Enter
|
Register
Home
Top
Catalog
Contests
Gym
Problemset
Groups
Rating
Edu
API
Calendar
Help
→ Pay attention
Before contest
Codeforces Round #849 (Div. 4)
43:05:35
Register now »
→ Filter Problems
Difficulty:
—
bitmasks
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
1792D
Fixed Prefix Permutations
binary search
,
bitmasks
,
data structures
,
hashing
,
math
,
sortings
x3345
1790E
Vlad and a Pair of Numbers
bitmasks
,
constructive algorithms
x7953
1787E
The Harmonization of XOR
bitmasks
,
constructive algorithms
,
greedy
,
math
x1274
1780F
Three Chairs
bitmasks
,
brute force
,
combinatorics
,
data structures
,
dp
,
number theory
,
sortings
x759
1780D
Bit Guessing Game
binary search
,
bitmasks
,
constructive algorithms
,
interactive
x2978
1779F
Xorcerer's Stones
bitmasks
,
constructive algorithms
,
dp
,
trees
2500
x938
1778E
The Tree Has Fallen!
dfs and similar
,
math
,
trees
x175
1778C
Flexible String
bitmasks
,
brute force
,
strings
x3120
1777F
Comfortably Numb
bitmasks
,
data structures
,
divide and conquer
,
strings
,
trees
x445
1777D
Score of a Tree
bitmasks
,
combinatorics
,
dfs and similar
,
dp
,
math
,
probabilities
,
trees
x1928
1775C
Interesting Sequence
bitmasks
,
math
1600
x6609
1775B
Gardener and the Array
bitmasks
,
constructive algorithms
1300
x8949
1773G
Game of Questions
bitmasks
,
combinatorics
,
dp
,
fft
,
math
,
probabilities
2800
x181
1771F
Hossam and Range Minimum Query
binary search
,
bitmasks
,
data structures
,
hashing
,
probabilities
,
strings
,
trees
2500
x572
1770F
Koxia and Sequence
bitmasks
,
combinatorics
,
dp
,
math
,
number theory
3100
x323
1767E
Algebra Flash
bitmasks
,
brute force
,
dp
,
graphs
,
math
,
meet-in-the-middle
,
trees
2500
x532
1765A
Access Levels
bitmasks
,
dsu
,
flows
,
graph matchings
2400
x465
1763A
Absolute Maximization
bitmasks
,
constructive algorithms
,
greedy
,
math
800
x13143
1760G
SlavicG's Favorite Problem
bitmasks
,
dfs and similar
,
graphs
1700
x4655
1748F
Circular Xor Reversal
bitmasks
,
constructive algorithms
3000
x247
1748D
ConstructOR
bitmasks
,
chinese remainder theorem
,
combinatorics
,
constructive algorithms
,
math
,
number theory
2100
x2172
1747D
Yet Another Problem
binary search
,
bitmasks
,
constructive algorithms
,
data structures
1900
x3622
1743G
Antifibonacci Cut
bitmasks
,
combinatorics
,
constructive algorithms
,
data structures
,
dp
,
hashing
,
math
3000
x175
1742G
Orray
bitmasks
,
brute force
,
greedy
,
math
,
sortings
1500
x6688
1741G
Kirill and Company
bitmasks
,
brute force
,
dfs and similar
,
dp
,
flows
,
graphs
,
shortest paths
2200
x1067
1739F
Keyboard Design
bitmasks
,
data structures
,
dp
,
string suffix structures
,
strings
2600
x376
1739E
Cleaning Robot
bitmasks
,
dp
2400
x932
1734F
Zeros and Ones
bitmasks
,
divide and conquer
,
dp
,
math
2500
x576
1732C2
Sheikh (Hard Version)
binary search
,
bitmasks
,
brute force
,
greedy
,
implementation
,
two pointers
2100
x1957
1732C1
Sheikh (Easy version)
