Problemset - Codeforces

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Ethflow Round 1 (Codeforces Round, Div. 1 + Div. 2)
3 days

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Difficulty: —

combinatorics

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Problems

#	Name
2063F2	Counting Is Not Fun (Hard Version) binary search, combinatorics, data structures, dfs and similar, dsu, trees		x218
2063F1	Counting Is Not Fun (Easy Version) combinatorics, data structures, dfs and similar, dp, dsu, implementation, math		x489
2063E	Triangle Tree combinatorics, data structures, dfs and similar, dp, dsu, trees		x797
2061G	Kevin and Teams 2-sat, binary search, bitmasks, brute force, chinese remainder theorem, combinatorics, constructive algorithms, data structures, dfs and similar, divide and conquer, dp, dsu, expression parsing, fft, flows, games, geometry, graph matchings, graphs, greedy, hashing, implementation, interactive, math, matrices, meet-in-the-middle, number theory, probabilities, schedules, shortest paths, sortings, string suffix structures, strings, ternary search, trees, two pointers		x222
2061F2	Kevin and Binary String (Hard Version) 2-sat, binary search, bitmasks, brute force, chinese remainder theorem, combinatorics, constructive algorithms, data structures, dfs and similar, divide and conquer, dp, dsu, expression parsing, fft, flows, games, geometry, graph matchings, graphs, greedy, hashing, implementation, interactive, math, matrices, meet-in-the-middle, number theory, probabilities, schedules, shortest paths, sortings, string suffix structures, strings, ternary search, trees, two pointers		x48
2061F1	Kevin and Binary String (Easy Version) 2-sat, binary search, bitmasks, brute force, chinese remainder theorem, combinatorics, constructive algorithms, data structures, dfs and similar, divide and conquer, dp, dsu, expression parsing, fft, flows, games, geometry, graph matchings, graphs, greedy, hashing, implementation, interactive, math, matrices, meet-in-the-middle, number theory, probabilities, schedules, shortest paths, sortings, string suffix structures, strings, ternary search, trees, two pointers		x1312
2061C	Kevin and Puzzle 2-sat, binary search, bitmasks, brute force, chinese remainder theorem, combinatorics, constructive algorithms, data structures, dfs and similar, divide and conquer, dp, dsu, expression parsing, fft, flows, games, geometry, graph matchings, graphs, greedy, hashing, implementation, interactive, math, matrices, meet-in-the-middle, number theory, probabilities, schedules, shortest paths, sortings, string suffix structures, strings, ternary search, trees, two pointers		x5565
2061B	Kevin and Geometry 2-sat, binary search, bitmasks, brute force, chinese remainder theorem, combinatorics, constructive algorithms, data structures, dfs and similar, divide and conquer, dp, dsu, expression parsing, fft, flows, games, geometry, graph matchings, graphs, greedy, hashing, implementation, interactive, math, matrices, meet-in-the-middle, number theory, probabilities, schedules, shortest paths, sortings, string suffix structures, strings, ternary search, trees, two pointers		x9773
2060F	Multiplicative Arrays combinatorics, dp, number theory		x1178
2056F2	Xor of Median (Hard Version) bitmasks, brute force, combinatorics, dp, math		x92
2056F1	Xor of Median (Easy Version) bitmasks, brute force, combinatorics, dp, math		x148
2056E	Nested Segments combinatorics, dfs and similar, dp, dsu, math		x510
2056D	Unique Median binary search, brute force, combinatorics, data structures, divide and conquer, dp		x2075
2048G	Kevin and Matrices brute force, combinatorics, dp, math	2800	x434
