Polycarp at the Radio

greedy

Cyclic Cipher

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

Research Rover

combinatorics, dp

Generating Sets

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

Destroying Array

data structures, dsu

Road to Home

binary search, dp

Maxim and Array

constructive algorithms, data structures, greedy, math

Journey

dp, graphs

Array Covering

data structures

Cipher

implementation

Slalom

data structures, dp, sortings

Homework

constructive algorithms

Cactusophobia

dfs and similar, flows

Closing ceremony

greedy

Matvey's Birthday

bitmasks, graphs

Andrew and Chemistry

dp, hashing, trees

Sasha and Array

data structures, math, matrices

Efim and Strange Grade

dp, implementation, math

Cowboy Beblop at his computer

geometry

Pokermon League challenge

math, probabilities

Underfail

flows

Heroes of Making Magic III

data structures

Paint it really, really dark gray

dfs and similar

Dexterina’s Lab

games, matrices, probabilities

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

Complete The Graph

binary search, constructive algorithms, graphs, shortest paths

Plus and Square Root

constructive algorithms, math

Sonya Partymaker

binary search, dp

Animals and Puzzle

binary search, data structures

Sonya and Problem Wihtout a Legend

dp, sortings

Searching Rectangles

binary search, constructive algorithms, interactive

Memory and Casinos

data structures, math, probabilities

Memory and Scores

combinatorics, dp, math

Memory and De-Evolution

greedy, math

ZS and The Birthday Paradox

math, number theory, probabilities

Directed Roads

combinatorics, dfs and similar, graphs, math

Coloring Trees

dp

String Set Queries

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

Generate a String

dfs and similar, dp

Two Arithmetic Progressions

math, number theory

Student's Camp

dp, math

Incorrect Flow

flows

Centroids

data structures, dfs and similar, dp, graphs, greedy, trees

Recover the String

constructive algorithms, greedy, implementation, math

Garlands

data structures

Persistent Bookcase

bitmasks, data structures, dfs and similar, implementation

Working routine

data structures, implementation

Vasiliy's Multiset

binary search, bitmasks, data structures, trees

Hard problem

dp, strings

Iron Man

data structures, geometry, trees

Captain America

flows, greedy

Black Widow

dp, graphs, implementation, math

Ant Man

dp, graphs, greedy

Thor

brute force, data structures, implementation

Mishka and Divisors

dp, number theory

Mishka and Interesting sum

data structures

Chris and Road

geometry, implementation

T-Shirts

data structures

Analysis of Pathes in Functional Graph

data structures, graphs

Road to Post Office

math

Cool Slogans

string suffix structures, strings

Huffman Coding on Segment

data structures, greedy

Break Up

dfs and similar, graphs

Connecting Universities

dfs and similar, dp, graphs, trees

As Fast As Possible

binary search, math

Coprime Permutation

combinatorics, number theory

Cron

Limak and Shooting Points

brute force, geometry, math

LRU

bitmasks, dp, math, probabilities

Fix a Tree

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

...Dary!

binary search, geometry, two pointers

...Wait for it...

data structures, dsu, trees

Legen...

data structures, dp, matrices, strings

PLEASE

combinatorics, dp, implementation, math, matrices

Puzzles

dfs and similar, math, probabilities, trees

Couple Cover

brute force, dp, number theory

Xor-sequences

matrices

Swaps in Permutation

dfs and similar, dsu, math

Exponential notation

implementation, strings

s-palindrome

implementation, strings

Tree of Life (hard)

trees

Tree of Life (medium)

constructive algorithms, hashing, trees

Photographs (II)

Photographs (I)

The Wall (hard)

dp

The Wall (medium)

combinatorics

Brain Network (hard)

trees

Recover Polygon (hard)

data structures

Recover Polygon (medium)

geometry

Recover Polygon (easy)

Collective Mindsets (hard)

Collective Mindsets (medium)

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