binary search
,
bitmasks
,
greedy
,
two pointers
1800
x4188
1731C
Even Subarrays
bitmasks
,
brute force
,
hashing
,
math
,
number theory
1700
x6834
1730F
Almost Sorted
bitmasks
,
data structures
,
dp
2700
x281
1728G
Illumination
binary search
,
bitmasks
,
brute force
,
combinatorics
,
dp
,
math
,
two pointers
2700
x301
1726B
Mainak and Interesting Sequence
bitmasks
,
constructive algorithms
,
math
1100
x13018
1725F
Field Photography
bitmasks
,
data structures
,
sortings
2100
x741
1725D
Deducing Sortability
binary search
,
bitmasks
,
math
2900
x88
1722G
Even-Odd XOR
bitmasks
,
constructive algorithms
,
greedy
1500
x7333
1721D
Maximum AND
bitmasks
,
dfs and similar
,
divide and conquer
,
greedy
,
sortings
1800
x4938
1720D2
Xor-Subsequence (hard version)
bitmasks
,
data structures
,
dp
,
strings
,
trees
2400
x1420
1720D1
Xor-Subsequence (easy version)
bitmasks
,
brute force
,
dp
,
strings
,
trees
,
two pointers
1800
x4741
1716E
Swap and Maximum Block
bitmasks
,
data structures
,
dfs and similar
,
divide and conquer
,
dp
2500
x810
1715D
2+ doors
2-sat
,
bitmasks
,
graphs
,
greedy
1900
x3971
1713F
Lost Array
bitmasks
,
combinatorics
,
constructive algorithms
,
dp
,
math
2900
x342
1710C
XOR Triangle
bitmasks
,
brute force
,
constructive algorithms
,
dp
,
greedy
,
math
2500
x1066
1709F
Multiset of Strings
bitmasks
,
brute force
,
dp
,
fft
,
flows
,
graphs
,
math
,
meet-in-the-middle
,
trees
2500
x445
1709E
XOR Tree
bitmasks
,
data structures
,
dfs and similar
,
dsu
,
greedy
,
trees
2400
x1669
1707F
Bugaboo
bitmasks
,
constructive algorithms
,
dp
,
number theory
3500
x89
1705F
Mark and the Online Exam
bitmasks
,
constructive algorithms
,
interactive
,
probabilities
2900
x450
1705E
Mark and Professor Koro
binary search
,
bitmasks
,
brute force
,
combinatorics
,
data structures
,
greedy
2300
x1653
1703G
Good Key, Bad Key
bitmasks
,
brute force
,
dp
,
greedy
,
math
1600
x7539
1699B
Almost Ternary Matrix
bitmasks
,
constructive algorithms
,
matrices
900
x16944
1698G
Long Binary String
bitmasks
,
math
,
matrices
,
meet-in-the-middle
,
number theory
2900
x231
1698A
XOR Mixup
bitmasks
,
brute force
800
x23647
1696A
NIT orz!
bitmasks
,
greedy
800
x16655
1689E
ANDfinity
bitmasks
,
brute force
,
constructive algorithms
,
dfs and similar
,
dsu
,
graphs
2500
x963
1688B
Patchouli's Magical Talisman
bitmasks
,
constructive algorithms
,
greedy
,
sortings
800
x16529
1688A
Cirno's Perfect Bitmasks Classroom
bitmasks
,
brute force
800
x18159
1682B
AND Sorting
bitmasks
,
constructive algorithms
,
sortings
1100
x14639
1680E
Moving Chips
bitmasks
,
dp
,
greedy
2000
x3072
1679F
Formalism for Formalism
bitmasks
,
dp
,
math
2600
x376
1679E
Typical Party in Dorm
bitmasks
,
combinatorics
,
dp
,
strings
2400
x907
1673F
Anti-Theft Road Planning
bitmasks
,
constructive algorithms
,
divide and conquer
,
greedy
,
interactive
,
math
2400
x648
1673E
Power or XOR?
bitmasks
,
combinatorics
,
math
,
number theory
2500
x551
1670F
Jee, You See?