2047B	Replace Character brute force, combinatorics, greedy, strings	900	x14001
2045E	Narrower Passageway combinatorics, data structures	2700	x163
2043F	Nim bitmasks, brute force, combinatorics, dp, games, greedy, implementation, shortest paths	2700	x618
2041H	Sheet Music combinatorics, dp, math	2300	x630
2040F	Number of Cubes combinatorics, dp, math, number theory	2700	x247
2040E	Control of Randomness combinatorics, dfs and similar, dp, graphs, greedy, math, probabilities, trees	2100	x1849
2040C	Ordered Permutations bitmasks, combinatorics, constructive algorithms, greedy, math, two pointers	1600	x8108
2039F1	Shohag Loves Counting (Easy Version) combinatorics, dp, math, number theory	2800	x347
2039E	Shohag Loves Inversions combinatorics, dp, implementation, math	2200	x1881
2038F	Alternative Platforms combinatorics, data structures, fft, math, sortings	2500	x376
2037G	Natlan Exploring bitmasks, combinatorics, data structures, dp, math, number theory	2000	x2621
2034F2	Khayyam's Royal Decree (Hard Version) combinatorics, dp, math, sortings	2800	x379
2034F1	Khayyam's Royal Decree (Easy Version) combinatorics, dp, math, sortings	2500	x646
2034E	Permutations Harmony combinatorics, constructive algorithms, greedy, hashing, math	2200	x1575
2032F	Peanuts combinatorics, dp, games, math	2700	x327
2030G2	The Destruction of the Universe (Hard Version) combinatorics, math	3100	x126
2030G1	The Destruction of the Universe (Easy Version) combinatorics, greedy, math	2900	x172
2030E	MEXimize the Score combinatorics, data structures, dp, greedy, implementation, math	2200	x1470
2030B	Minimise Oneness combinatorics, constructive algorithms, games, math	800	x21153
2029H	Message Spread bitmasks, brute force, combinatorics, dp	3500	x66
2028E	Alice's Adventures in the Rabbit Hole combinatorics, dfs and similar, dp, games, greedy, math, probabilities, trees	2300	x1440
2025E	Card Game combinatorics, dp, fft, greedy, math	2200	x1917
2025B	Binomial Coefficients, Kind Of combinatorics, dp, math	1100	x17198
2022E2	Billetes MX (Hard Version) binary search, combinatorics, data structures, dsu, graphs	2600	x432
2022E1	Billetes MX (Easy Version) 2-sat, binary search, combinatorics, constructive algorithms, dfs and similar, dsu, graphs	2500	x475
2018F1	Speedbreaker Counting (Easy Version) combinatorics, dp, greedy, math	2900	x226
2008F	Sakurako's Box combinatorics, math, number theory	1400	x13130
2006F	Dora's Paint brute force, combinatorics, constructive algorithms, graphs, implementation	3500	x123
2005A	Simple Palindrome combinatorics, constructive algorithms, greedy, math	900	x22664
2001E2	Deterministic Heap (Hard Version) combinatorics, dp, trees	2900	x232
2001E1	Deterministic Heap (Easy Version) combinatorics, dp, math, trees	2400	x1336
2000E	Photoshoot for Gorillas combinatorics, data structures, greedy, math	1400	x13817
1999F	Expected Median combinatorics, math	1500	x11161
1997F	Chips on a Line brute force, combinatorics, dp, greedy, math	2700	x1013
1996E	Decode combinatorics, data structures, implementation, math	1600	x10313
1996D	Fun binary search, brute force, combinatorics, math, number theory	1500	x16617
1994H	Fortnite combinatorics, constructive algorithms, games, greedy, hashing, interactive, math, number theory, strings	3500	x713
1992G	Ultra-Meow combinatorics, dp, math	2000	x3274
1989E	Distance to Different combinatorics, dp, math	2300	x2072
1988F	Heartbeat combinatorics, dp, fft, math	3000	x243
1986G1	Permutation Problem (Simple Version) binary search, brute force, combinatorics, data structures, math, number theory	2200	x1561
1985G	D-Function combinatorics, math, number theory	1600	x9884
