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Educational Codeforces Round 166 (Rated for Div. 2)
31:36:45
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Difficulty:
—
math
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
1845D
Rating System
binary search
,
brute force
,
data structures
,
dp
,
dsu
,
greedy
,
math
,
two pointers
1800
x7384
1845B
Come Together
geometry
,
implementation
,
math
900
x20974
1845A
Forbidden Integer
constructive algorithms
,
implementation
,
math
,
number theory
800
x24876
1844H
Multiple of Three Cycles
combinatorics
,
data structures
,
dp
,
dsu
,
math
3400
x132
1844G
Tree Weights
bitmasks
,
constructive algorithms
,
data structures
,
dfs and similar
,
implementation
,
math
,
matrices
,
number theory
,
trees
3000
x654
1844F2
Min Cost Permutation (Hard Version)
binary search
,
constructive algorithms
,
data structures
,
greedy
,
math
,
sortings
2800
x370
1844F1
Min Cost Permutation (Easy Version)
brute force
,
constructive algorithms
,
greedy
,
math
2600
x740
1844D
Row Major
constructive algorithms
,
greedy
,
math
,
number theory
,
strings
1400
x11711
1844C
Particles
dp
,
greedy
,
implementation
,
math
1300
x14969
1844B
Permutations & Primes
constructive algorithms
,
math
1000
x17573
1843F2
Omsk Metro (hard version)
data structures
,
dfs and similar
,
divide and conquer
,
dp
,
math
,
trees
2300
x1487
1843F1
Omsk Metro (simple version)
data structures
,
dfs and similar
,
dp
,
graphs
,
greedy
,
math
,
trees
1800
x5024
1843D
Apple Tree
combinatorics
,
dfs and similar
,
dp
,
math
,
trees
1200
x17149
1843C
Sum in Binary Tree
bitmasks
,
combinatorics
,
math
,
trees
800
x31316
1843B
Long Long
greedy
,
math
,
two pointers
800
x28170
1842H
Tenzing and Random Real Numbers
bitmasks
,
dp
,
graphs
,
math
,
probabilities
3000
x567
1842G
Tenzing and Random Operations
combinatorics
,
dp
,
math
,
probabilities
2800
x931
1842E
Tenzing and Triangle
data structures
,
dp
,
geometry
,
greedy
,
math
2300
x1547
1842B
Tenzing and Books
bitmasks
,
greedy
,
math
1100
x15852
1842A
Tenzing and Tsondu
games
,
math
800
x19529
1841E
Fill the Matrix
data structures
,
greedy
,
math
2200
x1897
1841C
Ranom Numbers
brute force
,
dp
,
greedy
,
math
,
strings
1800
x7359
1840G2
In Search of Truth (Hard Version)
constructive algorithms
,
interactive
,
math
,
meet-in-the-middle
,
probabilities
2500
x905
1840G1
In Search of Truth (Easy Version)
constructive algorithms
,
interactive
,
math
,
meet-in-the-middle
,
probabilities
2200
x2247
1840C
Ski Resort
combinatorics
,
math
,
two pointers
1000
x24969
1840B
Binary Cafe
bitmasks
,
combinatorics
,
math
1100
x21620
1839A
The Good Array
greedy
,
implementation
,
math
800
x17130
1838E
Count Supersequences
combinatorics
,
dp
,
math
2500
x1380
1838C
No Prime Differences
constructive algorithms
,
math
,
number theory
1400
x13580
1838B
Minimize Permutation Subarrays
constructive algorithms
,
math
1100
x15882
1838A
Blackboard List
constructive algorithms
,
math
800
x21118
1837A
Grasshopper on a Line
constructive algorithms
,
math
800
x29515
1836B
Astrophysicists
greedy
,
math
1100
x12311
1835D
Doctor's Brown Hypothesis
dfs and similar
,
graphs
,
math
,
number theory
2900
x451
1835C
Twin Clusters
bitmasks
,
brute force
,
constructive algorithms
,
math
,
probabilities
2600
x945
1835B
Lottery
binary search
,
brute force
,
greedy
,
math
,
two pointers
2500
x908
1835A
k-th equality
brute force
,
implementation
,
math
1700
x7496
1834F
Typewriter
brute force
,
math
2500
x491
1834E
MEX of LCM
binary search
,
data structures
,
implementation
,
math
,
number theory
2300
x2084
1834C
Game with Reversing
games
,
greedy
,
math
,
strings
1200
x12712
1834B
Maximum Strength
greedy
,
math
1000
x14612
1834A
Unit Array
greedy
,
math
800
x21642
1833F
Ira and Flamenco
combinatorics
,
constructive algorithms
,
data structures
,
implementation
,
math
,
sortings
,
two pointers
1700
x6808
1833C
Vlad Building Beautiful Array
greedy
,
math
800
x25588
1832D2
Red-Blue Operations (Hard Version)
binary search
,
constructive algorithms
,
greedy
,
implementation
,
math
2400
x1805
1832D1
Red-Blue Operations (Easy Version)
