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, 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

Anji's Binary Tree

dfs and similar, dp, trees

Unusual Entertainment

data structures, dfs and similar, dsu, shortest paths, sortings, trees, two pointers

Vova Escapes the Matrix

brute force, dfs and similar, divide and conquer, shortest paths

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

A Growing Tree

data structures, dfs and similar, trees

Doremy's Swapping Trees

dfs and similar, graphs, trees

Game of Stacks

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

Tree XOR

bitmasks, dfs and similar, dp, greedy, trees

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

wxhtzdy ORO Tree

binary search, bitmasks, brute force, data structures, dfs and similar, implementation, trees

Lexichromatography

combinatorics, dfs and similar, dsu, graphs, two pointers

Autosynthesis

constructive algorithms, dfs and similar, graphs, greedy, sortings

Jellyfish and Math

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

Mad City

dfs and similar, dsu, games, graphs, shortest paths, trees

Selling a Menagerie

dfs and similar, dsu, graphs, implementation, math

Most Different Tree

brute force, constructive algorithms, dfs and similar, greedy, hashing

Cyclic Operations

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

Completely Searching for Inversions

dfs and similar, dp, graphs

Speedrun

brute force, dfs and similar, dp, graphs, greedy, math, sortings, two pointers

Queries for the Array

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

Fast Travel Text Editor

data structures, dfs and similar, graphs, shortest paths

Teleportation in Byteland

data structures, dfs and similar, divide and conquer, graphs, shortest paths, trees

Rollbacks (Easy Version)

brute force, data structures, dfs and similar, trees

PermuTree (hard version)

bitmasks, dfs and similar, dp, fft, greedy, implementation, math, trees

PermuTree (easy version)

dfs and similar, dp, trees

Nastya and Potions

dfs and similar, dp, graphs, sortings

The Third Letter

dfs and similar, dsu, graphs, greedy, implementation

The Boss's Identity

binary search, bitmasks, data structures, dfs and similar, greedy, math, sortings

Tree Weights

bitmasks, constructive algorithms, data structures, dfs and similar, implementation, math, matrices, number theory, trees

Great Grids

2-sat, constructive algorithms, dfs and similar, dsu, graphs

Omsk Metro (hard version)

data structures, dfs and similar, divide and conquer, dp, math, trees

Omsk Metro (simple version)

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

Apple Tree

combinatorics, dfs and similar, dp, math, trees

Tenzing and Tree

dfs and similar, greedy, shortest paths, sortings, trees

Railguns

brute force, dfs and similar, dp, graphs

Decreasing Game

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

Good Graph

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

Doctor's Brown Hypothesis

dfs and similar, graphs, math, number theory

Ksyusha and Chinchilla

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

Round Dance

dfs and similar, dsu, graphs, shortest paths

Copil Copac Draws Trees

dfs and similar, dp, graphs, trees

Forever Winter

dfs and similar, graphs, math

The Lakes

dfs and similar, dsu, graphs, implementation

Gold Rush

brute force, dfs and similar, dp, implementation

Bus Routes

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

Two Centroids

data structures, dfs and similar, greedy, trees

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

Gardening Friends

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

Fish Graph

brute force, constructive algorithms, dfs and similar, graphs

Between

constructive algorithms, dfs and similar, graphs, greedy

Is It Flower?

dfs and similar, graphs, implementation

Monsters

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

Bouncy Ball

brute force, dfs and similar, implementation

Tree Master

brute force, data structures, dfs and similar, trees

There Should Be a Lot of Maximums

brute force, data structures, dfs and similar, dp, trees, two pointers

A Wide, Wide Graph

dfs and similar, dp, graphs, greedy, trees

Routing

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

Symmetree

dfs and similar, hashing, implementation, trees

Unforgivable Curse (hard version)

brute force, constructive algorithms, dfs and similar, dsu, graphs, greedy, strings

Tree Cutting

bitmasks, dfs and similar, dp

City Union

constructive algorithms, dfs and similar, dsu, geometry, greedy, implementation, math

Li Hua and Path

data structures, dfs and similar, divide and conquer, dsu, trees

Li Hua and Tree

brute force, data structures, dfs and similar, dp, implementation, trees

Colored Subgraphs

dfs and similar, dp, games, greedy, trees

Removal Sequences

bitmasks, dfs and similar, graphs

Blocking Chips

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

Divisors and Table

brute force, dfs and similar, dp, number theory

Tokens on Graph

constructive algorithms, dfs and similar, graphs, shortest paths

Timofey and Black-White Tree

brute force, dfs and similar, divide and conquer, graphs, greedy, math, shortest paths, trees

XOR, Tree, and Queries

bitmasks, constructive algorithms, dfs and similar, dsu, graphs, greedy, implementation, trees

Sum Over Zero

data structures, dfs and similar, dp

Game on Axis

combinatorics, dfs and similar, dsu, graphs, implementation

Double Sort II

dfs and similar, flows, graph matchings, graphs

Maximizing Root

dfs and similar, dp, graphs, math, number theory, trees

The Tree Has Fallen!

bitmasks, dfs and similar, math, trees

Edge Reverse

binary search, dfs and similar, graphs, trees

Score of a Tree

bitmasks, combinatorics, dfs and similar, dp, math, probabilities, trees

Friendly Spiders

dfs and similar, graphs, math, number theory, shortest paths

Two Chess Pieces

dfs and similar, dp, greedy, trees

Copy of a Copy of a Copy

constructive algorithms, dfs and similar, graphs, implementation, sortings

Hossam and (sub-)palindromic tree

brute force, data structures, dfs and similar, dp, strings, trees

Koxia and Tree

combinatorics, dfs and similar, dp, dsu, math, probabilities, trees

Koxia and Game

constructive algorithms, data structures, dfs and similar, dsu, flows, games, graph matchings, graphs, implementation

Lucky Permutation

constructive algorithms, dfs and similar, graphs, greedy

Doremy's Experimental Tree

brute force, constructive algorithms, dfs and similar, dsu, sortings, trees

Edge Queries

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

Set Construction

constructive algorithms, dfs and similar, graphs, greedy

SlavicG's Favorite Problem

bitmasks, dfs and similar, graphs

Tick, Tock

combinatorics, dfs and similar, dsu, graphs

The Beach

constructive algorithms, dfs and similar, graphs, shortest paths