Vladik and fractions

brute force, constructive algorithms, math, number theory

Arpa’s obvious problem and Mehrdad’s terrible solution

brute force, 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

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

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

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

Tourist Reform

dfs and similar, graphs

Sockets

greedy, sortings

Exams

binary search, greedy, sortings

Video Cards

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

Funny Game

dp, games

80-th Level Archeology

brute force, data structures, greedy, sortings

Socks

dfs and similar, dsu, graphs, greedy

Expression Queries

data structures

Roads Orientation Problem

graphs

Bottles

dp

Olympiad in Programming and Sports

dp, flows, graphs, greedy

Car Repair Shop

implementation

Ber Patio

Award Ceremony

greedy, implementation

Running Over The Bridges

greedy, implementation, math

Bulmart

binary search, dfs and similar

Minimum and Maximum

constructive algorithms, interactive

Toda 2

greedy, implementation

Financiers Game

dp

Subordinates

constructive algorithms, data structures, graphs, greedy, sortings

Sea Battle

constructive algorithms, greedy, math

Road to Cinema

binary search, greedy, sortings

Polycarp's problems

binary search, dp, greedy

Games on a CD

data structures, hashing, string suffix structures, strings

T-shirts Distribution

constructive algorithms, flows, greedy

Guess the Array

constructive algorithms, interactive, math

Bill Total Value

expression parsing, implementation, strings

Messages on a Tree

Family Photos

games, greedy

Too Much Money

brute force, greedy

Contest Balloons

data structures, greedy

Hidden Word

brute force, constructive algorithms, implementation, strings

Xor-matic Number of the Graph

bitmasks, graphs, math, number theory, trees

Uniformly Branched Trees

combinatorics, dp, trees

Goods transportation

dp, flows, greedy

Dense Subsequence

data structures, greedy, strings

Ray Tracing

greedy, hashing, implementation, math, number theory, sortings

Batch Sort

brute force, greedy, implementation, math

st-Spanning Tree

dsu, graphs, greedy, implementation

One-Way Reform

constructive algorithms, dfs and similar, flows, graphs, greedy

Lakes in Berland

dfs and similar, dsu, graphs, greedy, implementation

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

Anatoly and Cockroaches

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