Babysitting

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

Trees and XOR Queries Again

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

Collapsing Strings

data structures, strings, trees

Compressed Tree

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

Anji's Binary Tree

dfs and similar, dp, trees

Unusual Entertainment

data structures, dfs and similar, dsu, shortest paths, sortings, trees, two pointers

Alex's whims

constructive algorithms, graphs, greedy, shortest paths, trees

XOR Construction

bitmasks, constructive algorithms, data structures, math, string suffix structures, trees

A Growing Tree

data structures, dfs and similar, trees

Doremy's Average Tree

data structures, dp, greedy, trees

Doremy's Swapping Trees

dfs and similar, graphs, trees

Game of Stacks

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

Split

binary search, data structures, divide and conquer, dsu, math, trees, two pointers

Tree XOR

bitmasks, dfs and similar, dp, greedy, trees

Minimum Maximum Distance

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

Interactive Game with Coloring

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

wxhtzdy ORO Tree

binary search, bitmasks, brute force, data structures, dfs and similar, implementation, trees

Clubstep

binary search, brute force, data structures, greedy, trees

Ball-Stackable

constructive algorithms, data structures, dp, trees

Mad City

dfs and similar, dsu, games, graphs, shortest paths, trees

Standard Graph Problem

data structures, graphs, greedy, trees

Flower-like Pseudotree

constructive algorithms, graphs, greedy, implementation, trees

Travel Plan

combinatorics, dp, implementation, math, trees

Keen Tree Calculation

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

Guess Game

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

Redundant Routes

constructive algorithms, dp, trees

Goldberg Machine 3

dp, trees

Queries for the Array

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

Teleportation in Byteland

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

Rollbacks (Hard Version)

data structures, interactive, trees

Rollbacks (Easy Version)

brute force, data structures, dfs and similar, trees

Counting Graphs

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

Strong Vertices

math, sortings, trees

PermuTree (hard version)

bitmasks, dfs and similar, dp, fft, greedy, implementation, math, trees

PermuTree (easy version)

dfs and similar, dp, trees

Michael and Hotel

binary search, interactive, trees

Vlad and the Mountains

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

Lisa and the Martians

bitmasks, greedy, math, strings, trees

XOR Partition

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

Tree Weights

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

Omsk Metro (hard version)

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

Omsk Metro (simple version)

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

Apple Tree

combinatorics, dfs and similar, dp, math, trees

Sum in Binary Tree

bitmasks, combinatorics, math, trees

Tenzing and Tree

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

Playoff Fixing

combinatorics, trees

Ksyusha and Chinchilla

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

Mex Tree

brute force, dp, trees

Copil Copac Draws Trees

dfs and similar, dp, graphs, trees

Bus Routes

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

Two Centroids

data structures, dfs and similar, greedy, trees

Range Sorting (Easy Version)

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

LuoTianyi and Cartridge

data structures, trees

LuoTianyi and XOR-Tree

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

LuoTianyi and the Floating Islands (Hard Version)

combinatorics, dfs and similar, math, probabilities, trees

LuoTianyi and the Floating Islands (Easy Version)

combinatorics, math, probabilities, trees

Random Walk

dp, graphs, math, probabilities, trees

Gardening Friends

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

Roads in E City

interactive, math, probabilities, trees

The Fox and the Complete Tree Traversal

constructive algorithms, dp, implementation, math, trees

Sum Graph

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

M-tree

data structures, math, sortings, trees

Tree Master

brute force, data structures, dfs and similar, trees

There Should Be a Lot of Maximums

brute force, data structures, dfs and similar, dp, trees, two pointers

A Wide, Wide Graph

dfs and similar, dp, graphs, greedy, trees

Gasoline prices

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

Symmetree

dfs and similar, hashing, implementation, trees

Li Hua and Path

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

Li Hua and Tree

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

Colored Subgraphs

dfs and similar, dp, games, greedy, trees

Blocking Chips

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

Labeling the Tree with Distances

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

Timofey and Black-White Tree

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

XOR, Tree, and Queries

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

Colorful Tree Again

brute force, data structures, trees

Weighed Tree Radius

data structures, divide and conquer, implementation, trees

Diverse Coloring

constructive algorithms, trees

Bracket Insertion

combinatorics, dp, math, trees

Xorcerer's Stones

bitmasks, constructive algorithms, dp, trees

Maximizing Root

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

The Tree Has Fallen!

bitmasks, dfs and similar, math, trees

Comfortably Numb

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

Edge Reverse

binary search, dfs and similar, graphs, trees

Score of a Tree

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

Parmigiana With Seafood

binary search, dp, greedy, trees

Segment Covering

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

Two Chess Pieces

dfs and similar, dp, greedy, trees

BinCoin

binary search, divide and conquer, hashing, implementation, probabilities, trees

Hossam and Range Minimum Query

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

Hossam and (sub-)palindromic tree

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

Koxia and Tree

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

Two Subtrees

data structures, trees

Algebra Flash

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

Doremy's Experimental Tree

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

Edge Queries

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

Tree Sum

combinatorics, math, trees

Centroid Guess

interactive, probabilities, trees

Make It Connected

binary search, brute force, constructive algorithms, dsu, graphs, greedy, matrices, trees, two pointers

Distance to the Path

data structures, dfs and similar, trees

Yet Another Array Counting Problem

binary search, data structures, divide and conquer, dp, flows, math, trees