Nikita and game

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

Inverse Genealogy

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

Andrey's Tree

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

Directing Edges

dfs and similar, dp, graphs, trees

Red-Black Cobweb

data structures, divide and conquer, implementation, trees

Tiles Placement

constructive algorithms, dfs and similar, trees

Tree nesting

combinatorics, graphs, trees

Perfect Matching

data structures, divide and conquer, interactive, trees

Beautiful Tree

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

Alien DNA

data structures, dsu, trees

Imitating the Key Tree

combinatorics, dsu, trees

Visible Black Areas

data structures, dsu, geometry, trees

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

data structures, dfs and similar, trees

Odd Mineral Resource

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

Fox And Travelling

dp, trees

Max Mex

data structures, trees

Subsequence

brute force, divide and conquer, dp, greedy, trees

XOR and Distance

bitmasks, divide and conquer, trees

Pumping Stations

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

Edge Elimination

constructive algorithms, dfs and similar, dp, trees

Timofey and a flat tree

data structures, graphs, hashing, shortest paths, trees

Mashtali and Hagh Trees

combinatorics, dp, trees

Tree Elimination

dp, trees

Tree and XOR

strings, trees

Noble Knight's Path

data structures, trees

Cycles in product

combinatorics, divide and conquer, trees

Andrew and Chemistry

dp, hashing, trees

Snowy Mountain

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

May Holidays

data structures, trees

Tree or not Tree

data structures, divide and conquer, implementation, trees

Johnny and James

greedy, implementation, math, trees

Problem of offices

constructive algorithms, dfs and similar, dp, trees

Two Rooted Trees

data structures, implementation, trees

Cactus to Tree

dp, graphs, trees

Restore the Tree

graphs, greedy, trees

Pastoral Oddities

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

Misha and LCP on Tree

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

Freezing with Style

binary search, data structures, divide and conquer, trees

Logistical Questions

dfs and similar, divide and conquer, trees

Vladislav and a Great Legend

combinatorics, dp, trees

Tree Weights

bitmasks, constructive algorithms, data structures, dfs and similar, implementation, math, matrices, number theory, trees

James and the Chase

dfs and similar, graphs, probabilities, trees

Treeland and Viruses

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

Olha and Igor

interactive, probabilities, trees

Partial Virtual Trees

combinatorics, dfs and similar, dp, math, trees

Black, White and Grey Tree

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

Michael and Hotel

binary search, interactive, trees

Game of Stacks

brute force, dfs and similar, graphs, implementation, trees

...Wait for it...

data structures, dsu, trees

The Majestic Brown Tree Snake

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

Gasoline prices

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

Edge Queries

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

Around the World

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

Smooth Sailing (Hard Version)

binary search, data structures, dsu, geometry, graphs, trees

Colorful Tree Again

brute force, data structures, trees

Berland Miners

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

Parmigiana With Seafood

binary search, dp, greedy, trees

Anagram Paths

dp, implementation, trees

Li Hua and Path

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

Find String in a Grid

data structures, dp, strings, trees

Furukawa Nagisa's Tree

binary search, divide and conquer, sortings, trees

Flower-like Pseudotree

constructive algorithms, graphs, greedy, implementation, trees

Tree and Permutation Game

dfs and similar, games, graphs, trees

Escaping on Beaveractor

data structures, implementation, trees

Tree and Table

dfs and similar, dp, implementation, trees

Archaeology

data structures, dfs and similar, trees

Groceries in Meteor Town

binary search, data structures, dsu, trees

Surprise me!

divide and conquer, math, number theory, trees

Campus

binary search, data structures, dsu, trees

MST with Matching

bitmasks, brute force, dsu, graph matchings, trees

Tree-Tac-Toe

constructive algorithms, games, trees

String Transformation 2

bitmasks, dp, graphs, trees

AB Tree

dp, greedy, trees

Squid Game

data structures, dfs and similar, greedy, trees

Tavas on the Path

data structures, divide and conquer, trees

Legendary Tree

binary search, interactive, trees

Tree Calendar

brute force, constructive algorithms, data structures, dfs and similar, sortings, trees

Perpetual Motion Machine

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

Train Tracks

data structures, trees

Mashtali vs AtCoder

games, trees

Santa's Gift

data structures, trees

Two Subtrees

data structures, trees

Prefix Max Set Counting

data structures, dp, trees

Sloth

dfs and similar, dp, graph matchings, trees

Road Repair in Treeland

*special problem, binary search, dp, trees

Tourists

data structures, dfs and similar, graphs, trees

ALT

data structures, flows, graphs, trees

Restoring Map

bitmasks, constructive algorithms, trees

Clockwork Bomb

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

Mirror Box

matrices, trees

Reunion

combinatorics, dp, trees

In a Trap

trees

Shifting Dominoes

data structures, geometry, graphs, trees

Air Reform

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

Teleportation in Byteland

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

Segment Covering

brute force, combinatorics, constructive algorithms, data structures, dp, trees

Raining season

data structures, divide and conquer, trees

Distance Matching

constructive algorithms, dfs and similar, trees

New Year and Social Network

data structures, graph matchings, graphs, math, trees

Triameter

binary search, data structures, dfs and similar, trees