Olha and Igor

interactive, probabilities, trees

Death DBMS

data structures, string suffix structures, strings, trees

Minimal Height Tree

graphs, greedy, shortest paths, trees

Bandit in a City

binary search, dfs and similar, graphs, greedy, trees

Boring Card Game

data structures, greedy, trees

Dušan's Railway

divide and conquer, graphs, trees

Graph and Queries

data structures, dsu, graphs, implementation, trees

XOR Inverse

bitmasks, data structures, divide and conquer, dp, greedy, math, sortings, strings, trees

Roads and Ramen

data structures, trees

Clusterization Counting

combinatorics, dp, dsu, fft, graphs, trees

Avoid Rainbow Cycles

data structures, dsu, graphs, greedy, sortings, trees

Link Cut Centroids

constructive algorithms, dfs and similar, graphs, trees

Tree Tag

dfs and similar, dp, games, trees

Spring cleaning

*special problem, data structures, dfs and similar, graphs, trees

Star Trek

*special problem, combinatorics, dfs and similar, dp, games, graphs, matrices, trees

Maximum Distributed Tree

dfs and similar, dp, greedy, implementation, math, number theory, sortings, trees

Weights Division (hard version)

binary search, dfs and similar, greedy, sortings, trees, two pointers

Weights Division (easy version)

data structures, dfs and similar, greedy, trees

Distance Matching

constructive algorithms, dfs and similar, trees

Boboniu and Jianghu

dp, greedy, sortings, trees

Pairs of Pairs

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

Directing Edges

dfs and similar, dp, graphs, trees

Captain Flint and Treasure

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

Uncle Bogdan and Country Happiness

dfs and similar, greedy, math, trees

Village (Maximum)

*special problem, dfs and similar, trees

Village (Minimum)

*special problem, dp, greedy, trees

Removing Leaves

data structures, greedy, implementation, trees

String Transformation 2

bitmasks, dp, graphs, trees

String Transformation 1

dsu, graphs, greedy, sortings, strings, trees, two pointers

The Majestic Brown Tree Snake

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

Merging Towers

data structures, dsu, implementation, trees

Inverse Genealogy

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

Tree Modification

brute force, constructive algorithms, dfs and similar, graph matchings, graphs, trees

The Hidden Pair (Hard Version)

binary search, dfs and similar, graphs, interactive, shortest paths, trees

The Hidden Pair (Easy Version)

binary search, dfs and similar, graphs, interactive, shortest paths, trees

TediousLee

dp, graphs, greedy, math, trees

Shifting Dominoes

data structures, geometry, graphs, trees

Ehab's Last Corollary

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

Tree Shuffling

dfs and similar, dp, greedy, trees

Game On Leaves

games, trees

James and the Chase

dfs and similar, graphs, probabilities, trees

Johnny and James

greedy, implementation, math, trees

Train Tracks

data structures, trees

Nastya and Time Machine

constructive algorithms, dfs and similar, graphs, trees

Nested Rubber Bands

constructive algorithms, dfs and similar, dp, math, trees

Edge Weight Assignment

bitmasks, constructive algorithms, dfs and similar, greedy, math, trees

Journey

data structures, divide and conquer, graphs, trees

Linova and Kingdom

dfs and similar, dp, greedy, sortings, trees

Independent Set

dfs and similar, dp, trees

Tree Queries

dfs and similar, graphs, trees

Spiderweb Trees

dp, geometry, trees

Ehab and Path-etic MEXs

constructive algorithms, dfs and similar, greedy, trees

Maximum White Subtree

dfs and similar, dp, graphs, trees

Assigning Fares

dp, trees

Treeland and Viruses

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

Construct the Binary Tree

brute force, constructive algorithms, trees

Cow and Vacation

dfs and similar, dsu, trees

Kuroni and the Celebration

constructive algorithms, dfs and similar, interactive, trees

1-Trees and Queries

data structures, dfs and similar, shortest paths, trees

Sum of Prefix Sums

data structures, divide and conquer, geometry, trees

Around the World

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

Modernization of Treeland

*special problem, dfs and similar, trees

Berland Beauty

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

Three Paths on a Tree

dfs and similar, dp, greedy, trees

Chaotic V.

dp, graphs, greedy, math, number theory, trees

Xenon's Attack on the Gangs

combinatorics, dfs and similar, dp, greedy, trees

Numbers on Tree

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

Delete a Segment

brute force, constructive algorithms, data structures, dp, graphs, sortings, trees, two pointers

Dr. Evil Underscores

bitmasks, brute force, dfs and similar, divide and conquer, dp, greedy, strings, trees

New Year and Social Network

data structures, graph matchings, graphs, math, trees

DIY Garland

constructive algorithms, greedy, trees

Miss Punyverse

dp, greedy, trees

Jeremy Bearimy

dfs and similar, graphs, greedy, trees

Tests for problem D

constructive algorithms, dfs and similar, divide and conquer, trees

Segment Tree

data structures, dsu, graphs, trees

Tree Elimination

dp, trees

Economic Difficulties

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

Colored Tree

data structures, trees

Send Tree to Charlie

combinatorics, dfs and similar, dsu, trees

Tree Queries

data structures, probabilities, trees

Cheap Robot

binary search, dsu, graphs, shortest paths, trees

Regular Forestation

hashing, trees

Find String in a Grid

data structures, dp, strings, trees

Cleaning Robots

dp, trees

Maximum Weight Subset

dp, trees

Shichikuji and Power Grid

dsu, graphs, greedy, shortest paths, trees

Paint the Tree

brute force, constructive algorithms, dp, graphs, implementation, trees

The Maximum Subtree

dfs and similar, dp, graphs, trees

One Node is Gone

constructive algorithms, implementation, trees

Tree Factory

constructive algorithms, greedy, trees

Paint the Tree

dp, sortings, trees

Tourism

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

Forced Online Queries Problem

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

Tiles Placement

constructive algorithms, dfs and similar, trees

Petya and Construction Set

constructive algorithms, graphs, math, sortings, trees

Path Queries

divide and conquer, dsu, graphs, sortings, trees

Road Repair in Treeland

*special problem, binary search, dp, trees

King's Path

*special problem, math, trees

Kamil and Making a Stream

math, number theory, trees

Koala and Notebook

data structures, dfs and similar, graphs, shortest paths, strings, trees