Tree of Life (medium)

constructive algorithms, hashing, trees

Tree of Life (easy)

Photographs (II)

Photographs (I)

The Wall (hard)

dp

The Wall (medium)

combinatorics

The Wall (easy)

Brain Network (hard)

trees

Brain Network (medium)

dfs and similar, graphs, trees

Brain Network (easy)

Recover Polygon (hard)

data structures

Recover Polygon (medium)

geometry

Recover Polygon (easy)

Collective Mindsets (hard)

Collective Mindsets (medium)

Collective Mindsets (easy)

Mike and Geometry Problem

combinatorics, data structures, dp, geometry, implementation

Friends and Subsequences

binary search, data structures

Mike and Chocolate Thieves

binary search, combinatorics, math

Mike and Shortcuts

dfs and similar, graphs, greedy, shortest paths

Mike and Cellphone

brute force, constructive algorithms, implementation

Lovely Palindromes

constructive algorithms, math

Opponents

implementation

TOF

dfs and similar, graphs

Dividing Kingdom II

brute force, data structures, dsu, graphs, sortings

The Values You Can Make

dp

Remainders Game

chinese remainder theorem, math, number theory

NP-Hard Problem

dfs and similar, graphs

Little Robber Girl's Zoo

constructive algorithms, implementation, sortings

Free Ice Cream

constructive algorithms, implementation

Travelling Through the Snow Queen's Kingdom

bitmasks, brute force, divide and conquer, graphs

Kay and Eternity

brute force, implementation, sortings

Optimal Point

binary search, math

Kay and Snowflake

data structures, dfs and similar, dp, trees

Robbers' watch

brute force, combinatorics, dp, math

The Hero with Bombs

*special problem

Loader

*special problem, graphs

Exchange of Books

*special problem

The Fraction

*special problem

Reformat the String

*special problem

Hammer throwing

*special problem

Chocolate Bar

*special problem, math

Symmetric Difference

*special problem

The Teacher of Physical Education

*special problem

The Check of the Point

*special problem, geometry

Alyona and Triangles

geometry, two pointers

Alyona and Strings

dp, strings

Alyona and the Tree

dfs and similar, dp, graphs, trees

Alyona and Mex

sortings

Alyona and Numbers

constructive algorithms, math, number theory

Runaway to a Shadow

geometry, sortings

Gifts by the List

constructive algorithms, dfs and similar, graphs, trees

Heap Operations

constructive algorithms, data structures, greedy

Economy Game

brute force

A Good Contest

implementation

Bear and Finding Criminals

constructive algorithms, implementation

Bear and Five Cards

constructive algorithms, implementation

Bear and Bad Powers of 42

data structures

Bear and Chase

brute force, dfs and similar, graphs, implementation, math, probabilities

Bear and Square Grid

dfs and similar, dsu, implementation

Bear and Tower of Cubes

binary search, dp, greedy

Bear and Prime 100

constructive algorithms, interactive, math

Lena and Queries

data structures, divide and conquer, geometry

Another Sith Tournament

bitmasks, dp, math, probabilities

Iterated Linear Function

math, number theory

Joty and Chocolate

implementation, math, number theory

The Same Calendar

implementation

Johny Likes Numbers

implementation, math

Vanya and Balloons

binary search, brute force, dp, implementation

Vanya and Treasure

data structures, dp, graphs, shortest paths

Vanya and Label

bitmasks, combinatorics, implementation, strings

Vanya and Food Processor

implementation, math

Vanya and Fence

implementation

The Last Fight Between Human and AI

math

Theseus and labyrinth

graphs, implementation, shortest paths

Vasya and String

binary search, dp, strings, two pointers

Pyramid of Glasses

implementation, math, math

Nicholas and Permutation

constructive algorithms, implementation

Trains and Statistic

data structures, dp, greedy

Tree Construction

data structures, trees

Money Transfers

constructive algorithms, data structures, greedy, sortings

Restoring Painting

brute force, constructive algorithms, math

Infinite Sequence

math

Problems for Round

greedy, implementation

Bear and Game

implementation

Different is Good

constructive algorithms, implementation, strings

Summer Camp

implementation

Organizing a Race

data structures, greedy

Roads in Yusland

data structures, dp, greedy

Ultimate Weirdness of an Array

data structures, number theory

Robin Hood

binary search, greedy

Recycling Bottles

dp, geometry, greedy, implementation

Restore a Number

brute force, constructive algorithms, strings

Correct Bracket Sequence Editor

data structures, dsu, strings

Magic Powder - 2

binary search, implementation

Magic Powder - 1

binary search, brute force, implementation

Cinema

implementation, sortings

Game of Robots

implementation

Holidays

brute force, constructive algorithms, greedy, math

Little Artem and Presents

math