Mobile Communications

Merge Equal Elements

constructive algorithms, data structures

SUM and REPLACE

brute force, data structures, dsu, number theory

Connected Components?

data structures, dfs and similar, dsu, graphs

Congruence Equation

chinese remainder theorem, math, number theory

Jamie and Binary Sequence (changed after round)

bitmasks, greedy, math

Bash and a Tough Math Puzzle

data structures, number theory

Fishes

data structures, graphs, greedy, probabilities, shortest paths

Stack Sorting

constructive algorithms, data structures, greedy, implementation

Coprocessor

dfs and similar, dp, graphs, greedy

Colorful Points

data structures, greedy, implementation

Maximum Questions

data structures, dp, strings

Unusual Sequences

bitmasks, combinatorics, dp, math, number theory

Letters Removing

data structures, strings

Segments Removal

data structures, dsu, flows, implementation, two pointers

Ithea Plays With Chtholly

binary search, constructive algorithms, games, greedy, interactive

String Mark

combinatorics, math, strings

Square Subsets

bitmasks, combinatorics, dp, math

Ralph and Mushrooms

dp, graphs

Marco and GCD Sequence

constructive algorithms, math

Counting Arrays

combinatorics, dp, math, number theory

Credit Card

data structures, dp, greedy, implementation

Gluttony

constructive algorithms, greedy

Restoration of string

constructive algorithms, graphs, implementation

Photo Processing

binary search, dp

Orientation of Edges

dfs and similar, graphs

Danil and a Part-time Job

bitmasks, data structures, trees

Olya and Energy Drinks

data structures, dfs and similar, graphs, shortest paths

National Property

2-sat, dfs and similar, graphs, implementation

Something with XOR Queries

brute force, interactive, probabilities

Ordering Pizza

binary search, sortings, ternary search

Fire

dp, sortings

Turn Off The TV

data structures, sortings

Mahmoud and Ehab and the function

binary search, data structures, sortings

Mahmoud and Ehab and the binary string

binary search, divide and conquer, interactive

Mahmoud and Ehab and the xor

constructive algorithms

Desk Disorder

combinatorics, dfs and similar, dsu, graphs, trees

Third Month Insanity

dp, probabilities, trees

Helga Hufflepuff's Cup

dp, trees

Boredom

data structures

Casinos and travel

dp

Exploration plan

binary search, flows, graph matchings, shortest paths

Property

greedy, sortings

Neural Network country

dp, matrices

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