Labelling Cities

dfs and similar, graphs, hashing

Vus the Cossack and a Graph

dfs and similar, graphs, greedy, implementation

Autocompletion

data structures, dfs and similar, dp

The Red Button

combinatorics, dfs and similar, dsu, graphs, greedy

Wrong Floyd

brute force, constructive algorithms, dfs and similar, graphs

Nobody is needed

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

Vova Escapes the Matrix

brute force, dfs and similar, divide and conquer, shortest paths

One-Four Overload

2-sat, constructive algorithms, dfs and similar, dsu, graphs, implementation

Palindrome XOR

dfs and similar, graphs

Sweets Game

bitmasks, dfs and similar, dp, games, implementation

Yash And Trees

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

Two Centroids

data structures, dfs and similar, greedy, trees

Diverging Directions

data structures, dfs and similar, trees

Logistical Questions

dfs and similar, divide and conquer, trees

Maze

dfs and similar, dp, probabilities, trees

Colored Subgraphs

dfs and similar, dp, games, greedy, trees

Three-dimensional Turtle Super Computer

brute force, dfs and similar, graphs

Polo the Penguin and Trees

combinatorics, dfs and similar, trees

Graph

*special problem, binary search, dfs and similar, dp, math, ternary search

Pumping Stations

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

Ksenia and Pawns

dfs and similar, graphs, implementation, trees

Removal Sequences

bitmasks, dfs and similar, graphs

Edge Elimination

constructive algorithms, dfs and similar, dp, trees

Tree Weights

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

Santa Clauses and a Soccer Championship

constructive algorithms, dfs and similar, graphs, trees

Lenient Vertex Cover

dfs and similar, divide and conquer, dsu, graphs, trees

James and the Chase

dfs and similar, graphs, probabilities, trees

Yet Another DAG Problem

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

Pairs of Paths

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

Hyperspace Highways

dfs and similar, graphs, trees

Treeland and Viruses

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

Sereja and Sets

bitmasks, dfs and similar

Maximum Control (medium)

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

FreeDiv

dfs and similar, graphs, greedy

CNF 2

constructive algorithms, dfs and similar, graphs, greedy

Dominoes

dfs and similar, graphs

Summer Dichotomy

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

Maximize the Difference

bitmasks, brute force, dfs and similar

BareLee

dfs and similar, dp, games

Maximizing Root

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

Cyclic Coloring

dfs and similar

Clockwork Bomb

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

Occurrences

combinatorics, dfs and similar, dp, dsu, fft, graphs

Partial Virtual Trees

combinatorics, dfs and similar, dp, math, trees

Hidden Bipartite Graph

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

Cities Excursions

dfs and similar, graphs, trees

Cats on the Upgrade (hard version)

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

The Light Square

2-sat, dfs and similar, greedy

Cow and Vacation

dfs and similar, dsu, trees

Unordered Swaps

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

Dating

brute force, dfs and similar, graphs, trees

Black, White and Grey Tree

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

Mushroom Strife

brute force, dfs and similar

Wizards and Bets

dfs and similar, graphs, math, matrices

Caterpillar

dfs and similar, dp, graphs, trees

Words on Tree

2-sat, dfs and similar, dsu, graphs, trees

Upgrading Cities

dfs and similar, graphs

T-decomposition

dfs and similar, graphs, greedy, trees

Three Swaps

constructive algorithms, dfs and similar, greedy

Nezzar and Hidden Permutations

constructive algorithms, dfs and similar, graphs

Petya and Tree

binary search, dfs and similar, probabilities, sortings, trees

Colorado Potato Beetle

dfs and similar, implementation

Choosing Two Paths

dfs and similar, dp, greedy, trees

Falling Sand (Hard Version)

dfs and similar, dp, graphs, greedy

Birthday

data structures, dfs and similar, dp, trees

Game of Stacks

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

Tree Cutting (Hard Version)

combinatorics, dfs and similar, dp, trees

Rats

brute force, dfs and similar, graphs, implementation, shortest paths

Superhero's Job

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

Sum of Matchings

brute force, combinatorics, constructive algorithms, dfs and similar, graph matchings, greedy, math

Mashtali: a Space Oddysey

constructive algorithms, dfs and similar, graphs

Balance

constructive algorithms, dfs and similar, graphs, trees

Xenia and Dominoes

bitmasks, dfs and similar, dp

Rain of Fire

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

Distance to the Path

data structures, dfs and similar, trees

Neatness

constructive algorithms, dfs and similar

Game On Tree

data structures, dfs and similar, greedy, trees

A Serious Referee

bitmasks, brute force, dfs and similar, sortings

The Majestic Brown Tree Snake

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

Doctor's Brown Hypothesis

dfs and similar, graphs, math, number theory

Omkar and Pies

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

Broken Tree

dfs and similar, dp, graphs, greedy, trees

Down Below

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

Weighting a Tree

constructive algorithms, dfs and similar, graphs

Pilgrims

dfs and similar, dp, trees

Constrained Tree

dfs and similar

Ambiguous Dominoes

constructive algorithms, dfs and similar, graphs

Permutation Weight (Easy Version)

constructive algorithms, dfs and similar, dsu

Arkady and a Nobody-men

data structures, dfs and similar, trees

Harry Potter and the Sorting Hat

brute force, dfs and similar, hashing

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

Group Division

constructive algorithms, dfs and similar, graphs, greedy

Most Different Tree

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

Strongly Connected City 2

dfs and similar

Nikita and game

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

Squid Game

data structures, dfs and similar, greedy, trees

Bear and Chemistry

data structures, dfs and similar, graphs, trees

Cactusophobia

dfs and similar, flows