Enter
|
Register
Home
Top
Catalog
Contests
Gym
Problemset
Groups
Rating
Edu
API
Calendar
Help
→ Pay attention
Before contest
Codeforces Round #851 (Div. 2)
2 days
Register now »
*has extra registration
→ Filter Problems
Difficulty:
—
combine-tags-by-or
*combine tags by OR
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
Add tag
Main
acmsguru
|
Problems
Submit
Status
Standings
Custom test
Problems
#
Name
380C
Sereja and Brackets
data structures
,
schedules
2000
x10687
1438C
Engineer Artem
2-sat
,
chinese remainder theorem
,
constructive algorithms
,
fft
,
flows
2000
x9046
2B
The least round way
dp
,
math
2000
x8708
1366D
Two Divisors
constructive algorithms
,
math
,
number theory
2000
x8431
1370D
Odd-Even Subsequence
binary search
,
dp
,
dsu
,
greedy
,
implementation
2000
x8090
1359D
Yet Another Yet Another Task
data structures
,
dp
,
implementation
,
two pointers
2000
x7825
1311D
Three Integers
brute force
,
math
2000
x7660
1349B
Orac and Medians
constructive algorithms
,
greedy
,
math
2000
x6894
1244C
The Football Season
brute force
,
math
,
number theory
2000
x6750
432D
Prefixes and Suffixes
dp
,
string suffix structures
,
strings
,
two pointers
2000
x6621
242E
XOR on Segment
bitmasks
,
data structures
2000
x6413
540C
Ice Cave
dfs and similar
2000
x6287
449B
Jzzhu and Cities
graphs
,
greedy
,
shortest paths
2000
x6261
484B
Maximum Value
binary search
,
math
,
sortings
,
two pointers
2100
x6065
474F
Ant colony
data structures
,
math
,
number theory
2100
x6036
1363E
Tree Shuffling
dfs and similar
,
dp
,
greedy
,
trees
2000
x5899
1385E
Directing Edges
constructive algorithms
,
dfs and similar
,
graphs
2000
x5743
1288D
Minimax Problem
binary search
,
bitmasks
,
dp
2000
x5676
1388D
Captain Flint and Treasure
data structures
,
dfs and similar
,
graphs
,
greedy
,
implementation
,
trees
2000
x5597
1200E
Compress Words
brute force
,
hashing
,
implementation
,
string suffix structures
,
strings
2000
x5504
1132F
Clear the String
dp
2000
x5503
1187E
Tree Painting
dfs and similar
,
dp
,
trees
2100
x5465
321C
Ciel the Commander
constructive algorithms
,
dfs and similar
,
divide and conquer
,
greedy
,
trees
2100
x5454
514C
Watto and Mechanism
binary search
,
data structures
,
hashing
,
string suffix structures
,
strings
2000
x5446
1354C2
Not So Simple Polygon Embedding
binary search
,
brute force
,
geometry
,
math
2000
x5438
1344B
Monopole Magnets
constructive algorithms
,
dfs and similar
,
dsu
,
graphs
2000
x5424
1416B
Make Them Equal
constructive algorithms
,
greedy
,
math
2000
x5326
1486D
Max Median
binary search
,
data structures
,
dp
2100
x5288
999E
Reachability from the Capital
dfs and similar
,
graphs
,
greedy
2000
x5281
609E
Minimum spanning tree for each edge
data structures
,
dfs and similar
,
dsu
,
graphs
,
trees
2100
x5246
1399E1
Weights Division (easy version)
data structures
,
dfs and similar
,
greedy
,
trees
2000
x5188
1674E
Breaking the Wall
binary search
,
brute force
,
constructive algorithms
,
greedy
,
math
2000
x5130
1268B
Domino for Young
dp
,
greedy
,
math
2000
x5107
1359E
Modular Stability
combinatorics
,
math
,
number theory
2000
x5096
383C
Propagating tree
data structures
,
dfs and similar
,
trees
2000
x5093
1433F
Zero Remainder Sum
dp
2100
x5090
1372D
Omkar and Circle
brute force
,
dp
,
games
,
greedy
2100
x4960
118E
Bertown roads
dfs and similar
,
graphs
2000
x4951
478D
Red-Green Towers
dp
2000
x4925
1427C
The Hard Work of Paparazzi
dp
2000
x4919
920F
SUM and REPLACE
brute force
,
data structures
,
dsu
,
number theory
2000
x4907
1156C
Match Points
binary search
,
greedy
,
sortings
,
ternary search
,
two pointers
2000
x4899
1763C
Another Array Problem
brute force
,
constructive algorithms
,
greedy
2000
x4884
1450C1
Errich-Tac-Toe (Easy Version)
constructive algorithms
,
math
2100
x4855
519E
A and B and Lecture Rooms
binary search
,
data structures
,
dfs and similar
,
dp
,
trees
2100
x4851
1454E
Number of Simple Paths
combinatorics
,
dfs and similar
,
graphs
,
trees
2000
x4846
337D
Book of Evil
dfs and similar
,
divide and conquer
,
dp
,
trees
2000
x4831
1C
Ancient Berland Circus
geometry
,
math
2100
x4789
1379C
Choosing flowers
binary search
,
brute force
,
data structures
,
dfs and similar
,
dp
,
greedy
,
sortings
,
two pointers
2000
x4694
1312E
Array Shrinking
dp
,
greedy
2100
x4639
1499D
The Number of Pairs
dp
,
math
,
number theory
2100
x4604
455C
Civilization
dfs and similar
,
dp
,
dsu
,
ternary search
,
trees
2100
x4582
208E
Blood Cousins
binary search
,
data structures
,
dfs and similar
,
trees
2100
x4556
461B
Appleman and Tree
dfs and similar
,
dp
,
trees
2000
x4549
1415D
XOR-gun
bitmasks
,
brute force
,
constructive algorithms
2000
x4508
1294F
Three Paths on a Tree
dfs and similar
,
dp
,
greedy
,
trees
2000
x4487
1426F
Number of Subsequences
combinatorics
,
dp
,
strings
2000
x4462
1391D
505
bitmasks
,
brute force
,
constructive algorithms
,
dp
,
greedy
,
implementation
2000
x4446
920E
Connected Components?
