Problemset - Codeforces

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Codeforces Round (Div. 2)
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combinatorics

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Problems

#	Name
1648A	Weird Sum combinatorics, data structures, geometry, math, matrices, sortings	1400	x12137
1644F	Basis combinatorics, fft, math, number theory	2900	x318
1644E	Expand the Path brute force, combinatorics, data structures, implementation, math	1900	x3040
1641E	Special Positions combinatorics, divide and conquer, fft, math	3300	x205
1641D	Two Arrays bitmasks, brute force, combinatorics, greedy, hashing, math, two pointers	2700	x1069
1630E	Expected Components combinatorics, math, number theory, probabilities	2900	x432
1628D2	Game on Sum (Hard Version) combinatorics, dp, games, math	2400	x2009
1628D1	Game on Sum (Easy Version) combinatorics, dp, games, math	2100	x3056
1626F	A Random Code Problem combinatorics, dp, math, number theory, probabilities	2800	x718
1622D	Shuffle combinatorics, math, two pointers	2000	x3920
1620G	Subsequences Galore bitmasks, combinatorics, dp	2400	x868
1616H	Keep XOR Low bitmasks, combinatorics, data structures, divide and conquer, dp, math	3000	x813
1615F	LEGOndary Grandmaster combinatorics, dp, math	2800	x819
1614C	Divan and bitwise operations bitmasks, combinatorics, constructive algorithms, dp, math	1500	x10048
1613F	Tree Coloring combinatorics, divide and conquer, fft	2600	x675
1612G	Max Sum Array combinatorics, constructive algorithms, greedy, sortings	2500	x821
1610D	Not Quite Lee combinatorics, dp, math, number theory	2000	x2634
1608F	MEX counting combinatorics, dp, implementation	3200	x528
1608D	Dominoes combinatorics, fft, graphs, math, number theory	2400	x1359
1606E	Arena combinatorics, dp, math	2100	x3420
1605F	PalindORme combinatorics, dp	2900	x294
1603F	October 18, 2017 combinatorics, dp, implementation, math	2700	x269
1603E	A Perfect Problem combinatorics, dp, math	3200	x408
1599C	Bubble Strike combinatorics, math, probabilities, ternary search	2000	x1619
1598E	Staircases brute force, combinatorics, data structures, dfs and similar, dp, implementation, math	2100	x2263
1598D	Training Session combinatorics, data structures, geometry, implementation, math	1700	x8482
1594E1	Rubik's Cube Coloring (easy version) combinatorics, math	1300	x10958
1586I	Omkar and Mosaic combinatorics, constructive algorithms, math	3500	x190
1585F	Non-equal Neighbours combinatorics, dp, math	2400	x1172
1584D	Guess the Permutation binary search, combinatorics, interactive, math	2000	x3596
1582B	Luntik and Subsequences combinatorics, math	900	x19466
1581A	CQXYM Count Permutations combinatorics, math, number theory	800	x13329
1580F	Problems for Codeforces combinatorics, fft, math	3300	x131
1580B	Mathematics Curriculum brute force, combinatorics, dp, trees	2600	x998
1574F	Occurrences combinatorics, dfs and similar, dp, dsu, fft, graphs	2700	x596
1574E	Coloring combinatorics, constructive algorithms, implementation, math	2500	x882
1574B	Combinatorics Homework combinatorics, greedy, math	1100	x17137
1569C	Jury Meeting combinatorics, math	1500	x11803
1567C	Carrying Conundrum bitmasks, combinatorics, dp, math	1600	x11964
1559E	Mocha and Stars combinatorics, dp, fft, math, number theory	2200	x2246
1558D	Top-Notch Insertions combinatorics, data structures	2600	x937
1557C	Moamen and XOR bitmasks, combinatorics, dp, math, matrices	1700	x8430
1556F	Sports Betting bitmasks, combinatorics, dp, graphs, math, probabilities	2500	x1194
1553I	Stairs combinatorics, divide and conquer, dp, fft, math	3400	x198
1553E	Permutation Shift brute force, combinatorics, constructive algorithms, dfs and similar, dsu, graphs, math	2100	x3267
1552C	Maximize the Intersections combinatorics, constructive algorithms, geometry, greedy, sortings	1800	x5829
1552B	Running for Gold combinatorics, graphs, greedy, sortings	1500	x15164
1551F	Equidistant Vertices brute force, combinatorics, dfs and similar, dp, trees	2200	x1782
1550D	Excellent Arrays binary search, combinatorics, constructive algorithms, implementation, math, sortings, two pointers	2300	x1798