binary search
,
greedy
,
implementation
,
math
2100
x2809
1830E
Bully Sort
data structures
,
math
3500
x231
1830C
Hyperregular Bracket Strings
combinatorics
,
greedy
,
hashing
,
math
,
number theory
,
sortings
2400
x1541
1830B
The BOSS Can Count Pairs
brute force
,
math
2000
x4624
1829H
Don't Blame Me
bitmasks
,
combinatorics
,
dp
,
math
1700
x7155
1829G
Hits Different
data structures
,
dp
,
implementation
,
math
1600
x9528
1829F
Forever Winter
dfs and similar
,
graphs
,
math
1300
x16325
1828B
Permutation Swap
math
,
number theory
900
x20936
1828A
Divisible Array
constructive algorithms
,
math
800
x23085
1827A
Counting Orders
combinatorics
,
math
,
sortings
,
two pointers
1100
x17622
1826F
Fading into Fog
geometry
,
interactive
,
math
,
probabilities
2800
x339
1826C
Dreaming of Freedom
greedy
,
math
,
number theory
1300
x12892
1826B
Lunatic Never Content
math
,
number theory
1100
x15993
1825B
LuoTianyi and the Table
greedy
,
math
1000
x14247
1824B2
LuoTianyi and the Floating Islands (Hard Version)
combinatorics
,
dfs and similar
,
math
,
probabilities
,
trees
2300
x2506
1824B1
LuoTianyi and the Floating Islands (Easy Version)
combinatorics
,
math
,
probabilities
,
trees
1800
x4362
1823F
Random Walk
dp
,
graphs
,
math
,
probabilities
,
trees
2600
x797
1823E
Removing Graph
brute force
,
dp
,
games
,
graphs
,
math
2500
x1201
1823D
Unique Palindromes
constructive algorithms
,
math
,
strings
1900
x3672
1823C
Strongly Composite
greedy
,
math
,
number theory
1300
x11743
1823B
Sort with Step
brute force
,
math
,
sortings
900
x15396
1823A
A-characteristic
combinatorics
,
constructive algorithms
,
math
800
x15845
1822G2
Magic Triples (Hard Version)
brute force
,
data structures
,
math
,
number theory
2200
x2327
1822G1
Magic Triples (Easy Version)
brute force
,
data structures
,
math
,
number theory
1700
x6566
1822E
Making Anti-Palindromes
greedy
,
math
,
strings
1600
x9787
1822D
Super-Permutation
constructive algorithms
,
math
1200
x16007
1822C
Bun Lover
math
800
x22390
1822B
Karina and Array
greedy
,
math
,
sortings
800
x24152
1821F
Timber
combinatorics
,
dp
,
fft
,
math
2600
x713
1821D
Black Cells
binary search
,
brute force
,
greedy
,
math
1900
x4785
1821C
Tear It Apart
brute force
,
implementation
,
math
,
strings
1300
x13688
1821A
Matching
combinatorics
,
math
800
x19416
1820B
JoJo's Incredible Adventures
math
,
strings
,
two pointers
1100
x13531
1819E
Roads in E City
interactive
,
math
,
probabilities
,
trees
3200
x247
1819C
The Fox and the Complete Tree Traversal
constructive algorithms
,
dp
,
implementation
,
math
,
trees
2400
x1405
1817C
Similar Polynomials
combinatorics
,
math
2400
x931
1815F
OH NO1 (-2-3-4)
constructive algorithms
,
graphs
,
math
3500
x214
1815E
Bosco and Particle
dp
,
math
,
number theory
,
strings
3100
x329
1815D
XOR Counting
bitmasks
,
combinatorics
,
dp
,
math
2600
x1059
1815A
Ian and Array Sorting
greedy
,
math
1300
x13544
1814D
Balancing Weapons
binary search
,
brute force
,
data structures
,
math
,
two pointers
2500
x825
1814B
Long Legs
brute force
,
math
1700
x9599
1814A
Coins
implementation
,
math
800
x26042
1812E
Not a Geometry Problem
*special problem
,
*special problem
,
constructive algorithms
,
geometry
,
math
x3953
1812D
Trivial Conjecture
*special problem
,
constructive algorithms
,
math
,
number theory
x4345
1811G2
Vlad and the Nice Paths (hard version)
binary search
,
combinatorics
,
data structures
,
dp
,
math
,
two pointers
2200
x1636
1811G1
Vlad and the Nice Paths (easy version)
combinatorics
,
dp
,
math
2100
x1930
1811E
Living Sequence
binary search
,
dp
,
math
,
number theory
1500
x11656
1811D
Umka and a Long Flight
constructive algorithms
,
implementation
,
math
1600
x7096
1811B
Conveyor Belts
implementation
,
math
1000
x19795
1811A
Insert Digit
greedy
,
math
,
strings
800
x30172
1810H
Last Number
combinatorics
,
math
2900
x131
1810F
M-tree
data structures
,
math
,
sortings
,
trees
2800
x545
1810D
Climbing the Tree
binary search
,
math
1700
x7150
1810B
Candies
constructive algorithms
,
math
,
number theory
800
x17200
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