Problemset - Codeforces

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Codeforces Round (Div. 2)
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combinatorics

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Problems

#	Name
1989E	Distance to Different combinatorics, dp, math	2300	x1038
1986G1	Permutation Problem (Simple Version) binary search, brute force, combinatorics, data structures, math, number theory	2200	x955
1985G	D-Function combinatorics, math, number theory	1600	x7028
1985E	Secret Box brute force, combinatorics, math	1200	x16364
1984H	Tower Capturing combinatorics, dp, geometry	3300	x127
1984C2	Magnitude (Hard Version) combinatorics, dp, greedy, math	1700	x6044
1982E	Number of k-good subarrays bitmasks, brute force, combinatorics, divide and conquer, dp, math, meet-in-the-middle	2300	x1061
1979C	Earning on Bets binary search, combinatorics, constructive algorithms, number theory	1200	x16138
1976E	Splittable Permutations combinatorics, data structures, dfs and similar, greedy, math, trees	2500	x802
1976D	Invertible Bracket Sequences binary search, combinatorics, data structures, divide and conquer, implementation, two pointers	2000	x3424
1975F	Set bitmasks, brute force, combinatorics, dfs and similar, divide and conquer, dp, math	2600	x669
1974C	Beautiful Triple Pairs combinatorics, data structures	1400	x13859
1967E2	Again Counting Arrays (Hard Version) combinatorics, dp, math	3500	x83
1967E1	Again Counting Arrays (Easy Version) combinatorics, dp, fft, math	3100	x164
1967C	Fenwick Tree bitmasks, brute force, combinatorics, data structures, dp, math, trees	2300	x1469
1958F	Narrow Paths *special problem, combinatorics	2000	x164
1957E	Carousel of Combinations brute force, combinatorics, dp, math, number theory	2400	x1106
1957C	How Does the Rook Move? combinatorics, dp, math	1600	x8578
1954F	Unique Strings combinatorics, dp, math	3100	x231
1954D	Colored Balls combinatorics, dp, math, sortings	1800	x5423
1952E	Sweep Line combinatorics, games, math		x221
1951G	Clacking Balls combinatorics, math, probabilities	3100	x286
1948F	Rare Coins combinatorics, math, probabilities	2500	x1199
1946E	Girl Permutation combinatorics, dp, math, number theory	2200	x2230
1943D2	Counting Is Fun (Hard Version) combinatorics, dp	2800	x647
1943D1	Counting Is Fun (Easy Version) brute force, combinatorics, dp, math	2400	x1332
1942G	Bessie and Cards combinatorics, dp, math	2800	x405
1942E	Farm Game combinatorics, games	2300	x1537
1935D	Exam in MAC binary search, combinatorics, implementation, math	1800	x7661
1933G	Turtle Magic: Royal Turtle Shell Pattern bitmasks, brute force, combinatorics, constructive algorithms, dfs and similar, math	2300	x911
1931G	One-Dimensional Puzzle combinatorics, math, number theory	2000	x2557
1931F	Chat Screenshots combinatorics, dfs and similar, graphs	1700	x7327
1931D	Divisible Pairs combinatorics, math, number theory	1300	x16926
1930I	Counting Is Fun combinatorics	3500	x59
1930E	2..3...4.... Wonderful! Wonderful! combinatorics, dp, math	2400	x1043
1929F	Sasha and the Wedding Binary Search Tree brute force, combinatorics, data structures, dfs and similar, math, trees	2300	x1685
1929D	Sasha and a Walk in the City combinatorics, dp, math, trees	1900	x4353
1928F	Digital Patterns combinatorics, data structures, implementation, math	2900	x222
1925D	Good Trip combinatorics, dp, math, probabilities	1900	x3364
1924E	Paper Cutting Again combinatorics, probabilities	3100	x407
1924D	Balanced Subsequences combinatorics, dp, math	2700	x807
1922B	Forming Triangles combinatorics, constructive algorithms, math, sortings	1200	x19624
1920E	Counting Binary Strings combinatorics, dp, math	2100	x2467
1919E	Counting Prefixes combinatorics, constructive algorithms, dp, implementation, math	2600	x801
