Rare Coins

combinatorics, math, probabilities

Clique Partition

brute force, constructive algorithms, graphs, greedy, implementation

Tandem Repeats?

brute force, strings, two pointers

Arrow Path

brute force, constructive algorithms, dfs and similar, dp, graphs, shortest paths

Array Fix

brute force, dp, greedy, implementation

Special Characters

brute force, constructive algorithms

Nobody is needed

2-sat, data structures, dfs and similar, dp

Girl Permutation

combinatorics, dp, math, number theory

Birthday Gift

bitmasks, brute force, constructive algorithms, greedy, implementation

Tree Cutting

binary search, dp, greedy, implementation, trees

Maximum Sum

dp, greedy, math

Median of an Array

greedy, implementation, sortings

GCD is Greater

brute force, data structures, math, number theory

Cook and Porridge

binary search, constructive algorithms, data structures, implementation

Kirill and Mushrooms

data structures, sortings

Binary Search

binary search, constructive algorithms, greedy

Seraphim the Owl

dp, greedy

Left and Right Houses

brute force

Fireworks

math, number theory

Setting up Camp

greedy, math

Equal XOR

bitmasks, constructive algorithms

Destroying Bridges

graphs, greedy, math

Minimum Hamming Distance

dp

MEX Game 2 (Hard Version)

binary search, greedy, two pointers

MEX Game 2 (Easy Version)

binary search, brute force, greedy

Counting Is Fun (Hard Version)

combinatorics, dp

Counting Is Fun (Easy Version)

brute force, combinatorics, dp, math

Tree Compass

constructive algorithms, dfs and similar, greedy, trees

Non-Palindromic Substring

hashing, implementation, math, strings

MEX Game 1

games, greedy

Farmer John's Favorite Intern

data structures, dp, flows, trees

Bessie and Cards

combinatorics, dp, math

Farmer John's Favorite Function

brute force, data structures, implementation, math

Farm Game

combinatorics, games

Learning to Paint

binary search, data structures, dfs and similar, dp, greedy, implementation, sortings

Bessie's Birthday Cake (Hard Version)

geometry, greedy, math

Bessie's Birthday Cake (Easy Version)

geometry, greedy, math

Bessie and MEX

constructive algorithms, math

Farmer John's Challenge

constructive algorithms, math

Rudolf and Subway

constructive algorithms, dfs and similar, graphs, shortest paths

Rudolf and Imbalance

binary search, greedy, sortings, two pointers

Rudolf and k Bridges

binary search, data structures, dp, two pointers

Rudolf and the Ball Game

dfs and similar, dp, implementation

Rudolf and the Ugly String

dp, greedy, strings

Rudolf and 121

brute force, dp, greedy, math

Rudolf and the Ticket

brute force, math

Almost Certainly

*special problem, constructive algorithms, data structures, sortings

Burenka and Pether

*special problem, data structures, dfs and similar, divide and conquer, dsu, graphs, sortings, trees

Three Arrays

*special problem, constructive algorithms, implementation, sortings

Parallel Universes

*special problem, constructive algorithms, dfs and similar, dsu, graphs

Big Persimmon

*special problem, dp, games

More Gifts

*special problem, dfs and similar, two pointers

Evidence Board

*special problem, constructive algorithms, dfs and similar, graphs, trees

Draw Polygon Lines

*special problem, constructive algorithms, dp, geometry, interactive

Zig-zag

XOR Operations

Tree Quiz

There and Back Again

Symmetric Boundary

Pho Restaurant

Personality Test

Forming Groups

Duplicates

Bánh Bò

Bit Counting Sequence

Attraction Score

Antiparticle Antiphysics

Binary Path

dp, greedy, implementation

Shuffle Party

implementation, math

Grand Finale: Circles

binary search, geometry

Yet Yet Another Permutation Problem

divide and conquer, fft, math

Bitwise Paradox

binary search, bitmasks, data structures, greedy, two pointers

Pokémon Arena

data structures, graphs, greedy, implementation, shortest paths, sortings

Pinball

binary search, data structures, implementation, math, two pointers

Bitwise Operation Wizard

bitmasks, constructive algorithms, greedy, interactive, math

Andrey's Tree

binary search, constructive algorithms, data structures, dfs and similar, dsu, greedy, implementation, trees

Distance Learning Courses in MAC

bitmasks, brute force, data structures, greedy, math

Exam in MAC

binary search, combinatorics, implementation, math

Messenger in MAC

binary search, brute force, constructive algorithms, data structures, dp, greedy, sortings

Informatics in MAC

constructive algorithms

Entertainment in MAC

constructive algorithms, strings

Weird LCM Operations

brute force, constructive algorithms, number theory

XOR Break --- Game Version

bitmasks, games, greedy, interactive

XOR Break --- Solo Version

bitmasks, constructive algorithms, greedy

Find a Mine

binary search, constructive algorithms, geometry, greedy, interactive, math

Yet Another Coin Problem

brute force, dp, greedy, math

Too Min Too Max

greedy, math

Turtle Magic: Royal Turtle Shell Pattern

bitmasks, brute force, combinatorics, constructive algorithms, dfs and similar, math

Turtle Mission: Robot and the Earthquake

dfs and similar, dp, graphs, shortest paths

Turtle vs. Rabbit Race: Optimal Trainings

binary search, implementation, math, ternary search

Turtle Tenacity: Continual Mods

constructive algorithms, greedy, math, number theory, sortings

Turtle Fingers: Count the Values of k

brute force, implementation, math, number theory

Turtle Math: Fast Three Task

implementation, math, number theory

Turtle Puzzle: Rearrange and Negate

greedy, math, sortings

Moving Platforms

graphs, math, number theory, shortest paths

Feed Cats

data structures, dp, sortings

Final Countdown

implementation, math, number theory

Card Game

greedy, implementation

LR-remainders

brute force, data structures, implementation, math, two pointers

Chaya Calendar

number theory