data structures
,
dfs and similar
,
dsu
,
graphs
2100
x4406
1343E
Weights Distributing
brute force
,
graphs
,
greedy
,
shortest paths
,
sortings
2100
x4381
1217D
Coloring Edges
constructive algorithms
,
dfs and similar
,
graphs
2100
x4356
710E
Generate a String
dfs and similar
,
dp
2000
x4328
343D
Water Tree
data structures
,
dfs and similar
,
graphs
,
trees
2100
x4328
1613E
Crazy Robot
dfs and similar
,
graphs
2000
x4310
1370E
Binary Subsequence Rotation
binary search
,
constructive algorithms
,
data structures
,
greedy
2100
x4295
1304E
1-Trees and Queries
data structures
,
dfs and similar
,
shortest paths
,
trees
2000
x4275
359D
Pair of Numbers
binary search
,
brute force
,
data structures
,
math
,
two pointers
2000
x4275
451D
Count Good Substrings
math
2000
x4254
1380D
Berserk And Fireball
constructive algorithms
,
greedy
,
implementation
,
math
,
two pointers
2000
x4234
1296E2
String Coloring (hard version)
data structures
,
dp
2000
x4227
466B
Wonder Room
brute force
,
math
2000
x4219
1657D
For Gamers. By Gamers.
binary search
,
brute force
,
greedy
,
math
,
sortings
2000
x4202
796D
Police Stations
constructive algorithms
,
dfs and similar
,
dp
,
graphs
,
shortest paths
,
trees
2100
x4179
1536D
Omkar and Medians
data structures
,
greedy
,
implementation
2000
x4175
938D
Buy a Ticket
data structures
,
graphs
,
shortest paths
2000
x4168
776D
The Door Problem
2-sat
,
dfs and similar
,
dsu
,
graphs
2000
x4141
1355E
Restorer Distance
binary search
,
greedy
,
math
,
sortings
,
ternary search
2100
x4129
1513D
GCD and MST
constructive algorithms
,
dsu
,
graphs
,
greedy
,
number theory
,
sortings
2000
x4113
1244E
Minimizing Difference
binary search
,
constructive algorithms
,
greedy
,
sortings
,
ternary search
,
two pointers
2000
x4111
1493C
K-beautiful Strings
binary search
,
brute force
,
constructive algorithms
,
greedy
,
strings
2000
x4098
1493D
GCD of an Array
brute force
,
data structures
,
hashing
,
implementation
,
math
,
number theory
,
sortings
,
two pointers
2100
x4092
1716D
Chip Move
brute force
,
dp
,
math
2000
x4079
1616D
Keep the Average High
dp
,
greedy
,
math
2000
x4057
1567D
Expression Evaluation Error
constructive algorithms
,
greedy
,
implementation
,
math
2000
x4050
1420C2
Pokémon Army (hard version)
data structures
,
divide and conquer
,
dp
,
greedy
,
implementation
2100
x4013
453B
Little Pony and Harmony Chest
bitmasks
,
brute force
,
dp
2000
x4004
1481D
AB Graph
brute force
,
constructive algorithms
,
graphs
,
greedy
,
implementation
2000
x4003
620E
New Year Tree
bitmasks
,
data structures
,
trees
2100
x3976
1521C
Nastia and a Hidden Permutation
constructive algorithms
,
interactive
2000
x3967
1349C
Orac and Game of Life
dfs and similar
,
graphs
,
implementation
,
shortest paths
2000
x3947
1183E
Subsequences (easy version)
dp
,
graphs
,
implementation
,
shortest paths
2000
x3947
1360H
Binary Median
binary search
,
bitmasks
,
brute force
,
constructive algorithms
2100
x3936
319C
Kalila and Dimna in the Logging Industry
dp
,
geometry
2100
x3904
1365F
Swaps Again
constructive algorithms
,
implementation
,
sortings
2100
x3899
1574D
The Strongest Build
binary search
,
brute force
,
data structures
,
dfs and similar
,
graphs
,
greedy
,
hashing
,
implementation
2000
x3891
1408D
Searchlights
binary search
,
brute force
,
data structures
,
dp
,
implementation
,
sortings
,
two pointers
2000
x3851
1538G
Gift Set
binary search
,
greedy
,
math
,
ternary search
2100
x3850
1525C
Robot Collisions
data structures
,
greedy
,
implementation
,
sortings
2000
x3850
1418D
Trash Problem
data structures
,
implementation
2100
x3841
895C
Square Subsets
bitmasks
,
combinatorics
,
dp
,
math
2000
x3838
←
1
2
3
...
7
8
→
User lists
Name