Duff in the Army

data structures, trees

Tree Requests

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

Send the Fool Further! (medium)

dp, trees

Diverging Directions

data structures, dfs and similar, trees

Third Month Insanity

dp, probabilities, trees

Daleks' Invasion (medium)

dfs and similar, graphs, shortest paths, trees

Beavermuncher-0xFF

dfs and similar, dp, dsu, greedy, trees

World Eater Brothers

dfs and similar, dp, greedy, trees

Job Lookup

constructive algorithms, dp, shortest paths, trees

New Roads

constructive algorithms, graphs, trees

Black and White Tree

constructive algorithms, dsu, graphs, greedy, trees

Village (Minimum)

*special problem, dp, greedy, trees

Caisa and Tree

brute force, dfs and similar, math, number theory, trees

Cactus

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

Little Girl and Problem on Trees

data structures, graphs, trees

Invariance of Tree

constructive algorithms, dfs and similar, greedy, trees

Beard Graph

data structures, dsu, trees

Desk Disorder

combinatorics, dfs and similar, dsu, graphs, trees

Light Bulbs (Easy Version)

brute force, combinatorics, dfs and similar, dp, dsu, graphs, math, trees

Full Binary Tree Queries

brute force, implementation, trees

Infinite Inversions

binary search, data structures, implementation, sortings, trees

Apple Tree

dfs and similar, number theory, trees

Information Graph

dfs and similar, dsu, graphs, trees

Neko and Aki's Prank

dp, greedy, trees

Guess Game

bitmasks, data structures, games, math, probabilities, sortings, strings, trees

Paint the Tree

dp, sortings, trees

Hossam and (sub-)palindromic tree

brute force, data structures, dfs and similar, dp, strings, trees

Preorder

combinatorics, divide and conquer, dp, dsu, hashing, sortings, trees

Berland Beauty

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

Array Collapse

data structures, divide and conquer, dp, trees

Potion Brewing Class

dfs and similar, math, number theory, trees

Bear and Tree Jumps

dfs and similar, dp, trees

Mahmoud and a xor trip

bitmasks, constructive algorithms, data structures, dfs and similar, dp, math, trees

Treelabeling

bitmasks, constructive algorithms, dfs and similar, games, greedy, implementation, trees

How Many Paths?

dfs and similar, dp, graphs, trees

Beautiful Subarrays

data structures, divide and conquer, strings, trees

Timofey and Black-White Tree

brute force, dfs and similar, divide and conquer, graphs, greedy, math, shortest paths, trees

Recovering BST

brute force, dp, math, number theory, trees

Xor Tree

binary search, bitmasks, data structures, divide and conquer, dp, trees

01 Tree

constructive algorithms, data structures, dsu, greedy, sortings, trees

Segment Tree

data structures, dsu, graphs, trees

Anton and Tree

dfs and similar, dp, trees

Valid Sets

dfs and similar, dp, math, trees

Boring Segments

data structures, sortings, trees, two pointers

We Need More Bosses

dfs and similar, graphs, trees

Ehab's Last Corollary

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

Police Stations

constructive algorithms, dfs and similar, dp, graphs, shortest paths, trees

Civilization

dfs and similar, dp, dsu, ternary search, trees

New Year Tree

bitmasks, data structures, trees

Water Tree

data structures, dfs and similar, graphs, trees

Blood Cousins

binary search, data structures, dfs and similar, trees

A and B and Lecture Rooms

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

Ciel the Commander

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

Minimum spanning tree for each edge

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

Tree Painting

dfs and similar, dp, trees

Tree Diameter

interactive, trees

Build Railway Stations

*special problem, greedy, trees

T-decomposition

dfs and similar, graphs, greedy, trees

Inna and Sequence

binary search, data structures, dp, trees

Minimal Diameter Forest

constructive algorithms, dfs and similar, greedy, trees

Gifts by the List

constructive algorithms, dfs and similar, graphs, trees

Big Maximum Sum

data structures, dp, greedy, implementation, math, trees

Dasha and Puzzle

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

Helga Hufflepuff's Cup

dp, trees

An overnight dance in discotheque

dfs and similar, dp, geometry, greedy, trees

Running Track

dp, greedy, strings, trees

Work Group

dfs and similar, dp, graphs, strings, trees

Ant on the Tree

constructive algorithms, dfs and similar, trees

Mars rover

dfs and similar, graphs, implementation, trees

Jeremy Bearimy

dfs and similar, graphs, greedy, trees

Petya and Construction Set

constructive algorithms, graphs, math, sortings, trees

Choosing The Commander

bitmasks, data structures, trees

Destruction of a Tree

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

Lynyrd Skynyrd

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

Sum Graph

brute force, constructive algorithms, graphs, implementation, interactive, shortest paths, trees

Vlad and the Mountains

binary search, data structures, dsu, graphs, implementation, sortings, trees, two pointers

Sergey and Subway

dfs and similar, dp, trees

Pillars

binary search, data structures, dp, sortings, trees

Count Paths

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

Circular Spanning Tree

constructive algorithms, implementation, trees

Kamil and Making a Stream

math, number theory, trees

A Growing Tree

data structures, dfs and similar, trees

Ilya And The Tree

dfs and similar, graphs, math, number theory, trees

Weight the Tree

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

Edge Split

brute force, constructive algorithms, dfs and similar, dsu, graphs, probabilities, trees

Range Sorting (Easy Version)

binary search, dp, dsu, greedy, trees, two pointers

Garland

dfs and similar, graphs, greedy, trees

Buds Re-hanging

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

Counting Graphs

combinatorics, divide and conquer, dsu, graphs, greedy, sortings, trees

XOR Inverse

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

Danil and a Part-time Job

bitmasks, data structures, trees

Passable Paths (hard version)

data structures, dfs and similar, trees

GCD Counting

data structures, dfs and similar, dp, number theory, trees

1-Trees and Queries

data structures, dfs and similar, shortest paths, trees

Appleman and Tree

dfs and similar, dp, trees

Three Paths on a Tree

dfs and similar, dp, greedy, trees

Number of Simple Paths

combinatorics, dfs and similar, graphs, trees

Weights Division (easy version)

data structures, dfs and similar, greedy, trees

Book of Evil

dfs and similar, divide and conquer, dp, trees

Propagating tree

data structures, dfs and similar, trees