Gardener and the Array

bitmasks, constructive algorithms

Game of Questions

bitmasks, combinatorics, dp, fft, math, probabilities

Hossam and Range Minimum Query

binary search, bitmasks, data structures, hashing, probabilities, strings, trees

Koxia and Sequence

bitmasks, combinatorics, dp, math, number theory

Algebra Flash

bitmasks, brute force, dp, graphs, math, meet-in-the-middle, trees

Access Levels

bitmasks, dsu, flows, graph matchings

Absolute Maximization

bitmasks, constructive algorithms, greedy, math

SlavicG's Favorite Problem

bitmasks, dfs and similar, graphs

Circular Xor Reversal

bitmasks, constructive algorithms

ConstructOR

bitmasks, chinese remainder theorem, combinatorics, constructive algorithms, math, number theory

Yet Another Problem

binary search, bitmasks, constructive algorithms, data structures

Antifibonacci Cut

bitmasks, combinatorics, constructive algorithms, data structures, dp, hashing, math

Orray

bitmasks, brute force, greedy, math, sortings

Kirill and Company

bitmasks, brute force, dfs and similar, dp, flows, graphs, shortest paths

Keyboard Design

bitmasks, data structures, dp, string suffix structures, strings

Cleaning Robot

bitmasks, dp

Zeros and Ones

bitmasks, divide and conquer, dp, math

Sheikh (Hard Version)

binary search, bitmasks, brute force, greedy, implementation, two pointers

Sheikh (Easy version)

binary search, bitmasks, greedy, two pointers

Even Subarrays

bitmasks, brute force, hashing, math, number theory

Almost Sorted

bitmasks, data structures, dp

Illumination

binary search, bitmasks, brute force, combinatorics, dp, math, two pointers

Mainak and Interesting Sequence

bitmasks, constructive algorithms, math

Field Photography

bitmasks, data structures, sortings

Deducing Sortability

binary search, bitmasks, math

Even-Odd XOR

bitmasks, constructive algorithms, greedy

Maximum AND

bitmasks, dfs and similar, divide and conquer, greedy, sortings

Xor-Subsequence (hard version)

bitmasks, data structures, dp, strings, trees

Xor-Subsequence (easy version)

bitmasks, brute force, dp, strings, trees, two pointers

Swap and Maximum Block

bitmasks, data structures, dfs and similar, divide and conquer, dp

2+ doors

2-sat, bitmasks, graphs, greedy

Lost Array

bitmasks, combinatorics, constructive algorithms, dp, math

XOR Triangle

bitmasks, brute force, constructive algorithms, dp, greedy, math

Multiset of Strings

bitmasks, brute force, dp, fft, flows, graphs, math, meet-in-the-middle, trees

XOR Tree

bitmasks, data structures, dfs and similar, dsu, greedy, trees

Bugaboo

bitmasks, constructive algorithms, dp, number theory

Mark and the Online Exam

bitmasks, constructive algorithms, interactive, probabilities

Mark and Professor Koro

binary search, bitmasks, brute force, combinatorics, data structures, greedy

Good Key, Bad Key

bitmasks, brute force, dp, greedy, math

Almost Ternary Matrix

bitmasks, constructive algorithms, matrices

Long Binary String

bitmasks, math, matrices, meet-in-the-middle, number theory

XOR Mixup

bitmasks, brute force

NIT orz!

bitmasks, greedy

ANDfinity

bitmasks, brute force, constructive algorithms, dfs and similar, dsu, graphs

Patchouli's Magical Talisman

bitmasks, constructive algorithms, greedy, sortings

Cirno's Perfect Bitmasks Classroom

bitmasks, brute force

AND Sorting

bitmasks, constructive algorithms, sortings

Moving Chips

bitmasks, dp, greedy

Formalism for Formalism

bitmasks, dp, math

Typical Party in Dorm

bitmasks, combinatorics, dp, strings

Anti-Theft Road Planning

bitmasks, constructive algorithms, divide and conquer, greedy, interactive, math

Power or XOR?

bitmasks, combinatorics, math, number theory

Jee, You See?

bitmasks, combinatorics, dp

Hemose on the Tree

bitmasks, constructive algorithms, dfs and similar, trees

Maximal AND

bitmasks, greedy, math

MinimizOR

bitmasks, brute force, data structures, divide and conquer, greedy, implementation, two pointers

GCD Guess

bitmasks, chinese remainder theorem, constructive algorithms, games, interactive, math, number theory

Getting Zero

bitmasks, brute force, dfs and similar, dp, graphs, greedy, shortest paths

AND-MEX Walk

bitmasks, brute force, constructive algorithms, dfs and similar, dsu, graphs

Bit Flipping

bitmasks, constructive algorithms, greedy, strings

388535 (Hard Version)

bitmasks, brute force, data structures, math

388535 (Easy Version)

bitmasks, math

Minimal String Xoration

bitmasks, data structures, divide and conquer, greedy, hashing, sortings, strings

Factorials and Powers of Two

bitmasks, brute force, constructive algorithms, dp, math

Two Arrays

bitmasks, brute force, combinatorics, greedy, hashing, math, two pointers

Infinite Set

bitmasks, dp, math, matrices, number theory, strings

Min Or Sum

bitmasks, greedy

Fortune Telling

bitmasks, math

Strange Test

binary search, bitmasks, brute force, dp, math

Roof Construction

bitmasks, constructive algorithms

And Matching

bitmasks, constructive algorithms

Binary Spiders

bitmasks, data structures, implementation, math, sortings, trees

Ancient Civilization

bitmasks, greedy, math

MinOr Tree

bitmasks, dfs and similar, dsu, graphs, greedy

Math Test

bitmasks, brute force, greedy

Subsequences Galore

bitmasks, combinatorics, dp

Reverse

bitmasks, constructive algorithms, dfs and similar, implementation, math, strings

Keep XOR Low

bitmasks, combinatorics, data structures, divide and conquer, dp, math

X(or)-mas Tree

bitmasks, dfs and similar, dsu, graphs, trees

And It's Non-Zero

bitmasks, greedy, math

Divan and bitwise operations

bitmasks, combinatorics, constructive algorithms, dp, math

William The Oblivious

bitmasks, data structures, dp, matrices

Treelabeling

bitmasks, constructive algorithms, dfs and similar, games, greedy, implementation, trees

Array Elimination

bitmasks, greedy, math, number theory

Robot Factory

bitmasks, dfs and similar

Bob's Beautiful Array

bitmasks, brute force, greedy

RBS

binary search, bitmasks, brute force, data structures, dp

Special Numbers

bitmasks, math

Bored Bakry

bitmasks, greedy, math, two pointers

Bakry and Partitioning

bitmasks, constructive algorithms, dfs and similar, dp, graphs, trees

Strange LCS

bitmasks, dp, graphs, greedy, strings

Defender of Childhood Dreams

bitmasks, constructive algorithms, divide and conquer

Korney Korneevich and XOR (easy version)

bitmasks, dp, greedy

Fix the String

*special problem, bitmasks, dp, greedy

Playoff Restoration

bitmasks, brute force, hashing, implementation, meet-in-the-middle

Carrying Conundrum

bitmasks, combinatorics, dp, math

MEXor Mixup

bitmasks, greedy

MAX-MEX Cut

bitmasks, constructive algorithms, dp, greedy

MIN-MEX Cut

bitmasks, constructive algorithms, dp, greedy

Nearest Beautiful Number (hard version)

bitmasks, brute force, constructive algorithms, dfs and similar, dp, greedy