAMMING 130135
2115 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
1214 Turtle and Intersected Segments data structures dsu graphs greedy Statement E Codeforces Round 949 (Div. 2) {1981} PROGRAMMING 2500.0 Simplified Chinese Tutorial
7206 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
6390 Non-academic Problem combinatorics dfs and similar dsu graphs Statement F Codeforces Round 954 (Div. 3) {1986} PROGRAMMING 130762
245 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
342 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
23267 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
602 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
7869 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
5101 Coloring Game constructive algorithms games graphs greedy interactive Statement E Pinely Round 4 (Div. 1 + Div. 2) {1991} PROGRAMMING 2000.0 Video Tutorial
1523 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
7349 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
396 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
2877 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
4082 Determine Winning Islands in Race data structures dp graphs shortest paths Statement D Codeforces Round 965 (Div. 2) {1998} PROGRAMMING 1500.0 Video Tutorial
3117 Call During the Journey binary search brute force graphs greedy shortest paths Statement G Codeforces Round 966 (Div. 3) {2000} PROGRAMMING 132689
798 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
4627 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
13205 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
164 Dora's Paint brute force combinatorics constructive algorithms graphs Statement F Codeforces Round 969 (Div. 1) {2006} PROGRAMMING 3000.0 Tutorial
9292 Iris and Game on the Tree games graphs greedy trees Statement A Codeforces Round 969 (Div. 1) {2006} PROGRAMMING 750.0 Tutorial
23367 Sakurako's Hobby dp dsu graphs math Statement D Codeforces Round 970 (Div. 3) {2008} PROGRAMMING Codeforces Round 970 (Div. 3) Editorial
57 Strange Matrix *special graphs greedy Statement H Kotlin Heroes: Episode 11 {2011} PROGRAMMING Kotlin Heroes 11 — Editorial
8643 Rendez-vous de Marian et Robin graphs shortest paths Statement E Codeforces Round 974 (Div. 3) {2014} PROGRAMMING Discussion stream (With Hints)
7392 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
1918 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
676 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
754 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
703 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
1369 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
7042 Skipping brute force data structures dp graphs greedy shortest paths Statement B Codeforces Round 980 (Div. 1) {2023} PROGRAMMING 1000.0 135341
1047 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
2005 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
6929 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
13608 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
3724 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
3906 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
146 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
6175 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
9098 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
2656 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
4681 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)
1816 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
3796 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
7267 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
2210 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
929 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
550 For the Emperor! flows graphs Statement D Codeforces Round 990 (Div. 1) {2046} PROGRAMMING 2500.0 Разбор Codeforces Round 990 (Div. 2 + Div. 1)
3478 Kevin and Bipartite Graph constructive algorithms graphs greedy Statement E Codeforces Global Round 28 {2048} PROGRAMMING 1750.0 Tutorial
2419 Snakes bitmasks dp graphs Statement G Codeforces Round 995 (Div. 3) {2051} PROGRAMMING 137623
1210 DAG Serialization brute force graphs Statement D 2024-2025 ICPC, NERC, Northern Eurasia Finals (Unrated, Online Mirror, ICPC Rules, Teams Preferred) {2052} PROGRAMMING
395 Managing Cluster dp graphs math trees Statement M 2024-2025 ICPC, NERC, Northern Eurasia Finals (Unrated, Online Mirror, ICPC Rules, Teams Preferred) {2052} PROGRAMMING
152 Incompetent Delivery Guy graphs shortest paths Statement I 2024-2025 ICPC, NERC, Northern Eurasia Finals (Unrated, Online Mirror, ICPC Rules, Teams Preferred) {2052} PROGRAMMING
105 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
4503 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
17777 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
2594 Another Exercise on Graphs (Easy Version) binary search brute force dp graphs shortest paths Statement E1 Hello 2025 {2057} PROGRAMMING 1000.0
