Density of subarrays

dp, math

Strange device

binary search, interactive, math, trees

Winding polygonal line

constructive algorithms, geometry, greedy, math

Permutation recovery

constructive algorithms, data structures, dfs and similar, graphs, greedy, math, sortings

The minimal unique substring

constructive algorithms, math, strings

The Party and Sweets

binary search, constructive algorithms, greedy, implementation, math, sortings, two pointers

Inverse of Rows and Columns

brute force, constructive algorithms

Maximum Balanced Circle

constructive algorithms, dp, greedy, two pointers

Minimum Array

binary search, data structures, greedy

N Problems During K Days

constructive algorithms, greedy, math

Increasing Subsequence (hard version)

greedy

Increasing Subsequence (easy version)

greedy

Long Number

greedy

Reachable Numbers

implementation

Optimizer

graphs, greedy, hashing, implementation

Card Bag

dp, math, probabilities

Special Segments of Permutation

data structures, divide and conquer, dsu, two pointers

0-1-Tree

dfs and similar, divide and conquer, dp, dsu, trees

Match Points

binary search, greedy, sortings, ternary search, two pointers

Ugly Pairs

dfs and similar, greedy, implementation, sortings, strings

Inscribed Figures

geometry

Delivery Oligopoly

brute force, dp, graphs

Guess the Root

brute force, interactive, math

Beautiful Array

brute force, data structures, divide and conquer, dp, greedy

Alarm Clocks Everywhere

math, number theory

Game with Telephone Numbers

games, greedy, implementation

Reverse a Substring

implementation, sortings, strings

Minimum Possible LCM

brute force, greedy, math, number theory

Shovels Shop

dp, greedy, sortings

Two Teams

data structures, implementation, sortings

Walking Robot

greedy

Gourmet Cat

implementation, math

Make Them Equal

math

Restoring Three Numbers

math

Serval and Bonus Problem

combinatorics, dp, math, probabilities

Serval and Snake

binary search, brute force, interactive

Serval and Rooted Tree

binary search, dfs and similar, dp, greedy, trees

Serval and Parenthesis Sequence

greedy, strings

Serval and Toy Bricks

constructive algorithms, greedy

Serval and Bus

brute force, math

Neko Rules the Catniverse (Large Version)

bitmasks, dp, matrices

Neko Rules the Catniverse (Small Version)

bitmasks, dp, matrices

Neko and Flashback

constructive algorithms, dfs and similar, graphs

Neko and Aki's Prank

dp, greedy, trees

Neko does Maths

brute force, math, number theory

Neko Performs Cat Furrier Transform

bitmasks, constructive algorithms, dfs and similar, math

Neko Finds Grapes

greedy, implementation, math

Sonya and Informatics

combinatorics, dp, matrices, probabilities

Number of Components

combinatorics, data structures, dp, math

Stas and the Queue at the Buffet

greedy, math, sortings

Problem for Nazar

constructive algorithms, math

Dima and a Bad XOR

bitmasks, brute force, constructive algorithms, dp

Maxim and Biology

brute force, strings

Tiling Challenge

greedy, implementation

Stock Arbitraging

greedy, implementation

Election Promises

games, graphs

Abandoning Roads

brute force, dp, graphs, greedy

Tree Generator™

data structures, implementation, trees

Three Religions

dp, implementation, strings

Prefix Sum Primes

constructive algorithms, greedy, math, number theory

Holy Diver

data structures

Gold Experience

constructive algorithms, graphs, math, number theory, probabilities

Foo Fighters

bitmasks, constructive algorithms

Earth Wind and Fire

constructive algorithms, greedy, math, sortings, two pointers

Dirty Deeds Done Dirt Cheap

greedy, sortings

Crazy Diamond

constructive algorithms, sortings

Born This Way

binary search, brute force, two pointers

Another One Bites The Dust

greedy

Zigzag Game

games, interactive

Rainbow Coins

interactive

Palindrome XOR

dfs and similar, graphs

Thanos Nim

games

Chladni Figure

brute force, strings

Hide and Seek

graphs

Satanic Panic

dp, geometry

Zoning Restrictions

dp, flows, graphs

Leaf Partition

dp, trees

Hot is Cold

bitmasks, data structures, divide and conquer, implementation

Frog Jumping

dfs and similar, math, number theory

Tree Diameter

bitmasks, graphs, interactive

Hate "A"

implementation, strings

Love "A"

implementation, strings

AI Takeover

interactive

Neat Words

Fourier Doodles

Pigeon d'Or

implementation

Mystery Circuit

bitmasks, brute force

Kanban Numbers

brute force

Thanos Sort

implementation

Two Merged Sequences

dp, greedy

Graph Without Long Directed Paths

dfs and similar, graphs

Median String

bitmasks, math, number theory, strings

Equalize Them All

constructive algorithms, greedy

Two Shuffled Sequences

constructive algorithms, sortings

Parity Alternated Deletions

greedy, implementation, sortings

Diverse Strings

implementation, strings

Queen

dfs and similar, trees

Nirvana

brute force, math, number theory

The Doors

implementation

Pink Floyd

graphs, interactive