PolandBall and White-Red graph

constructive algorithms, graphs, shortest paths

PolandBall and Polygon

data structures

PolandBall and Forest

dfs and similar, dsu, graphs, interactive, trees

PolandBall and Game

binary search, data structures, games, greedy, sortings, strings

PolandBall and Hypothesis

brute force, graphs, math, number theory

Dasha and cyclic table

bitmasks, brute force, fft, strings, trees

Fedor and coupons

binary search, data structures, greedy, sortings

Vladik and chat

brute force, constructive algorithms, dp, implementation, strings

Ilya and tic-tac-toe game

brute force, implementation

Lesha and array splitting

constructive algorithms, greedy, implementation

Interactive Bulls and Cows (Hard)

brute force, constructive algorithms, interactive

Interactive Bulls and Cows (Easy)

brute force, constructive algorithms, implementation

Santa Claus and Candies

dp, greedy, math

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

New Year and Fireworks

brute force, data structures, dfs and similar, dp, implementation

New Year and Rating

binary search, greedy, math

New Year and North Pole

geometry, implementation

New Year and Hurry

binary search, brute force, implementation, math

Inversions After Shuffle

data structures, probabilities

Leaving Auction

binary search, data structures

Voting

greedy, implementation, two pointers

Parallelogram is Back

brute force, constructive algorithms, geometry

Bachgold Problem

greedy, implementation, math, number theory

Santa Clauses and a Soccer Championship

constructive algorithms, dfs and similar, graphs, trees

Santa Claus and Tangerines

binary search, data structures, greedy, two pointers

Santa Claus and a Palindrome

constructive algorithms, data structures, greedy

Santa Claus and Robot

constructive algorithms, math

Santa Claus and Keyboard Check

implementation, strings

Santa Claus and a Place in a Class

implementation, math

Igor and Interesting Numbers

brute force, combinatorics, dp, math

Comments

dfs and similar, expression parsing, implementation, strings

Winter Is Coming

dp, greedy, sortings

Servers

implementation

Mammoth's Genome Decoding

implementation, strings

Display Size

brute force, math

New Roads

constructive algorithms, graphs, trees

Music in Car

data structures, greedy, two pointers

Numbers Exchange

greedy, implementation, math

Green and Black Tea

constructive algorithms, greedy, math

Tram

constructive algorithms, implementation, math

Decoding

implementation, strings

Compote

implementation, math

Hongcow Solves A Puzzle

implementation

Hongcow Learns the Cyclic Shift

implementation, strings

Hongcow Masters the Cyclic Shift

strings, two pointers

Hongcow Draws a Circle

geometry

Hongcow Buys a Deck of Cards

bitmasks, brute force, dp

Hongcow's Game

bitmasks, divide and conquer, interactive

Hongcow Builds A Nation

dfs and similar, graphs

Vladik and cards

binary search, bitmasks, brute force, dp

Chloe and pleasant prizes

dfs and similar, dp, graphs, trees

Vladik and fractions

brute force, constructive algorithms, math, number theory

Chloe and the sequence

binary search, bitmasks, constructive algorithms, implementation

Vladik and flights

constructive algorithms, greedy, implementation

Arpa’s obvious problem and Mehrdad’s terrible solution

brute force, math, number theory

Arpa’s hard exam and Mehrdad’s naive cheat

implementation, math, number theory

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

Arpa's weak amphitheater and Mehrdad's valuable Hoses

dfs and similar, dp, dsu

Arpa's loud Owf and Mehrdad's evil plan

dfs and similar, math

Alyona and flowers

constructive algorithms

Alyona and copybooks

brute force, implementation

Gosha is hunting

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

Recover a functional graph

graph matchings

Alyona and towers

data structures

Alyona and a tree

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

Alyona and mex

constructive algorithms, greedy

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

Taxes

math, number theory

Tennis Championship

combinatorics, constructive algorithms, greedy, math

Urbanization

greedy, number theory, sortings

Ostap and Grasshopper

implementation, strings

Anton and School

bitmasks, constructive algorithms, implementation, math

Anton and Tree

dfs and similar, dp, trees

Anton and Chess

implementation

Anton and Making Potions

binary search, dp, greedy, two pointers

Anton and Digits

brute force, greedy, implementation, math

Anton and Danik

implementation, strings

Drivers Dissatisfaction

data structures, dsu, graphs, trees

Sleep in Class

constructive algorithms, data structures, math, two pointers

Kostya the Sculptor

data structures, hashing

Epidemic in Monstropolis

constructive algorithms, dp, greedy, two pointers

Parade

math

Grasshopper And the String

implementation

Tourist Reform

dfs and similar, graphs

Sockets

greedy, sortings

Exams

binary search, greedy, sortings

Sanatorium

binary search, constructive algorithms, greedy, implementation, math

Cormen --- The Best Friend Of a Man

dp, greedy

Buy a Shovel

brute force, constructive algorithms, implementation, math

Video Cards

brute force, data structures, implementation, math, number theory

Funny Game

dp, games