Modular Sequence

brute force, constructive algorithms, dp, graphs, greedy, math, number theory

Walk the Runway

bitmasks, brute force, data structures, dp, graphs, implementation, sortings

Jellyfish and EVA

dp, graphs, greedy, math, probabilities

Shortest Path Problem?

dfs and similar, graphs, math

Prefix Enlightenment

dfs and similar, dsu, graphs

Tree Destruction

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

Session in BSU

binary search, dfs and similar, dsu, graph matchings, graphs

Vanya and Treasure

data structures, dp, graphs, shortest paths

On Changing Tree

data structures, graphs, trees

Vladik and Favorite Game

constructive algorithms, dfs and similar, graphs, interactive

Cactus

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

Scheme

dfs and similar, graphs, trees

Little Girl and Problem on Trees

data structures, graphs, trees

Wires

dfs and similar, graphs, greedy

Yet Another Segments Subset

data structures, dp, graphs, sortings

Daleks' Invasion (easy)

graphs, trees

Ant Man

dp, graphs, greedy

Little Pony and Summer Sun Celebration

constructive algorithms, dfs and similar, graphs

Graph Transpositions

dfs and similar, graphs, greedy, shortest paths

Presents in Bankopolis

dp, graphs, shortest paths

Cheap Robot

binary search, dsu, graphs, shortest paths, trees

Square Root of Permutation

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

Build String

flows, graphs

Triangles

combinatorics, graphs, math

Cactus Wall

constructive algorithms, dfs and similar, graphs, shortest paths

Flawed Flow

constructive algorithms, flows, graphs, greedy

Long Way Home

data structures, divide and conquer, dp, geometry, graphs, greedy, shortest paths

Fair Share

constructive algorithms, data structures, dfs and similar, graph matchings, graphs

Berland and the Shortest Paths

brute force, dfs and similar, graphs, shortest paths

President and Roads

dfs and similar, graphs, hashing, shortest paths

Egor in the Republic of Dagestan

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

Arthur and Walls

constructive algorithms, data structures, graphs, greedy, shortest paths

Light Bulbs (Easy Version)

brute force, combinatorics, dfs and similar, dp, dsu, graphs, math, trees

Maximize Mex

flows, graph matchings, graphs

Tree Modification

brute force, constructive algorithms, dfs and similar, graph matchings, graphs, trees

Desk Disorder

combinatorics, dfs and similar, dsu, graphs, trees

Quantifier Question

dfs and similar, dp, graphs, math

Delete a Segment

brute force, constructive algorithms, data structures, dp, graphs, sortings, trees, two pointers

A-Z Graph

constructive algorithms, data structures, graphs, hashing

Greg and Friends

combinatorics, dp, graphs, shortest paths

The Beach

constructive algorithms, dfs and similar, graphs, shortest paths

Railguns

brute force, dfs and similar, dp, graphs

Edge Reverse

binary search, dfs and similar, graphs, trees

Ehab's Last Theorem

constructive algorithms, dfs and similar, graphs, greedy

Phoenix and Earthquake

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

The Maximum Subtree

dfs and similar, dp, graphs, trees

Great Grids

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

Node Pairs

dp, graphs, math, number theory

Anya's Simultaneous Exhibition

constructive algorithms, graphs, greedy, interactive, sortings

Permutation recovery

constructive algorithms, data structures, dfs and similar, graphs, greedy, math, sortings

Sereja and the Arrangement of Numbers

graphs, greedy, sortings

Is It Flower?

dfs and similar, graphs, implementation

Make It Connected

binary search, brute force, constructive algorithms, dsu, graphs, greedy, matrices, trees, two pointers

Gifts by the List

constructive algorithms, dfs and similar, graphs, trees

Lights

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

Restoration of string

constructive algorithms, graphs, implementation

Love Triangles

dfs and similar, dsu, graphs

Number of Groups

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

Polycarp and Hay

dfs and similar, dsu, graphs, greedy, sortings

Valuable Paper

binary search, flows, graph matchings, graphs

Fedor and Essay

dfs and similar, dp, graphs, hashing, strings

Transitive Graph

dfs and similar, dp, dsu, graphs, implementation

Police Station

dp, graphs, shortest paths

Boboniu Walks on Graph

brute force, dfs and similar, graphs, hashing

Ehab's REAL Number Theory Problem

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

Data Center Drama

dfs and similar, graphs

Dispute

dfs and similar, graphs, greedy

Ela and the Wiring Wizard

brute force, dp, graphs, greedy, implementation, shortest paths

X(or)-mas Tree

bitmasks, dfs and similar, dsu, graphs, trees

Graph and Queries

data structures, dsu, graphs, implementation, trees

Theseus and labyrinth

graphs, implementation, shortest paths

Two Houses

brute force, graphs, greedy, interactive, sortings

Between

constructive algorithms, dfs and similar, graphs, greedy

Lost Array

graphs, greedy, interactive, shortest paths

Catowice City

2-sat, dfs and similar, graph matchings, graphs

Avoid Rainbow Cycles

data structures, dsu, graphs, greedy, sortings, trees

Robot on the Board 2

brute force, dfs and similar, graphs, implementation

One-Way Reform

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

3-cycles

constructive algorithms, graphs, greedy

Dasha and Puzzle

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

Elongated Matrix

binary search, bitmasks, brute force, dp, graphs

National Property

2-sat, dfs and similar, graphs, implementation

Petya and Graph

flows, graphs

Olympiad in Programming and Sports

dp, flows, graphs, greedy

Ski Accidents

constructive algorithms, graphs, greedy

Fishes

data structures, graphs, greedy, probabilities, shortest paths

Table Compression

dfs and similar, dp, dsu, graphs, greedy

Pursuit For Artifacts

dfs and similar, dsu, graphs, trees

Robots on a Grid

data structures, dfs and similar, dsu, graphs, greedy, matrices

Coprocessor

dfs and similar, dp, graphs, greedy

Data Center Maintenance

dfs and similar, graphs

Arithmetic Operations

brute force, data structures, graphs, math

The Great Mixing

dfs and similar, graphs, shortest paths

Mr. Kitayuta's Colorful Graph

brute force, dfs and similar, dsu, graphs

Nastya and Unexpected Guest

dfs and similar, dp, graphs, shortest paths

The way home

binary search, data structures, dp, graphs, greedy, shortest paths, sortings

Subset with Zero Sum

constructive algorithms, dfs and similar, graphs, math

Partial Teacher

dp, graphs, greedy, implementation

Information Graph

dfs and similar, dsu, graphs, trees

Instant Noodles

graphs, hashing, math, number theory