Xenia and Bit Operations

data structures, trees

Decorate Apple Tree

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

Kuro and Walking Route

dfs and similar, trees

Bear and Forgotten Tree 3

constructive algorithms, graphs, trees

Alex's whims

constructive algorithms, graphs, greedy, shortest paths, trees

Social Network

dsu, graphs, greedy, implementation, trees

Alyona and the Tree

dfs and similar, dp, graphs, trees

Tree Infection

binary search, greedy, sortings, trees

Add on a Tree

trees

Sum in the tree

constructive algorithms, dfs and similar, greedy, trees

Compression and Expansion

brute force, data structures, greedy, implementation, trees

Tree Cutting

binary search, dp, greedy, implementation, trees

Andryusha and Colored Balloons

dfs and similar, graphs, greedy, trees

Valera and Elections

dfs and similar, graphs, trees

Military Problem

dfs and similar, graphs, trees

Queries for the Array

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

Timofey and a tree

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

Infected Tree

dfs and similar, dp, trees

Gardener and Tree

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

Minimal Height Tree

graphs, greedy, shortest paths, trees

Parsa's Humongous Tree

dfs and similar, divide and conquer, dp, greedy, trees

Game On Leaves

games, trees

Linova and Kingdom

dfs and similar, dp, greedy, sortings, trees

k-Tree

dp, implementation, trees

IT Restaurants

dfs and similar, dp, trees

Brain Network (medium)

dfs and similar, graphs, trees

Hashing Trees

constructive algorithms, trees

Misha and Forest

constructive algorithms, data structures, greedy, sortings, trees

Mahmoud and Ehab and the wrong algorithm

constructive algorithms, trees

Lorenzo Von Matterhorn

brute force, data structures, implementation, trees

Okabe and Boxes

data structures, greedy, trees

Peculiar apple-tree

dfs and similar, graphs, trees

Weights Assignment For Tree Edges

constructive algorithms, trees

Cut 'em all!

dfs and similar, dp, graphs, greedy, trees

13th Labour of Heracles

data structures, greedy, sortings, trees

Edgy Trees

dfs and similar, dsu, graphs, math, trees

Ehab and Path-etic MEXs

constructive algorithms, dfs and similar, greedy, trees

Journey

dfs and similar, dp, graphs, probabilities, trees

Kefa and Park

dfs and similar, graphs, trees

Spiders

dp, greedy, trees

Send the Fool Further! (easy)

dfs and similar, graphs, trees

Useful Decomposition

implementation, trees

Queen

dfs and similar, trees

Copil Copac Draws Trees

dfs and similar, dp, graphs, trees

Mocha and Diana (Easy Version)

brute force, constructive algorithms, dsu, graphs, greedy, trees

Not Assigning

constructive algorithms, dfs and similar, number theory, trees

Petya and Catacombs

dsu, greedy, implementation, trees

Xor-tree

dfs and similar, trees

Anji's Binary Tree

dfs and similar, dp, trees

PolandBall and Forest

dfs and similar, dsu, graphs, interactive, trees

Vertical Paths

graphs, implementation, trees

White-Black Balanced Subtrees

dfs and similar, dp, graphs, trees

Masha and a Beautiful Tree

dfs and similar, divide and conquer, graphs, sortings, trees

Mahmoud and Ehab and the bipartiteness

dfs and similar, graphs, trees

Strong Vertices

math, sortings, trees

Omkar and Heavenly Tree

constructive algorithms, trees

Christmas Spruce

implementation, trees

Reposts

*special problem, dfs and similar, dp, graphs, trees

Apple Tree

combinatorics, dfs and similar, dp, math, trees

Begginer's Zelda

greedy, trees

Yet Another Card Deck

brute force, data structures, implementation, trees

Bmail Computer Network

*special problem, dfs and similar, trees

Party

dfs and similar, graphs, trees

Sum in Binary Tree

bitmasks, combinatorics, math, trees