bitmasks
,
combinatorics
,
dp
2400
x762
1670E
Hemose on the Tree
bitmasks
,
constructive algorithms
,
dfs and similar
,
trees
2200
x1411
1669H
Maximal AND
bitmasks
,
greedy
,
math
1300
x12075
1665E
MinimizOR
bitmasks
,
brute force
,
data structures
,
divide and conquer
,
greedy
,
implementation
,
two pointers
2500
x1131
1665D
GCD Guess
bitmasks
,
chinese remainder theorem
,
constructive algorithms
,
games
,
interactive
,
math
,
number theory
2000
x3036
1661B
Getting Zero
bitmasks
,
brute force
,
dfs and similar
,
dp
,
graphs
,
greedy
,
shortest paths
1300
x13958
1659E
AND-MEX Walk
bitmasks
,
brute force
,
constructive algorithms
,
dfs and similar
,
dsu
,
graphs
2200
x1169
1659B
Bit Flipping
bitmasks
,
constructive algorithms
,
greedy
,
strings
1300
x9202
1658D2
388535 (Hard Version)
bitmasks
,
brute force
,
data structures
,
math
2300
x2026
1658D1
388535 (Easy Version)
bitmasks
,
math
1600
x7560
1654F
Minimal String Xoration
bitmasks
,
data structures
,
divide and conquer
,
greedy
,
hashing
,
sortings
,
strings
2800
x786
1646C
Factorials and Powers of Two
bitmasks
,
brute force
,
constructive algorithms
,
dp
,
math
1500
x10789
1641D
Two Arrays
bitmasks
,
brute force
,
combinatorics
,
greedy
,
hashing
,
math
,
two pointers
2700
x814
1635D
Infinite Set
bitmasks
,
dp
,
math
,
matrices
,
number theory
,
strings
1800
x5048
1635A
Min Or Sum
bitmasks
,
greedy
800
x19597
1634B
Fortune Telling
bitmasks
,
math
1400
x13819
1632C
Strange Test
binary search
,
bitmasks
,
brute force
,
dp
,
math
1600
x10468
1632B
Roof Construction
bitmasks
,
constructive algorithms
1000
x18204
1630A
And Matching
bitmasks
,
constructive algorithms
1500
x12273
1625D
Binary Spiders
bitmasks
,
data structures
,
implementation
,
math
,
sortings
,
trees
2300
x1727
1625A
Ancient Civilization
bitmasks
,
greedy
,
math
800
x15995
1624G
MinOr Tree
bitmasks
,
dfs and similar
,
dsu
,
graphs
,
greedy
1900
x4471
1622E
Math Test
bitmasks
,
brute force
,
greedy
2200
x1474
1620G
Subsequences Galore
bitmasks
,
combinatorics
,
dp
2400
x723
1618F
Reverse
bitmasks
,
constructive algorithms
,
dfs and similar
,
implementation
,
math
,
strings
2000
x3447
1616H
Keep XOR Low
bitmasks
,
combinatorics
,
data structures
,
divide and conquer
,
dp
,
math
3000
x489
1615D
X(or)-mas Tree
bitmasks
,
dfs and similar
,
dsu
,
graphs
,
trees
2200
x1613
1615B
And It's Non-Zero
bitmasks
,
greedy
,
math
1300
x12946
1614C
Divan and bitwise operations
bitmasks
,
combinatorics
,
constructive algorithms
,
dp
,
math
1500
x8644
1609E
William The Oblivious
bitmasks
,
data structures
,
dp
,
matrices
2400
x1583
1605D
Treelabeling
bitmasks
,
constructive algorithms
,
dfs and similar
,
games
,
greedy
,
implementation
,
trees
2100
x2482
1601A
Array Elimination
bitmasks
,
greedy
,
math
,
number theory
1300
x10896
1600J
Robot Factory
bitmasks
,
dfs and similar
1400
x3256
1599J
Bob's Beautiful Array
bitmasks
,
brute force
,
greedy
2600
x243
1598F
RBS
binary search
,
bitmasks
,
brute force
,
data structures
,
dp
2400
x1063
1594B
Special Numbers
bitmasks
,
math
1100
x16032
1592E
Bored Bakry
bitmasks
,
greedy
,
math
,
two pointers
2400
x1352
←
1
2
3
4
5
→
User lists
Name