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Codeforces Global Round 28
25:59:30
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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
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Custom test
Problems
#
Name
2052J
Judicious Watching
binary search
,
greedy
,
sortings
2000
x416
2052E
Expression Correction
brute force
,
expression parsing
,
strings
1900
x536
2052D
DAG Serialization
brute force
,
graphs
2100
x358
2050G
Tree Destruction
dfs and similar
,
dp
,
trees
1900
x2759
2046C
Adventurers
binary search
,
data structures
,
greedy
,
sortings
,
ternary search
,
two pointers
2100
x1394
2045I
Microwavable Subsequence
data structures
2100
x582
2045B
ICPC Square
math
,
number theory
2000
x738
2042D
Recommendations
data structures
,
implementation
,
sortings
,
two pointers
1900
x2885
2041M
Selection Sort
binary search
,
data structures
,
greedy
,
two pointers
2000
x740
2041C
Cube
bitmasks
,
dfs and similar
,
dp
2000
x1063
2040E
Control of Randomness
combinatorics
,
dfs and similar
,
dp
,
graphs
,
greedy
,
math
,
probabilities
,
trees
2100
x1465
2040D
Non Prime Tree
brute force
,
constructive algorithms
,
dfs and similar
,
greedy
,
number theory
,
trees
,
two pointers
1900
x3455
2038K
Grid Walk
brute force
,
dp
,
greedy
,
math
,
number theory
2100
x1171
2038G
Guess One Character
constructive algorithms
,
implementation
,
interactive
1900
x2020
2038B
Make It Equal
binary search
,
brute force
,
greedy
,
math
2100
x1305
2037G
Natlan Exploring
bitmasks
,
combinatorics
,
data structures
,
dp
,
math
,
number theory
2000
x2379
2037F
Ardent Flames
binary search
,
data structures
,
math
,
sortings
,
two pointers
2100
x1940
2036F
XORificator 3000
bitmasks
,
dp
,
number theory
,
two pointers
1900
x3593
2031E
Penchick and Chloe's Trees
data structures
,
dfs and similar
,
dp
,
greedy
,
implementation
,
math
,
sortings
,
trees
2100
x1970
2029E
Common Generator
brute force
,
constructive algorithms
,
math
,
number theory
2100
x2591
2029D
Cool Graph
constructive algorithms
,
data structures
,
dfs and similar
,
dsu
,
graphs
,
greedy
,
trees
1900
x2847
2028D
Alice's Adventures in Cards
constructive algorithms
,
data structures
,
dp
,
graphs
,
greedy
,
implementation
,
ternary search
2000
x2639
2026D
Sums of Segments
binary search
,
data structures
,
dp
,
implementation
,
math
1900
x4233
2022D1
Asesino (Easy Version)
binary search
,
brute force
,
constructive algorithms
,
implementation
,
interactive
1900
x2955
2021C2
Adjust The Presentation (Hard Version)
constructive algorithms
,
data structures
,
greedy
,
implementation
,
sortings
1900
x3658
2020E
Expected Power
bitmasks
,
dp
,
math
,
probabilities
2000
x3077
2018B
Speedbreaker
binary search
,
data structures
,
dp
,
greedy
,
implementation
,
two pointers
1900
x4075
2014H
Robin Hood Archery
data structures
,
divide and conquer
,
greedy
,
hashing
1900
x3629
2014F
Sheriff's Defense
dfs and similar
,
dp
,
greedy
,
trees
2000
x3681
2013D
Minimize the Difference
binary search
,
greedy
1900
x6159
2009G1
Yunli's Subarray Queries (easy version)
binary search
,
data structures
,
two pointers
1900
x3908
2008H
Sakurako's Test
binary search
,
brute force
,
greedy
,
math
