Problemset - Codeforces

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combinatorics

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Problems

#	Name
1994H	Fortnite combinatorics, constructive algorithms, games, greedy, hashing, interactive, math, number theory, strings		x75
1992G	Ultra-Meow combinatorics, dp, math	2000	x2074
1989E	Distance to Different combinatorics, dp, math	2300	x1503
1988F	Heartbeat combinatorics, dp, fft, math	3000	x83
1986G1	Permutation Problem (Simple Version) binary search, brute force, combinatorics, data structures, math, number theory	2200	x1192
1985G	D-Function combinatorics, math, number theory	1600	x7786
1985E	Secret Box brute force, combinatorics, math	1200	x17518
1984H	Tower Capturing combinatorics, dp, geometry	3300	x141
1984C2	Magnitude (Hard Version) combinatorics, dp, greedy, math	1700	x6450
1983E	I Love Balls combinatorics, math, probabilities	2300	x1649
1982E	Number of k-good subarrays bitmasks, brute force, combinatorics, divide and conquer, dp, math, meet-in-the-middle	2300	x1331
1979C	Earning on Bets binary search, combinatorics, constructive algorithms, number theory	1200	x16926
1976E	Splittable Permutations combinatorics, data structures, dfs and similar, greedy, math, trees	2500	x869
1976D	Invertible Bracket Sequences binary search, combinatorics, data structures, divide and conquer, implementation, two pointers	2000	x3647
1975F	Set bitmasks, brute force, combinatorics, dfs and similar, divide and conquer, dp, math	2600	x717
1974C	Beautiful Triple Pairs combinatorics, data structures	1400	x14366
1967E2	Again Counting Arrays (Hard Version) combinatorics, dp, math	3500	x85
1967E1	Again Counting Arrays (Easy Version) combinatorics, dp, fft, math	3100	x172
1967C	Fenwick Tree bitmasks, brute force, combinatorics, data structures, dp, math, trees	2300	x1514
1958F	Narrow Paths *special problem, combinatorics	2000	x170
1957E	Carousel of Combinations brute force, combinatorics, dp, math, number theory	2400	x1137
1957C	How Does the Rook Move? combinatorics, dp, math	1600	x8800
1954F	Unique Strings combinatorics, dp, math	3100	x235
1954D	Colored Balls combinatorics, dp, math, sortings	1800	x5552
1952E	Sweep Line combinatorics, games, math		x227
1951G	Clacking Balls combinatorics, math, probabilities	3100	x305
1948F	Rare Coins combinatorics, math, probabilities	2500	x1227
1946E	Girl Permutation combinatorics, dp, math, number theory	2200	x2276
1943D2	Counting Is Fun (Hard Version) combinatorics, dp	2800	x663
1943D1	Counting Is Fun (Easy Version) brute force, combinatorics, dp, math	2400	x1352
1942G	Bessie and Cards combinatorics, dp, math	2800	x414
1942E	Farm Game combinatorics, games	2300	x1573
1935D	Exam in MAC binary search, combinatorics, implementation, math	1800	x7762
1933G	Turtle Magic: Royal Turtle Shell Pattern bitmasks, brute force, combinatorics, constructive algorithms, dfs and similar, math	2300	x919
1931G	One-Dimensional Puzzle combinatorics, math, number theory	2000	x2606
1931F	Chat Screenshots combinatorics, dfs and similar, graphs	1700	x7478
1931D	Divisible Pairs combinatorics, math, number theory	1300	x17328
1930I	Counting Is Fun combinatorics	3500	x62
1930E	2..3...4.... Wonderful! Wonderful! combinatorics, dp, math	2400	x1058
1929F	Sasha and the Wedding Binary Search Tree brute force, combinatorics, data structures, dfs and similar, math, trees	2300	x1708
1929D	Sasha and a Walk in the City combinatorics, dp, math, trees	1900	x4449
1928F	Digital Patterns combinatorics, data structures, implementation, math	2900	x228
1925D	Good Trip combinatorics, dp, math, probabilities	1900	x3415
1924E	Paper Cutting Again combinatorics, probabilities	3100	x413
1924D	Balanced Subsequences combinatorics, dp, math	2700	x896
1922B	Forming Triangles combinatorics, constructive algorithms, math, sortings	1200	x19807
1920E	Counting Binary Strings combinatorics, dp, math	2100	x2496
1919E	Counting Prefixes combinatorics, constructive algorithms, dp, implementation, math	2600	x814
1917D	Yet Another Inversions Problem combinatorics, data structures, dp, implementation, math, number theory	2300	x1714
