Dušan's Railway

divide and conquer, graphs, trees

Spiderweb Trees

dp, geometry, trees

Assigning Fares

dp, trees

My Beautiful Madness

data structures, trees

Range Diameter Sum

data structures, trees

Finding the Vertex

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

Red Blue Tree

data structures, implementation, trees

Cheat and Win

bitmasks, data structures, games, trees

Communism

bitmasks, dp, trees

Journey

data structures, divide and conquer, graphs, trees

Euler tour

constructive algorithms, trees

Pisces

data structures, flows, trees

Strange device

binary search, interactive, math, trees

Upside Down

data structures, string suffix structures, strings, trees

Rap God

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

Ember and Storm's Tree Game

combinatorics, dp, games, trees

Island Puzzle

dfs and similar, dsu, graphs, trees

Tree

fft, graphs, trees

Iqea

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

Can Bash Save the Day?

data structures, divide and conquer, graphs, trees

Niyaz and Small Degrees

data structures, dp, trees

Matches Are Not a Child's Play

data structures, trees

Harry Vs Voldemort

dfs and similar, dp, graphs, trees

Send Tree to Charlie

combinatorics, dfs and similar, dsu, trees

Iron Man

data structures, geometry, 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

Boring Card Game

data structures, greedy, trees

Ants

2-sat, data structures, trees

ELCA

data structures, trees

Sasha and Algorithm of Silence's Sounds

data structures, trees

Shifting Dominoes

data structures, geometry, graphs, trees

New Year and Social Network

data structures, graph matchings, graphs, math, trees

Distance Matching

constructive algorithms, dfs and similar, trees

Raining season

data structures, divide and conquer, trees

In a Trap

trees

Mirror Box

matrices, trees

ALT

data structures, flows, graphs, trees

Restoring Map

bitmasks, constructive algorithms, trees

Clockwork Bomb

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

Tourists

data structures, dfs and similar, graphs, trees

Road Repair in Treeland

*special problem, binary search, dp, trees

Sloth

dfs and similar, dp, graph matchings, trees

Train Tracks

data structures, trees

Santa's Gift

data structures, trees

Perpetual Motion Machine

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

AB Tree

dp, greedy, trees

Tavas on the Path

data structures, divide and conquer, 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

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

Find String in a Grid

data structures, dp, strings, trees

Furukawa Nagisa's Tree

binary search, divide and conquer, sortings, trees

Anagram Paths

dp, implementation, trees

Berland Miners

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

Black, White and Grey Tree

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

Around the World

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

The Majestic Brown Tree Snake

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

James and the Chase

dfs and similar, graphs, probabilities, trees

Olha and Igor

interactive, probabilities, trees

...Wait for it...

data structures, dsu, trees

Vladislav and a Great Legend

combinatorics, dp, trees

Logistical Questions

dfs and similar, divide and conquer, trees

Treeland and Viruses

data structures, dfs and similar, dp, shortest paths, trees

Freezing with Style

binary search, data structures, divide and conquer, trees

Misha and LCP on Tree

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

Pastoral Oddities

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

Restore the Tree

graphs, greedy, trees

Cactus to Tree

dp, graphs, trees

Two Rooted Trees

data structures, implementation, trees

Problem of offices

constructive algorithms, dfs and similar, dp, trees

Tree or not Tree

data structures, divide and conquer, implementation, trees

Johnny and James

greedy, implementation, math, trees

Tree Elimination

dp, trees

May Holidays

data structures, trees

Andrew and Chemistry

dp, hashing, trees

Cycles in product

combinatorics, divide and conquer, trees

Tree and XOR

strings, trees

Timofey and a flat tree

data structures, graphs, hashing, shortest paths, trees

Noble Knight's Path

data structures, trees

Odd Mineral Resource

binary search, bitmasks, brute force, data structures, probabilities, trees

Pumping Stations

brute force, dfs and similar, divide and conquer, flows, graphs, greedy, trees

Max Mex

data structures, trees

Fox And Travelling

dp, trees

Arpa’s letter-marked tree and Mehrdad’s Dokhtar-kosh paths

data structures, dfs and similar, trees

Visible Black Areas

data structures, dsu, geometry, trees

Tree nesting

combinatorics, graphs, trees

Inverse Genealogy

constructive algorithms, divide and conquer, dp, math, trees

Nikita and game

binary search, dfs and similar, divide and conquer, graphs, trees