Problemset - Codeforces

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Codeforces Round 945 (Div. 2)
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combinatorics

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Problems

#	Name
1967E2	Again Counting Arrays (Hard Version) combinatorics, dp, math	3500	x51
1967E1	Again Counting Arrays (Easy Version) combinatorics, dp, fft, math	3100	x116
1967C	Fenwick Tree bitmasks, brute force, combinatorics, data structures, dp, math, trees	2300	x1222
1958F	Narrow Paths *special problem, combinatorics		x126
1957E	Carousel of Combinations brute force, combinatorics, dp, math, number theory	2400	x989
1957C	How Does the Rook Move? combinatorics, dp, math	1600	x7526
1954F	Unique Strings combinatorics, dp, math	3100	x203
1954D	Colored Balls combinatorics, dp, math, sortings	1800	x4886
1952E	Sweep Line combinatorics, games, math		x209
1951G	Clacking Balls combinatorics, math, probabilities	3100	x255
1948F	Rare Coins combinatorics, math, probabilities	2500	x1148
1946E	Girl Permutation combinatorics, dp, math, number theory	2200	x2097
1943D2	Counting Is Fun (Hard Version) combinatorics, dp	2800	x595
1943D1	Counting Is Fun (Easy Version) brute force, combinatorics, dp, math	2400	x1254
1942G	Bessie and Cards combinatorics, dp, math	2800	x370
1942E	Farm Game combinatorics, games	2300	x1441
1935D	Exam in MAC binary search, combinatorics, implementation, math	1800	x7334
1933G	Turtle Magic: Royal Turtle Shell Pattern bitmasks, brute force, combinatorics, constructive algorithms, dfs and similar, math	2300	x866
1931G	One-Dimensional Puzzle combinatorics, math, number theory	2000	x2449
1931F	Chat Screenshots combinatorics, dfs and similar, graphs	1700	x6959
1931D	Divisible Pairs combinatorics, math, number theory	1300	x15869
1930I	Counting Is Fun combinatorics	3500	x50
1930E	2..3...4.... Wonderful! Wonderful! combinatorics, dp, math	2400	x986
1929F	Sasha and the Wedding Binary Search Tree brute force, combinatorics, data structures, dfs and similar, math, trees	2300	x1628
1929D	Sasha and a Walk in the City combinatorics, dp, math, trees	1900	x4174
1928F	Digital Patterns combinatorics, data structures, implementation, math	2900	x210
1925D	Good Trip combinatorics, dp, math, probabilities	1900	x3228
1924E	Paper Cutting Again combinatorics, probabilities	3100	x394
1924D	Balanced Subsequences combinatorics, dp, math	2700	x778
1922B	Forming Triangles combinatorics, constructive algorithms, math, sortings	1200	x19034
1920E	Counting Binary Strings combinatorics, dp, math	2100	x2364
1919E	Counting Prefixes combinatorics, constructive algorithms, dp, implementation, math	2600	x777
1917D	Yet Another Inversions Problem combinatorics, data structures, dp, implementation, math, number theory	2300	x1658
1917B	Erase First or Second Letter brute force, combinatorics, data structures, dp, strings	1100	x19433
1916H2	Matrix Rank (Hard Version) combinatorics, dp, math, matrices, string suffix structures	2700	x502
1916H1	Matrix Rank (Easy Version) brute force, combinatorics, dp, math, matrices	2700	x584
1914G2	Light Bulbs (Hard Version) combinatorics, data structures, dfs and similar, dp, graphs, hashing	2300	x1226
1914G1	Light Bulbs (Easy Version) brute force, combinatorics, dfs and similar, dp, dsu, graphs, math, trees	2100	x1676
1912K	Kim's Quest bitmasks, combinatorics, dp	1800	x2041
1912B	Blueprint for Seating combinatorics, divide and conquer, math	2100	x922
1910I	Inverse Problem *special problem, combinatorics, dp	2700	x40
1909I	Short Permutation Problem combinatorics, dp, fft, math	1900	x75
1909F2	Small Permutation Problem (Hard Version) combinatorics, dp, math	2500	x831
1909F1	Small Permutation Problem (Easy Version) brute force, combinatorics, dp, math	2200	x1637
1907E	Good Triples brute force, combinatorics, number theory	1600	x8823
1906J	Count BFS Graph combinatorics, dp	2100	x636
1906H	Twin Friends combinatorics, dp	2200	x606
1905E	One-X combinatorics, dfs and similar, dp, math, trees	2400	x855
1895F	Fancy Arrays combinatorics, dp, math, matrices	2600	x628