1917B	Erase First or Second Letter brute force, combinatorics, data structures, dp, strings	1100	x20728
1916H2	Matrix Rank (Hard Version) combinatorics, dp, math, matrices, string suffix structures	2700	x518
1916H1	Matrix Rank (Easy Version) brute force, combinatorics, dp, math, matrices	2700	x598
1914G2	Light Bulbs (Hard Version) combinatorics, data structures, dfs and similar, dp, graphs, hashing	2300	x1271
1914G1	Light Bulbs (Easy Version) brute force, combinatorics, dfs and similar, dp, dsu, graphs, math, trees	2100	x1748
1912K	Kim's Quest bitmasks, combinatorics, dp	1800	x2228
1912B	Blueprint for Seating combinatorics, divide and conquer, math	2100	x972
1910I	Inverse Problem *special problem, combinatorics, dp	2700	x47
1909I	Short Permutation Problem combinatorics, dp, fft, math	1900	x115
1909F2	Small Permutation Problem (Hard Version) combinatorics, dp, math	2500	x873
1909F1	Small Permutation Problem (Easy Version) brute force, combinatorics, dp, math	2200	x1706
1907E	Good Triples brute force, combinatorics, number theory	1600	x9528
1906J	Count BFS Graph combinatorics, dp	2100	x701
1906H	Twin Friends combinatorics, dp	2200	x636
1905E	One-X combinatorics, dfs and similar, dp, math, trees	2400	x901
1895F	Fancy Arrays combinatorics, dp, math, matrices	2600	x692
1893E	Cacti Symphony combinatorics, dfs and similar, dp, graphs	3500	x187
1886D	Monocarp and the Set combinatorics, data structures, math	2100	x3448
1879D	Sum of XOR Functions bitmasks, combinatorics, divide and conquer, dp, math	1700	x7019
1879C	Make it Alternating combinatorics, dp, greedy	1300	x15971
1876D	Lexichromatography combinatorics, dfs and similar, dsu, graphs, two pointers	2500	x840
1876B	Effects of Anti Pimples combinatorics, number theory, sortings	1500	x7927
1868C	Travel Plan combinatorics, dp, implementation, math, trees	2400	x1114
1866M	Mighty Rock Tower brute force, combinatorics, dp, math, probabilities	2400	x709
1866H	Happy Sets combinatorics	2100	x1568
1866B	Battling with Numbers combinatorics, math, number theory	1400	x7457
1864G	Magic Square combinatorics, constructive algorithms, implementation	3100	x255
1863G	Swaps combinatorics, dp, graphs, math	2800	x588
1862D	Ice Cream Balls binary search, combinatorics, constructive algorithms, math	1300	x16649
1861E	Non-Intersecting Subpermutations combinatorics, dp, implementation, math	2300	x1660
1857G	Counting Graphs combinatorics, divide and conquer, dsu, graphs, greedy, sortings, trees	2000	x4262
1855B	Longest Divisors Interval brute force, combinatorics, greedy, math, number theory	900	x25163
1854C	Expected Destruction combinatorics, dp, math, probabilities	2500	x1431
1850G	The Morning Star combinatorics, data structures, geometry, implementation, math, sortings	1500	x11813
1848F	Vika and Wiki binary search, bitmasks, combinatorics, divide and conquer, dp, math	2400	x1500
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	x17560
1843C	Sum in Binary Tree bitmasks, combinatorics, math, trees	800	x32145
1842G	Tenzing and Random Operations combinatorics, dp, math, probabilities	2800	x968
1840C	Ski Resort combinatorics, math, two pointers	1000	x26128
1840B	Binary Cafe bitmasks, combinatorics, math	1100	x22049
1838E	Count Supersequences combinatorics, dp, math	2500	x1410
1837E	Playoff Fixing combinatorics, trees	2200	x2137
1835E	Old Mobile combinatorics, dp, probabilities	3500	x220
1833F	Ira and Flamenco combinatorics, constructive algorithms, data structures, implementation, math, sortings, two pointers	1700	x7059
1832E	Combinatorics Problem brute force, combinatorics, dp	2200	x2113
1830C	Hyperregular Bracket Strings combinatorics, greedy, hashing, math, number theory, sortings	2400	x1578
1829H	Don't Blame Me bitmasks, combinatorics, dp, math	1700	x7439
1827A	Counting Orders combinatorics, math, sortings, two pointers	1100	x18243
1824B2	LuoTianyi and the Floating Islands (Hard Version) combinatorics, dfs and similar, math, probabilities, trees	2300	x2542

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