XOR, Tree, and Queries

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

Tick, Tock

combinatorics, dfs and similar, dsu, graphs

Caterpillar on a Tree

dfs and similar, graphs, greedy, implementation, sortings, trees

Connecting Vertices

dp, graphs

Smile House

binary search, graphs, matrices

Bear and Fair Set

flows, graphs

Traveling in Berland

binary search, data structures, graphs, greedy, implementation

Degree Set

constructive algorithms, graphs, implementation

CNF 2

constructive algorithms, dfs and similar, graphs, greedy

Italian Data Centers

graphs, shortest paths

Babysitting

2-sat, binary search, data structures, graphs, trees

Minimal k-covering

flows, graphs

Multiset of Strings

bitmasks, brute force, dp, fft, flows, graphs, math, meet-in-the-middle, trees

Madoka and The First Session

constructive algorithms, flows, graph matchings, graphs, implementation

Virus

data structures, divide and conquer, dsu, graphs

Gang Up

flows, graphs

Balance

constructive algorithms, dfs and similar, graphs, trees

Fetch the Treasure

brute force, data structures, graphs, shortest paths

Garden

bitmasks, dp, graphs, trees

Keen Tree Calculation

binary search, data structures, dp, geometry, graphs, implementation, trees

Wilbur and Strings

dfs and similar, dp, graphs, strings

Last chance

data structures, flows, graph matchings, graphs, trees

Deputies

constructive algorithms, graphs, greedy, implementation

Poachers

dp, games, graphs, trees

Loader

*special problem, graphs

Mike and Fish

constructive algorithms, dfs and similar, graphs

Arpa’s overnight party and Mehrdad’s silent entering

constructive algorithms, dfs and similar, graphs

Graph and Queries

data structures, dsu, graphs, implementation, trees

Ehab's REAL Number Theory Problem

brute force, dfs and similar, graphs, number theory, shortest paths

Data Center Drama

dfs and similar, graphs

Phoenix and Earthquake

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

Quantifier Question

dfs and similar, dp, graphs, math

Pairs of Pairs

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

Graph Subset Problem

constructive algorithms, data structures, graphs

Break Up

dfs and similar, graphs

BFS Trees

combinatorics, dfs and similar, graphs, math, shortest paths, trees

Koala and Notebook

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

Super Jaber

dfs and similar, graphs, implementation, shortest paths

Xor-matic Number of the Graph

bitmasks, graphs, math, number theory, trees

Flights

graphs, shortest paths

Parametric MST

binary search, constructive algorithms, graphs, greedy, math, sortings

Guard Towers

binary search, dsu, geometry, graphs, sortings

The Chocolate Spree

dfs and similar, dp, graphs, trees

Mobile Phone Network

dfs and similar, dsu, graphs, trees

Tree Recovery

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

Strange LCS

bitmasks, dp, graphs, greedy, strings

Vladik and Entertaining Flags

data structures, dsu, graphs

Opening Portals

dsu, graphs, shortest paths

Playing on Graph

graphs, shortest paths

Nastya and Time Machine

constructive algorithms, dfs and similar, graphs, trees

Preorder Test

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

Random Walk

dp, graphs, math, probabilities, trees

Phoenix and Memory

data structures, dfs and similar, graphs, greedy

Vasya and Endless Credits

dp, flows, graph matchings, graphs, sortings

Button Lock

flows, graph matchings, graphs

Robot Control

dp, graphs, shortest paths

Beads

dp, graphs

An unavoidable detour for home

combinatorics, dp, graphs, shortest paths

Lenient Vertex Cover

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

Four Melodies

flows, graphs

Yet Another DAG Problem

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

Maximizing Root

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

Trial for Chief

graphs, greedy, shortest paths

Words on Tree

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

Forced Online Queries Problem

data structures, divide and conquer, dsu, graphs, trees

Politics

flows, graphs

Two Paths

constructive algorithms, dsu, graphs, implementation

Foolprüf Security

graphs

Parcels

dp, graphs

Broken Tree

dfs and similar, dp, graphs, greedy, trees

Maximum Waterfall

data structures, dp, graphs, sortings

Upgrading Tree

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

Meeting Her

dp, graphs, shortest paths

Berland Army

constructive algorithms, graphs, greedy

Monsters and Diamonds

dfs and similar, graphs, shortest paths

A Game With Numbers

games, graphs, shortest paths

Amanda the Amoeba

graphs, implementation, trees, two pointers

Doe Graphs

constructive algorithms, divide and conquer, dp, graphs, shortest paths

Grocer's Problem

constructive algorithms, graphs, greedy

Star Trek

*special problem, combinatorics, dfs and similar, dp, games, graphs, matrices, trees

Escaping on Beaveractor

graphs

Subset with Zero Sum

constructive algorithms, dfs and similar, graphs, math

The Hidden Pair (Hard Version)

binary search, dfs and similar, graphs, interactive, shortest paths, trees

Best Edge Weight

data structures, dfs and similar, graphs, trees

Capitalism

constructive algorithms, dfs and similar, graphs, shortest paths

Common Divisor Graph

brute force, constructive algorithms, dsu, graphs, hashing, math, number theory

Phoenix and Odometers

dfs and similar, graphs, math, number theory

Clusterization Counting

combinatorics, dp, dsu, fft, graphs, trees

Tournament

data structures, graphs

Mother of Dragons

brute force, graphs, math, meet-in-the-middle

Approximate Diameter

binary search, divide and conquer, graphs, shortest paths

Christmas Chocolates

dfs and similar, dp, games, graphs, implementation, math, number theory, shortest paths, trees

Good Graph

data structures, dsu, graphs, trees

Off by One

constructive algorithms, dfs and similar, geometry, graphs, sortings, trees

Zoning Restrictions

dp, flows, graphs

Johnny Solving

constructive algorithms, dfs and similar, graphs, math

Chaotic V.

dp, graphs, greedy, math, number theory, trees

One-Four Overload

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

Graph Coloring (easy version)

combinatorics, dp, graphs

Removal Sequences

bitmasks, dfs and similar, graphs