Problemset - Codeforces

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Codeforces Round (Div. 3)
4 days

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Difficulty: —

combinatorics

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Problems

#	Name
1989E	Distance to Different combinatorics, dp, math	2300	x1233
1986G1	Permutation Problem (Simple Version) binary search, brute force, combinatorics, data structures, math, number theory	2200	x1054
1985G	D-Function combinatorics, math, number theory	1600	x7284
1985E	Secret Box brute force, combinatorics, math	1200	x16765
1984H	Tower Capturing combinatorics, dp, geometry	3300	x132
1984C2	Magnitude (Hard Version) combinatorics, dp, greedy, math	1700	x6176
1983E	I Love Balls combinatorics, math, probabilities		x528
1982E	Number of k-good subarrays bitmasks, brute force, combinatorics, divide and conquer, dp, math, meet-in-the-middle	2300	x1177
1979C	Earning on Bets binary search, combinatorics, constructive algorithms, number theory	1200	x16427
1976E	Splittable Permutations combinatorics, data structures, dfs and similar, greedy, math, trees	2500	x815
1976D	Invertible Bracket Sequences binary search, combinatorics, data structures, divide and conquer, implementation, two pointers	2000	x3487
1975F	Set bitmasks, brute force, combinatorics, dfs and similar, divide and conquer, dp, math	2600	x685
1974C	Beautiful Triple Pairs combinatorics, data structures	1400	x14036
1967E2	Again Counting Arrays (Hard Version) combinatorics, dp, math	3500	x83
1967E1	Again Counting Arrays (Easy Version) combinatorics, dp, fft, math	3100	x167
1967C	Fenwick Tree bitmasks, brute force, combinatorics, data structures, dp, math, trees	2300	x1480
1958F	Narrow Paths *special problem, combinatorics	2000	x164
1957E	Carousel of Combinations brute force, combinatorics, dp, math, number theory	2400	x1116
1957C	How Does the Rook Move? combinatorics, dp, math	1600	x8647
1954F	Unique Strings combinatorics, dp, math	3100	x233
1954D	Colored Balls combinatorics, dp, math, sortings	1800	x5480
1952E	Sweep Line combinatorics, games, math		x222
1951G	Clacking Balls combinatorics, math, probabilities	3100	x287
1948F	Rare Coins combinatorics, math, probabilities	2500	x1203
1946E	Girl Permutation combinatorics, dp, math, number theory	2200	x2240
1943D2	Counting Is Fun (Hard Version) combinatorics, dp	2800	x651
1943D1	Counting Is Fun (Easy Version) brute force, combinatorics, dp, math	2400	x1339
1942G	Bessie and Cards combinatorics, dp, math	2800	x408
1942E	Farm Game combinatorics, games	2300	x1548
1935D	Exam in MAC binary search, combinatorics, implementation, math	1800	x7689
1933G	Turtle Magic: Royal Turtle Shell Pattern bitmasks, brute force, combinatorics, constructive algorithms, dfs and similar, math	2300	x913
1931G	One-Dimensional Puzzle combinatorics, math, number theory	2000	x2570
1931F	Chat Screenshots combinatorics, dfs and similar, graphs	1700	x7366
1931D	Divisible Pairs combinatorics, math, number theory	1300	x17035
1930I	Counting Is Fun combinatorics	3500	x59
1930E	2..3...4.... Wonderful! Wonderful! combinatorics, dp, math	2400	x1047
1929F	Sasha and the Wedding Binary Search Tree brute force, combinatorics, data structures, dfs and similar, math, trees	2300	x1693
1929D	Sasha and a Walk in the City combinatorics, dp, math, trees	1900	x4380
1928F	Digital Patterns combinatorics, data structures, implementation, math	2900	x222
1925D	Good Trip combinatorics, dp, math, probabilities	1900	x3382
1924E	Paper Cutting Again combinatorics, probabilities	3100	x408
1924D	Balanced Subsequences combinatorics, dp, math	2700	x810
1922B	Forming Triangles combinatorics, constructive algorithms, math, sortings	1200	x19671
1920E	Counting Binary Strings combinatorics, dp, math	2100	x2474
1919E	Counting Prefixes combinatorics, constructive algorithms, dp, implementation, math	2600	x804
1917D	Yet Another Inversions Problem combinatorics, data structures, dp, implementation, math, number theory	2300	x1704
1917B	Erase First or Second Letter brute force, combinatorics, data structures, dp, strings	1100	x20476
1916H2	Matrix Rank (Hard Version) combinatorics, dp, math, matrices, string suffix structures	2700	x510
