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Codeforces Round #851 (Div. 2)
3 days
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2-sat
binary search
bitmasks
brute force
chinese remainder theorem
combinatorics
constructive algorithms
data structures
dfs and similar
divide and conquer
dp
dsu
expression parsing
fft
flows
games
geometry
graph matchings
graphs
greedy
hashing
implementation
interactive
math
matrices
meet-in-the-middle
number theory
probabilities
schedules
shortest paths
sortings
string suffix structures
strings
ternary search
trees
two pointers
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Custom test
Problems
#
Name
1772F
Copy of a Copy of a Copy
constructive algorithms
,
dfs and similar
,
graphs
,
implementation
,
sortings
2000
x1466
730I
Olympiad in Programming and Sports
dp
,
flows
,
graphs
,
greedy
2000
x1450
1250N
Wires
dfs and similar
,
graphs
,
greedy
2000
x1431
1080D
Olya and magical square
constructive algorithms
,
implementation
,
math
2000
x1430
995A
Tesla
constructive algorithms
,
implementation
2100
x1420
899F
Letters Removing
data structures
,
strings
2100
x1414
1092E
Minimal Diameter Forest
constructive algorithms
,
dfs and similar
,
greedy
,
trees
2000
x1410
993C
Careful Maneuvering
bitmasks
,
brute force
,
geometry
2100
x1410
490E
Restoring Increasing Sequence
binary search
,
brute force
,
greedy
,
implementation
2000
x1409
379D
New Year Letter
bitmasks
,
brute force
,
dp
2000
x1409
513C
Second price auction
bitmasks
,
probabilities
2000
x1408
1787E
The Harmonization of XOR
bitmasks
,
constructive algorithms
,
greedy
,
math
2100
x1404
314B
Sereja and Periods
binary search
,
dfs and similar
,
strings
2000
x1389
237E
Build String
flows
,
graphs
2000
x1384
1032E
The Unbearable Lightness of Weights
dp
,
math
2100
x1382
748E
Santa Claus and Tangerines
binary search
,
data structures
,
greedy
,
two pointers
2100
x1372
280A
Rectangle Puzzle
geometry
2000
x1361
811D
Vladik and Favorite Game
constructive algorithms
,
dfs and similar
,
graphs
,
interactive
2100
x1359
1005F
Berland and the Shortest Paths
brute force
,
dfs and similar
,
graphs
,
shortest paths
2100
x1352
165D
Beard Graph
data structures
,
dsu
,
trees
2100
x1350
837E
Vasya's Function
binary search
,
implementation
,
math
2100
x1348
276E
Little Girl and Problem on Trees
data structures
,
graphs
,
trees
2100
x1347
439E
Devu and Birthday Celebration
combinatorics
,
dp
,
math
2100
x1346
1098B
Nice table
brute force
,
constructive algorithms
,
greedy
,
math
2100
x1342
427E
Police Patrol
greedy
,
implementation
,
math
,
ternary search
2000
x1341
587B
Duff in Beach
dp
2100
x1335
552E
Vanya and Brackets
brute force
,
dp
,
expression parsing
,
greedy
,
implementation
,
strings
2100
x1332
382B
Number Busters
binary search
,
math
2000
x1330
853C
Boredom
data structures
2100
x1323
821E
Okabe and El Psy Kongroo
dp
,
matrices
2100
x1292
5D
Follow Traffic Rules
implementation
,
math
2100
x1291
1599C
Bubble Strike
combinatorics
,
math
,
probabilities
,
ternary search
2000
x1284
452C
Magic Trick
combinatorics
,
math
,
probabilities
2100
x1284
231E
Cactus
data structures
,
dfs and similar
,
dp
,
graphs
,
trees
2100
x1283
313D
Ilya and Roads
dp
2100
x1270
266C
Below the Diagonal
constructive algorithms
,
greedy
,
math
2100
x1270
10C
Digital Root
number theory
2000
x1243
1252G
Performance Review
data structures
2100
x1240
463E
Caisa and Tree
brute force
,
dfs and similar
,
math
,
number theory
,
trees
2100
x1237
286C
Main Sequence
greedy
,
implementation
2100
x1232
862E
Mahmoud and Ehab and the function
binary search
,
data structures
,
sortings
2100
x1228
190E
Counter Attack
data structures
,
dsu
,
graphs
,
hashing
,
sortings
