Sakurako, Kosuke, and the Permutation

brute force, data structures, dfs and similar, dsu, graphs, greedy, math

Genokraken

constructive algorithms, data structures, graphs, greedy, implementation, interactive, trees, two pointers

Variance Challenge

flows, graphs, greedy

Palindrome Everywhere

constructive algorithms, graphs, greedy

Cool Graph

constructive algorithms, data structures, dfs and similar, dsu, graphs, greedy, trees

Alice's Adventures in Cards

constructive algorithms, data structures, dp, graphs, greedy, implementation, ternary search

The Endspeaker (Easy Version)

binary search, dp, graphs, greedy, implementation, two pointers

Add Zeros

brute force, data structures, dfs and similar, dp, graphs, greedy

Best Subsequence

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

Choose Your Queries

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

C+K+S

constructive algorithms, dfs and similar, graphs, greedy, hashing, implementation, strings

Skipping

binary search, dp, graphs, shortest paths

Billetes MX (Hard Version)

binary search, combinatorics, data structures, dsu, graphs

Billetes MX (Easy Version)

2-sat, binary search, combinatorics, constructive algorithms, dfs and similar, dsu, graphs

Digital Village (Extreme Version)

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

Digital Village (Hard Version)

data structures, dp, dsu, graphs, math, trees

Digital Village (Easy Version)

brute force, data structures, dfs and similar, dp, dsu, fft, graphs, greedy, implementation, math, trees

Connect the Dots

brute force, dp, dsu, graphs, math, trees

Rendez-vous de Marian et Robin

dfs and similar, graphs, shortest paths

Strange Matrix

*special problem, graphs, greedy

Sakurako's Hobby

dp, dsu, graphs, math

Dora's Paint

brute force, combinatorics, constructive algorithms, graphs, implementation

Iris and Game on the Tree

constructive algorithms, dfs and similar, games, graphs, greedy, trees

Colored Portals

binary search, brute force, data structures, graphs, greedy, implementation, shortest paths

Turtle and a MEX Problem (Hard Version)

dfs and similar, dp, graphs, greedy, implementation, math

DFS Checker (Hard Version)

binary search, data structures, dfs and similar, graphs, hashing, trees

DFS Checker (Easy Version)

brute force, data structures, dfs and similar, graphs, hashing, trees

Call During the Journey

binary search, brute force, graphs, greedy, shortest paths

Determine Winning Islands in Race

data structures, dp, graphs, greedy, shortest paths

Penacony

brute force, data structures, graphs, greedy, hashing

Minecraft

bitmasks, brute force, dp, graphs, math

Stardew Valley

constructive algorithms, dfs and similar, graphs, trees

Funny Game

constructive algorithms, dsu, graphs, greedy, math, number theory, trees

Coloring Game

constructive algorithms, dfs and similar, games, graphs, greedy, interactive

Prime XOR Coloring

bitmasks, constructive algorithms, graphs, greedy, math, number theory

Simultaneous Coloring

dfs and similar, divide and conquer, graphs

Non-academic Problem

dfs and similar, graphs, trees

Maximize the Largest Component (Easy Version)

brute force, data structures, dfs and similar, dsu, graphs, implementation

Turtle and Intersected Segments

data structures, dsu, graphs, greedy

Turtle and Multiplication

constructive algorithms, dfs and similar, graphs, number theory

Yasya and the Mysterious Tree

bitmasks, data structures, dfs and similar, graphs, greedy, strings, trees

Kostyanych's Theorem

brute force, constructive algorithms, graphs, interactive

Large Graph

data structures, dfs and similar, dsu, graphs, number theory, two pointers

Tensor

constructive algorithms, graphs, interactive

Cat, Fox and Swaps

graphs, math, sortings

±1

2-sat, dfs and similar, graphs

Min-Fund Prison (Hard)

bitmasks, dfs and similar, dp, graphs, trees

Min-Fund Prison (Medium)

