Spiderweb Trees

dp, geometry, trees

Assigning Fares

dp, trees

LuoTianyi and Cartridge

data structures, trees

Centroid Guess

interactive, probabilities, trees

Dušan's Railway

divide and conquer, graphs, trees

Trains and Airplanes

dfs and similar, graphs, shortest paths, trees

Finding the Vertex

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

Red Blue Tree

data structures, implementation, trees

Alphabetic Tree

binary search, data structures, dfs and similar, hashing, string suffix structures, strings, trees

Lost Nodes

constructive algorithms, dp, graphs, interactive, sortings, trees

Journey

data structures, divide and conquer, graphs, trees

Euler tour

constructive algorithms, trees

Cheat and Win

bitmasks, data structures, games, trees

Range Diameter Sum

data structures, trees

Communism

bitmasks, dp, trees

My Beautiful Madness

data structures, trees

Pisces

data structures, flows, trees

Upside Down

data structures, string suffix structures, strings, trees

Rap God

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

Strange device

binary search, interactive, math, trees

Bus Routes

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

Iqea

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

Ember and Storm's Tree Game

combinatorics, dp, games, trees

Tree

fft, graphs, trees

Island Puzzle

dfs and similar, dsu, graphs, trees

Exam

data structures, string suffix structures, trees

Recover the Tree

constructive algorithms, trees

Can Bash Save the Day?

data structures, divide and conquer, graphs, trees

Matches Are Not a Child's Play

data structures, trees

Niyaz and Small Degrees

data structures, dp, trees

Yuezheng Ling and Dynamic Tree

data structures, trees

MEX Tree Manipulation

data structures, trees

Harry Vs Voldemort

dfs and similar, dp, graphs, trees

Squares

constructive algorithms, data structures, dp, graphs, trees

Permutation for Burenka

data structures, graph matchings, greedy, math, trees

Send Tree to Charlie

combinatorics, dfs and similar, dsu, trees

Iron Man

data structures, geometry, trees

Omkar and Tours

data structures, divide and conquer, sortings, trees

Bear and Chemistry

data structures, dfs and similar, graphs, trees

Cow and Vacation

dfs and similar, dsu, trees

Spiders Evil Plan

greedy, trees

Tree of Life (hard)

trees

Public Service

constructive algorithms, graphs, trees

An easy problem about trees

dp, games, greedy, trees

New Year Running

number theory, trees

Verifying Kingdom

binary search, divide and conquer, interactive, trees

Roads in E City

interactive, math, probabilities, trees

ELCA

data structures, trees

Diverse Coloring

constructive algorithms, trees

Boring Card Game

data structures, greedy, trees

Ants

2-sat, data structures, trees

Triameter

binary search, data structures, dfs and similar, trees

Sasha and Algorithm of Silence's Sounds

data structures, trees

Segment Covering

brute force, combinatorics, constructive algorithms, data structures, dp, trees

Distance Matching

constructive algorithms, dfs and similar, trees

New Year and Social Network

data structures, graph matchings, graphs, math, trees

Shifting Dominoes

data structures, geometry, graphs, trees

Raining season

data structures, divide and conquer, trees

Air Reform

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

Reunion

combinatorics, dp, trees

In a Trap

trees

Mirror Box

matrices, trees

Restoring Map

bitmasks, constructive algorithms, trees

Clockwork Bomb

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

ALT

data structures, flows, graphs, trees

Tourists

data structures, dfs and similar, graphs, trees

Road Repair in Treeland

*special problem, binary search, dp, trees

Two Subtrees

data structures, trees

Sloth

dfs and similar, dp, graph matchings, trees

Perpetual Motion Machine

constructive algorithms, dp, graphs, implementation, math, trees

Santa's Gift

data structures, trees

Train Tracks

data structures, trees

Mashtali vs AtCoder

games, trees

Squid Game

data structures, dfs and similar, greedy, trees

Tree Calendar

brute force, constructive algorithms, data structures, dfs and similar, sortings, trees

Tavas on the Path

data structures, divide and conquer, trees

AB Tree

dp, greedy, trees

Legendary Tree

binary search, interactive, trees

String Transformation 2

bitmasks, dp, graphs, trees

Tree-Tac-Toe

constructive algorithms, games, trees

Campus

binary search, data structures, dsu, trees

Groceries in Meteor Town

binary search, data structures, dsu, trees

Surprise me!

divide and conquer, math, number theory, trees

Archaeology

data structures, dfs and similar, trees

Tree and Table

dfs and similar, dp, implementation, trees

Escaping on Beaveractor

data structures, implementation, trees

Tree and Permutation Game

dfs and similar, games, graphs, trees

Li Hua and Path

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

Furukawa Nagisa's Tree

binary search, divide and conquer, sortings, trees

Parmigiana With Seafood

binary search, dp, greedy, trees

Find String in a Grid

data structures, dp, strings, trees

Anagram Paths

dp, implementation, trees

Gasoline prices

data structures, divide and conquer, dsu, hashing, trees

Edge Queries

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

Colorful Tree Again

brute force, data structures, trees

Berland Miners

binary search, data structures, dfs and similar, greedy, trees

Around the World

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

The Majestic Brown Tree Snake

dfs and similar, dp, greedy, trees, two pointers

...Wait for it...

data structures, dsu, trees

Olha and Igor

interactive, probabilities, trees