Palindromes in a Tree

bitmasks, data structures, divide and conquer, trees

Bear and Forgotten Tree 2

dfs and similar, dsu, graphs, trees

The Hidden Pair (Easy Version)

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

Split the Tree

binary search, data structures, dp, greedy, trees

Koxia and Tree

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

Sasha and Interesting Fact from Graph Theory

brute force, combinatorics, dp, math, trees

Diameter Cuts

combinatorics, dfs and similar, dp, trees

Leaf Sets

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

Binary Tree on Plane

flows, trees

Simple Cycles Edges

dfs and similar, graphs, trees

Interactive Game with Coloring

brute force, constructive algorithms, dfs and similar, graphs, implementation, interactive, trees

Happy Tree Party

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

Connectivity Addicts

constructive algorithms, dsu, graphs, greedy, interactive, shortest paths, trees

Distance Tree (easy version)

binary search, data structures, dfs and similar, graphs, shortest paths, trees

Acyclic Organic Compounds

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

Travel Plan

combinatorics, dp, implementation, math, trees

Blocking Chips

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

Little Elephant and Tree

data structures, dfs and similar, trees

Magic Matrix

brute force, divide and conquer, graphs, matrices, trees

Frequency Queries

data structures, dfs and similar, trees

Sonya and Ice Cream

binary search, data structures, dp, greedy, shortest paths, trees

Labeling the Tree with Distances

data structures, dp, greedy, hashing, implementation, trees

Greedy Subsequences

data structures, dp, trees

Cookies

binary search, data structures, dfs and similar, dp, games, trees

Vasya and Maximum Matching

dp, trees

Trees and XOR Queries Again

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

Flow Control

dfs and similar, dp, greedy, trees

Regular Forestation

hashing, trees

Construct a tree

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

Zublicanes and Mumocrates

dp, trees, two pointers

One-X

combinatorics, dfs and similar, dp, math, trees

Economic Difficulties

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

Comfortably Numb

bitmasks, data structures, divide and conquer, strings, trees

Complete Mirror

constructive algorithms, dfs and similar, dp, hashing, implementation, trees

Polo the Penguin and Trees

combinatorics, dfs and similar, trees

Daleks' Invasion (hard)

data structures, dsu, graphs, trees

Masha and Cactus

dp, trees

Berland SU Computer Network

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

Send the Fool Further! (hard)

dfs and similar, dp, math, trees

Mocha and Diana (Hard Version)

brute force, constructive algorithms, dfs and similar, dsu, graphs, greedy, trees, two pointers

Nastia Plays with a Tree

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

Towers

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

Cheap Robot

binary search, dsu, graphs, shortest paths, trees

Complete the MST

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

Distinctive Roots in a Tree

data structures, dfs and similar, dp, trees

Power Tree

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

Expected diameter of a tree

binary search, brute force, dfs and similar, dp, sortings, trees

Rollbacks (Easy Version)

brute force, data structures, dfs and similar, trees

LuoTianyi and XOR-Tree

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

Tenzing and Tree

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

Xorcerer's Stones

bitmasks, constructive algorithms, dp, trees

Move and Swap

dfs and similar, dp, greedy, trees

Tree Queries

dfs and similar, graphs, trees

Up and Down the Tree

dfs and similar, dp, trees

Leaf Partition

dp, trees

Middle Duplication

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

Add on a Tree: Revolution

constructive algorithms, dfs and similar, implementation, trees

Roads in the Kingdom

dfs and similar, dp, graphs, trees

Independent Set

dfs and similar, dp, trees

Cats on the Upgrade (easy version)

brute force, data structures, dfs and similar, divide and conquer, dp, graphs, trees

Hossam and Range Minimum Query

binary search, bitmasks, data structures, hashing, probabilities, strings, trees

Miss Punyverse

dp, greedy, trees

Narrow Components

brute force, data structures, dp, dsu, math, trees

K-Set Tree

combinatorics, dfs and similar, dp, math, trees

Construct Tree

bitmasks, constructive algorithms, dp, trees

Doremy's Experimental Tree

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

Tree Factory

constructive algorithms, greedy, trees

Peterson Polyglot

brute force, dfs and similar, dsu, hashing, strings, trees

Christmas Game

bitmasks, data structures, dfs and similar, dp, games, math, trees

Ostap and Tree

dp, trees

Tree

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

Algebra Flash

bitmasks, brute force, dp, graphs, math, meet-in-the-middle, trees

The Tree Has Fallen!

bitmasks, dfs and similar, math, trees

Tree Queries

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

Village (Maximum)

*special problem, dfs and similar, trees

XOR, Tree, and Queries

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

Caterpillar on a Tree

dfs and similar, graphs, greedy, implementation, sortings, trees

Maze

dfs and similar, dp, probabilities, trees

Colored Subgraphs

dfs and similar, dp, games, greedy, trees

Genetic engineering

dp, string suffix structures, trees

Babysitting

2-sat, binary search, data structures, graphs, trees

Multiset of Strings

bitmasks, brute force, dp, fft, flows, graphs, math, meet-in-the-middle, trees

Choosing Two Paths

dfs and similar, dp, greedy, trees

Balance

constructive algorithms, dfs and similar, graphs, trees

Rowena Ravenclaw's Diadem

trees

Garden

bitmasks, dp, graphs, trees

Electrical Efficiency

combinatorics, data structures, dp, math, number theory, trees

One Node is Gone

constructive algorithms, implementation, trees

Keen Tree Calculation

binary search, data structures, dp, geometry, graphs, implementation, trees

Journey

dp, trees

Last chance

data structures, flows, graph matchings, graphs, trees

Madness

constructive algorithms, dfs and similar, trees

Poachers

dp, games, graphs, trees

King's Path

*special problem, math, trees

Graph and Queries

data structures, dsu, graphs, implementation, trees

Phoenix and Earthquake

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

Nearest Leaf

data structures, trees

Pairs of Pairs

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

BFS Trees

combinatorics, dfs and similar, graphs, math, shortest paths, trees

Koala and Notebook

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