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Codeforces Round (Div. 2)
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brute force
combine-tags-by-or
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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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Problems
#
Name
1992E
Novice's Mistake
brute force
,
constructive algorithms
,
math
,
strings
1700
x5391
1992A
Only Pluses
brute force
,
constructive algorithms
,
greedy
,
math
,
sortings
800
x28620
1989D
Smithing Skill
brute force
,
data structures
,
dp
,
greedy
,
math
,
sortings
,
two pointers
1900
x4485
1989B
Substring and Subsequence
brute force
,
greedy
,
strings
1200
x16191
1987E
Wonderful Tree!
brute force
,
data structures
,
dfs and similar
,
dsu
,
greedy
,
trees
2000
x2478
1986G2
Permutation Problem (Hard Version)
brute force
,
data structures
,
hashing
,
math
,
number theory
2500
x780
1986G1
Permutation Problem (Simple Version)
binary search
,
brute force
,
combinatorics
,
data structures
,
math
,
number theory
2200
x1120
1986D
Mathematical Problem
brute force
,
dp
,
greedy
,
implementation
,
math
,
two pointers
1400
x12677
1986B
Matrix Stabilization
brute force
,
data structures
,
greedy
,
sortings
1000
x23279
1986A
X Axis
brute force
,
geometry
,
math
,
sortings
800
x34771
1985H1
Maximize the Largest Component (Easy Version)
brute force
,
data structures
,
dfs and similar
,
dsu
,
graphs
,
implementation
1700
x4449
1985E
Secret Box
brute force
,
combinatorics
,
math
1200
x17126
1985B
Maximum Multiple Sum
brute force
,
math
,
number theory
800
x39151
1984F
Reconstruction
brute force
,
dp
,
math
2500
x774
1984D
''a'' String Problem
brute force
,
hashing
,
implementation
,
math
,
string suffix structures
,
strings
2000
x2759
1983G
Your Loss
bitmasks
,
brute force
,
dp
,
trees
3000
x126
1983C
Have Your Cake and Eat It Too
binary search
,
brute force
,
greedy
,
implementation
1400
x9789
1982E
Number of k-good subarrays
bitmasks
,
brute force
,
combinatorics
,
divide and conquer
,
dp
,
math
,
meet-in-the-middle
2300
x1247
1982D
Beauty of the mountains
brute force
,
data structures
,
implementation
,
math
,
number theory
1700
x5830
1982B
Collatz Conjecture
brute force
,
implementation
,
math
,
number theory
1200
x14522
1981C
Turtle and an Incomplete Sequence
bitmasks
,
brute force
,
constructive algorithms
,
greedy
,
implementation
,
math
1800
x4444
1981A
Turtle and Piggy Are Playing a Game
brute force
,
greedy
,
math
800
x20250
1979F
Kostyanych's Theorem
brute force
,
constructive algorithms
,
graphs
,
interactive
2900
x243
1979D
Fixing a Binary String
bitmasks
,
brute force
,
constructive algorithms
,
dp
,
greedy
,
hashing
,
strings
1800
x5686
1979A
Guess the Maximum
brute force
,
greedy
,
implementation
800
x26671
1978E
Computing Machine
brute force
,
data structures
,
dp
,
greedy
,
implementation
2000
x3067
1977D
XORificator
bitmasks
,
brute force
,
greedy
,
hashing
2300
x1570
1977C
Nikita and LCM
brute force
,
data structures
,
dp
,
greedy
,
math
,
number theory
,
sortings
1900
x5876
1975F
Set
bitmasks
,
brute force
,
combinatorics
,
dfs and similar
,
divide and conquer
,
dp
,
math
2600