1905 Another Exercise on Graphs (hard version) binary search brute force dsu graphs shortest paths sortings trees Statement E2 Hello 2025 {2057} PROGRAMMING 2000.0
6493 Graph and Graph data structures graphs greedy shortest paths Statement D Codeforces Round 1002 (Div. 2) {2059} PROGRAMMING 2000.0 139094
12171 Graph Composition dfs and similar dsu graphs greedy Statement E Codeforces Round 998 (Div. 3) {2060} PROGRAMMING Codeforces Round 998 (Div. 3) Editorial
489 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
101 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
60 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
444 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
4313 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
167 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
14529 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
7049 Skibidus and Slay data structures dfs and similar graphs greedy trees Statement F Codeforces Round 1003 (Div. 4) {2065} PROGRAMMING Video Tutorial
7121 Object Identification graphs implementation interactive Statement A Codeforces Round 1004 (Div. 1) {2066} PROGRAMMING 750.0 139415
993 Condorcet Elections constructive algorithms graphs probabilities Statement A European Championship 2025 - Online Mirror (Unrated, ICPC Rules, Teams Preferred) {2068} PROGRAMMING 140239
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
205 Amusement Park Rides flows graphs Statement K European Championship 2025 - Online Mirror (Unrated, ICPC Rules, Teams Preferred) {2068} PROGRAMMING 140239
61 Pinball graphs shortest paths Statement I European Championship 2025 - Online Mirror (Unrated, ICPC Rules, Teams Preferred) {2068} PROGRAMMING 140239
754 Graph Inclusion data structures divide and conquer dsu Statement F Educational Codeforces Round 174 (Rated for Div. 2) {2069} PROGRAMMING 139774
133 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
18221 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
44 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
1170 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
16043 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
1492 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
3798 She knows... combinatorics constructive algorithms graphs math Statement E Codeforces Round 1014 (Div. 2) {2092} PROGRAMMING 2250.0 Codeforces Round #1014 (Div. 2) Editorial
1886 Baggage Claim combinatorics dsu graphs math trees Statement B Codeforces Round 1021 (Div. 1) {2097} PROGRAMMING 1000.0 142316
270 Kia Bakes a Cake data structures dp graphs greedy Statement E Codeforces Round 1024 (Div. 1) {2101} PROGRAMMING 3250.0 142788
3960 Local Construction constructive algorithms dfs and similar graphs implementation two pointers Statement D Codeforces Round 1019 (Div. 2) {2103} PROGRAMMING 2000.0 142149
875 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
14566 Neo's Escape data structures dsu graphs greedy implementation Statement C Codeforces Round 1022 (Div. 2) {2108} PROGRAMMING 1500.0 Codeforces Round 1022 Editorial
270 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
5560 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
8529 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
2658 Melody dfs and similar graphs Statement E Codeforces Round 1026 (Div. 2) {2110} PROGRAMMING 2250.0 Codeforces Round 1026 (Div. 2) Editorial
3306 Tree Colorings combinatorics dp graphs math trees Statement E Educational Codeforces Round 180 (Rated for Div. 2) {2112} PROGRAMMING Educational Codeforces Round 180 — Editorial
626 Variables and Operations graphs greedy shortest paths Statement F Educational Codeforces Round 180 (Rated for Div. 2) {2112} PROGRAMMING Educational Codeforces Round 180 — Editorial
402 From Kazan with Love brute force graphs trees Statement E Codeforces Round 1031 (Div. 2) {2113} PROGRAMMING 2500.0 Codeforces Round #1031 Editorial
948 Two Arrays constructive algorithms dfs and similar graphs math Statement F Codeforces Round 1031 (Div. 2) {2113} PROGRAMMING 3000.0 Codeforces Round #1031 Editorial
3945 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
235 Gellyfish and Mayflower dp graphs Statement E Codeforces Round 1028 (Div. 1) {2115} PROGRAMMING 3000.0 Codeforces Round 1028 (Div.1, Div.2) Editorial
5115 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
2481 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
8397 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
280 Shifts and Swaps graphs hashing strings Statement F Codeforces Round 1030 (Div. 2) {2118} PROGRAMMING 3500.0 Codeforces Round 1030 (Div. 2) Editorial
455 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
107 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
2456 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
4272 1-1-1, Free Tree! data structures dfs and similar graphs trees Statement F Codeforces Round 1037 (Div. 3) {2126} PROGRAMMING 144845
104 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
565 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
6159 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