1548C	The Three Little Pigs combinatorics, dp, fft, math	2500	x1769
1545C	AquaMoon and Permutations 2-sat, brute force, combinatorics, constructive algorithms, graph matchings, graphs	2800	x595
1545B	AquaMoon and Chess combinatorics, math	1900	x5716
1543B	Customising the Track combinatorics, greedy, math	900	x22836
1542E2	Abnormal Permutation Pairs (hard version) combinatorics, dp, fft, math	2700	x823
1542E1	Abnormal Permutation Pairs (easy version) combinatorics, dp, fft, math	2400	x1207
1542D	Priority Queue combinatorics, dp, implementation, math, ternary search	2200	x2561
1540B	Tree Array brute force, combinatorics, dp, graphs, math, probabilities, trees	2300	x2515
1539A	Contest Start combinatorics, geometry, greedy, math	1000	x19790
1536F	Omkar and Akmar chinese remainder theorem, combinatorics, constructive algorithms, fft, games, geometry, math, meet-in-the-middle, string suffix structures	2600	x921
1536E	Omkar and Forest combinatorics, graphs, math, shortest paths	2300	x2361
1534C	Little Alawn's Puzzle combinatorics, dp, dsu, graphs, math	1300	x12626
1530F	Bingo bitmasks, combinatorics, dp, math, probabilities	2600	x759
1528F	AmShZ Farm combinatorics, fft, math	3300	x280
1528E	Mashtali and Hagh Trees combinatorics, dp, trees	2900	x514
1528B	Kavi on Pairing Duty combinatorics, dp, math	1700	x8556
1527D	MEX Tree combinatorics, dfs and similar, implementation, math, trees	2400	x1854
1526E	Oolimry and Suffix Array combinatorics, constructive algorithms, math	2400	x1035
1525E	Assimilation IV combinatorics, dp, math, probabilities, two pointers	2100	x2010
1523E	Crypto Lights combinatorics, dp, math, probabilities	2600	x1553
1517F	Reunion combinatorics, dp, trees	3200	x451
1516E	Baby Ehab Plays with Permutations combinatorics, dp, math	2500	x826
1515E	Phoenix and Computers combinatorics, dp, math	2200	x3430
1514B	AND 0, Sum Big bitmasks, combinatorics, math	1200	x23673
1513E	Cost Equilibrium combinatorics, constructive algorithms, math, sortings	2300	x1430
1513B	AND Sequences bitmasks, combinatorics, constructive algorithms, math	1400	x14129
1511E	Colorings and Dominoes combinatorics, dp, greedy, math	2100	x2493
1508B	Almost Sorted binary search, combinatorics, constructive algorithms, implementation	1800	x3888
1503E	2-Coloring combinatorics, dp, math	3100	x599
1499F	Diameter Cuts combinatorics, dfs and similar, dp, trees	2400	x1265
1499E	Chaotic Merge combinatorics, dp, math, strings	2400	x1427
1499A	Domino on Windowsill combinatorics, constructive algorithms, math	800	x21072
1495D	BFS Trees combinatorics, dfs and similar, graphs, math, shortest paths, trees	2600	x1199
1488H	Build From Suffixes *special problem, combinatorics, data structures	2800	x57
1487G	String Counting combinatorics, dp, fft, math	2700	x580
1486F	Pairs of Paths combinatorics, data structures, dfs and similar, dp, trees	2600	x644
1485F	Copy or Prefix Sum combinatorics, data structures, dp, sortings	2400	x1888
1477F	Nezzar and Chocolate Bars combinatorics, fft, math, probabilities	3500	x125
1475E	Advertising Agency combinatorics, math, sortings	1600	x13188
1475C	Ball in Berland combinatorics, graphs, math	1400	x20418
1473G	Tiles combinatorics, dp, fft, math	2800	x385
1470E	Strange Permutation binary search, combinatorics, data structures, dp, graphs, implementation, two pointers	3200	x296
1467D	Sum of Paths combinatorics, dp, math	2200	x3568
1466H	Finding satisfactory solutions combinatorics, dp, graphs, greedy, math	3300	x270
1466G	Song of the Sirens combinatorics, divide and conquer, hashing, math, string suffix structures, strings	2600	x860
1462E2	Close Tuples (hard version) binary search, combinatorics, implementation, math, sortings, two pointers	1700	x9388
1462E1	Close Tuples (easy version) binary search, combinatorics, math, sortings, two pointers	1500	x13408
1454E	Number of Simple Paths combinatorics, dfs and similar, graphs, trees	2000	x5600
1452D	Radio Towers combinatorics, dp, math	1600	x7807
1450H2	Multithreading (Hard Version) combinatorics, implementation, math	3300	x170
1450H1	Multithreading (Easy Version) combinatorics, fft, math	2900	x383