Dasha and cyclic table

bitmasks, brute force, fft, strings, trees

Interactive Bulls and Cows (Hard)

brute force, constructive algorithms, interactive

New Year and Snowy Grid

dfs and similar, dsu, graphs, interactive

New Year and Binary Tree Paths

bitmasks, brute force, combinatorics, dp

New Year and Finding Roots

constructive algorithms, implementation, interactive, trees

New Year and Old Subsequence

data structures, divide and conquer, dp, matrices

Inversions After Shuffle

data structures, probabilities

Igor and Interesting Numbers

brute force, combinatorics, dp, math

Hongcow Masters the Cyclic Shift

strings, two pointers

Hongcow Draws a Circle

geometry

Hongcow Buys a Deck of Cards

bitmasks, brute force, dp

Arpa’s abnormal DNA and Mehrdad’s deep interest

data structures, string suffix structures

Arpa’s letter-marked tree and Mehrdad’s Dokhtar-kosh paths

data structures, dfs and similar, trees

Arpa’s overnight party and Mehrdad’s silent entering

constructive algorithms, dfs and similar, graphs

Gosha is hunting

brute force, data structures, dp, flows, math, probabilities, sortings

Recover a functional graph

graph matchings

Alyona and towers

data structures

Dirty plates

constructive algorithms, math

Tanya is 5!

graph matchings, graphs, greedy, schedules

Chess Championship

constructive algorithms, flows, greedy, math

Permutations

math, matrices

Ostap and Tree

dp, trees

Anton and School

bitmasks, constructive algorithms, implementation, math

Sleep in Class

constructive algorithms, data structures, math, two pointers

Expression Queries

data structures

Roads Orientation Problem

graphs

Ber Patio

Financiers Game

dp

Messages on a Tree

Family Photos

games, greedy

Too Much Money

brute force, greedy

Xor-matic Number of the Graph

bitmasks, graphs, math, number theory, trees

Uniformly Branched Trees

combinatorics, dp, trees

Goods transportation

dp, flows, greedy

Cyclic Cipher

chinese remainder theorem, data structures, implementation, number theory, two pointers

Research Rover

combinatorics, dp

Road to Home

binary search, dp

Array Covering

data structures

Cipher

implementation

Slalom

data structures, dp, sortings

Homework

constructive algorithms

Cactusophobia

dfs and similar, flows

Matvey's Birthday

bitmasks, graphs

Andrew and Chemistry

dp, hashing, trees

Cowboy Beblop at his computer

geometry

Pokermon League challenge

math, probabilities

Underfail

flows

Heroes of Making Magic III

data structures

R3D3’s Summer Adventure

dp, greedy

Festival Organization

combinatorics, math, number theory

Complete the Permutations

combinatorics, fft, graphs, math

Create a Maze

constructive algorithms

Digit Tree

dfs and similar, divide and conquer, dsu, trees

Sonya Partymaker

binary search, dp

Animals and Puzzle

binary search, data structures

Memory and Casinos

data structures, math, probabilities

String Set Queries

brute force, data structures, hashing, interactive, string suffix structures, strings

Two Arithmetic Progressions

math, number theory

Student's Camp

dp, math

Incorrect Flow

flows

Garlands

data structures

Working routine

data structures, implementation

Iron Man

data structures, geometry, trees

Captain America

flows, greedy

Black Widow

dp, graphs, implementation, math

Ant Man

dp, graphs, greedy

Mishka and Divisors

dp, number theory

T-Shirts

data structures

Cool Slogans

string suffix structures, strings

Huffman Coding on Segment

data structures, greedy

Break Up

dfs and similar, graphs

Coprime Permutation

combinatorics, number theory

Cron

Limak and Shooting Points

brute force, geometry, math

LRU

bitmasks, dp, math, probabilities

...Dary!

binary search, geometry, two pointers

...Wait for it...

data structures, dsu, trees

Legen...

data structures, dp, matrices, strings

Tree of Life (hard)

trees

Tree of Life (medium)

constructive algorithms, hashing, trees

Photographs (II)

Recover Polygon (hard)

data structures

Recover Polygon (medium)

geometry

Collective Mindsets (hard)

TOF

dfs and similar, graphs

Dividing Kingdom II

brute force, data structures, dsu, graphs, sortings

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

The Hero with Bombs

*special problem

Loader

*special problem, graphs

Alyona and Triangles

geometry, two pointers

Runaway to a Shadow

geometry, sortings

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

Lena and Queries

data structures, divide and conquer, geometry

The Last Fight Between Human and AI

math

Organizing a Race

data structures, greedy

Roads in Yusland

data structures, dp, greedy