1985E	Secret Box brute force, combinatorics, math	1200	x20686
1984H	Tower Capturing combinatorics, dp, geometry	3300	x174
1984C2	Magnitude (Hard Version) combinatorics, dp, greedy, math	1700	x7666
1983E	I Love Balls combinatorics, math, probabilities	2300	x2090
1982E	Number of k-good subarrays bitmasks, brute force, combinatorics, divide and conquer, dp, math, meet-in-the-middle	2300	x1652
1979C	Earning on Bets binary search, combinatorics, constructive algorithms, number theory	1200	x19438
1976E	Splittable Permutations combinatorics, data structures, dfs and similar, greedy, math, trees	2500	x1106
1976D	Invertible Bracket Sequences binary search, combinatorics, data structures, divide and conquer, implementation, two pointers	2000	x4796
1975F	Set bitmasks, brute force, combinatorics, dfs and similar, divide and conquer, dp, math	2600	x873
1974C	Beautiful Triple Pairs combinatorics, data structures	1400	x16344
1967E2	Again Counting Arrays (Hard Version) combinatorics, dp, math	3500	x107
1967E1	Again Counting Arrays (Easy Version) combinatorics, dp, fft, math	3100	x221
1967C	Fenwick Tree bitmasks, brute force, combinatorics, data structures, dp, math, trees	2300	x1825
1958F	Narrow Paths *special problem, combinatorics	2000	x209
1957E	Carousel of Combinations brute force, combinatorics, dp, math, number theory	2400	x1328
1957C	How Does the Rook Move? combinatorics, dp, math	1600	x10072
1954F	Unique Strings combinatorics, dp, math	3100	x270
1954D	Colored Balls combinatorics, dp, math, sortings	1800	x6497
1952E	Sweep Line *special problem, combinatorics, games, math		x266
1951G	Clacking Balls combinatorics, math, probabilities	3100	x346
1948F	Rare Coins combinatorics, math, probabilities	2500	x1378
1946E	Girl Permutation combinatorics, dp, math, number theory	2200	x2655
1943D2	Counting Is Fun (Hard Version) combinatorics, dp	2800	x857
1943D1	Counting Is Fun (Easy Version) brute force, combinatorics, dp, math	2400	x1581
1942G	Bessie and Cards combinatorics, dp, math	2800	x495
1942E	Farm Game combinatorics, games	2300	x1745
1935D	Exam in MAC binary search, combinatorics, implementation, math	1800	x8552
1933G	Turtle Magic: Royal Turtle Shell Pattern bitmasks, brute force, combinatorics, constructive algorithms, dfs and similar, math	2300	x1010
1931G	One-Dimensional Puzzle combinatorics, math, number theory	2000	x2957
1931F	Chat Screenshots combinatorics, dfs and similar, graphs	1700	x8430
1931D	Divisible Pairs combinatorics, math, number theory	1300	x20364
1930I	Counting Is Fun combinatorics	3500	x75
1930E	2..3...4.... Wonderful! Wonderful! combinatorics, dp, math	2400	x1220
1929F	Sasha and the Wedding Binary Search Tree brute force, combinatorics, data structures, dfs and similar, math, trees	2300	x1845
1929D	Sasha and a Walk in the City combinatorics, dp, math, trees	1900	x4979
1928F	Digital Patterns combinatorics, data structures, implementation, math	2900	x275
1925D	Good Trip combinatorics, dp, math, probabilities	1900	x3787
1924E	Paper Cutting Again combinatorics, probabilities	3100	x445
1924D	Balanced Subsequences combinatorics, dp, math	2700	x1070
1922B	Forming Triangles combinatorics, constructive algorithms, math, sortings	1200	x21304
1920E	Counting Binary Strings combinatorics, dp, math	2100	x2814
1919E	Counting Prefixes combinatorics, constructive algorithms, dp, implementation, math	2600	x901
1917D	Yet Another Inversions Problem combinatorics, data structures, dp, implementation, math, number theory	2300	x1845
1917B	Erase First or Second Letter brute force, combinatorics, data structures, dp, strings	1100	x23924

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