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

Permutation Game

brute force, dfs and similar, games, graphs, greedy, math

Long Way to be Non-decreasing

binary search, dfs and similar, graphs, implementation, shortest paths, two pointers

Equal Trees

*special problem, graphs, meet-in-the-middle

Nene and the Passing Game

constructive algorithms, data structures, dsu, graphs, sortings

Growing Trees

binary search, constructive algorithms, flows, graphs, greedy

Shuffling Songs

bitmasks, dfs and similar, dp, graphs, hashing, implementation, strings

Amanda the Amoeba

graphs, implementation, trees, two pointers

Disks

dfs and similar, geometry, graph matchings, graphs

Scooter

graphs, greedy

Clique Partition

brute force, constructive algorithms, graphs, greedy, implementation

Arrow Path

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

Destroying Bridges

graphs, greedy, math

Rudolf and Subway

constructive algorithms, dfs and similar, graphs, shortest paths

Burenka and Pether

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

Parallel Universes

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

Evidence Board

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

Pokémon Arena

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

Turtle Mission: Robot and the Earthquake

dfs and similar, dp, graphs, shortest paths

Moving Platforms

graphs, math, number theory, shortest paths

Chat Screenshots

combinatorics, dfs and similar, graphs

Sasha and the Happy Tree Cutting

bitmasks, brute force, dfs and similar, dp, graphs, greedy, math, trees

Modular Sequence

brute force, constructive algorithms, dp, graphs, greedy, math, number theory

Microcycle

data structures, dfs and similar, dsu, graphs, greedy, implementation, sortings, trees

Vlad and Trouble at MIT

dfs and similar, dp, flows, graphs, greedy, implementation, trees

Count Paths

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

Smooth Sailing (Hard Version)

binary search, data structures, dsu, geometry, graphs, trees

Smooth Sailing (Easy Version)

binary search, brute force, data structures, dfs and similar, dsu, graphs, shortest paths

Caterpillar on a Tree

dfs and similar, graphs, greedy, implementation, sortings, trees

Group Division

constructive algorithms, dfs and similar, graphs, greedy

Bicycles

graphs, greedy, implementation, shortest paths, sortings

Light Bulbs (Hard Version)

combinatorics, data structures, dfs and similar, dp, graphs, hashing

Light Bulbs (Easy Version)

brute force, combinatorics, dfs and similar, dp, dsu, graphs, math, trees

Matrix Problem

flows, graphs

Hypercatapult Commute

graphs

Lights

brute force, constructive algorithms, dfs and similar, graphs, greedy, implementation

Beautiful Tree

data structures, dfs and similar, graphs, implementation, trees

Tree Queries

data structures, dfs and similar, graphs, implementation, trees

Babysitting

2-sat, binary search, data structures, graphs, trees

Trees and XOR Queries Again

data structures, dfs and similar, divide and conquer, graphs, implementation, math, trees

Compressed Tree

dfs and similar, dp, graphs, greedy, sortings, trees

Transitive Graph

dfs and similar, dp, dsu, graphs, implementation

Alex's whims

constructive algorithms, graphs, greedy, shortest paths, trees

Infinite Card Game

binary search, brute force, data structures, dfs and similar, dp, dsu, games, graphs, greedy, sortings, two pointers

Cacti Symphony

combinatorics, dfs and similar, dp, graphs

Anonymous Informant

brute force, dfs and similar, graphs, implementation

Doremy's Swapping Trees

dfs and similar, graphs, trees

Game of Stacks

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

Good Colorings

binary search, constructive algorithms, graphs, interactive

Time Travel

binary search, graphs, shortest paths

Minimum Maximum Distance

dfs and similar, dp, graphs, shortest paths, trees

Interactive Game with Coloring

brute force, constructive algorithms, dfs and similar, graphs, implementation, interactive, trees

Indefinite Clownfish

binary search, graphs