,
number theory
2100
x2954
2005E1
Subtangle Game (Easy Version)
dp
,
games
,
greedy
,
implementation
2100
x2773
2004E
Not a Nim Problem
brute force
,
games
,
math
,
number theory
2100
x4127
2003D2
Turtle and a MEX Problem (Hard Version)
dfs and similar
,
dp
,
graphs
,
greedy
,
implementation
,
math
2100
x4049
2002D1
DFS Checker (Easy Version)
brute force
,
data structures
,
dfs and similar
,
graphs
,
hashing
,
trees
1900
x4395
2001D
Longest Max Min Subsequence
brute force
,
constructive algorithms
,
data structures
,
greedy
,
implementation
1900
x5115
2000G
Call During the Journey
binary search
,
brute force
,
graphs
,
greedy
,
shortest paths
2100
x2399
2000F
Color Rows and Columns
dp
,
greedy
,
implementation
,
math
1900
x5481
1998D
Determine Winning Islands in Race
data structures
,
dp
,
graphs
,
greedy
,
shortest paths
2100
x3385
1998C
Perform Operations to Maximize Score
binary search
,
brute force
,
constructive algorithms
,
greedy
,
implementation
1900
x6228
1996F
Bomb
binary search
,
greedy
,
math
1900
x4882
1994E
Wooden Game
bitmasks
,
greedy
,
math
,
trees
2000
x4591
1994D
Funny Game
constructive algorithms
,
dsu
,
graphs
,
greedy
,
math
,
number theory
,
trees
1900
x5863
1992G
Ultra-Meow
combinatorics
,
dp
,
math
2000
x3192
1992F
Valuable Cards
brute force
,
dp
,
greedy
,
number theory
,
two pointers
1900
x5842
1991E
Coloring Game
constructive algorithms
,
dfs and similar
,
games
,
graphs
,
greedy
,
interactive
1900
x4290
1991D
Prime XOR Coloring
bitmasks
,
constructive algorithms
,
graphs
,
greedy
,
math
,
number theory
1900
x6766
1989D
Smithing Skill
brute force
,
data structures
,
dp
,
greedy
,
math
,
sortings
,
two pointers
1900
x6066
1988D
The Omnipotent Monster Killer
brute force
,
dfs and similar
,
dp
,
trees
2000
x5013
1987E
Wonderful Tree!
brute force
,
data structures
,
dfs and similar
,
dsu
,
greedy
,
trees
2000
x3453
1986F
Non-academic Problem
dfs and similar
,
graphs
,
trees
1900
x4682
1984D
''a'' String Problem
brute force
,
hashing
,
implementation
,
math
,
string suffix structures
,
strings
2000
x3334
1980F1
Field Division (easy version)
data structures
,
math
,
sortings
1900
x3811
1978E
Computing Machine
brute force
,
data structures
,
dp
,
greedy
,
implementation
2000
x3887
1977C
Nikita and LCM
brute force
,
data structures
,
dp
,
greedy
,
math
,
number theory
,
sortings
1900
x6851
1976D
Invertible Bracket Sequences
binary search
,
combinatorics
,
data structures
,
divide and conquer
,
implementation
,
two pointers
2000
x4694
1975E
Chain Queries
binary search
,
data structures
,
dfs and similar
,
implementation
,
trees
2100
x2364
1974G
Money Buys Less Happiness Now
data structures
,
greedy
,
sortings
2000
x4451
1974F
Cutting Game
binary search
,
brute force
,
data structures
,
implementation
,
sortings
,
two pointers
1900
x3642
1971H
±1
2-sat
,
dfs and similar
,
graphs
2100
x1903
1970G1
Min-Fund Prison (Easy)
dfs and similar
,
trees
1900
x1396
1970E2
Trails (Medium)
dp
,
matrices
2000
x1354
1970D1
Arithmancy (Easy)
brute force
,
constructive algorithms
,
interactive
,
strings
2100
x673
1970C3
Game on Tree (Hard)
dfs and similar
,
dp
,
games
,
trees
1900
x1646
1970B2
Exact Neighbours (Medium)
constructive algorithms
2100
