0-1-Tree

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

Programming Competition

dfs and similar, dp, graph matchings, greedy, trees

Chemical table

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

Koxia and Game

constructive algorithms, data structures, dfs and similar, dsu, flows, games, graph matchings, graphs, implementation

Li Hua and Tree

brute force, data structures, dfs and similar, dp, implementation, trees

Microcycle

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

Nauuo and Circle

combinatorics, dfs and similar, dp, trees

Anton and Tree

dfs and similar, dp, trees

Kay and Snowflake

data structures, dfs and similar, dp, trees

Rarity and New Dress

dfs and similar, dp, implementation, shortest paths

Connecting Universities

dfs and similar, dp, graphs, trees

Robot Factory

bitmasks, dfs and similar

Missile Silos

data structures, dfs and similar, graphs, shortest paths

Two Sets

2-sat, dfs and similar, dsu, graph matchings, greedy

Fish Graph

brute force, constructive algorithms, dfs and similar, graphs

Valid Sets

dfs and similar, dp, math, trees

Fun with Integers

dfs and similar, graphs, implementation, math

We Need More Bosses

dfs and similar, graphs, trees

Olya and Energy Drinks

data structures, dfs and similar, graphs, shortest paths

Quantity of Strings

combinatorics, dfs and similar, graphs, math

Garland

dfs and similar, graphs, greedy, trees

Kilani and the Game

dfs and similar, graphs, implementation, shortest paths

Buds Re-hanging

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

Ehab's Last Corollary

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

Reverse

bitmasks, constructive algorithms, dfs and similar, implementation, math, strings

Hanging Hearts

constructive algorithms, data structures, dfs and similar, dp, greedy, trees

Nearest Beautiful Number (hard version)

bitmasks, brute force, constructive algorithms, dfs and similar, dp, greedy

Orac and Game of Life

dfs and similar, graphs, implementation, shortest paths

Chloe and pleasant prizes

dfs and similar, dp, graphs, trees

Send the Fool Further! (easy)

dfs and similar, graphs, trees

Passable Paths (hard version)

data structures, dfs and similar, trees

Two Paths

dfs and similar, dp, graphs, shortest paths, trees, two pointers

Igor and his way to work

dfs and similar, graphs, implementation, shortest paths

The Strongest Build

binary search, brute force, data structures, dfs and similar, graphs, greedy, hashing, implementation

Directed Roads

combinatorics, dfs and similar, graphs, math

Undoubtedly Lucky Numbers

bitmasks, brute force, dfs and similar

Numbers on Tree

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

GCD Counting

data structures, dfs and similar, dp, number theory, trees

pSort

dfs and similar, dsu, graphs

Moving to the Capital

dfs and similar, dp, graphs, shortest paths

Paths on the Tree

dfs and similar, dp, greedy, sortings, trees

Alyona and a tree

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

Serial Time!

dfs and similar, dsu

Hierarchy

dfs and similar, dsu, greedy, shortest paths

Om Nom and Dark Park

dfs and similar, greedy, implementation

Subway

dfs and similar, graphs

Mail Stamps

data structures, dfs and similar, graphs, implementation

Toss a Coin to Your Graph...

binary search, dfs and similar, dp, graphs

Bertown Subway

dfs and similar, greedy, math

Two Fairs

combinatorics, dfs and similar, dsu, graphs

Kuroni and the Celebration

constructive algorithms, dfs and similar, interactive, trees

Frog Traveler

data structures, dfs and similar, dp, graphs, shortest paths, two pointers

The Door Problem

2-sat, dfs and similar, dsu, graphs

Nearest Excluded Points

binary search, data structures, dfs and similar, graphs, shortest paths

Serval and Rooted Tree

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

Road Map

dfs and similar, graphs

Reset K Edges

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

1-Trees and Queries

data structures, dfs and similar, shortest paths, trees

PermuTree (easy version)

dfs and similar, dp, trees

Bear and Compressing

brute force, dfs and similar, dp, strings

Zero Tree

dfs and similar, dp, greedy, trees

Ksyusha and Chinchilla

constructive algorithms, dfs and similar, dp, dsu, greedy, implementation, trees

Dorm Water Supply

dfs and similar, graphs

Treasure Island

dfs and similar, dp, flows, hashing

Coloring Edges

constructive algorithms, dfs and similar, graphs

Tree XOR

bitmasks, dfs and similar, dp, greedy, trees

Omsk Metro (simple version)

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

Generate a String

dfs and similar, dp

Crazy Robot

dfs and similar, graphs

Design Tutorial: Inverse the Problem

dfs and similar, dsu, shortest paths, trees

Restore Graph

dfs and similar, graphs, sortings

Vlad and Unfinished Business

dfs and similar, dp, greedy, trees

Passable Paths (easy version)

dfs and similar, trees

Police Stations

constructive algorithms, dfs and similar, dp, graphs, shortest paths, trees

Civilization

dfs and similar, dp, dsu, ternary search, trees

Necklace Assembly

brute force, dfs and similar, dp, graphs, greedy, number theory

Recover it!

dfs and similar, graphs, greedy, number theory, sortings

Tournament

bitmasks, brute force, dfs and similar, greedy

Arpa's weak amphitheater and Mehrdad's valuable Hoses

dfs and similar, dp, dsu

Need for Pink Slips

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

Swaps in Permutation

dfs and similar, dsu, math

The Labyrinth

dfs and similar

Cyclic Operations

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

Appleman and Tree

dfs and similar, dp, trees

Three Paths on a Tree

dfs and similar, dp, greedy, trees

Arpa's loud Owf and Mehrdad's evil plan

dfs and similar, math

Choosing flowers

binary search, brute force, data structures, dfs and similar, dp, greedy, sortings, two pointers

Water Tree

data structures, dfs and similar, graphs, trees

Number of Simple Paths

combinatorics, dfs and similar, graphs, trees

MinOr Tree

bitmasks, dfs and similar, dsu, graphs, greedy

Sorting by Subsequences

dfs and similar, dsu, implementation, math, sortings

Gardening Friends

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

Mike and Shortcuts

dfs and similar, graphs, greedy, shortest paths

Tree Cutting (Easy Version)

dfs and similar, trees

Fix a Tree

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

Decorate Apple Tree

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

A Lot of Games

dfs and similar, dp, games, implementation, strings, trees

The Tag Game

dfs and similar, graphs

Weights Division (easy version)

data structures, dfs and similar, greedy, trees

Friendly Spiders

dfs and similar, graphs, math, number theory, shortest paths