Orientation of Edges

dfs and similar, graphs

Solitaire

dfs and similar, dp

Ice Cave

dfs and similar

Directing Edges

constructive algorithms, dfs and similar, graphs

Tree Shuffling

dfs and similar, dp, greedy, trees

Reachability from the Capital

dfs and similar, graphs, greedy

Captain Flint and Treasure

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

Propagating tree

data structures, dfs and similar, trees

Bertown roads

dfs and similar, graphs

Book of Evil

dfs and similar, divide and conquer, dp, trees

Monopole Magnets

constructive algorithms, dfs and similar, dsu, graphs

Weights Division (easy version)

data structures, dfs and similar, greedy, trees

Number of Simple Paths

combinatorics, dfs and similar, graphs, trees

Choosing flowers

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

Three Paths on a Tree

dfs and similar, dp, greedy, trees

Appleman and Tree

dfs and similar, dp, trees

Crazy Robot

dfs and similar, graphs

Generate a String

dfs and similar, dp

1-Trees and Queries

data structures, dfs and similar, shortest paths, trees

The Door Problem

2-sat, dfs and similar, dsu, graphs

GCD Counting

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

The Strongest Build

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

Passable Paths (hard version)

data structures, dfs and similar, trees

Orac and Game of Life

dfs and similar, graphs, implementation, shortest paths

Reverse

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

Buds Re-hanging

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

Garland

dfs and similar, graphs, greedy, trees

Two Sets

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

Koxia and Game

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

Edge Split

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

Weight the Tree

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

Ilya And The Tree

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

A Growing Tree

data structures, dfs and similar, trees

Mahmoud and a Dictionary

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

Nash Matrix

constructive algorithms, dfs and similar, graphs, implementation

Count Paths

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

Gourmet choice

dfs and similar, dp, dsu, graphs, greedy

Sergey and Subway

dfs and similar, dp, trees

Rudolf and Subway

constructive algorithms, dfs and similar, graphs, shortest paths

Destruction of a Tree

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

Lynyrd Skynyrd

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

Cycle

dfs and similar, graphs

Jeremy Bearimy

dfs and similar, graphs, greedy, trees

Remove Directed Edges

dfs and similar, dp, graphs

Mars rover

dfs and similar, graphs, implementation, trees

Berzerk

dfs and similar, dp, games

Work Group

dfs and similar, dp, graphs, strings, trees

Ant on the Tree

constructive algorithms, dfs and similar, trees

Unusual Minesweeper

binary search, dfs and similar, dsu, greedy, sortings

Copy of a Copy of a Copy

constructive algorithms, dfs and similar, graphs, implementation, sortings

Vitaly and Cycle

combinatorics, dfs and similar, graphs, math

An overnight dance in discotheque

dfs and similar, dp, geometry, greedy, trees

Infinite Maze

dfs and similar, graphs

Dasha and Puzzle

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

Giving Awards

dfs and similar

Polycarp and Hay

dfs and similar, dsu, graphs, greedy, sortings

Gifts by the List

constructive algorithms, dfs and similar, graphs, trees

Minimal Diameter Forest

constructive algorithms, dfs and similar, greedy, trees

Wires

dfs and similar, graphs, greedy

Sereja and Periods

binary search, dfs and similar, strings

Weak Memory

dfs and similar, dsu

Dima and Trap Graph

binary search, data structures, dfs and similar, dsu, shortest paths, two pointers

Tree-String Problem

*special problem, dfs and similar, hashing, strings

Circle of Numbers

brute force, dfs and similar, implementation

Chocolate

dfs and similar, implementation

General Mobilization

data structures, dfs and similar, sortings

Sweets Game

bitmasks, dfs and similar, dp, games, implementation

Dominoes

dfs and similar, graphs

T-decomposition

dfs and similar, graphs, greedy, trees

Tree Painting

dfs and similar, dp, trees

Minimum spanning tree for each edge

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

Ciel the Commander

constructive algorithms, dfs and similar, divide and conquer, greedy, trees

A and B and Lecture Rooms

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

Blood Cousins

binary search, data structures, dfs and similar, trees

Connected Components?

data structures, dfs and similar, dsu, graphs

Water Tree

data structures, dfs and similar, graphs, trees

Civilization

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

Police Stations

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

Coloring Edges

constructive algorithms, dfs and similar, graphs

Moving to the Capital

dfs and similar, dp, graphs, shortest paths

Nearest Beautiful Number (hard version)

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

Ehab's Last Corollary

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

Olya and Energy Drinks

data structures, dfs and similar, graphs, shortest paths

We Need More Bosses

dfs and similar, graphs, trees

Valid Sets

dfs and similar, dp, math, trees

Rarity and New Dress

dfs and similar, dp, implementation, shortest paths

Anton and Tree

dfs and similar, dp, trees

Permutation Shift

brute force, combinatorics, constructive algorithms, dfs and similar, dsu, graphs, math

Timofey and Black-White Tree

brute force, dfs and similar, divide and conquer, graphs, greedy, math, shortest paths, trees

Graph Coloring

dfs and similar, dp, graphs

Sleepy Game

dfs and similar, dp, games, graphs

Monsters

brute force, data structures, dfs and similar, dsu, graphs, greedy

How Many Paths?

dfs and similar, dp, graphs, trees

Treelabeling

bitmasks, constructive algorithms, dfs and similar, games, greedy, implementation, trees

Mahmoud and a xor trip

bitmasks, constructive algorithms, data structures, dfs and similar, dp, math, trees

Euclid's nightmare

bitmasks, dfs and similar, dsu, graphs, greedy, math, sortings

Bear and Tree Jumps

dfs and similar, dp, trees

Potion Brewing Class

dfs and similar, math, number theory, trees

Berland Beauty

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

Speedrun

brute force, dfs and similar, dp, graphs, greedy, math, sortings, two pointers