Colored Rooks

constructive algorithms, graphs

Random Forest Rank

dp, graph matchings, math, trees

Computer Game

dp, greedy, math, probabilities

Knights

constructive algorithms

Multihedgehog

dfs and similar, graphs, shortest paths

Array Without Local Maximums

dp

Yet another 2D Walking

dp

Binary Numbers AND Sum

data structures, implementation, math

Boxes Packing

binary search, implementation

Fibonacci Suffix

strings

Up and Down the Tree

dfs and similar, dp, trees

Side Transmutations

combinatorics, strings

Three Pieces

dfs and similar, dp, shortest paths

Make It Equal

greedy

String Journey

data structures, dp, string suffix structures

Lasers and Mirrors

constructive algorithms, math

Candies for Children

brute force, math

Dwarves, Hats and Extrasensory Abilities

binary search, constructive algorithms, geometry, interactive

Labyrinth

graphs, shortest paths

Upgrading Cities

dfs and similar, graphs

Company

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

Fun with Integers

dfs and similar, graphs, implementation, math

Banh-mi

greedy, implementation, math

Lost Root

interactive, probabilities

Politics

flows, graphs

TV Shows

data structures, greedy, implementation, sortings

Multiplicity

data structures, dp, implementation, math, number theory

Sophisticated Device

constructive algorithms

Balls and Pockets

data structures

Shrinking Tree

combinatorics, dp

Sergey and Subway

dfs and similar, dp, trees

Social Circles

greedy, math

Maximum Subrectangle

binary search, implementation, two pointers

Split the Tree

binary search, data structures, dp, greedy, trees

Nature Reserve

binary search, geometry, ternary search

Sequence Transformation

constructive algorithms, math

Tanya and Colored Candies

*special problem, dp

Detect Robots

data structures, strings

Take Metro

brute force, data structures, graphs

Write The Contest

binary search, dp, math

Check Transcription

brute force, data structures, hashing, strings

Decorate Apple Tree

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

Pick Heroes

greedy, implementation, interactive, sortings

Divide Candies

math, number theory

Jellyfish Nightmare

Tree and XOR

strings, trees

Segments on the Line

binary search, dp

Refactoring

greedy, implementation, strings

Lucky Days

math, number theory

Epic Convolution

chinese remainder theorem, fft, math, number theory

New Road Network

constructive algorithms, greedy, math

Electric Scheme

flows, graph matchings

Chips Puzzle

constructive algorithms, implementation, math

Changing Array

greedy, implementation

Euler tour

constructive algorithms, trees

Distinctification

data structures, dsu, greedy

The Shortest Statement

graphs, shortest paths, trees

Vasya and Big Integers

binary search, data structures, dp, hashing, strings

Bicolorings

bitmasks, dp

Say Hello

geometry

Moonwalk challenge

data structures, strings, trees

Palindrome Pairs

hashing, strings

Self-exploration

math

AI robots

data structures

Shady Lady

geometry, math

Ancient civilizations

constructive algorithms, geometry

Interstellar battle

math, probabilities, trees

Hyperspace Highways

dfs and similar, graphs, trees

Space Isaac

hashing, number theory

Last chance

data structures, flows, graph matchings, graphs, trees

DFS

data structures

Grid Sort

implementation

Deduction Queries

data structures, dsu

Optimal Polygon Perimeter

dp, geometry

Intersecting Subtrees

dfs and similar, interactive, trees

The Tower is Going Home

binary search, two pointers

Speckled Band

data structures, divide and conquer, hashing, string suffix structures, strings

Make It One

bitmasks, combinatorics, dp, math, number theory, shortest paths

Train Hard, Win Easy

constructive algorithms, greedy, math, sortings

Mysterious Crime

brute force, combinatorics, math, meet-in-the-middle, two pointers

Leaf Sets

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

Vasya and Magic Matrix

dp, math, probabilities

Petya and Array

data structures, divide and conquer, two pointers

Array Product

constructive algorithms, greedy, math

Ray in the tube

data structures, divide and conquer, dp, math

Tree Reconstruction

constructive algorithms, data structures, graphs, greedy

Glider

binary search, data structures, two pointers

Coffee Break

binary search, data structures, greedy, two pointers

Summer Oenothera Exhibition

data structures

You Are Given a Tree

data structures, dp, trees

Network Safety

dfs and similar, dsu, graphs, math, sortings

Subway Pursuit

binary search, interactive, probabilities

Timetable

constructive algorithms, data structures, greedy, math

Wrap Around

dp, strings

Maximum Matching

bitmasks, brute force, dfs and similar, dp, graphs

Slime

dp, greedy, implementation

Security

data structures, string suffix structures

A Game on Strings

games

Maximum Reduction

combinatorics, data structures, math

Trips

graphs