x695
1975D
Paint the Tree
brute force
,
dfs and similar
,
dp
,
greedy
,
shortest paths
,
trees
1700
x5163
1975C
Chamo and Mocha's Array
binary search
,
brute force
,
greedy
1200
x12921
1975B
378QAQ and Mocha's Array
brute force
,
greedy
,
math
,
sortings
1000
x15904
1975A
Bazoka and Mocha's Array
brute force
,
greedy
,
implementation
,
sortings
800
x17346
1974F
Cutting Game
binary search
,
brute force
,
data structures
,
implementation
,
sortings
,
two pointers
1900
x3156
1973F
Maximum GCD Sum Queries
bitmasks
,
brute force
,
dp
,
implementation
,
number theory
3100
x179
1973D
Cat, Fox and Maximum Array Split
brute force
,
interactive
,
math
2400
x1710
1973A
Chess For Three
brute force
,
dp
,
implementation
,
math
900
x22222
1972A
Contest Proposal
brute force
,
greedy
,
two pointers
800
x21342
1971F
Circle Perimeter
binary search
,
brute force
,
dfs and similar
,
geometry
,
implementation
,
math
1600
x8742
1970G2
Min-Fund Prison (Medium)
brute force
,
dfs and similar
,
dp
,
graphs
,
trees
2200
x460
1970D1
Arithmancy (Easy)
brute force
,
constructive algorithms
,
interactive
,
strings
2100
x500
1970A2
Balanced Unshuffle (Medium)
brute force
,
constructive algorithms
,
trees
2400
x383
1968G2
Division + LCP (hard version)
binary search
,
brute force
,
data structures
,
dp
,
hashing
,
math
,
string suffix structures
,
strings
2200
x1711
1968D
Permutation Game
brute force
,
dfs and similar
,
games
,
graphs
,
greedy
,
math
1300
x13614
1968A
Maximize?
brute force
,
math
,
number theory
800
x31157
1967F
Next and Prev
brute force
,
data structures
,
implementation
3200
x50
1967C
Fenwick Tree
bitmasks
,
brute force
,
combinatorics
,
data structures
,
dp
,
math
,
trees
2300
x1495
1967B2
Reverse Card (Hard Version)
brute force
,
math
,
number theory
2200
x3546
1967B1
Reverse Card (Easy Version)
brute force
,
math
,
number theory
1400
x11923
1957E
Carousel of Combinations
brute force
,
combinatorics
,
dp
,
math
,
number theory
2400
x1119
1957D
A BIT of an Inequality
bitmasks
,
brute force
,
dp
,
math
1900
x4088
1956E2
Nene vs. Monsters (Hard Version)
brute force
,
greedy
,
implementation
,
math
2700
x757
1956E1
Nene vs. Monsters (Easy Version)
brute force
,
implementation
,
math
2500
x1346
1956D
Nene and the Mex Operator
bitmasks
,
brute force
,
constructive algorithms
,
divide and conquer
,
dp
,
greedy
,
implementation
,
math
2000
x3560
1956A
Nene's Game
binary search
,
brute force
,
data structures
,
games
,
greedy
800
x20490
1955H
The Most Reckless Defense
bitmasks
,
brute force
,
constructive algorithms
,
dp
,
flows
,
graph matchings
,
shortest paths
2300
x1147
1955G
GCD on a grid
brute force
,
dfs and similar
,
dp
,
implementation
,
math
,
number theory
1900
x4023
1955E
Long Inversions
brute force
,
greedy
,
implementation
,
sortings
1700
x7904
1952J
Help, what does it mean to be "Based"
brute force
,
constructive algorithms
,
expression parsing
,
implementation
,
sortings
x726
1952F
Grid
brute force
x1695
1952C
They Have Fooled
brute force
,
schedules
x2807
1951E
No Palindromes
brute force
,
constructive algorithms
,
divide and conquer
,
greedy
,
hashing
,
implementation
,
math
,
strings
2000
x3316
1950F
0, 1, 2, Tree!