1916H1	Matrix Rank (Easy Version) brute force, combinatorics, dp, math, matrices	2700	x592
1914G2	Light Bulbs (Hard Version) combinatorics, data structures, dfs and similar, dp, graphs, hashing	2300	x1258
1914G1	Light Bulbs (Easy Version) brute force, combinatorics, dfs and similar, dp, dsu, graphs, math, trees	2100	x1735
1912K	Kim's Quest bitmasks, combinatorics, dp	1800	x2188
1912B	Blueprint for Seating combinatorics, divide and conquer, math	2100	x961
1910I	Inverse Problem *special problem, combinatorics, dp	2700	x46
1909I	Short Permutation Problem combinatorics, dp, fft, math	1900	x114
1909F2	Small Permutation Problem (Hard Version) combinatorics, dp, math	2500	x860
1909F1	Small Permutation Problem (Easy Version) brute force, combinatorics, dp, math	2200	x1686
1907E	Good Triples brute force, combinatorics, number theory	1600	x9393
1906J	Count BFS Graph combinatorics, dp	2100	x690
1906H	Twin Friends combinatorics, dp	2200	x631
1905E	One-X combinatorics, dfs and similar, dp, math, trees	2400	x891
1895F	Fancy Arrays combinatorics, dp, math, matrices	2600	x662
1893E	Cacti Symphony combinatorics, dfs and similar, dp, graphs	3500	x184
1886D	Monocarp and the Set combinatorics, data structures, math	2100	x3410
1879D	Sum of XOR Functions bitmasks, combinatorics, divide and conquer, dp, math	1700	x6967
1879C	Make it Alternating combinatorics, dp, greedy	1300	x15789
1876D	Lexichromatography combinatorics, dfs and similar, dsu, graphs, two pointers	2500	x835
1876B	Effects of Anti Pimples combinatorics, number theory, sortings	1500	x7846
1868C	Travel Plan combinatorics, dp, implementation, math, trees	2400	x1107
1866M	Mighty Rock Tower brute force, combinatorics, dp, math, probabilities	2400	x707
1866H	Happy Sets combinatorics	2100	x1561
1866B	Battling with Numbers combinatorics, math, number theory	1400	x7422
1864G	Magic Square combinatorics, constructive algorithms, implementation	3100	x255
1863G	Swaps combinatorics, dp, graphs, math	2800	x587
1862D	Ice Cream Balls binary search, combinatorics, constructive algorithms, math	1300	x16518
1861E	Non-Intersecting Subpermutations combinatorics, dp, implementation, math	2300	x1654
1857G	Counting Graphs combinatorics, divide and conquer, dsu, graphs, greedy, sortings, trees	2000	x4215
1855B	Longest Divisors Interval brute force, combinatorics, greedy, math, number theory	900	x24938
1854C	Expected Destruction combinatorics, dp, math, probabilities	2500	x1417
1850G	The Morning Star combinatorics, data structures, geometry, implementation, math, sortings	1500	x11715
1848F	Vika and Wiki binary search, bitmasks, combinatorics, divide and conquer, dp, math	2400	x1490
1847E	Triangle Platinum? brute force, combinatorics, implementation, interactive, math, probabilities	2900	x321
1844H	Multiple of Three Cycles combinatorics, data structures, dp, dsu, math	3400	x133
1843D	Apple Tree combinatorics, dfs and similar, dp, math, trees	1200	x17422
1843C	Sum in Binary Tree bitmasks, combinatorics, math, trees	800	x31924
1842G	Tenzing and Random Operations combinatorics, dp, math, probabilities	2800	x960
1840C	Ski Resort combinatorics, math, two pointers	1000	x25851
1840B	Binary Cafe bitmasks, combinatorics, math	1100	x21944
1838E	Count Supersequences combinatorics, dp, math	2500	x1396
1837E	Playoff Fixing combinatorics, trees	2200	x2129
1835E	Old Mobile combinatorics, dp, probabilities	3500	x218
1833F	Ira and Flamenco combinatorics, constructive algorithms, data structures, implementation, math, sortings, two pointers	1700	x6999
1832E	Combinatorics Problem brute force, combinatorics, dp	2200	x2097
1830C	Hyperregular Bracket Strings combinatorics, greedy, hashing, math, number theory, sortings	2400	x1571
1829H	Don't Blame Me bitmasks, combinatorics, dp, math	1700	x7358
1827A	Counting Orders combinatorics, math, sortings, two pointers	1100	x18100
1824B2	LuoTianyi and the Floating Islands (Hard Version) combinatorics, dfs and similar, math, probabilities, trees	2300	x2532
1824B1	LuoTianyi and the Floating Islands (Easy Version) combinatorics, math, probabilities, trees	1800	x4419
1823A	A-characteristic combinatorics, constructive algorithms, math	800	x15938
1821F	Timber combinatorics, dp, fft, math	2600	x725

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