x845
1970B1
Exact Neighbours (Easy)
constructive algorithms
1900
x1190
1969D
Shop Game
data structures
,
greedy
,
math
,
sortings
1900
x4720
1968G1
Division + LCP (easy version)
binary search
,
data structures
,
dp
,
hashing
,
string suffix structures
,
strings
1900
x4359
1958F
Narrow Paths
*special problem
,
combinatorics
2000
x207
1958E
Yet Another Permutation Constructive
*special problem
,
constructive algorithms
1900
x275
1957D
A BIT of an Inequality
bitmasks
,
brute force
,
dp
,
math
1900
x4597
1956D
Nene and the Mex Operator
bitmasks
,
brute force
,
constructive algorithms
,
divide and conquer
,
dp
,
greedy
,
implementation
,
math
2000
x3996
1955G
GCD on a grid
brute force
,
dfs and similar
,
dp
,
implementation
,
math
,
number theory
1900
x4652
1951E
No Palindromes
brute force
,
constructive algorithms
,
divide and conquer
,
greedy
,
hashing
,
implementation
,
math
,
strings
2000
x3696
1951D
Buying Jewels
constructive algorithms
,
greedy
,
math
2000
x5494
1950G
Shuffling Songs
bitmasks
,
dfs and similar
,
dp
,
graphs
,
hashing
,
implementation
,
strings
1900
x4528
1949C
Annual Ants' Gathering
dfs and similar
,
dp
,
greedy
,
trees
1900
x1831
1948E
Clique Partition
brute force
,
constructive algorithms
,
graphs
,
greedy
,
implementation
2100
x3047
1946D
Birthday Gift
bitmasks
,
brute force
,
constructive algorithms
,
greedy
,
implementation
1900
x4809
1945F
Kirill and Mushrooms
data structures
,
sortings
1900
x4317
1943B
Non-Palindromic Substring
hashing
,
implementation
,
math
,
strings
2000
x3930
1942D
Learning to Paint
binary search
,
data structures
,
dfs and similar
,
dp
,
greedy
,
implementation
,
sortings
2100
x2852
1941G
Rudolf and Subway
constructive algorithms
,
dfs and similar
,
graphs
,
shortest paths
2000
x3647
1938J
There and Back Again
2100
x1321
1938C
Bit Counting Sequence
1900
x1505
1936B
Pinball
binary search
,
data structures
,
implementation
,
math
,
two pointers
2000
x3017
1934D1
XOR Break --- Solo Version
bitmasks
,
constructive algorithms
,
greedy
2100
x3592
1933F
Turtle Mission: Robot and the Earthquake
dfs and similar
,
dp
,
graphs
,
shortest paths
2100
x2539
1932F
Feed Cats
data structures
,
dp
,
sortings
1900
x4277
1931G
One-Dimensional Puzzle
combinatorics
,
math
,
number theory
2000
x2918
1930D2
Sum over all Substrings (Hard Version)
bitmasks
,
divide and conquer
,
dp
,
dsu
,
greedy
,
implementation
,
strings
2100
x2689
1929D
Sasha and a Walk in the City
combinatorics
,
dp
,
math
,
trees
1900
x4912
1928D
Lonely Mountain Dungeons
brute force
,
data structures
,
greedy
,
math
,
ternary search
1900
x4392
1927F
Microcycle
data structures
,
dfs and similar
,
dsu
,
graphs
,
greedy
,
implementation
,
sortings
,
trees
1900
x4513
1926G
Vlad and Trouble at MIT
dfs and similar
,
dp
,
flows
,
graphs
,
greedy
,
implementation
,
trees
1900
x3703
1925D
Good Trip
combinatorics
,
dp
,
math
,
probabilities
1900
x3740
1924B
Space Harbour
data structures
,
implementation
,
math
,
sortings
2100
x2642
1923E
Count Paths
data structures
,
dfs and similar
,
dp
,
dsu
,
graphs
,
trees
2000
x4025
1922D
Berserk Monsters
brute force
,
data structures
,
dsu
,
implementation
,
math
1900
x5821
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