1917D	Yet Another Inversions Problem combinatorics, data structures, dp, implementation, math, number theory	2300	x1698
1917B	Erase First or Second Letter brute force, combinatorics, data structures, dp, strings	1100	x20379
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	x591
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	x1731
1912K	Kim's Quest bitmasks, combinatorics, dp	1800	x2169
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	x103
1909F2	Small Permutation Problem (Hard Version) combinatorics, dp, math	2500	x855
1909F1	Small Permutation Problem (Easy Version) brute force, combinatorics, dp, math	2200	x1678
1907E	Good Triples brute force, combinatorics, number theory	1600	x9353
1906J	Count BFS Graph combinatorics, dp	2100	x686
1906H	Twin Friends combinatorics, dp	2200	x629
1905E	One-X combinatorics, dfs and similar, dp, math, trees	2400	x885
1895F	Fancy Arrays combinatorics, dp, math, matrices	2600	x660
1893E	Cacti Symphony combinatorics, dfs and similar, dp, graphs	3500	x184
1886D	Monocarp and the Set combinatorics, data structures, math	2100	x3402
1879D	Sum of XOR Functions bitmasks, combinatorics, divide and conquer, dp, math	1700	x6933
1879C	Make it Alternating combinatorics, dp, greedy	1300	x15687
1876D	Lexichromatography combinatorics, dfs and similar, dsu, graphs, two pointers	2500	x834
1876B	Effects of Anti Pimples combinatorics, number theory, sortings	1500	x7809
1868C	Travel Plan combinatorics, dp, implementation, math, trees	2400	x1106
1866M	Mighty Rock Tower brute force, combinatorics, dp, math, probabilities	2400	x704
1866H	Happy Sets combinatorics	2100	x1558
1866B	Battling with Numbers combinatorics, math, number theory	1400	x7411
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	x16481
1861E	Non-Intersecting Subpermutations combinatorics, dp, implementation, math	2300	x1648
1857G	Counting Graphs combinatorics, divide and conquer, dsu, graphs, greedy, sortings, trees	2000	x4208
1855B	Longest Divisors Interval brute force, combinatorics, greedy, math, number theory	900	x24843
1854C	Expected Destruction combinatorics, dp, math, probabilities	2500	x1414
1850G	The Morning Star combinatorics, data structures, geometry, implementation, math, sortings	1500	x11661
1848F	Vika and Wiki binary search, bitmasks, combinatorics, divide and conquer, dp, math	2400	x1486
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	x17390
1843C	Sum in Binary Tree bitmasks, combinatorics, math, trees	800	x31849
1842G	Tenzing and Random Operations combinatorics, dp, math, probabilities	2800	x960
1840C	Ski Resort combinatorics, math, two pointers	1000	x25738
1840B	Binary Cafe bitmasks, combinatorics, math	1100	x21915
1838E	Count Supersequences combinatorics, dp, math	2500	x1395
1837E	Playoff Fixing combinatorics, trees	2200	x2125
1835E	Old Mobile combinatorics, dp, probabilities	3500	x217
1833F	Ira and Flamenco combinatorics, constructive algorithms, data structures, implementation, math, sortings, two pointers	1700	x6957
1832E	Combinatorics Problem brute force, combinatorics, dp	2200	x2089
1830C	Hyperregular Bracket Strings combinatorics, greedy, hashing, math, number theory, sortings	2400	x1569
1829H	Don't Blame Me bitmasks, combinatorics, dp, math	1700	x7334
1827A	Counting Orders combinatorics, math, sortings, two pointers	1100	x18030
1824B2	LuoTianyi and the Floating Islands (Hard Version) combinatorics, dfs and similar, math, probabilities, trees	2300	x2525
1824B1	LuoTianyi and the Floating Islands (Easy Version) combinatorics, math, probabilities, trees	1800	x4407
1823A	A-characteristic combinatorics, constructive algorithms, math	800	x15929
1821F	Timber combinatorics, dp, fft, math	2600	x723
1821A	Matching combinatorics, math	800	x19541

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