Multihedgehog

dfs and similar, graphs, shortest paths

Vasya and Isolated Vertices

constructive algorithms, graphs

Labyrinth

graphs, shortest paths

Upgrading Cities

dfs and similar, graphs

Fun with Integers

dfs and similar, graphs, implementation, math

Politics

flows, graphs

Take Metro

brute force, data structures, graphs

Decorate Apple Tree

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

Metro

graphs

The Shortest Statement

graphs, shortest paths, trees

Hyperspace Highways

dfs and similar, graphs, trees

Last chance

data structures, flows, graph matchings, graphs, trees

Leaf Sets

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

Tree Reconstruction

constructive algorithms, data structures, graphs, greedy

Network Safety

dfs and similar, dsu, graphs, math, sortings

Maximum Matching

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

Trips

graphs

Valid BFS?

dfs and similar, graphs, shortest paths, trees

Hidden Bipartite Graph

binary search, constructive algorithms, dfs and similar, graphs, interactive

King Escape

dfs and similar, graphs, implementation

Familiar Operations

brute force, graphs, math

Tree with Small Distances

dp, graphs, greedy

Session in BSU

binary search, dfs and similar, dsu, graph matchings, graphs

Mouse Hunt

dfs and similar, graphs

Mobile Phone Network

dfs and similar, dsu, graphs, trees

Badge

brute force, dfs and similar, graphs

Sergey's problem

constructive algorithms, graphs

Chemical table

constructive algorithms, dfs and similar, dsu, graphs, matrices

Tree

fft, graphs, trees

Mars rover

dfs and similar, graphs, implementation, trees

Allowed Letters

bitmasks, flows, graph matchings, graphs, greedy

Relatively Prime Graph

brute force, constructive algorithms, graphs, greedy, math

Military Problem

dfs and similar, graphs, trees

Berland and the Shortest Paths

brute force, dfs and similar, graphs, shortest paths

Tree Constructing

constructive algorithms, graphs

We Need More Bosses

dfs and similar, graphs, trees

Reachability from the Capital

dfs and similar, graphs, greedy

Number Clicker

divide and conquer, graphs, meet-in-the-middle, number theory

Graph And Its Complement

constructive algorithms, graphs, implementation

A Mist of Florescence

constructive algorithms, graphs

Oppa Funcan Style Remastered

graphs, math, number theory, shortest paths

AND Graph

bitmasks, dfs and similar, dsu, graphs

Fair

graphs, greedy, number theory, shortest paths

Elevator

dp, graphs, shortest paths

The Meeting Place Cannot Be Changed

dfs and similar, graphs

Cut 'em all!

dfs and similar, dp, graphs, greedy, trees

Cactus to Tree

dp, graphs, trees

Cyclic Components

dfs and similar, dsu, graphs

Minimal k-covering

flows, graphs

Degree Set

constructive algorithms, graphs, implementation

Simple Cycles Edges

dfs and similar, graphs, trees

Pathwalks

data structures, dp, graphs

Mahmoud and Ehab and the xor-MST

bitmasks, dp, graphs, implementation, math

Maximum Control (medium)

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

Fight Against Traffic

dfs and similar, graphs, shortest paths

Data Center Maintenance

dfs and similar, graphs

Protect Sheep

brute force, dfs and similar, graphs, implementation

Love Rescue

dfs and similar, dsu, graphs, greedy, strings

Love Triangle

graphs

Shortest Path Queries

bitmasks, data structures, dsu, graphs

Buy a Ticket

data structures, graphs, shortest paths

Sleepy Game

dfs and similar, dp, games, graphs

A Colourful Prospect

geometry, graphs

Peculiar apple-tree

dfs and similar, graphs, trees

Dependency management

*special problem, graphs, implementation

Public Service

constructive algorithms, graphs, trees

Connected Components?

data structures, dfs and similar, dsu, graphs

A Game With Numbers

games, graphs, shortest paths

Substring

dfs and similar, dp, graphs

MADMAX

dfs and similar, dp, games, graphs

Jamie and Interesting Graph

constructive algorithms, graphs, shortest paths

Imbalance Value of a Tree

data structures, dsu, graphs, trees

Almost Acyclic Graph

dfs and similar, graphs

Strongly Connected Tournament

dp, graphs, math, probabilities

Fishes

data structures, graphs, greedy, probabilities, shortest paths

Tree Destruction

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

Coprocessor

dfs and similar, dp, graphs, greedy

New Year and Rainbow Roads

graphs, greedy, implementation

Party

bitmasks, brute force, dp, graphs

Yet Another Maxflow Problem

data structures, flows, graphs

Weighting a Tree

constructive algorithms, dfs and similar, graphs

Bipartite Segments

binary search, data structures, dfs and similar, dsu, graphs, two pointers

Dividing the numbers

constructive algorithms, graphs, math

Ralph and Mushrooms

dp, graphs

Rumor

dfs and similar, graphs, greedy

Envy

data structures, dsu, graphs

Connecting Vertices

dp, graphs

Restoration of string

constructive algorithms, graphs, implementation

Anti-Palindromize

flows, graphs, greedy

Orientation of Edges

dfs and similar, graphs

Berland Army

constructive algorithms, graphs, greedy

Tournament

data structures, graphs

Olya and Energy Drinks

data structures, dfs and similar, graphs, shortest paths

Royal Questions

dsu, graphs, greedy

National Property

2-sat, dfs and similar, graphs, implementation

Restore the Tree

graphs, greedy, trees

Points, Lines and Ready-made Titles

dfs and similar, dsu, graphs, trees

The Overdosing Ubiquity

brute force, dfs and similar, graphs

Policeman and a Tree

dp, graphs, trees

Hex Dyslexia

bitmasks, brute force, dp, graphs