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Codeforces Global Round 26
12:44:21
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Difficulty:
—
dp
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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Problems
#
Name
1981F
Turtle and Paths on a Tree
data structures
,
dp
,
trees
x119
1977C
Nikita and LCM
brute force
,
data structures
,
dp
,
greedy
,
math
,
number theory
,
sortings
1900
x5150
1976F
Remove Bridges
data structures
,
dfs and similar
,
dp
,
greedy
,
sortings
,
trees
x335
1976C
Job Interview
binary search
,
dp
,
greedy
,
implementation
,
two pointers
x7762
1975I
Mind Bloom
dp
3500
x35
1975F
Set
bitmasks
,
brute force
,
combinatorics
,
dfs and similar
,
divide and conquer
,
dp
,
math
2600
x574
1975D
Paint the Tree
brute force
,
dfs and similar
,
dp
,
greedy
,
shortest paths
,
trees
1700
x4561
1974E
Money Buys Happiness
dp
1800
x6079
1973F
Maximum GCD Sum Queries
bitmasks
,
brute force
,
dp
,
implementation
,
number theory
3100
x151
1973A
Chess For Three
brute force
,
dp
,
implementation
,
math
900
x20577
1971D
Binary Cut
dp
,
greedy
,
implementation
,
sortings
,
strings
1100
x21596
1970G3
Min-Fund Prison (Hard)
bitmasks
,
dfs and similar
,
dp
,
graphs
,
trees
2400
x217
1970G2
Min-Fund Prison (Medium)
brute force
,
dfs and similar
,
dp
,
graphs
,
trees
2200
x392
1970E3
Trails (Hard)
dp
,
matrices
2200
x458
1970E2
Trails (Medium)
dp
,
matrices
2000
x821
1970E1
Trails (Easy)
dp
1800
x1289
1970C3
Game on Tree (Hard)
dfs and similar
,
dp
,
games
,
trees
1900
x962
1970C2
Game on Tree (Medium)
dfs and similar
,
dp
,
games
,
trees
1700
x1647
1969F
Card Pairing
dp
,
greedy
,
hashing
,
implementation
3000
x162
1969E
Unique Array
binary search
,
data structures
,
divide and conquer
,
dp
,
greedy
2400
x1054
1969C
Minimizing the Sum
dp
,
implementation
1700
x6893
1968G2
Division + LCP (hard version)
binary search
,
brute force
,
data structures
,
dp
,
hashing
,
math
,
string suffix structures
,
strings
2200
x1537
1968G1
Division + LCP (easy version)
binary search
,
data structures
,
dp
,
hashing
,
string suffix structures
,
strings
1900
x3481
1967E2
Again Counting Arrays (Hard Version)
combinatorics
,
dp
,
math
3500
x73
1967E1
Again Counting Arrays (Easy Version)
combinatorics
,
dp
,
fft
,
math
3100
x148
1967C
Fenwick Tree
bitmasks
,
brute force
,
combinatorics
,
data structures
,
dp
,
math
,
trees
2300
x1409
1958H
Composite Spells
*special problem
,
dp
2600
x65
1958A
1-3-5
*special problem
,
dp
1100
x1186
1957E
Carousel of Combinations
brute force
,
combinatorics
,
dp
,
math
,
number theory
2400
x1067
1957D
A BIT of an Inequality
bitmasks
,
brute force
,
dp
,
math
1900
x3898
1957C
How Does the Rook Move?
combinatorics
,
dp
,
math
1600
x8253
1956D
Nene and the Mex Operator
bitmasks
,
brute force
,
constructive algorithms
,
divide and conquer
,
dp
,
greedy
,
implementation
,
math
2000
x3412
1955H
The Most Reckless Defense
bitmasks
,
brute force
,
constructive algorithms
,
dp
,
flows
,
graph matchings
,
shortest paths
2300
x1087
1955G
GCD on a grid
brute force
,
dfs and similar
,
dp
,
implementation
,
math
,
number theory
1900
x3779
1955F
Unfair Game
dp
,
games
,
greedy
,
math
,
schedules
1800
x6210
1954F
Unique Strings
combinatorics
,
dp
,
math
3100
x217
1954D
Colored Balls
combinatorics
,
dp
,
math
,
sortings
1800
x5236
1951H
Thanos Snap
binary search
,
dp
,
games
,
greedy
,
trees
3200
x217
1950G
Shuffling Songs
bitmasks
,
dfs and similar
,
dp
,
graphs
,
hashing
,
implementation
,
strings
1900
x3706
1950D
Product of Binary Decimals
brute force
,
dp
,
implementation
,
number theory
1100
x21030
1949C
Annual Ants' Gathering
dfs and similar
,
dp
,
greedy
,
trees
1900
x1346
1949A
Grove
brute force
,
dfs and similar
,
dp
,
geometry
,
probabilities
3300
x91
1948C
Arrow Path
brute force
,
constructive algorithms
,
dfs and similar
,
dp
,
graphs
,
shortest paths
1300
x14994
1948B
Array Fix
brute force
,
dp
,
greedy
,
implementation
1100
x21026
1946F
Nobody is needed
2-sat
,
data structures
,
dfs and similar
,
dp
2500
x805
1946E
Girl Permutation
combinatorics
,
dp
,
math
,
number theory
2200
x2180
1946C
Tree Cutting
binary search
,
dp
,
greedy
,
implementation
,
trees
1600
x9518
1946B
Maximum Sum
dp
,
greedy
,
math
1100
x18577
1945D
Seraphim the Owl
dp
,
greedy
1300
x12771
1943F
Minimum Hamming Distance
dp
3500
x87
1943D2
Counting Is Fun (Hard Version)
combinatorics
,
dp
2800
x634
1943D1
Counting Is Fun (Easy Version)
