Problemset - Codeforces

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Codeforces Round #661 (Div. 3)
2 days
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number theory

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Problems

#	Name
1025D	Recovering BST brute force, dp, math, number theory, trees	2100	x2248
731F	Video Cards brute force, data structures, implementation, math, number theory	1900	x2197
959D	Mahmoud and Ehab and another array construction task constructive algorithms, greedy, math, number theory	1900	x2139
498C	Array and Operations flows, graph matchings, number theory	2100	x2069
359C	Prime Number math, number theory	1900	x2067
603B	Moodular Arithmetic combinatorics, dfs and similar, dsu, math, number theory	1800	x2055
354C	Vasya and Beautiful Arrays brute force, dp, number theory	2100	x2054
172B	Pseudorandom Sequence Period *special problem, implementation, number theory	1200	x2023
27E	Number With The Given Amount Of Divisors brute force, dp, number theory	2000	x2003
1254B2	Send Boxes to Alice (Hard Version) constructive algorithms, greedy, math, number theory, ternary search, two pointers	2100	x1937
177B2	Rectangular Game number theory	1200	x1927
66D	Petya and His Friends constructive algorithms, math, number theory	1700	x1919
839D	Winter is here combinatorics, dp, math, number theory	2200	x1908
665D	Simple Subset constructive algorithms, greedy, number theory	1800	x1892
336C	Vasily the Bear and Sequence brute force, greedy, implementation, number theory	1800	x1878
1166E	The LCMs Must be Large bitmasks, brute force, constructive algorithms, math, number theory	2100	x1872
1114E	Arithmetic Progression binary search, interactive, number theory, probabilities	2200	x1856
1097D	Makoto and a Blackboard dp, math, number theory, probabilities	2200	x1830
402D	Upgrading Array dp, greedy, math, number theory	1800	x1829
490D	Chocolate brute force, dfs and similar, math, meet-in-the-middle, number theory	1900	x1771
1389E	Calendar Ambiguity math, number theory	2200	x1763
632D	Longest Subsequence brute force, math, number theory	2100	x1740
1081E	Missing Numbers binary search, constructive algorithms, greedy, math, number theory	1900	x1738
724C	Ray Tracing greedy, hashing, implementation, math, number theory, sortings	1800	x1725
1334E	Divisor Paths combinatorics, graphs, greedy, math, number theory	2200	x1721
893E	Counting Arrays combinatorics, dp, math, number theory	2000	x1704
547C	Mike and Foam bitmasks, combinatorics, dp, math, number theory	2300	x1694
785D	Anton and School - 2 combinatorics, dp, math, number theory	2300	x1686
900D	Unusual Sequences bitmasks, combinatorics, dp, math, number theory	2000	x1677
55D	Beautiful numbers dp, number theory	2500	x1677
1029F	Multicolored Markers binary search, brute force, math, number theory	2000	x1653
1371E2	Asterism (Hard Version) binary search, combinatorics, dp, math, number theory, sortings	2300	x1609
446C	DZY Loves Fibonacci Numbers data structures, math, number theory	2400	x1609
449C	Jzzhu and Apples constructive algorithms, number theory	2500	x1592
955C	Sad powers binary search, math, number theory	2100	x1584
1154G	Minimum Possible LCM brute force, greedy, math, number theory	2200	x1583
1033D	Divisors interactive, math, number theory	2000	x1576
451E	Devu and Flowers bitmasks, combinatorics, number theory	2300	x1574
1182E	Product Oriented Recurrence dp, math, matrices, number theory	2300	x1537
348B	Apple Tree dfs and similar, number theory, trees	2100	x1521
1055C	Lucky Days math, number theory	1900	x1517
1070A	Find a Number dp, graphs, number theory, shortest paths	2200	x1492
850B	Arpa and a list of numbers implementation, number theory	2100	x1490
776E	The Holmes Children math, number theory	2100	x1465
487C	Prefix Product Sequence constructive algorithms, math, number theory	2300	x1460
551D	GukiZ and Binary Operations combinatorics, implementation, math, matrices, number theory	2100	x1388
222C	Reducing Fractions implementation, math, number theory, sortings	1800	x1376
520E	Pluses everywhere combinatorics, dp, math, number theory	2200	x1372
