Most Different Tree

brute force, constructive algorithms, dfs and similar, greedy, hashing

Nikita and game

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

Bear and Chemistry

data structures, dfs and similar, graphs, trees

Cactusophobia

dfs and similar, flows

Andrey's Tree

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

Wilbur and Strings

dfs and similar, dp, graphs, strings

Chests and Keys

bitmasks, brute force, dfs and similar, dp, flows

Air Reform

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

Directing Edges

dfs and similar, dp, graphs, trees

Tiles Placement

constructive algorithms, dfs and similar, trees

Leaders

dfs and similar, dsu, graphs, trees

Teleportation in Byteland

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

Berland Miners

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

Sources and Sinks

bitmasks, brute force, dfs and similar

Bus Routes

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

Matching Reduction

brute force, constructive algorithms, dfs and similar, flows, graph matchings, graphs, interactive

Spring cleaning

*special problem, data structures, dfs and similar, graphs, trees

Snowy Mountain

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

Wormhouse

dfs and similar, graphs

Road Repairs

dfs and similar, graphs, greedy

Upgrading Tree

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

Almost Same Distance

dfs and similar, graphs

Monsters and Diamonds

dfs and similar, graphs, shortest paths

Li Hua and Path

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

Tree Calendar

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

Delete The Edges

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

Long Way to be Non-decreasing

binary search, dfs and similar, graphs, implementation, shortest paths, two pointers

Sagheer and Kindergarten

dfs and similar, graphs, implementation, trees

Pairs

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

Distance Matching

constructive algorithms, dfs and similar, trees

Berland SU Computer Network

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

Bear and Chase

brute force, dfs and similar, graphs, implementation, math, probabilities

TOF

dfs and similar, graphs

Beautiful Tree

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

Triameter

binary search, data structures, dfs and similar, trees

Cycle

brute force, dfs and similar, implementation

Madness

constructive algorithms, dfs and similar, trees

Send the Fool Further! (hard)

dfs and similar, dp, math, trees

More Gifts

*special problem, dfs and similar, two pointers

Tree Cutting

bitmasks, dfs and similar, dp

BHTML+BCSS

*special problem, dfs and similar, expression parsing

Just Add an Edge

dfs and similar, dp, graphs

Send Tree to Charlie

combinatorics, dfs and similar, dsu, trees

Frequency Mismatch (Hard Version)

binary search, data structures, dfs and similar, hashing, probabilities, trees

Min-Fund Prison (Medium)

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

Bitonix' Patrol

bitmasks, brute force, combinatorics, dfs and similar, math

Problem of offices

constructive algorithms, dfs and similar, dp, trees

Hard Cut

constructive algorithms, dfs and similar, divide and conquer, math

The Overdosing Ubiquity

brute force, dfs and similar, graphs

Island Puzzle

dfs and similar, dsu, graphs, trees

Palindromic Hamiltonian Path

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

Just Kingdom

brute force, data structures, dfs and similar

Evidence Board

*special problem, constructive algorithms, dfs and similar, graphs, trees

Cactus Not Enough

dfs and similar, graph matchings, graphs

Wavy numbers

brute force, dfs and similar, meet-in-the-middle, sortings

Harry Vs Voldemort

dfs and similar, dp, graphs, trees

Modernization of Treeland

*special problem, dfs and similar, trees

Star Trek

*special problem, combinatorics, dfs and similar, dp, games, graphs, matrices, trees

Escaping on Beaveractor

dfs and similar, implementation

New Year and Snowy Grid

dfs and similar, dsu, graphs, interactive

Baldman and the military

dfs and similar, graphs, trees

Iqea

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

Tree and Permutation Game

dfs and similar, games, graphs, trees

The Meeting Place Cannot Be Changed

dfs and similar, graphs

Cacti Symphony

combinatorics, dfs and similar, dp, graphs

Sloth

dfs and similar, dp, graph matchings, trees

Alice and the Cactus

dfs and similar, graphs, math, probabilities

Tree and Table

dfs and similar, dp, implementation, trees

Two Sorts

binary search, dfs and similar, math, meet-in-the-middle

Suns and Rays

dfs and similar, implementation

Suns and Rays

constructive algorithms, dfs and similar, implementation

Trains and Airplanes

dfs and similar, graphs, shortest paths, trees

Alphabetic Tree

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

Good Graph

bitmasks, dfs and similar, graph matchings, graphs, implementation

Fake bullions

combinatorics, dfs and similar, dp, graphs, number theory

Rap God

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

Min-Fund Prison (Hard)

bitmasks, dfs and similar, dp, graphs, trees

Finding the Vertex

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

Greedy Petya

*special problem, dfs and similar, graphs, greedy

Colored Jenga

dfs and similar, dp, probabilities

Organizing a Music Festival

dfs and similar, math

Interactive Mex Tree

constructive algorithms, dfs and similar, interactive, trees

Function Composition

dfs and similar

Harder Satisfiability

2-sat, dfs and similar, graphs

Two Avenues

data structures, dfs and similar, graphs

Biome Map

*special problem, constructive algorithms, dfs and similar, graphs

Doremy's Swapping Trees

dfs and similar, graphs, trees

Harry Potter and Moving Staircases

dfs and similar, implementation

Grove

brute force, dfs and similar, dp, geometry, probabilities

Parallel Universes

*special problem, constructive algorithms, dfs and similar, dsu, graphs

Long Recovery

constructive algorithms, dfs and similar

Chain Letter

*special problem, dfs and similar, graphs

Battleship

*special problem, dfs and similar, implementation

Excursions

*special problem, constructive algorithms, dfs and similar, flows, graph matchings, graphs

Burenka and Pether

*special problem, data structures, dfs and similar, divide and conquer, dsu, graphs, sortings, trees