New Year and Snowy Grid

dfs and similar, dsu, graphs, interactive

Harder Satisfiability

2-sat, dfs and similar, graphs

Rap God

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

Fake bullions

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

Island Puzzle

dfs and similar, dsu, graphs, trees

Iqea

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

Harry Vs Voldemort

dfs and similar, dp, graphs, trees

Send Tree to Charlie

combinatorics, dfs and similar, dsu, trees

Bear and Chemistry

data structures, dfs and similar, graphs, trees

Cow and Vacation

dfs and similar, dsu, trees

Distance Matching

constructive algorithms, dfs and similar, trees

Summer Dichotomy

2-sat, data structures, dfs and similar, greedy

Clockwork Bomb

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

Tourists

data structures, dfs and similar, graphs, trees

Sloth

dfs and similar, dp, graph matchings, trees

Cycling City

dfs and similar, graphs

Archaeology

data structures, dfs and similar, trees

Alice and the Cactus

dfs and similar, graphs, math, probabilities

Tree and Table

dfs and similar, dp, implementation, trees

The Awesomest Vertex

data structures, dfs and similar

Berland Miners

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

The Majestic Brown Tree Snake

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

Around the World

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

James and the Chase

dfs and similar, graphs, probabilities, trees

Treeland and Viruses

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

Logistical Questions

dfs and similar, divide and conquer, trees

Misha and LCP on Tree

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

Harry Potter and Moving Staircases

dfs and similar, implementation

Function Composition

dfs and similar

Wavy numbers

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

Problem of offices

constructive algorithms, dfs and similar, dp, trees

Almost Same Distance

dfs and similar, graphs

Bitonix' Patrol

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

Omkar and Pies

bitmasks, dfs and similar, dp, math, shortest paths

Upgrading Cities

dfs and similar, graphs

TOF

dfs and similar, graphs

Bear and Chase

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

Wizards and Bets

dfs and similar, graphs, math, matrices

Pumping Stations

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

Fairy

dfs and similar, divide and conquer, dsu

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

data structures, dfs and similar, trees

Greedy Petya

*special problem, dfs and similar, graphs, greedy

The Overdosing Ubiquity

brute force, dfs and similar, graphs

Nikita and game

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

Directing Edges

dfs and similar, dp, graphs, trees

Tiles Placement

constructive algorithms, dfs and similar, trees

Road Repairs

dfs and similar, graphs, greedy

Pilgrims

dfs and similar, dp, trees

Rain of Fire

binary search, data structures, dfs and similar, dsu, graphs, implementation

Hidden Bipartite Graph

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

x-prime Substrings

brute force, dfs and similar, dp, string suffix structures, strings

Caterpillar

dfs and similar, dp, graphs, trees

The Red Button

combinatorics, dfs and similar, dsu, graphs, greedy

Yash And Trees

bitmasks, data structures, dfs and similar, math, number theory

Game of Pairs

constructive algorithms, dfs and similar, interactive, math, number theory

Drazil and Morning Exercise

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

e-Government

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

Tree Modification

brute force, constructive algorithms, dfs and similar, graph matchings, graphs, trees

Kingdom and its Cities

dfs and similar, divide and conquer, dp, graphs, sortings, trees

Case of Computer Network

dfs and similar, graphs, trees

The Meeting Place Cannot Be Changed

dfs and similar, graphs

Baldman and the military

dfs and similar, graphs, trees

Pairs

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

Strongly Connected City 2

dfs and similar

Sources and Sinks

bitmasks, brute force, dfs and similar

Tree Cutting (Hard Version)

combinatorics, dfs and similar, dp, trees

Sagheer and Kindergarten

dfs and similar, graphs, implementation, trees

Weighting a Tree

constructive algorithms, dfs and similar, graphs

Arkady and a Nobody-men

data structures, dfs and similar, trees

BareLee

dfs and similar, dp, games

Birthday

data structures, dfs and similar, dp, trees

Indie Album

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

Three Swaps

constructive algorithms, dfs and similar, greedy

Cities Excursions

dfs and similar, graphs, trees

Nested Rubber Bands

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

Johnny Solving

constructive algorithms, dfs and similar, graphs, math

Best Edge Weight

data structures, dfs and similar, graphs, trees

Subset with Zero Sum

constructive algorithms, dfs and similar, graphs, math

The Hidden Pair (Hard Version)

binary search, dfs and similar, graphs, interactive, shortest paths, trees

Digit Tree

dfs and similar, divide and conquer, dsu, trees

Star Trek

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

Yet Another DAG Problem

bitmasks, dfs and similar, dp, flows, graphs, math

Monsters and Diamonds

dfs and similar, graphs, shortest paths

Upgrading Tree

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

Broken Tree

dfs and similar, dp, graphs, greedy, trees

Superhero's Job

dfs and similar, dp, hashing, math, number theory

Road Projects

dfs and similar, dp, trees

Autocompletion

data structures, dfs and similar, dp

The Chocolate Spree

dfs and similar, dp, graphs, trees

Nastya and Time Machine

constructive algorithms, dfs and similar, graphs, trees

Phoenix and Memory

data structures, dfs and similar, graphs, greedy

Preorder Test

binary search, dfs and similar, dp, graphs, greedy, trees

Choosing Subtree is Fun

binary search, data structures, dfs and similar, trees, two pointers

Mobile Phone Network

dfs and similar, dsu, graphs, trees

Koala and Notebook

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

Super Jaber

dfs and similar, graphs, implementation, shortest paths

Pairs of Pairs

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

Break Up

dfs and similar, graphs

Bits And Pieces

bitmasks, dfs and similar, dp, greedy

Data Center Drama

dfs and similar, graphs