623B	Array GCD dp, greedy, number theory	2300	x1371
980D	Perfect Groups dp, math, number theory	2100	x1352
575H	Bots combinatorics, number theory	1800	x1303
117B	Very Interesting Game brute force, number theory	1800	x1298
616E	Sum of Remainders implementation, math, number theory	2200	x1296
803F	Coprime Subsequences bitmasks, combinatorics, number theory	2000	x1280
919E	Congruence Equation chinese remainder theorem, math, number theory	2100	x1245
78C	Beaver Game dp, games, number theory	2000	x1213
818E	Card Game Again binary search, data structures, number theory, two pointers	1900	x1203
1325E	Ehab's REAL Number Theory Problem brute force, dfs and similar, graphs, number theory, shortest paths	2600	x1179
1305F	Kuroni and the Punishment math, number theory, probabilities	2500	x1146
1322C	Instant Noodles graphs, hashing, math, number theory	2300	x1133
396A	On Number of Decompositions into Multipliers combinatorics, math, number theory		x1124
172D	Calendar Reform *special problem, number theory	1500	x1102
223C	Partial Sums combinatorics, math, number theory	1900	x1074
448E	Divisors brute force, dfs and similar, implementation, number theory	2200	x1070
279E	Beautiful Decomposition dp, games, greedy, number theory	1900	x1061
134B	Pairs of Numbers brute force, dfs and similar, math, number theory	1900	x1056
979D	Kuro and GCD and XOR and SUM binary search, bitmasks, brute force, data structures, dp, dsu, greedy, math, number theory, strings, trees	2200	x1048
463E	Caisa and Tree brute force, dfs and similar, math, number theory, trees	2100	x1045
711E	ZS and The Birthday Paradox math, number theory, probabilities	2300	x1038
1043F	Make It One bitmasks, combinatorics, dp, math, number theory, shortest paths	2500	x1037
920G	List Of Integers binary search, bitmasks, brute force, combinatorics, math, number theory	2200	x1010
1139D	Steps to One dp, math, number theory, probabilities	2300	x1008
1036E	Covered Points fft, geometry, number theory	2400	x1001
121C	Lucky Permutation brute force, combinatorics, number theory	1900	x979
1114F	Please, another Queries on Array? bitmasks, data structures, divide and conquer, math, number theory	2400	x965
10C	Digital Root number theory	2000	x930
1204E	Natasha, Sasha and the Prefix Sums combinatorics, dp, math, number theory	2300	x911
772C	Vulnerable Kerbals constructive algorithms, dp, graphs, math, number theory	2300	x904
171F	ucyhf *special problem, brute force, implementation, number theory	1600	x896
438E	The Child and Binary Tree combinatorics, divide and conquer, fft, number theory	3100	x854
251C	Number Transformation dp, greedy, number theory	2000	x850
113C	Double Happiness brute force, math, number theory	2200	x850
1146D	Frog Jumping dfs and similar, math, number theory	2100	x828
396B	On Sum of Fractions math, number theory		x828
1036F	Relatively Prime Powers combinatorics, math, number theory	2400	x823
912E	Prime Gift binary search, dfs and similar, math, meet-in-the-middle, number theory, two pointers	2400	x821
830C	Bamboo Partition brute force, data structures, implementation, math, number theory, sortings, two pointers	2300	x813
990G	GCD Counting divide and conquer, dp, dsu, number theory, trees	2400	x806
691F	Couple Cover brute force, dp, number theory	2200	x805
337E	Divisor Tree brute force, number theory, trees	2200	x800
585C	Alice, Bob, Oranges and Apples number theory	2400	x772
757E	Bash Plays with Functions brute force, combinatorics, dp, number theory	2500	x752
594D	REQ data structures, number theory	2500	x751
1097F	Alex and a TV Show bitmasks, combinatorics, number theory	2500	x737
498D	Traffic Jams in the Land data structures, dp, number theory	2400	x736
1184A2	Heidi Learns Hashing (Medium) brute force, number theory	2100	x734
1174E	Ehab and the Expected GCD Problem combinatorics, dp, math, number theory	2500	x732
300E	Empire Strikes Back binary search, math, number theory	2300	x721
768F	Barrels and boxes brute force, combinatorics, math, number theory, probabilities	2300	x715
659G	Fence Divercity combinatorics, dp, number theory	2300	x708