bitmasks
,
brute force
,
greedy
,
implementation
,
trees
1700
x8377
1950E
Nearly Shortest Repeating Substring
brute force
,
implementation
,
number theory
,
strings
1500
x13243
1950D
Product of Binary Decimals
brute force
,
dp
,
implementation
,
number theory
1100
x21788
1949E
Damage per Second
brute force
,
math
2900
x89
1949B
Charming Meals
binary search
,
brute force
,
greedy
,
sortings
1500
x2538
1949A
Grove
brute force
,
dfs and similar
,
dp
,
geometry
,
probabilities
3300
x96
1948G
MST with Matching
bitmasks
,
brute force
,
dsu
,
graph matchings
,
trees
3100
x657
1948E
Clique Partition
brute force
,
constructive algorithms
,
graphs
,
greedy
,
implementation
2100
x2789
1948D
Tandem Repeats?
brute force
,
strings
,
two pointers
1700
x8717
1948C
Arrow Path
brute force
,
constructive algorithms
,
dfs and similar
,
dp
,
graphs
,
shortest paths
1300
x15559
1948B
Array Fix
brute force
,
dp
,
greedy
,
implementation
1100
x21682
1948A
Special Characters
brute force
,
constructive algorithms
800
x27437
1946D
Birthday Gift
bitmasks
,
brute force
,
constructive algorithms
,
greedy
,
implementation
1900
x4350
1945H
GCD is Greater
brute force
,
data structures
,
math
,
number theory
2600
x567
1945C
Left and Right Houses
brute force
1200
x13939
1943E1
MEX Game 2 (Easy Version)
binary search
,
brute force
,
greedy
2900
x405
1943D1
Counting Is Fun (Easy Version)
brute force
,
combinatorics
,
dp
,
math
2400
x1346
1942F
Farmer John's Favorite Function
brute force
,
data structures
,
implementation
,
math
2700
x622
1941B
Rudolf and 121
brute force
,
dp
,
greedy
,
math
1000
x28035
1941A
Rudolf and the Ticket
brute force
,
math
800
x40650
1935E
Distance Learning Courses in MAC
bitmasks
,
brute force
,
data structures
,
greedy
,
math
2400
x1240
1935C
Messenger in MAC
binary search
,
brute force
,
constructive algorithms
,
data structures
,
dp
,
greedy
,
sortings
1800
x7585
1934E
Weird LCM Operations
brute force
,
constructive algorithms
,
number theory
3000
x203
1934B
Yet Another Coin Problem
brute force
,
dp
,
greedy
,
math
1200
x17723
1933G
Turtle Magic: Royal Turtle Shell Pattern
bitmasks
,
brute force
,
combinatorics
,
constructive algorithms
,
dfs and similar
,
math
2300
x915
1933C
Turtle Fingers: Count the Values of k
brute force
,
implementation
,
math
,
number theory
1100
x21601
1932C
LR-remainders
brute force
,
data structures
,
implementation
,
math
,
two pointers
1400
x14727
1931C
Make Equal Again
brute force
,
greedy
,
math
1000
x27489
1931A
Recovering a Small String
brute force
,
strings
800
x34717
1930F
Maximize the Difference
bitmasks
,
brute force
,
dfs and similar
2700
x662
1930D1
Sum over all Substrings (Easy Version)
brute force
,
dp
,
greedy
,
strings
1800
x3878
1930B
Permutation Printing
brute force
,
constructive algorithms
,
math
1000
x14387
1929F
Sasha and the Wedding Binary Search Tree
brute force
,
combinatorics
,
data structures
,
dfs and similar
,
math
,
trees
2300
x1697
1929E
Sasha and the Happy Tree Cutting
bitmasks
,
brute force
,
dfs and similar
,
dp
,
graphs
,
greedy
,
math
,
trees
2300
x1581
1929C
Sasha and the Casino
binary search
,
brute force
,
constructive algorithms
,
games
,
greedy
,
math
1400
x13960
1928E
Modular Sequence
brute force
,
constructive algorithms
,
dp
,
graphs
,
greedy
,
math
,
number theory
2300
x1609
1928D
Lonely Mountain Dungeons
brute force
,
data structures
,
greedy
,
math
,
ternary search
1900
x3974
1928C
Physical Education Lesson
brute force
,
math
,
number theory
1600
x7992
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