Number of Simple Paths

combinatorics, dfs and similar, graphs, trees

Water Tree

data structures, dfs and similar, graphs, trees

Choosing flowers

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

Arpa's loud Owf and Mehrdad's evil plan

dfs and similar, math

Three Paths on a Tree

dfs and similar, dp, greedy, trees

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

Swaps in Permutation

dfs and similar, dsu, math

Need for Pink Slips

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

Tournament

bitmasks, brute force, dfs and similar, greedy

Arpa's weak amphitheater and Mehrdad's valuable Hoses

dfs and similar, dp, dsu

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

Police Stations

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

Passable Paths (easy version)

dfs and similar, trees

Vlad and Unfinished Business

dfs and similar, dp, greedy, trees

Design Tutorial: Inverse the Problem

dfs and similar, dsu, shortest paths, trees

Restore Graph

dfs and similar, graphs, sortings

Crazy Robot

dfs and similar, graphs

Omsk Metro (simple version)

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

Tree XOR

bitmasks, dfs and similar, dp, greedy, trees

Generate a String

dfs and similar, dp

Dorm Water Supply

dfs and similar, graphs

Ksyusha and Chinchilla

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

Coloring Edges

constructive algorithms, dfs and similar, graphs

Treasure Island

dfs and similar, dp, flows, hashing

1-Trees and Queries

data structures, dfs and similar, shortest paths, trees

PermuTree (easy version)

dfs and similar, dp, trees

Zero Tree

dfs and similar, dp, greedy, trees

Bear and Compressing

brute force, dfs and similar, dp, strings

Reset K Edges

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

Road Map

dfs and similar, graphs

Serval and Rooted Tree

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

Nearest Excluded Points

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

The Door Problem

2-sat, dfs and similar, dsu, graphs

Frog Traveler

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

Kuroni and the Celebration

constructive algorithms, dfs and similar, interactive, trees

Circle Perimeter

binary search, brute force, dfs and similar, geometry, implementation, math

Two Fairs

combinatorics, dfs and similar, dsu, graphs

Bertown Subway

dfs and similar, greedy, math

Toss a Coin to Your Graph...

binary search, dfs and similar, dp, graphs

Mail Stamps

data structures, dfs and similar, graphs, implementation

Subway

dfs and similar, graphs

Hierarchy

dfs and similar, dsu, greedy, shortest paths

Om Nom and Dark Park

dfs and similar, greedy, implementation

Serial Time!

dfs and similar, dsu

Paths on the Tree

dfs and similar, dp, greedy, sortings, trees

Alyona and a tree

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

Numbers on Tree

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

Undoubtedly Lucky Numbers

bitmasks, brute force, dfs and similar

Directed Roads

combinatorics, dfs and similar, graphs, math

The Strongest Build

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

Igor and his way to work

dfs and similar, graphs, implementation, shortest paths

Passable Paths (hard version)

data structures, dfs and similar, trees

Two Paths

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

Send the Fool Further! (easy)

dfs and similar, graphs, trees

Chloe and pleasant prizes

dfs and similar, dp, graphs, trees

Orac and Game of Life

dfs and similar, graphs, implementation, shortest paths

Nearest Beautiful Number (hard version)

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

Hanging Hearts

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

Reverse

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

Buds Re-hanging

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

Ehab's Last Corollary

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

Kilani and the Game

dfs and similar, graphs, implementation, shortest paths

Garland

dfs and similar, graphs, greedy, trees

Quantity of Strings

combinatorics, dfs and similar, graphs, math

Olya and Energy Drinks

data structures, dfs and similar, graphs, shortest paths

Two Sets

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

We Need More Bosses

dfs and similar, graphs, trees

Fish Graph

brute force, constructive algorithms, dfs and similar, graphs

Fun with Integers

dfs and similar, graphs, implementation, math

Valid Sets

dfs and similar, dp, math, trees

Microcycle

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

Missile Silos

data structures, dfs and similar, graphs, shortest paths

Kay and Snowflake

data structures, dfs and similar, dp, trees

Robot Factory

bitmasks, dfs and similar

Connecting Universities

dfs and similar, dp, graphs, trees

Rarity and New Dress

dfs and similar, dp, implementation, shortest paths

Nauuo and Circle

combinatorics, dfs and similar, dp, trees

Anton and Tree

dfs and similar, dp, trees

Li Hua and Tree

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

0-1-Tree

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

Programming Competition

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

Koxia and Game

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

Escape The Maze (hard version)

dfs and similar, dp, greedy, shortest paths, trees

Chemical table

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

Cow Program

dfs and similar, dp, graphs

Misha, Grisha and Underground

dfs and similar, graphs, trees

Brain Network (medium)

dfs and similar, graphs, trees

Strange Housing

constructive algorithms, dfs and similar, graph matchings, graphs, greedy

Weight the Tree

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

Edge Split

brute force, constructive algorithms, dfs and similar, dsu, graphs, probabilities, trees

To Go Or Not To Go?

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

MADMAX

dfs and similar, dp, games, graphs

Shuffling Songs

bitmasks, dfs and similar, dp, graphs, hashing, implementation, strings