377 Strict Triangle graphs shortest paths Statement F Codeforces Round 1039 (Div. 2) {2128} PROGRAMMING 4000.0 Codeforces Round #1039 — Editorial
473 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
877 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
14193 Arboris Contractio graphs greedy trees Statement D Codeforces Round 1042 (Div. 3) {2131} PROGRAMMING Codeforces Round 1042 (Div. 3) Editorial
2734 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
12716 The Nether graphs interactive Statement C Codeforces Round 1044 (Div. 2) {2133} PROGRAMMING 1750.0 Codeforces Round 1044 (Div. 2) Editorial
3853 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
1916 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
5391 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
83 Merging Vertices in a Graph *special dfs and similar dsu graphs Statement H Kotlin Heroes: Episode 13 {2141} PROGRAMMING Kotlin Heroes 13 Editorial
14005 Max Tree dfs and similar graphs greedy Statement C Codeforces Round 1051 (Div. 2) {2143} PROGRAMMING 1500.0 Codeforces Round 1051 (Div. 2) Editorial
974 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
9658 Rabbits 2-sat dp graphs greedy implementation Statement C Codeforces Global Round 29 (Div. 1 + Div. 2) {2147} PROGRAMMING 1500.0
185 Maxflow GCD Coloring flows graphs Statement H Codeforces Global Round 29 (Div. 1 + Div. 2) {2147} PROGRAMMING 5500.0
201 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)
2757 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
580 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
4726 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
16873 Abraham's Great Escape constructive algorithms graphs Statement B Codeforces Round 1056 (Div. 2) {2155} PROGRAMMING 1000.0 Codeforces Round 1056 (Div. 2) Editorial
625 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
209 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
373 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
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
1672 Twin Polynomials combinatorics graph matchings graphs math Statement C Codeforces Round 1058 (Div. 1) {2159} PROGRAMMING 1500.0 Codeforces Round 1058 Editorial
2752 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
338 SubMST combinatorics graphs trees Statement F Pinely Round 5 (Div. 1 + Div. 2) {2161} PROGRAMMING 3250.0
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
13965 Cyclic Merging brute force constructive algorithms graphs greedy trees Statement A Codeforces Round 1064 (Div. 1) {2165} PROGRAMMING 500.0 148452
867 Intercepting Butterflies bitmasks constructive algorithms graphs interactive Statement C Testing Round 20 (Unrated, Communication Problems) {2168} PROGRAMMING Testing Round 20 Editorial (officially unofficial)
5686 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
6653 Xmas or Hysteria constructive algorithms graphs greedy implementation Statement D Good Bye 2025 {2178} PROGRAMMING 1750.0
2713 Blackslex and Another RGB Walking graphs interactive number theory Statement F Codeforces Round 1071 (Div. 3) {2179} PROGRAMMING Codeforces Round 1071 (Div. 3) Editorial
140 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
3807 Cherry Tree dfs and similar dp graphs trees Statement F Codeforces Round 1072 (Div. 3) {2184} PROGRAMMING Codeforces Round 1072 (Div. 3) Editorial
1332 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
93 Maximize Determinant graphs Statement G Codeforces Round 1073 (Div. 1) {2190} PROGRAMMING 3750.0 Codeforces Round 1073 (Div. 1, Div. 2) Editorial
2002 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
2545 The Turtle Strikes Back dp graphs greedy Statement E Codeforces Round 1078 (Div. 2) {2194} PROGRAMMING 2500.0 Codeforces Round #1078 Editorial
1014 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
2628 Parabola Independence dp graphs math Statement F Codeforces Round 1080 (Div. 3) {2195} PROGRAMMING Codeforces Round 1080 (Div. 3) Editorial
3535 Interactive Graph (Simple Version) combinatorics dfs and similar dp graphs interactive Statement C1 Codeforces Round 1079 (Div. 1) {2196} PROGRAMMING 750.0 Tutorial
2471 Interactive Graph (Hard Version) combinatorics dfs and similar dp graphs interactive Statement C2 Codeforces Round 1079 (Div. 1) {2196} PROGRAMMING 750.0 Tutorial
97 Indivisible constructive algorithms graphs Statement F Codeforces Round 1079 (Div. 1) {2196} PROGRAMMING 3500.0 Tutorial
8488 Alternating Path dfs and similar graphs Statement D Educational Codeforces Round 188 (Rated for Div. 2) {2204} PROGRAMMING Educational Codeforces Round 188 Editorial
385 Grid Path dp graphs matrices Statement G Educational Codeforces Round 188 (Rated for Div. 2) {2204} PROGRAMMING Educational Codeforces Round 188 Editorial
615 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
260 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
4041 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
1745 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
477 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