Pattern Matching

bitmasks, data structures, dfs and similar, graphs, hashing, sortings, strings

Leha and another game about graph

constructive algorithms, data structures, dfs and similar, dp, graphs

Copy of a Copy of a Copy

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

Envy

data structures, dsu, graphs

Count Seconds

brute force, constructive algorithms, dp, graphs, implementation, math

Block Tower

constructive algorithms, dfs and similar, graphs

Turtle Mission: Robot and the Earthquake

dfs and similar, dp, graphs, shortest paths

Case of Computer Network

dfs and similar, graphs, trees

AND Graph

bitmasks, dfs and similar, dsu, graphs

Privatization of Roads in Treeland

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

Cars

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

Moment of Bloom

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

Subordinates

constructive algorithms, data structures, graphs, greedy, sortings

Instant Noodles

graphs, hashing, math, number theory

Ralph and Mushrooms

dp, graphs

Tourists

data structures, dfs and similar, graphs, trees

Autosynthesis

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

Vitaly and Cycle

combinatorics, dfs and similar, graphs, math

Infinite Maze

dfs and similar, graphs

Yaroslav and Time

binary search, graphs, shortest paths

Cycle In Maze

*special problem, dfs and similar, graphs, greedy, shortest paths

Roma and Poker

dp, graphs

Strictly Positive Matrix

graphs, math

World Tour

graphs, shortest paths

Water Level

brute force, graphs, greedy, implementation, math

Information Graph

dfs and similar, dsu, graphs, trees

Partial Teacher

dp, graphs, greedy, implementation

The way home

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

Subset with Zero Sum

constructive algorithms, dfs and similar, graphs, math

Mr. Kitayuta's Colorful Graph

brute force, dfs and similar, dsu, graphs

Nastya and Unexpected Guest

dfs and similar, dp, graphs, shortest paths

The Great Mixing

dfs and similar, graphs, shortest paths

Arithmetic Operations

brute force, data structures, graphs, math

Coprocessor

dfs and similar, dp, graphs, greedy

Robots on a Grid

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

Data Center Maintenance

dfs and similar, graphs

Pursuit For Artifacts

dfs and similar, dsu, graphs, trees

Fishes

data structures, graphs, greedy, probabilities, shortest paths

Petya and Graph

flows, graphs

Olympiad in Programming and Sports

dp, flows, graphs, greedy

Ski Accidents

constructive algorithms, graphs, greedy

Table Compression

dfs and similar, dp, dsu, graphs, greedy

National Property

2-sat, dfs and similar, graphs, implementation

Elongated Matrix

binary search, bitmasks, brute force, dp, graphs

3-cycles

constructive algorithms, graphs, greedy

Dasha and Puzzle

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

Catowice City

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

Robot on the Board 2

brute force, dfs and similar, graphs, implementation

One-Way Reform

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

Avoid Rainbow Cycles

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

Graph and Queries

data structures, dsu, graphs, implementation, trees

Between

constructive algorithms, dfs and similar, graphs, greedy

Lost Array

graphs, greedy, interactive, shortest paths

Ehab's REAL Number Theory Problem

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

X(or)-mas Tree

bitmasks, dfs and similar, dsu, graphs, trees

Transitive Graph

dfs and similar, dp, dsu, graphs, implementation

Two Houses

brute force, graphs, greedy, interactive, sortings

Theseus and labyrinth

graphs, implementation, shortest paths

Ela and the Wiring Wizard

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

Data Center Drama

dfs and similar, graphs

Dispute

dfs and similar, graphs, greedy

Boboniu Walks on Graph

brute force, dfs and similar, graphs, hashing

Police Station

dp, graphs, shortest paths

Valuable Paper

binary search, flows, graph matchings, graphs

Fedor and Essay

dfs and similar, dp, graphs, hashing, strings

Lights

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

Number of Groups

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

Polycarp and Hay

dfs and similar, dsu, graphs, greedy, sortings

Make It Connected

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

Ehab's Last Theorem

constructive algorithms, dfs and similar, graphs, greedy

Is It Flower?

dfs and similar, graphs, implementation

Love Triangles

dfs and similar, dsu, graphs

Restoration of string

constructive algorithms, graphs, implementation

Gifts by the List

constructive algorithms, dfs and similar, graphs, trees

Railguns

brute force, dfs and similar, dp, graphs

Sereja and the Arrangement of Numbers

graphs, greedy, sortings

Node Pairs

dp, graphs, math, number theory

Edge Reverse

binary search, dfs and similar, graphs, trees

Permutation recovery

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

Anya's Simultaneous Exhibition

constructive algorithms, graphs, greedy, interactive, sortings

The Maximum Subtree

dfs and similar, dp, graphs, trees

Great Grids

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

Phoenix and Earthquake

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

Light Bulbs (Easy Version)

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

The Beach

constructive algorithms, dfs and similar, graphs, shortest paths

Delete a Segment

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

Maximize Mex

flows, graph matchings, graphs

A-Z Graph

constructive algorithms, data structures, graphs, hashing

Greg and Friends

combinatorics, dp, graphs, shortest paths

Desk Disorder

combinatorics, dfs and similar, dsu, graphs, trees

Tree Modification

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

President and Roads

dfs and similar, graphs, hashing, shortest paths

Quantifier Question

dfs and similar, dp, graphs, math

Arthur and Walls

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

Flawed Flow

constructive algorithms, flows, graphs, greedy

Berland and the Shortest Paths

brute force, dfs and similar, graphs, shortest paths

Long Way Home

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

Cactus Wall

constructive algorithms, dfs and similar, graphs, shortest paths

Egor in the Republic of Dagestan

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

Build String

flows, graphs