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	x1131
1986G1	Permutation Problem (Simple Version) binary search, brute force, combinatorics, data structures, math, number theory	2200	x1009
1985G	D-Function combinatorics, math, number theory	1600	x7127
1985E	Secret Box brute force, combinatorics, math	1200	x16514
1984H	Tower Capturing combinatorics, dp, geometry	3300	x131
1984C2	Magnitude (Hard Version) combinatorics, dp, greedy, math	1700	x6104
1982E	Number of k-good subarrays bitmasks, brute force, combinatorics, divide and conquer, dp, math, meet-in-the-middle	2300	x1116
1979C	Earning on Bets binary search, combinatorics, constructive algorithms, number theory	1200	x16259
1976E	Splittable Permutations combinatorics, data structures, dfs and similar, greedy, math, trees	2500	x809
1976D	Invertible Bracket Sequences binary search, combinatorics, data structures, divide and conquer, implementation, two pointers	2000	x3450
1975F	Set bitmasks, brute force, combinatorics, dfs and similar, divide and conquer, dp, math	2600	x676
1974C	Beautiful Triple Pairs combinatorics, data structures	1400	x13932
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	x1477
1958F	Narrow Paths *special problem, combinatorics	2000	x164
1957E	Carousel of Combinations brute force, combinatorics, dp, math, number theory	2400	x1112
1957C	How Does the Rook Move? combinatorics, dp, math	1600	x8610
1954F	Unique Strings combinatorics, dp, math	3100	x233
1954D	Colored Balls combinatorics, dp, math, sortings	1800	x5448
1952E	Sweep Line combinatorics, games, math		x221
1951G	Clacking Balls combinatorics, math, probabilities	3100	x286
1948F	Rare Coins combinatorics, math, probabilities	2500	x1200
1946E	Girl Permutation combinatorics, dp, math, number theory	2200	x2234
1943D2	Counting Is Fun (Hard Version) combinatorics, dp	2800	x649
1943D1	Counting Is Fun (Easy Version) brute force, combinatorics, dp, math	2400	x1335
1942G	Bessie and Cards combinatorics, dp, math	2800	x408
1942E	Farm Game combinatorics, games	2300	x1545
1935D	Exam in MAC binary search, combinatorics, implementation, math	1800	x7674
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	x2562
1931F	Chat Screenshots combinatorics, dfs and similar, graphs	1700	x7346
1931D	Divisible Pairs combinatorics, math, number theory	1300	x16971
1930I	Counting Is Fun combinatorics	3500	x59
1930E	2..3...4.... Wonderful! Wonderful! combinatorics, dp, math	2400	x1046
1929F	Sasha and the Wedding Binary Search Tree brute force, combinatorics, data structures, dfs and similar, math, trees	2300	x1691
1929D	Sasha and a Walk in the City combinatorics, dp, math, trees	1900	x4367
1928F	Digital Patterns combinatorics, data structures, implementation, math	2900	x222
1925D	Good Trip combinatorics, dp, math, probabilities	1900	x3374
1924E	Paper Cutting Again combinatorics, probabilities	3100	x408
1924D	Balanced Subsequences combinatorics, dp, math	2700	x808
1922B	Forming Triangles combinatorics, constructive algorithms, math, sortings	1200	x19642
1920E	Counting Binary Strings combinatorics, dp, math	2100	x2472
1919E	Counting Prefixes combinatorics, constructive algorithms, dp, implementation, math	2600	x802
1917D	Yet Another Inversions Problem combinatorics, data structures, dp, implementation, math, number theory	2300	x1700
1917B	Erase First or Second Letter brute force, combinatorics, data structures, dp, strings	1100	x20424
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	x1734
1912K	Kim's Quest bitmasks, combinatorics, dp	1800	x2176
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	x856
1909F1	Small Permutation Problem (Easy Version) brute force, combinatorics, dp, math	2200	x1680
1907E	Good Triples brute force, combinatorics, number theory	1600	x9366
1906J	Count BFS Graph combinatorics, dp	2100	x687
1906H	Twin Friends combinatorics, dp	2200	x630
1905E	One-X combinatorics, dfs and similar, dp, math, trees	2400	x886
1895F	Fancy Arrays combinatorics, dp, math, matrices	2600	x661
1893E	Cacti Symphony combinatorics, dfs and similar, dp, graphs	3500	x184
1886D	Monocarp and the Set combinatorics, data structures, math	2100	x3406
1879D	Sum of XOR Functions bitmasks, combinatorics, divide and conquer, dp, math	1700	x6951
1879C	Make it Alternating combinatorics, dp, greedy	1300	x15723
1876D	Lexichromatography combinatorics, dfs and similar, dsu, graphs, two pointers	2500	x835
1876B	Effects of Anti Pimples combinatorics, number theory, sortings	1500	x7821
1868C	Travel Plan combinatorics, dp, implementation, math, trees	2400	x1107
1866M	Mighty Rock Tower brute force, combinatorics, dp, math, probabilities	2400	x704
1866H	Happy Sets combinatorics	2100	x1560
1866B	Battling with Numbers combinatorics, math, number theory	1400	x7414
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	x16496
1861E	Non-Intersecting Subpermutations combinatorics, dp, implementation, math	2300	x1650
1857G	Counting Graphs combinatorics, divide and conquer, dsu, graphs, greedy, sortings, trees	2000	x4209
1855B	Longest Divisors Interval brute force, combinatorics, greedy, math, number theory	900	x24886
1854C	Expected Destruction combinatorics, dp, math, probabilities	2500	x1415
1850G	The Morning Star combinatorics, data structures, geometry, implementation, math, sortings	1500	x11684
1848F	Vika and Wiki binary search, bitmasks, combinatorics, divide and conquer, dp, math	2400	x1488
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	x17405
1843C	Sum in Binary Tree bitmasks, combinatorics, math, trees	800	x31887
1842G	Tenzing and Random Operations combinatorics, dp, math, probabilities	2800	x960
1840C	Ski Resort combinatorics, math, two pointers	1000	x25784
1840B	Binary Cafe bitmasks, combinatorics, math	1100	x21928
1838E	Count Supersequences combinatorics, dp, math	2500	x1395
1837E	Playoff Fixing combinatorics, trees	2200	x2127
1835E	Old Mobile combinatorics, dp, probabilities	3500	x218
1833F	Ira and Flamenco combinatorics, constructive algorithms, data structures, implementation, math, sortings, two pointers	1700	x6966
1832E	Combinatorics Problem brute force, combinatorics, dp	2200	x2096
1830C	Hyperregular Bracket Strings combinatorics, greedy, hashing, math, number theory, sortings	2400	x1570
1829H	Don't Blame Me bitmasks, combinatorics, dp, math	1700	x7343
1827A	Counting Orders combinatorics, math, sortings, two pointers	1100	x18067
1824B2	LuoTianyi and the Floating Islands (Hard Version) combinatorics, dfs and similar, math, probabilities, trees	2300	x2530
1824B1	LuoTianyi and the Floating Islands (Easy Version) combinatorics, math, probabilities, trees	1800	x4417
1823A	A-characteristic combinatorics, constructive algorithms, math	800	x15932
1821F	Timber combinatorics, dp, fft, math	2600	x723
1821A	Matching combinatorics, math	800	x19550

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