Character Blocking

data structures, hashing, implementation

Wooden Toy Festival

binary search, greedy, sortings

Ski Resort

combinatorics, math, two pointers

Binary Cafe

bitmasks, combinatorics, math

Cipher Shifer

implementation, strings, two pointers

Decreasing Game

constructive algorithms, dfs and similar, dp, greedy, interactive

Ball Sorting

data structures, dp, sortings

Insert Zero and Invert Prefix

constructive algorithms

Lamps

greedy, sortings

The Good Array

greedy, implementation, math

Stuck Conveyor

binary search, constructive algorithms, interactive

Count Supersequences

combinatorics, dp, math

Bracket Walk

data structures, greedy, strings

No Prime Differences

constructive algorithms, math, number theory

Minimize Permutation Subarrays

constructive algorithms, math

Blackboard List

constructive algorithms, math

Editorial for Two

binary search, data structures, greedy, implementation

Playoff Fixing

combinatorics, trees

Bracket Coloring

constructive algorithms, greedy

Best Binary String

constructive algorithms, greedy

Comparison String

greedy

Grasshopper on a Line

constructive algorithms, math

Astrophysicists

greedy, math

Destroyer

implementation, sortings

Good Graph

bitmasks, dfs and similar, graph matchings, graphs, implementation

Old Mobile

combinatorics, dp, probabilities

Doctor's Brown Hypothesis

dfs and similar, graphs, math, number theory

Twin Clusters

bitmasks, brute force, constructive algorithms, math, probabilities

Lottery

binary search, brute force, greedy, math, two pointers

k-th equality

brute force, implementation, math

Typewriter

brute force, math

MEX of LCM

binary search, data structures, implementation, math, number theory

Survey in Class

brute force, data structures, greedy, implementation, sortings

Game with Reversing

games, greedy, math, strings

Maximum Strength

greedy, math

Unit Array

greedy, math

Ksyusha and Chinchilla

constructive algorithms, dfs and similar, dp, dsu, greedy, implementation, trees

Ira and Flamenco

combinatorics, constructive algorithms, data structures, implementation, math, sortings, two pointers

Round Dance

dfs and similar, dsu, graphs, shortest paths

Flipper

brute force, constructive algorithms, greedy

Vlad Building Beautiful Array

greedy, math

Restore the Weather

greedy, sortings

Musical Puzzle

implementation, strings

Zombies

binary search, dp

Combinatorics Problem

brute force, combinatorics, dp

Red-Blue Operations (Hard Version)

binary search, constructive algorithms, greedy, implementation, math

Red-Blue Operations (Easy Version)

binary search, greedy, implementation, math

Contrast Value

greedy, implementation

Maximum Sum

brute force, sortings, two pointers

New Palindrome

strings

Array merging

constructive algorithms, greedy

Twin Permutations

constructive algorithms

The Third Grace

data structures, dp

Bully Sort

data structures, math

Mex Tree

brute force, dp, trees

Hyperregular Bracket Strings

combinatorics, greedy, hashing, math, number theory, sortings

The BOSS Can Count Pairs

brute force, math

Copil Copac Draws Trees

dfs and similar, dp, graphs, trees

Don't Blame Me

bitmasks, combinatorics, dp, math

Hits Different

data structures, dp, implementation, math

Forever Winter

dfs and similar, graphs, math

The Lakes

dfs and similar, dsu, graphs, implementation

Gold Rush

brute force, dfs and similar, dp, implementation

Mr. Perfectly Fine

bitmasks, greedy, implementation

Blank Space

implementation

Love Story

implementation, strings

Permutation Swap

math, number theory

Divisible Array

constructive algorithms, math

Copium Permutation

constructive algorithms, data structures, greedy

Bus Routes

binary search, constructive algorithms, dfs and similar, greedy, trees

Two Centroids

data structures, dfs and similar, greedy, trees

Palindrome Partition

binary search, brute force, data structures, dp, hashing, strings

Range Sorting (Hard Version)

binary search, data structures, dp, greedy

Range Sorting (Easy Version)

binary search, dp, dsu, greedy, trees, two pointers

Counting Orders

combinatorics, math, sortings, two pointers

Fading into Fog

geometry, interactive, math, probabilities

Walk the Runway

bitmasks, brute force, data structures, dp, graphs, implementation, sortings

Running Miles

brute force, dp, greedy

Dreaming of Freedom

greedy, math, number theory

Lunatic Never Content

math, number theory

Trust Nobody

brute force, greedy, implementation, sortings

LuoTianyi and the Table

greedy, math

LuoTianyi and the Palindrome String

greedy, strings

LuoTianyi and Cartridge

data structures, trees

LuoTianyi and the Function

data structures

LuoTianyi and XOR-Tree

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

LuoTianyi and the Floating Islands (Hard Version)

combinatorics, dfs and similar, math, probabilities, trees

LuoTianyi and the Floating Islands (Easy Version)

combinatorics, math, probabilities, trees

LuoTianyi and the Show

greedy, implementation

Random Walk

dp, graphs, math, probabilities, trees

Removing Graph

brute force, dp, games, graphs, math

Unique Palindromes

constructive algorithms, math, strings

Strongly Composite

greedy, math, number theory

Sort with Step

brute force, math, sortings

A-characteristic

combinatorics, constructive algorithms, math

Magic Triples (Hard Version)

brute force, data structures, math, number theory

Magic Triples (Easy Version)

brute force, data structures, math, number theory

Gardening Friends

brute force, dfs and similar, dp, graphs, trees

Making Anti-Palindromes

greedy, math, strings

Super-Permutation

constructive algorithms, math