Arpa and a list of numbers

implementation, number theory

Rooter's Song

constructive algorithms, data structures, geometry, implementation, sortings, two pointers

Noise Level

dfs and similar, implementation, math

Berland Elections

greedy, sortings

Monitor

binary search, data structures

Interactive LowerBound

brute force, interactive, probabilities

Vitya and Strange Lesson

binary search, data structures

Ilya And The Tree

dfs and similar, graphs, math, number theory, trees

Leha and another game about graph

constructive algorithms, data structures, dfs and similar, dp, graphs

Game of the Rows

brute force, greedy, implementation

Diverging Directions

data structures, dfs and similar, trees

Vasya's Function

binary search, implementation, math

Round Subset

dp, math

Palindromic characteristics

brute force, dp, hashing, strings

Misha, Grisha and Underground

dfs and similar, graphs, trees

DNA Evolution

data structures, strings

Okabe and El Psy Kongroo

dp, matrices

Mister B and PR Shifts

data structures, implementation, math

Level Generation

binary search, math, ternary search

Card Game Again

binary search, data structures, number theory, two pointers

Sofa Thief

brute force, implementation

Choosing The Commander

bitmasks, data structures, trees

Imbalanced Array

data structures, divide and conquer, dsu, sortings

An overnight dance in discotheque

dfs and similar, dp, geometry, greedy, trees

Vladik and Favorite Game

constructive algorithms, dfs and similar, graphs, interactive

Vladik and Memorable Trip

dp, implementation

Array Division

binary search, data structures, implementation

Coprime Subsequences

bitmasks, combinatorics, number theory

Roma and Poker

dp, graphs

Magazine Ad

binary search, greedy

Maximal GCD

constructive algorithms, greedy, math

Send the Fool Further! (medium)

dp, trees

Marmots (easy)

math

Field expansion

brute force, dp, meet-in-the-middle

Array Queries

brute force, data structures, dp

Broken BST

data structures, dfs and similar

Police Stations

constructive algorithms, dfs and similar, dp, graphs, shortest paths, trees

Bank Hacking

constructive algorithms, data structures, dp, trees

Presents in Bankopolis

dp, graphs, shortest paths

Paths in a Complete Binary Tree

bitmasks, trees

Divide by Three

dp, greedy, math, number theory

Weird journey

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

Berzerk

dfs and similar, dp, games

BF Calculator

*special problem

Crunching Numbers Just for You

*special problem, implementation

Twisted Circuit

*special problem, brute force, implementation

Touchy-Feely Palindromes

*special problem, implementation

Kids' Riddle

*special problem

Underground Lab

constructive algorithms, dfs and similar, graphs

Innokenty and a Football League

2-sat, graphs, greedy, implementation, shortest paths, strings

Hanoi Factory

brute force, data structures, dp, greedy, sortings

The Holmes Children

math, number theory

The Door Problem

2-sat, dfs and similar, dsu, graphs

Bars

*special problem, binary search

Stepan's Series

*special problem, dp

Significant Cups

*special problem, binary search, data structures, two pointers

Amusement Park

*special problem, ternary search

Dynamic Problem Scoring

brute force, greedy

Bear and Tree Jumps

dfs and similar, dp, trees

Game of Stones

bitmasks, dp, games

Cartons of milk

binary search, data structures, greedy, sortings, two pointers

Garland

dfs and similar, graphs, greedy, trees

The Queue

brute force, greedy

Mahmoud and a xor trip

bitmasks, constructive algorithms, data structures, dfs and similar, dp, math, trees

Mahmoud and a Dictionary

data structures, dfs and similar, dp, dsu, graphs

Timofey and rectangles

constructive algorithms, geometry

Two strings

binary search, hashing, strings, two pointers

Dasha and Puzzle

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

Ability To Convert

constructive algorithms, dp, greedy, math, strings

Felicity is Coming!

data structures, hashing, sortings, strings

PolandBall and Polygon

data structures

Fedor and coupons

binary search, data structures, greedy, sortings

New Year and Fireworks

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

Leaving Auction

binary search, data structures

Santa Claus and Tangerines

binary search, data structures, greedy, two pointers

Santa Claus and a Palindrome

constructive algorithms, data structures, greedy

New Roads

constructive algorithms, graphs, trees

Numbers Exchange

greedy, implementation, math

Hongcow's Game

bitmasks, divide and conquer, interactive

Alyona and a tree

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

Anton and Tree

dfs and similar, dp, trees

Sockets

greedy, sortings

Video Cards

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

Bottles

dp

Olympiad in Programming and Sports

dp, flows, graphs, greedy

Bulmart

binary search, dfs and similar

Subordinates

constructive algorithms, data structures, graphs, greedy, sortings

Dense Subsequence

data structures, greedy, strings

Generating Sets

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

Maxim and Array

constructive algorithms, data structures, greedy, math

Closing ceremony

greedy

Paint it really, really dark gray

dfs and similar

Dexterina’s Lab

games, matrices, probabilities

Directed Roads

combinatorics, dfs and similar, graphs, math

Generate a String

dfs and similar, dp

Recover the String

constructive algorithms, greedy, implementation, math

Mishka and Interesting sum

data structures

Chris and Road

geometry, implementation

Analysis of Pathes in Functional Graph

data structures, graphs

Road to Post Office

math