1893E	Cacti Symphony combinatorics, dfs and similar, dp, graphs	3500	x179
1886D	Monocarp and the Set combinatorics, data structures, math	2100	x3330
1879D	Sum of XOR Functions bitmasks, combinatorics, divide and conquer, dp, math	1700	x6598
1879C	Make it Alternating combinatorics, dp, greedy	1300	x14961
1876D	Lexichromatography combinatorics, dfs and similar, dsu, graphs, two pointers	2500	x815
1876B	Effects of Anti Pimples combinatorics, number theory, sortings	1500	x7530
1868C	Travel Plan combinatorics, dp, implementation, math, trees	2400	x1076
1866M	Mighty Rock Tower brute force, combinatorics, dp, math, probabilities	2400	x691
1866H	Happy Sets combinatorics	2100	x1532
1866B	Battling with Numbers combinatorics, math, number theory	1400	x7213
1864G	Magic Square combinatorics, constructive algorithms, implementation	3100	x252
1863G	Swaps combinatorics, dp, graphs, math	2800	x558
1862D	Ice Cream Balls binary search, combinatorics, constructive algorithms, math	1300	x16052
1861E	Non-Intersecting Subpermutations combinatorics, dp, implementation, math	2300	x1620
1857G	Counting Graphs combinatorics, divide and conquer, dsu, graphs, greedy, sortings, trees	2000	x4092
1855B	Longest Divisors Interval brute force, combinatorics, greedy, math, number theory	900	x23833
1854C	Expected Destruction combinatorics, dp, math, probabilities	2500	x1402
1850G	The Morning Star combinatorics, data structures, geometry, implementation, math, sortings	1500	x11243
1848F	Vika and Wiki binary search, bitmasks, combinatorics, divide and conquer, dp, math	2400	x1451
1847E	Triangle Platinum? brute force, combinatorics, implementation, interactive, math, probabilities	2900	x317
1844H	Multiple of Three Cycles combinatorics, data structures, dp, dsu, math	3400	x131
1843D	Apple Tree combinatorics, dfs and similar, dp, math, trees	1200	x17054
1843C	Sum in Binary Tree bitmasks, combinatorics, math, trees	800	x31128
1842G	Tenzing and Random Operations combinatorics, dp, math, probabilities	2800	x928
1840C	Ski Resort combinatorics, math, two pointers	1000	x24662
1840B	Binary Cafe bitmasks, combinatorics, math	1100	x21526
1838E	Count Supersequences combinatorics, dp, math	2500	x1372
1837E	Playoff Fixing combinatorics, trees	2200	x2101
1835E	Old Mobile combinatorics, dp, probabilities	3500	x202
1833F	Ira and Flamenco combinatorics, constructive algorithms, data structures, implementation, math, sortings, two pointers	1700	x6717
1832E	Combinatorics Problem brute force, combinatorics, dp	2200	x2058
1830C	Hyperregular Bracket Strings combinatorics, greedy, hashing, math, number theory, sortings	2400	x1529
1829H	Don't Blame Me bitmasks, combinatorics, dp, math	1700	x7091
1827A	Counting Orders combinatorics, math, sortings, two pointers	1100	x17506
1824B2	LuoTianyi and the Floating Islands (Hard Version) combinatorics, dfs and similar, math, probabilities, trees	2300	x2495
1824B1	LuoTianyi and the Floating Islands (Easy Version) combinatorics, math, probabilities, trees	1800	x4335
1823A	A-characteristic combinatorics, constructive algorithms, math	800	x15813
1821F	Timber combinatorics, dp, fft, math	2600	x705
1821A	Matching combinatorics, math	800	x19375
1817C	Similar Polynomials combinatorics, math	2400	x926
1815D	XOR Counting bitmasks, combinatorics, dp, math	2600	x1037
1811G2	Vlad and the Nice Paths (hard version) binary search, combinatorics, data structures, dp, math, two pointers	2200	x1621
1811G1	Vlad and the Nice Paths (easy version) combinatorics, dp, math	2100	x1916
1810H	Last Number combinatorics, math	2900	x130
1809G	Prediction combinatorics, dp, math	2800	x411
1808E3	Minibuses on Venus (hard version) brute force, combinatorics, dp, math	2800	x419
1808E2	Minibuses on Venus (medium version) combinatorics, divide and conquer, dp, matrices	2500	x648
1808E1	Minibuses on Venus (easy version) combinatorics, divide and conquer, dp	2200	x1253
1806D	DSU Master combinatorics, dp, dsu, math	2500	x849
1799G	Count Voting combinatorics, dp, math	2600	x699
1795D	Triangle Coloring combinatorics, math	1600	x8486

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