Greedy Petya

*special problem, dfs and similar, graphs, greedy

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

data structures, dfs and similar, trees

Fairy

dfs and similar, divide and conquer, dsu

Pumping Stations

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

Edge Elimination

constructive algorithms, dfs and similar, dp, trees

Upgrading Cities

dfs and similar, graphs

Wizards and Bets

dfs and similar, graphs, math, matrices

Doctor's Brown Hypothesis

dfs and similar, graphs, math, number theory

Omkar and Pies

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

Group Division

constructive algorithms, dfs and similar, graphs, greedy

Snowy Mountain

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

Almost Same Distance

dfs and similar, graphs

Delete The Edges

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

Bear and Chase

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

TOF

dfs and similar, graphs

Bitonix' Patrol

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

Problem of offices

constructive algorithms, dfs and similar, dp, trees

Wavy numbers

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

Cactus Not Enough

dfs and similar, graph matchings, graphs

Function Composition

dfs and similar

Harry Potter and Moving Staircases

dfs and similar, implementation

Misha and LCP on Tree

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

Logistical Questions

dfs and similar, divide and conquer, trees

Treeland and Viruses

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

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

Game of Stacks

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

Falling Sand (Hard Version)

dfs and similar, dp, graphs, greedy

Mashtali: a Space Oddysey

constructive algorithms, dfs and similar, graphs

A Serious Referee

bitmasks, brute force, dfs and similar, sortings

The Majestic Brown Tree Snake

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

Down Below

binary search, dfs and similar, graphs, greedy, meet-in-the-middle, shortest paths

Edge Queries

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

Around the World

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

The Awesomest Vertex

data structures, dfs and similar

Berland Miners

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

Li Hua and Path

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

Palindromic Hamiltonian Path

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

Tree and Permutation Game

dfs and similar, games, graphs, trees

Alice and the Cactus

dfs and similar, graphs, math, probabilities

Tree and Table

dfs and similar, dp, implementation, trees

Archaeology

data structures, dfs and similar, trees

Cycling City

dfs and similar, graphs

Squid Game

data structures, dfs and similar, greedy, trees

Tree Calendar

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

Just Kingdom

brute force, data structures, dfs and similar

Sloth

dfs and similar, dp, graph matchings, trees

Tourists

data structures, dfs and similar, graphs, trees

Summer Dichotomy

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

Clockwork Bomb

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

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

Teleportation in Byteland

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

Distance Matching

constructive algorithms, dfs and similar, trees

Triameter

binary search, data structures, dfs and similar, trees

Tree Cutting

bitmasks, dfs and similar, dp

Cow and Vacation

dfs and similar, dsu, trees

Bear and Chemistry

data structures, dfs and similar, graphs, trees

Send Tree to Charlie

combinatorics, dfs and similar, dsu, trees

Harry Vs Voldemort

dfs and similar, dp, graphs, trees

Interactive Mex Tree

constructive algorithms, dfs and similar, interactive, trees

Grove

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

Bus Routes

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

Hard Cut

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

Island Puzzle

dfs and similar, dsu, graphs, trees

Iqea

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

Two Sorts

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

Fake bullions

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

Rap God

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

Organizing a Music Festival

dfs and similar, math

Harder Satisfiability

2-sat, dfs and similar, graphs

Just Add an Edge

dfs and similar, dp, graphs

New Year and Snowy Grid

dfs and similar, dsu, graphs, interactive

Cacti Symphony

combinatorics, dfs and similar, dp, graphs

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

Finding the Vertex

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

Two Avenues

data structures, dfs and similar, graphs

Doremy's Swapping Trees

dfs and similar, graphs, trees

Long Recovery

constructive algorithms, dfs and similar