brute force
,
combinatorics
,
dp
,
math
2400
x1296
1942H
Farmer John's Favorite Intern
data structures
,
dp
,
flows
,
trees
3500
x70
1942G
Bessie and Cards
combinatorics
,
dp
,
math
2800
x383
1942D
Learning to Paint
binary search
,
data structures
,
dfs and similar
,
dp
,
greedy
,
implementation
,
sortings
2100
x2514
1941E
Rudolf and k Bridges
binary search
,
data structures
,
dp
,
two pointers
1600
x8502
1941D
Rudolf and the Ball Game
dfs and similar
,
dp
,
implementation
1200
x17032
1941C
Rudolf and the Ugly String
dp
,
greedy
,
strings
900
x30514
1941B
Rudolf and 121
brute force
,
dp
,
greedy
,
math
1000
x27188
1939D
Big Persimmon
*special problem
,
dp
,
games
x84
1939A
Draw Polygon Lines
*special problem
,
constructive algorithms
,
dp
,
geometry
,
interactive
x20
1937B
Binary Path
dp
,
greedy
,
implementation
1300
x13531
1935C
Messenger in MAC
binary search
,
brute force
,
constructive algorithms
,
data structures
,
dp
,
greedy
,
sortings
1800
x7351
1934B
Yet Another Coin Problem
brute force
,
dp
,
greedy
,
math
1200
x17154
1933F
Turtle Mission: Robot and the Earthquake
dfs and similar
,
dp
,
graphs
,
shortest paths
2100
x2260
1932F
Feed Cats
data structures
,
dp
,
sortings
1900
x3536
1932A
Thorns and Coins
dp
,
greedy
,
implementation
800
x27421
1930G
Prefix Max Set Counting
data structures
,
dp
,
trees
3100
x299
1930E
2..3...4.... Wonderful! Wonderful!
combinatorics
,
dp
,
math
2400
x1022
1930D2
Sum over all Substrings (Hard Version)
bitmasks
,
divide and conquer
,
dp
,
dsu
,
greedy
,
implementation
,
strings
2100
x2421
1930D1
Sum over all Substrings (Easy Version)
brute force
,
dp
,
greedy
,
strings
1800
x3780
1929E
Sasha and the Happy Tree Cutting
bitmasks
,
brute force
,
dfs and similar
,
dp
,
graphs
,
greedy
,
math
,
trees
2300
x1547
1929D
Sasha and a Walk in the City
combinatorics
,
dp
,
math
,
trees
1900
x4278
1928E
Modular Sequence
brute force
,
constructive algorithms
,
dp
,
graphs
,
greedy
,
math
,
number theory
2300
x1587
1927G
Paint Charges
data structures
,
dp
,
greedy
,
math
2300
x1522
1927D
Find the Different Ones!
binary search
,
brute force
,
data structures
,
dp
,
dsu
,
greedy
,
two pointers
1300
x18848
1926G
Vlad and Trouble at MIT
dfs and similar
,
dp
,
flows
,
graphs
,
greedy
,
implementation
,
trees
1900
x3080
1926F
Vlad and Avoiding X
bitmasks
,
brute force
,
dfs and similar
,
dp
,
implementation
2200
x1541
1926E
Vlad and an Odd Ordering
binary search
,
bitmasks
,
data structures
,
dp
,
implementation
,
math
,
number theory
1500
x10500
1926C
Vlad and a Sum of Sum of Digits
dp
,
implementation
1200
x23926
1925D
Good Trip
combinatorics
,
dp
,
math
,
probabilities
1900
x3311
1924F
Anti-Proxy Attendance
constructive algorithms
,
dp
,
interactive
,
ternary search
3500
x134
1924D
Balanced Subsequences
combinatorics
,
dp
,
math
2700
x793
1924A
Did We Get Everything Covered?
constructive algorithms
,
dp
,
greedy
,
shortest paths
,
strings
1500
x12652
1923E
Count Paths
data structures
,
dfs and similar
,
dp
,
dsu
,
graphs
,
trees
2000
x3310
1923B
Monsters Attack!
dp
,
greedy
,
implementation
1100
x16520
1922F
Replace on Segment
dp
,
graph matchings
2500
x1188
1921G
Mischievous Shooter
brute force
,
data structures
,
divide and conquer
,
dp
,
implementation
2200
x1149
1921F
Sum of Progression
brute force
,
data structures
,
dp
,
implementation
,
math
1900
x3530
1920E
Counting Binary Strings
combinatorics
,
dp
,
math
2100
x2419
1919F2
Wine Factory (Hard Version)
data structures
,
dp
,
flows
,
greedy
,
matrices
2800
x752
1919E
Counting Prefixes
combinatorics
,
constructive algorithms
,
dp
,
implementation
,
math
2600
x787
1919C
Grouping Increases
data structures
,
dp
,
greedy
1400
x17179
1918D
Blocking Elements
binary search
,
data structures
,
dp
,
implementation
,
two pointers
1900
x4363
1917F
Construct Tree
bitmasks
,
constructive algorithms
,
dp
,
trees
2500
x913
1917D
Yet Another Inversions Problem
combinatorics
,
data structures
,
dp
,
implementation
,
math
,
number theory
2300
x1682
1917B
Erase First or Second Letter
brute force
,
combinatorics
,
data structures
,
dp
,
strings
1100
x19896
1916H2
Matrix Rank (Hard Version)
combinatorics
,
dp
,
math
,
matrices
,
string suffix structures
2700
x506
1916H1
Matrix Rank (Easy Version)
brute force
,
combinatorics
,
dp
,
math
,
matrices
2700
x588
1916G
Optimizations From Chelsu
divide and conquer
,
dp
,
number theory
,
trees
3500
x138
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