Subsequences of Length Two

dp, strings

Send the Fool Further! (easy)

dfs and similar, graphs, trees

Nastia and a Hidden Permutation

constructive algorithms, interactive

Guess Your Way Out!

implementation, math, trees

Binary Median

binary search, bitmasks, brute force, constructive algorithms

Mind the Gap

implementation

Marco and GCD Sequence

constructive algorithms, math

Passable Paths (hard version)

data structures, dfs and similar, trees

Sereja and Algorithm

data structures, implementation

Block Towers

brute force, greedy, math, number theory

Jumping Jack

math

Two Paths

dfs and similar, dp, graphs, shortest paths, trees, two pointers

Tolik and His Uncle

constructive algorithms

Poster

greedy, implementation

Identify the Operations

combinatorics, data structures, dsu, greedy, implementation

Swaps Again

constructive algorithms, implementation, sortings

Messages

math

LuoTianyi and the Floating Islands (Easy Version)

combinatorics, math, probabilities, trees

Rectangles

geometry, implementation, sortings

Mahmoud and a Message

brute force, dp, greedy, strings

Dreamoon and Sets

constructive algorithms, greedy, math

Save Energy!

binary search, implementation, math

Efim and Strange Grade

dp, implementation, math

Robot Collisions

data structures, greedy, implementation, sortings

Petya and Exam

implementation, strings

Spongebob and Joke

implementation

Shift and Reverse

greedy, sortings

Igor and his way to work

dfs and similar, graphs, implementation, shortest paths

Trivial Conjecture

*special problem, constructive algorithms, math, number theory

Survey in Class

brute force, data structures, greedy, implementation, sortings

Checkout Assistant

dp

Masha and geometric depression

brute force, implementation, math

Mysterious numbers - 1

*special problem, constructive algorithms

The Strongest Build

binary search, brute force, data structures, dfs and similar, graphs, greedy, hashing, implementation

Gift Set

binary search, greedy, math, ternary search

Treasure Hunt

greedy

Directed Roads

combinatorics, dfs and similar, graphs, math

Keyboard

implementation

Multi-judge Solving

greedy, implementation

The Intriguing Obsession

combinatorics, dp, math

Thematic Contests

greedy, sortings

Shaass and Bookshelf

dp, greedy

Success Rate

binary search, math

Vanya and Triangles

brute force, combinatorics, data structures, geometry, math, sortings

Cheap Dinner

brute force, data structures, graphs, greedy, implementation, sortings, two pointers

Graph and String

constructive algorithms, graphs

Progress Bar

implementation, math

You Are Given a Decimal String...

brute force, dp, shortest paths

Maximum Xor Secondary

data structures, implementation, two pointers

Strange Device

constructive algorithms, interactive, math, sortings

Undoubtedly Lucky Numbers

bitmasks, brute force, dfs and similar

Jury Marks

brute force, constructive algorithms

Mysterious Crime

brute force, combinatorics, math, meet-in-the-middle, two pointers

Ralph And His Magic Field

combinatorics, constructive algorithms, math, number theory

Parliament of Berland

*special problem, constructive algorithms

Paths and Trees

graphs, greedy, shortest paths

Lefthanders and Righthanders

implementation

Sereja and Contests

greedy, implementation, math

Beautiful Lyrics

data structures, greedy, strings

Numbers on Tree

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

Imbalanced Array

data structures, divide and conquer, dsu, sortings

AB Graph

brute force, constructive algorithms, graphs, greedy, implementation

Farewell Party

constructive algorithms, implementation

pSort

dfs and similar, dsu, graphs

GCD Counting

data structures, dfs and similar, dp, number theory, trees

Moving to the Capital

dfs and similar, dp, graphs, shortest paths

Bouncing Boomerangs

constructive algorithms, greedy, implementation

Expression Evaluation Error

constructive algorithms, greedy, implementation, math

Number Reduction

greedy

Array and Segments (Easy version)

brute force, greedy, implementation

Send Boxes to Alice (Easy Version)

constructive algorithms, greedy, math, number theory, ternary search, two pointers

Remove Extra One

brute force, data structures, math

Accommodation

brute force, dp, greedy, implementation

Divisibility

math

Anya and Ghosts

constructive algorithms, greedy

Submarine in the Rybinsk Sea (hard edition)

combinatorics, math, number theory

Paths on the Tree

dfs and similar, dp, greedy, sortings, trees

Skyscrapers

implementation, sortings

Inversion Counting

brute force, math

Alyona and a tree

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

Vasya And The Matrix

constructive algorithms, flows, math

A Simple Task

bitmasks, dp, graphs

Vasya and Public Transport

greedy, implementation

MEX Sequences

dp, math

Serial Time!

dfs and similar, dsu

Great Vova Wall (Version 1)

greedy, implementation, math

CGCDSSQ

brute force, data structures, math

Teleporters (Hard Version)

binary search, greedy, sortings

Finite or not?

implementation, math

Planets

binary search, data structures, graphs, shortest paths

K-beautiful Strings

binary search, brute force, constructive algorithms, greedy, strings

New Year Concert

binary search, data structures, greedy, math, number theory, two pointers

Chocolate Bar

brute force, dp

Firecrackers

binary search, sortings

Hierarchy

dfs and similar, dsu, greedy, shortest paths

Yet Another Problem

binary search, bitmasks, constructive algorithms, data structures

Grandma Laura and Apples

Om Nom and Dark Park

dfs and similar, greedy, implementation

Servers

implementation

Battleship

implementation