2100
x1213
87C
Interesting Game
dp
,
games
,
math
2000
x1208
746G
New Roads
constructive algorithms
,
graphs
,
trees
2100
x1201
260D
Black and White Tree
constructive algorithms
,
dsu
,
graphs
,
greedy
,
trees
2100
x1198
187C
Weak Memory
dfs and similar
,
dsu
2000
x1192
1250C
Trip to Saint Petersburg
data structures
2100
x1188
201C
Fragile Bridges
dp
2000
x1188
56D
Changing a String
dp
2100
x1183
291E
Tree-String Problem
*special problem
,
dfs and similar
,
hashing
,
strings
2000
x1167
171E
MYSTERIOUS LANGUAGE
*special problem
2000
x1167
282D
Yet Another Number Game
dp
,
games
2100
x1161
21B
Intersection
implementation
,
math
2000
x1157
283C
Coin Troubles
dp
2100
x1156
1510G
Guide
2100
x1151
356C
Compartments
combinatorics
,
constructive algorithms
,
greedy
,
implementation
2100
x1142
366D
Dima and Trap Graph
binary search
,
data structures
,
dfs and similar
,
dsu
,
shortest paths
,
two pointers
2000
x1140
1070E
Getting Deals Done
binary search
,
data structures
2100
x1137
852B
Neural Network country
dp
,
matrices
2000
x1137
870D
Something with XOR Queries
brute force
,
interactive
,
probabilities
2000
x1123
243B
Hydra
graphs
,
sortings
2000
x1112
1090L
Berland University
greedy
,
math
2000
x1111
1163D
Mysterious Code
dp
,
strings
2100
x1109
773B
Dynamic Problem Scoring
brute force
,
greedy
2000
x1109
818C
Sofa Thief
brute force
,
implementation
2000
x1107
111C
Petya and Spiders
bitmasks
,
dp
,
dsu
2100
x1106
1666J
Job Lookup
constructive algorithms
,
dp
,
shortest paths
,
trees
2100
x1096
818F
Level Generation
binary search
,
math
,
ternary search
2100
x1095
1725C
Circular Mirror
binary search
,
combinatorics
,
geometry
,
math
,
two pointers
2000
x1092
1044C
Optimal Polygon Perimeter
dp
,
geometry
2100
x1091
137E
Last Chance
data structures
,
implementation
,
strings
2000
x1091
542C
Idempotent functions
constructive algorithms
,
graphs
,
math
2000
x1059
54C
First Digit Law
dp
,
math
,
probabilities
2000
x1039
371E
Subway Innovation
greedy
,
math
,
two pointers
2000
x1018
33D
Knights
geometry
,
graphs
,
shortest paths
,
sortings
2000
x1014
263C
Circle of Numbers
brute force
,
dfs and similar
,
implementation
2000
x1013
433D
Nanami's Digital Board
dsu
,
implementation
2000
x1004
1146D
Frog Jumping
dfs and similar
,
math
,
number theory
2100
x997
128D
Numbers
constructive algorithms
,
implementation
2000
x997
441D
Valera and Swaps
constructive algorithms
,
dsu
,
graphs
,
implementation
,
math
,
string suffix structures
2100
x993
958C2
Encryption (medium)
dp
2000
x990
163B
Lemmings
binary search
2000
x979
895D
String Mark
combinatorics
,
math
,
strings
2100
x977
204C
Little Elephant and Furik and Rubik
math
,
probabilities
2000
x970
43D
Journey
brute force
,
constructive algorithms
,
implementation
2000
x969
251C
Number Transformation
dp
,
greedy
,
number theory
2000
x965
730C
Bulmart
binary search
,
dfs and similar
2100
x959
12E
Start of the session
constructive algorithms
2100
x953
238C
World Eater Brothers
dfs and similar
,
dp
,
greedy
,
trees
2100
x950
1387B1
Village (Minimum)
*special problem
,
dp
,
greedy
,
trees
2100
x941
900E
Maximum Questions
data structures
,
dp
,
strings
2100
x931
575F
Bulbo
dp
,
greedy
2100
x929
18D
Seller Bob
brute force
,
dp
,
greedy
2000
x925
1575L
Longest Array Deconstruction
data structures
,
divide and conquer
,
dp
,
sortings
2100
x920
268E
Playlist
math
,
probabilities
,
sortings
2100
x915
615E
Hexagons
binary search
,
implementation
,
math
2100
x909
1090K
Right Expansion Of The Mind
math
2000
x907
524D
Social Network
greedy
,
two pointers
2100
x907
1090I
Minimal Product
2000
x895
292C
Beautiful IP Addresses
brute force
2000
x893
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